Search

The sex determination mechanism in large-scale loach (Paramisgurnus dabryanus) follows a ZZ/ZW system, with sexual differentiation regulated by both genotypic factors and temperature effects (GSD+TSD), where elevated temperatures result in a higher proportion of males. Currently, research on the sex determination mechanisms in large-scale loach is limited, and the specific gene expression profiles and the role of temperature in influencing sex remain largely unknown. This study investigated the impact of temperature on the sex ratio in cultured populations of the large-scale loach, and then identified a female-specific genetic marker by whole genome sequencing, facilitating the distinguishing of females, males, and pseudo-males within this population. Transcriptomic analysis was subsequently performed on these groups, and the data revealed a similar expression pattern between pseudo-males and true-males. The research combined differential expression analysis with WGCNA to construct a regulatory network of nine sex differentiation-related genes (SDG) (map3k4, trpv4, hsd17b12a, wt1, ar, dmrt1, bcar1, sox9a, cyp17a1), indicating that sex differentiation in large-scale loach is probably driven by the regulation of male-related genes. The transcriptomic analysis suggested that temperature significantly modified the expression of SDG in the ovaries, while in the testes, it predominantly affects metabolism-related pathways. We established a temperature-sensitive gene network in females, based on the correlation between gene expression and temperature, as well as the number of co-regulated genes in female data. We propose that, with increasing temperature, wt1 serves as a central regulator, leading to the down-regulation of foxl2a, cyp19a1a, and the cholesterol biosynthesis-related gene sqlea, ultimately resulting in the development of pseudo-males., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In Brief: Gender-affirming treatments for gender dysphoria can impact fertility. This review describes the impact of gender-affirming treatments on fertility and options to preserve fertility in transgender or gender-diverse children, adolescents, and young adults., Abstract: Transgender individuals who pursue alignment with their gender identity through medical treatments or surgery face challenges to family building because the medical community lacks the understanding or infrastructure to serve the reproductive needs of transgender or non-binary people. Fertility preservation (FP) offers a crucial opportunity for the transgender community, enabling individuals to exercise autonomy over their reproductive choices. While fertility preservation has been extensively studied in other populations such as cancer patients, the unique biology and clinical care of transgender and gender-diverse (TGD) individuals have challenged the direct translation of what can be offered for cisgender individuals. Additionally, the FP services in transgender communities are reportedly under-utilized, despite the prevalent desire of TGD individuals to have children. This review aims to provide up-to-date information on the current standard of care and experimental FP options available to TGD individuals and their potential reproductive outcomes. We will also discuss the barriers to the success of FP utilization from both the biology/medical aspect and the perspectives of the TGD population. By recognizing the unique family-building challenges faced by TGD people and potential areas of improvement, appropriate adjustments can be made to better support fertility preservation in the TGD community.

Gonadal sex steroid hormones are well-studied modulators of reproductive physiology and behavior. Recent behavioral endocrinology research has focused on how the brain dynamically responds to - and may even produce - sex steroids, but the gonadal tissues that primarily release these hormones receive much less attention as a potential mediator of behavioral variation. This Commentary revisits mechanisms by which the reproductive hypothalamic-pituitary-gonadal (HPG) axis can be modulated specifically at the gonadal level. These mechanisms include those that may allow the gonad to be regulated independently of the HPG axis, such as receptors for non-HPG hormones, neural inputs and local production of conventional 'neuropeptides'. Here, I highlight studies that examine variation in these gonadal mechanisms in diverse taxa, with an emphasis on recent transcriptomic work. I then outline how future work can establish functional roles of gonadal mechanisms in reproductive behavior and evaluate gonad responsiveness to environmental cues. When integrated with neural mechanisms, further investigation of gonadal hormone regulation can yield new insight into the control and evolution of steroid-mediated traits, including behavior., Competing Interests: Competing interests The author declares no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

It has now been about a century since a flurry of discoveries identified first the pituitary, then more specifically the anterior pituitary and soon thereafter the central nervous system as components regulating gonadal and downstream reproductive functions. This was an era of ablation/replacement designs using at first rudimentary and then increasingly pure preparations of gonadal and pituitary "activities" or transplanting actual glands, whole or homogenized, among subjects. There was, of course, controversy as is typical of lively and productive scientific debates to this day. The goals of this commentary are to briefly review the history of this work and how the terms referring to interactions among the components of the hypothalamo (as the central neural component was soon associated with)-pituitary-gonadal (HPG) axis evolved, and then to question if the current terms used have kept up with our understanding of the system. The focus in this review will be the actions of estradiol primarily upon the hypothalamus. Important actions of progesterone on the hypothalamus as well as both steroids on the pituitary response to hypothalamic factors are both acknowledged and largely ignored in this document, as are any sex differences as we focus on females., (© 2024 The Authors. Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of British Society for Neuroendocrinology.)

The red spotted grouper Epinephelus akaara is a marine species of economic importance and also at risk of extinction. This study investigated the effects of high water temperature on the growth and maturation of juvenile E. akaara females. From 160-420 days post-hatching (dph), the fish were maintained under natural water temperature (NT) and a constant high-water temperature (HT). From 240 dph, both the total length and body weight in the HT group were greater than in NT group. After 360 dph, the gonadosomatic index was also increased in the HT group compared to NT group. Mature oocytes were only observed in the HT group at 330, 360, and 390 dph. Both kiss1 and kiss2 levels increased at 240 and 270 dph in both groups; however, they were greater in the HT group at 240 dph. Similarly, gpr54 levels after 360 dph were greater in the HT group, suggesting that kisspeptin is related to maturation via its receptor gpr54. Levels of fshβ and lhβ were greater in the HT group after 360 dph. Estradiol-17β (E 2 ) levels after 160 dph (except 300 dph) were greater in the HT group than in the NT group, suggesting that the higher E 2 levels trigger maturation, and is related to increased fshβ and lhβ. This study provides evidence that high water temperature is effective in accelerating growth and triggering early maturation of juvenile E. akaara, via regulating gpr54, fshβ, lhβ, and E 2 levels., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

G protein-coupled receptors (GPCRs) are central to the functioning of the hypothalamic-pituitary-gonadal axis (HPG axis) and include the rhodopsin-like GPCR family members, neurokinin 3 receptor, kappa-opioid receptor, kisspeptin 1 receptor, gonadotropin-releasing hormone receptor, and the gonadotropin receptors, luteinizing hormone/choriogonadotropin receptor and follicle-stimulating hormone receptor. Unsurprisingly, inactivating variants of these receptors have been implicated in a spectrum of reproductive phenotypes, including failure to undergo puberty, and infertility. Clinical induction of puberty in patients harbouring such variants is possible, but restoration of fertility is not always a realisable outcome, particularly for those patients suffering from primary hypogonadism. Thus, novel pharmaceuticals and/or a fundamental change in approach to treating these patients are required. The increasing wealth of data describing the effects of coding-region genetic variants on GPCR function has highlighted that the majority appear to be dysfunctional as a result of misfolding of the encoded receptor protein, which, in turn, results in impaired receptor trafficking through the secretory pathway to the cell surface. As such, these intracellularly retained receptors may be amenable to 'rescue' using a pharmacological chaperone (PC)-based approach. PCs are small, cell permeant molecules hypothesised to interact with misfolded intracellularly retained proteins, stabilising their folding and promoting their trafficking through the secretory pathway. In support of the use of this approach as a viable therapeutic option, it has been observed that many rescued variant GPCRs retain at least a degree of functionality when 'rescued' to the cell surface. In this review, we examine the GPCR PC research landscape, focussing on the rescue of inactivating variant GPCRs with important roles in the HPG axis, and describe what is known regarding the mechanisms by which PCs restore trafficking and function. We also discuss some of the merits and obstacles associated with taking this approach forward into a clinical setting., (© 2024 The Author(s). Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of British Society for Neuroendocrinology.)

Aspects of the reproductive biology of Donax striatus were studied from individuals collected from Gado Bravo Beach in the municipality of Tibau do Norte, state of Rio Grande do Norte, Brazil. Donax striatus is a dioic species without external (on the shell) or internal (gonads) macroscopic dimorphism. Thus, a microscopic examination of the reproductive cells is necessary. For the characterization of the gonadal development stages and determination of the size at first sexual maturity (L50), 30 specimens were selected monthly between February 2021 and January 2022 and submitted to histological processing. The condition index (CI) of each individual was estimated and monthly variations were statistically assessed. The size at first maturity (L50) was estimated to be 14.2 mm in shell length. To foster conservation of the species, catches of individuals larger than 14.2 mm is recommended. The lowest condition indices were found in the dry season, with a greater occurrence of organisms in the elimination stage and exhibiting gonad tissue reorganization. Higher indices were found in the rainy season, with the presence of mature individuals. The continuous nature of gametogenesis in Donax stritatus reflects the influence of rainfall in the region. Males and females have peak gamete elimination with pauses during the year, but with the presence of maturing and eliminating individuals throughout the year. As shellfish gathering targeting Donax striatus is excessive on Gado Bravo Beach in the state of Rio Grande do Norte, it is hoped that the results of the present study can contribute to the establishment of management measures for the activity and conservation strategies for the species.

The objective of this study is to provide information on the reproductive biology of tomato hind grouper, Cephalopholis sonnerati (Valenciennes, 1828) for conservation and management purposes. Fish caught by artisanal fishermen from September 2019 to August 2021 were analysed. A total of 280 females, 31 males, and 4 transitional and 178 sex-undetermined fish were analysed. The female to male sex proportion was 9:1, and the fish reached a maximum total body length of 38.5 and 54.5 cm for females and males, respectively. The following microscopic stages were identified: immature, developing, ripe, running ripe/releasing, and spent in both males and females. Several asynchronous development patterns were observed in the studied gonads, including multiple oocyte stages and early and advanced stages of sexual transition. High gonadosomatic index (GSI) for both males and females was recorded in March, May, and November. Running ripe and releasing stages in females were identified in the months from March to June, which indicates the spawning season. The absolute and relative fecundity of the species ranged from 162,723 ± 207,267 and 239 ± 285, respectively. An exponential relationship was found between fecundity and total body length (TL), fecundity and total body weight (TW), and fecundity and gonad weight (GW)., (© 2024 Fisheries Society of the British Isles.)

This study aimed to understand the reproductive biology and migrative behavior of the largehead hairtail Trichiurus lepturus in a tropical area, specifically off Pernambuco coast, northeastern Brazil. Commercial catches from fish corrals provided samples for analysis, including measurements, weight recording, and examination of gonads to determine its maturation stage. Reproductive analyses were performed, such as sex ratio, gonado-somatic index, and sizes at first maturity. There was a slightly higher proportion of females among the 141 largehead hairtail specimens analysed. No significant differences were observed in length distributions between males and females. However, during the winter, significant differences were observed in length distributions for grouped sexes. The species exhibited a seasonal migratory pattern, with a higher presence on the continental shelf during the winter. The study identified strategic allocation of energy in feeding activities and temporal spacing of reproductive cycles, as indicated by the sex ratio and abundance of individuals during different seasons. Fish corrals probably do not harm largehead hairtail population off the southwestern Atlantic tropical coast, with minimal capture of individuals below the size of first maturity. The insights of the study into reproductive and migration patterns contribute to future assessments and management strategies for this species and corral fisheries., (© 2024 Fisheries Society of the British Isles.)

Animal research has shown that the hypothalamus-pituitary-gonadal (HPG) axis is inhibited by (chronic and/or severe) stress, which can lead to impaired fertility and reproductive functioning, presumably caused by the inhibition of gonadal steroid secretion and in interactions with glucocorticoids. However, what has not been clarified is how acute psychosocial stress modulates gonadal steroid secretion in humans. Here we summarize the experimental research on the acute effects of stress on the secretion of gonadal steroids in humans. A systematic literature search revealed 21 studies (with N=881 individuals) measuring testosterone, progesterone or estradiol in response to a standardized acute laboratory stressor in healthy humans. Both our literature review and quantitative meta-analysis suggest that in humans, acute stress stimulates rather than inhibits HPG axis activity, although there is a considerable heterogeneity in the reported methods and results. Increased gonadal steroids in response to acute stress contrasts with many animal studies reporting the opposite pattern, at least regarding severe and/or chronic stressors. We discuss methodological issues and challenges for future research and hope to stimulate experimental studies within this area. A better understanding of these mechanisms is needed, and may have important implications for health and disease, as well as the modulation of various behaviors by acute stressors., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to declare., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Germ cells (reproductive cells and their progenitors) give rise to the next generation in sexually reproducing organisms. The loss or removal of germ cells often leads to sterility in established research organisms such as the fruit fly, nematodes, frog, and mouse. The failure to regenerate germ cells in these organisms reinforced the dogma of germline-soma barrier in which germ cells are set-aside during embryogenesis and cannot be replaced by somatic cells. However, in stark contrast, many animals including segmented worms (annelids), hydrozoans, planaria, sea stars, sea urchins, and tunicates can regenerate germ cells. Here I review germ cell and gonad regeneration in annelids, a rich history of research that dates back to the early 20th century in this highly regenerative group. Examples include annelids from across the annelid phylogeny, across developmental stages, and reproductive strategies. Adult annelids regenerate germ cells as a part of regeneration, grafting, and asexual reproduction. Annelids can also recover germ cells after ablation of germ cell progenitors in the embryos. I present a framework to investigate cellular sources of germ cell regeneration in annelids, and discuss the literature that supports different possibilities within this framework, where germ-soma separation may or may not be preserved. With contemporary genetic-lineage tracing and bioinformatics tools, and several genetically enabled annelid models, we are at the brink of answering the big questions that puzzled many for over more than a century., (© 2023 Wiley Periodicals LLC.)

The use of reduced-intensity conditioning (RIC) regimens has increased in an effort to minimize hematopoietic stem cell transplantation (HCT) end-organ toxicity, including gonadal toxicity. We aimed to describe the incidence of fertility potential and gonadal function impairment in adolescent and young adult survivors of HCT and to identify risk factors (including conditioning intensity) for impairment. We performed a multi-institutional, international retrospective cohort study of patients age 10 to 40 years who underwent first allogeneic HCT before December 1, 2019, and who were alive, in remission, and available for follow-up at 1 to 2 years post-HCT. For females, an AMH level of ≥.5 ng/mL defined preserved fertility potential; an AMH level of ≥.03 ng/mL was considered detectable. Gonadal failure was defined for females as an elevated follicle-stimulating hormone (FSH) level >30 mIU/mL with an estradiol (E2) level <17 pg/mL or current use of hormone replacement therapy (regardless of specific indication or intent). For males, gonadal failure was defined as an FSH level >10.4 mIU/mL or current use of hormone replacement therapy. A total of 326 patients (147 females) were available for analysis from 17 programs (13 pediatric, 4 adult). At 1 to 2 years post-HCT, 114 females (77.6%) had available FSH and E2 levels and 71 (48.3%) had available AMH levels. FSH levels were reported for 125 males (69.8%). Nearly all female HCT recipients had very low levels of AMH. One of 45 (2.2%) recipients of myeloablative conditioning (MAC) and four of 26 (15.4%) recipients of reduced-intensity conditioning (RIC) (P = .06) had an AMH ≥.5 ng/m, and 8 of 45 MAC recipients (17.8%) and 12 of 26 RIC recipients (46.2%) (P = .015) had a detectable AMH level. Total body irradiation (TBI) dose and cyclophosphamide equivalent dose (CED) were not associated with detectable AMH. The incidence of female gonadal hormone failure was 55.3%. In univariate analysis, older age at HCT was associated with greater likelihood of gonadal failure (median age, 17.6 versus 13.9; P < .0001), whereas conditioning intensity (RIC versus MAC), TBI, chronic graft-versus-host disease requiring systemic therapy, and CED were not significantly associated with gonadal function. In multivariable analysis, age remained statistically significant (odds ratio [OR]. 1.11; 95% confidence interval [CI], 1.03 to 1.22) for each year increase; P = .012), Forty-four percent of the males had gonadal failure. In univariate analysis, older age (median, 16.2 years versus 14.4 years; P = .0005) and TBI dose (P = .002) were both associated with gonadal failure, whereas conditioning intensity (RIC versus MAC; P = .06) and CED (P = .07) were not statistically significant. In multivariable analysis, age (OR, 1.16; 95% CI, 1.06-1.27 for each year increase; P = .0016) and TBI ≥600 cGy (OR, 6.23; 95% CI, 2.21 to 19.15; P = .0008) remained significantly associated with gonadal failure. Our data indicate that RIC does not significantly mitigate the risk for gonadal failure in females or males. Age at HCT and (specifically in males) TBI use seem to be independent predictors of post-transplantation gonadal function and fertility status. All patients should receive pre-HCT infertility counseling and be offered appropriate fertility preservation options and be screened post-HCT for gonadal failure., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Gonadotropin-releasing hormone (GnRH) plays an important role in reproduction in both vertebrates and invertebrates; however, little is known about GnRH during gonadal development in bivalves. We developed a time-resolved fluoroimmunoassay (TR-FIA) for Manila clam Ruditapes philippinarum GnRH (rpGnRH) and measured the amount of rpGnRH in the cerebral ganglion (CG) and sex steroid hormones in the hemolymph during gonadal development. The cross-reactivity of the anti-rpGnRH antibody against other forms of GnRH was <0.15%, and the displacement curve obtained for serially diluted CG extracts was parallel to the rpGnRH standard curve, confirming the suitability of the TR-FIA system. Based on histological observation, gonadal development of the clams was classified into early developing (stage 1), late developing (stage 2), ripe (stage 3), and partially spent (stage 4). In female clams, rpGnRH levels in the CG peaked at stage 1, and 17β-estradiol (E2) levels in the hemolymph peaked at stage 2. The rpGnRH levels in males and hemolymph testosterone levels in both sexes did not differ significantly across stages. Hemolymph E2 levels in males were below the detection limit for the TR-FIA. These results suggest that rpGnRH and E2 secretion in females can activate ovarian development of the Manila clam at the early and late developing stages, respectively., (Copyright © 2022 Elsevier Inc. All rights reserved.)

DNA methylation involved in sex determination mechanism by regulating gene expression related to sex determination networks are common in vertebrates. However, the mechanism linking epigenetics in invertebrates and sex determination has remained elusive. Here, methylome of the male and female gonads in the oyster Crassostrea gigas were conducted to explore the role of epigenetics in invertebrate sex determination. Comparative analysis of gonadal DNA methylation of females and males revealed that male gonads displayed a higher level of DNA methylation and a greater number of hypermethylated genes. Luxury genes presented hypomethylation, while housekeeping genes got hypermethylation. Genes in the conserved signaling pathways, rather than the key master genes in the sex determination pathway, were the major targets of substantial DNA methylation modification. The negative correlation of expression and promoter methylation in the diacylglycerol kinase delta gene (Dgkd) - a ubiquitously expressed gene - indicated DNA methylation may fine turn the expression of Dgkd and be involved in the process of sex determination. Dgkd can be used as an epigenetic marker to distinguish male C. gigas based on the different methylation regions in the promoter region. The results suggest that DNA methylation mechanisms played potential functional impacts in the sex determination in oysters, which is helpful to deepen the understanding of sex determination in invertebrate., (Copyright © 2022 Elsevier B.V. All rights reserved.)

In this study, sexual dimorphism in Chinese dark sleeper (Odontobutis sinensis) brain-pituitary-gonad axis and liver was highlighted by histological and transcriptomic approach. The results showed that there were two significant differences between males and females. Firstly, males grew larger and faster than females. Transcriptomic analysis and qPCR validation indicated that two key growth genes, insulin-like growth factor (igf) and 25-hydroxyvitamin D-1 alpha hydroxylase (cyp27b), were more highly detected in male liver than that in female liver. Secondly, histological analysis displayed that the liver in males showed an obvious ivory fatty phenomenon with more fat vacuoles and lipid droplet aggregation compared to that in females. Transcriptomic analysis indicated that the transcript level of vitellogenin (vtg) in male liver were significantly lower than that in female liver. After 17β-estradiol (E2) treatment of primary cultured hepatocytes, the vtg mRNA expression was induced significantly, while dihydrotestosterone (DHT) treatment had little effect on it. Generally, this study will provide some ideas for further exploring the mechanism of sexual dimorphism in Odontobutis sinensis., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Objective: To present an overview of different approaches and recent advances for long-term preservation of germ cells and gonadal tissues at ambient temperatures., Methods: Review of the existing literature., Results: Preserving viable spermatozoa, eggs, embryos, and gonadal tissues for the long term is critical in human fertility treatment and for the management of animal populations (livestock, biomedical models, and wild species). The need and number of banked germplasms are growing very fast in all disciplines, but current storage options at freezing temperatures are often constraining and not always sustainable. Recent research indicates that structures and functions of gametes or gonadal tissues can be preserved for the long term using different strategies based on dehydration and storage at supra-zero temperatures. However, more studies are needed in rehydration and reanimation of germplasms (including proper molecular and cellular evaluations)., Conclusions: While a lot of research is still warranted to optimize drying and rehydration conditions for each sample type and each species, alternative preservation methods will change the paradigm in fertility preservation and biobanking. It will transform the way we maintain and manage precious biomaterials for the long term., Lay Summary: Living sperm cells, eggs, embryos, and reproductive tissues can be preserved at freezing temperatures for human fertility treatments and used to manage breeding in livestock, laboratory animals, and wild species through assisted reproduction. These cells can be stored in cell banks and demand for them is growing fast. However, current long-term storage options at freezing temperatures are expensive. Instead of using low temperatures, recent research indicates that these cells can be dried and stored above freezing temperatures for an extended amount of time. While a lot of research is still needed to optimize how different samples are dried and rehydrated, alternative methods of preserving cells will make fertility preservation and cell banking easier. It will also transform the way we keep and manage samples for the long term., (© The authors.)

Animals that live in groups often form hierarchies in which an individual's behaviour and physiology varies based on their social rank. Occasionally, a subordinate can ascend into a dominant position and the ascending individual must make rapid behavioural and physiological adjustments to solidify their dominance. These periods of social transition and instability can be stressful and ascending individuals often incur large metabolic costs that could influence their oxidative status. Most previous investigations examining the link between oxidative status and the social environment have done so under stable social conditions and have evaluated oxidative status in a single tissue. Therefore, evaluations of how oxidative status is regulated across multiple tissues during periods of social flux would greatly enhance our understanding of the relationship between oxidative status and the social environment. Here, we assessed how antioxidant capacity in three tissues (brain, gonad, and muscle) varied among dominant, subordinate, and ascending males of the group-living cichlid fish, Neolamprologus pulcher. Antioxidant capacity in the brain and muscle of ascending males was intermediate to that of dominant (highest levels) and subordinate males (lowest levels) and correlated with differences in social and locomotor behaviours, respectively. Gonad antioxidant capacity was lower in ascending males than in dominant males. However, gonad antioxidant capacity was positively correlated with the size of ascending males' gonads suggesting that ascending males may increase gonad antioxidant capacity as they develop their gonads. Overall, our results highlight the widespread physiological consequences of social ascension and emphasize the importance of tissue-specific measures of oxidative status., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Photoperiod impacts reproduction in many species of mammals. Mating occurs at specific seasons to achieve reproductive advantages, such as optimization of offspring survival. Light is the main regulator of these changes during the photoperiod. Seasonally breeding mammals detect and transduce light signals through extraocular photoreceptor, regulating downstream melatonin-dependent peripheral circadian events. In rodents, hormonal reduction and gonadal atrophy occur quickly and consensually with short-day periods. It remains unclear whether photoperiod influences human reproduction. Seasonal fluctuations of sex hormones have been described in humans, although they seem to not imply adaptative seasonal pattern in human gonads. This review discusses current knowledge about seasonal changes in the gonadal function of vertebrates, including humans. The photoperiod-dependent regulation of hypothalamic-pituitary-gonadal axis, as well as morphological and functional changes of the gonads is evaluated herein. Endocrine and morphological variations of reproductive functions, in response to photoperiod, are of interest as they may reflect the nature of past population selection for adaptative mechanisms that occurred during evolution., (© The Author(s) 2021. Published by Oxford University Press on behalf of Society for the Study of Reproduction.)

The stunning sexual transformation commonly triggered by age, size or social context in some fishes is one of the best examples of phenotypic plasticity thus far described. To date our understanding of this process is dominated by studies on a handful of subtropical and tropical teleosts, often in wild settings. Here we have established the protogynous New Zealand spotty wrasse, Notolabrus celidotus, as a temperate model for the experimental investigation of sex change. Captive fish were induced to change sex using aromatase inhibition or manipulation of social groups. Complete female-to-male transition occurred over 60 days in both cases and time-series sampling was used to quantify changes in hormone production, gene expression and gonadal cellular anatomy. Early-stage decreases in plasma 17β-estradiol (E2) concentrations or gonadal aromatase (cyp19a1a) expression were not detected in spotty wrasse, despite these being commonly associated with the onset of sex change in subtropical and tropical protogynous (female-to-male) hermaphrodites. In contrast, expression of the masculinising factor amh (anti-Müllerian hormone) increased during early sex change, implying a potential role as a proximate trigger for masculinisation. Collectively, these data provide a foundation for the spotty wrasse as a temperate teleost model to study sex change and cell fate in vertebrates., (© 2021. The Author(s).)

The Chinese soft-shelled ( Pelodiscus sinensis ) turtle exhibits obvious sex dimorphism, which leads to the higher economic and nutritional value of male individuals. Exogenous hormones can cause the transformation from male to female phenotype during gonadal differentiation. However, the molecular mechanism related to the sexual reversal process is unclear. In this study, we compared the difference between the small RNAs of male, female, and pseudo-female turtles by small RNA-seq to understand the sexual reversal process of Chinese soft-shelled turtles. A certain dose of estrogen can cause the transformation of Chinese soft-shelled turtles from male to female, which are called pseudo-female individuals. The result of small RNA-seq has revealed that the characteristics of pseudo-females are very similar to females, but are strikingly different from males. The number of the microRNAs (miRNAs) of male individuals was significantly less than the number of female individuals or pseudo-female individuals, while the expression level of miRNAs of male individuals were significantly higher than the other two types. Furthermore, we found 533 differentially expressed miRNAs, including 173 up-regulated miRNAs and 360 down-regulated miRNAs, in the process of transformation from male to female phenotype. Cluster analysis of the total 602 differential miRNAs among females, males, and pseudo-females showed that miRNAs played a crucial role during the sexual differentiation. Among these differential miRNAs, we found 12 miRNAs related to gonadal development and verified their expression by qPCR. The TR-qPCR results confirmed the differential expression of 6 of the 12 miRNAs: miR-26a-5p, miR-212-5p, miR-202-5p, miR-301a, miR-181b-3p and miR-96-5p were involved in sexual reversal process, which was consistent with the results of omics. Using these six miRNAs and some of their target genes, we constructed a network diagram related to gonadal development. We suggest that these miRNAs may play an important role in the process of effective sex reversal, which would contribute to the breeding of all male strains of Chinese soft-shelled turtles.

Objective: Female patients treated with alkylating agents in childhood are at risk for ovarian impairment. We aimed at describing the pattern of residual ovarian function in a cohort of survivors of hematological malignancies and/or hematopoietic stem cell transplantation (HSCT) and assessing the relationship between cyclophosphamide equivalent dose (CED) and anti-Müllerian hormone (AMH)., Design and Methods: Gonadal health was clinically and biochemically assessed in 124 post-menarchal survivors who underwent treatment for pediatric hematological malignancies and/or HSCT between 1992 and 2019., Results: Overt 'premature ovarian insufficiency' (POI) was detected in 72.1 and 3.7% of transplanted and non-transplanted patients, respectively; milder 'diminished ovarian reserve' (DOR) in 16.3 and 22.2%. In non-transplanted patients, increasing CED values were associated with lower AMH-SDS (P = 0.04), with the threshold of 7200 g/m2 being the best discriminator between DOR/POI and normal ovarian function (AUC: 0.75 on ROC analysis) and with an observed decrease of 0.14 AMH-SDS for each CED increase of 1 g/m2. In addition, age at diagnosis ≥10 years played a detrimental role on ovarian reserve (P = 0.003). In the HSCT group, irradiation was associated with a statistically significant reduction in AMH-SDS (P = 0.04)., Conclusions: In non-transplanted patients, CED ≥ 7200 mg/m2 was associated with a DOR, while younger age at diagnosis played a protective role on ovarian reserve. As a result of the data collected, we propose a systematic algorithm to assess iatrogenic gonadal impairment in young female patients exposed to chemo-radiotherapy in childhood for hematological disorders.

During development of the mouse urogenital complex, the gonads undergo changes in three-dimensional structure, body position and spatial relationship with the mesonephric ducts, kidneys and adrenals. The complexity of genital ridge development obscures potential connections between morphogenesis and gonadal sex determination. To characterize the morphogenic processes implicated in regulating gonad shape and fate, we used whole-embryo tissue clearing and light sheet microscopy to assemble a time course of gonad development in native form and context. Analysis revealed that gonad morphology is determined through anterior-to-posterior patterns as well as increased rates of growth, rotation and separation in the central domain that may contribute to regionalization of the gonad. We report a close alignment of gonad and mesonephric duct movements as well as delayed duct development in a gonad dysgenesis mutant, which together support a mechanical dependency linking gonad and mesonephric duct morphogenesis., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)

Compared with the well-described XY sex determination system in mammals, the avian ZW sex determination system is poorly understood. Knockdown and overexpression studies identified doublesex and mab-3-related transcription factor 1 (DMRT1) as the testis-determining gene in chicken. However, the detailed effects of DMRT1 gene disruption from embryonic to adult development are not clear. Herein, we have generated DMRT1-disrupted chickens using the clustered regularly interspaced short palindromic repeats-associated protein 9 system, followed by an analysis of physiological, hormonal, and molecular changes in the genome-modified chickens. In the early stages of male chicken development, disruption of DMRT1 induced gonad feminization with extensive physiological and molecular changes; however, functional feminine reproductivity could not be implemented with disturbed hormone synthesis. Subsequent RNA-sequencing analysis of the DMRT1-disrupted chicken gonads revealed gene networks, including several novel genes linearly and non-linearly associated with DMRT1, which are involved in gonad feminization. By comparing the gonads of wild type with the genome-modified chickens, a set of genes were identified that is involved in the ZW sex determination system independent of DMRT1. Our results extend beyond the Z-dosage hypothesis to provide further information about the avian ZW sex determination system and epigenetic effects of gonad feminization., (© 2021 Federation of American Societies for Experimental Biology.)

The starry flounder (Platichthys stellatus), a flatfish cultured at the margins of the North Pacific, displays an obvious female-biased growth advantage, similar to many other fish species. To reveal the molecular mechanism underlying sexual size dimorphism, a comparative transcriptomic analysis of the somatotropic and reproductive axes was conducted. In total, 156, 67, 3434, and 378 differentially expressed genes (DEGs) between female and male samples were obtained in the brain, liver, gonad, and muscle tissues (q < 0.05). These DEGs were significantly enriched for various GO terms, including ion channel activity, protein binding, lipid transporter activity, and glycolytic process. The significantly enriched KEGG pathways included insulin secretion, axon guidance, and glycolysis/gluconeogenesis. In a detailed analysis of DEGs in these significantly enriched pathways, 35 genes showed higher expression levels in female muscle tissues than in male muscle tissues. A protein-protein interaction network further revealed specific interactions involving the glycolysis related-protein enolase (ENO), triosephosphate isomerase (TPI), Bisphosphoglycerate mutase (BPGM), fructose-bisphosphate aldolase (ALDO), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Interestingly, the role of glycolysis/gluconeogenesis was supported by an analysis of common DEGs between P. stellatus and Chinese tongue sole (Cynoglossus semilaevis). These results indicate that the activation of glycolysis in female muscle tissues contributes to flatfish sexual size dimorphism., (Copyright © 2021. Published by Elsevier Inc.)

We here analysed the populations' genetic structure of Coscinasterias tenuispina, an Atlantic-Mediterranean fissiparous starfish, focusing on the western Mediterranean, to investigate: the distribution and prevalence of genetic variants, the relative importance of asexual reproduction, connectivity across the Atlantic-Mediterranean transition, and the potential recent colonisation of the Mediterranean Sea. Individuals from 11 Atlantic-Mediterranean populations of a previous study added to 172 new samples from five new W Mediterranean sites. Individuals were genotyped at 12 microsatellite loci and their gonads histologically analysed for sex determination. Additionally, four populations were genotyped at two-time points. Results demonstrated genetic homogeneity and low clonal richness within the W Mediterranean, due to the dominance of a superclone, but large genetic divergence with adjacent areas. The lack of new genotypes recruitment over time, and the absence of females, confirmed that W Mediterranean populations were exclusively maintained by fission and reinforced the idea of its recent colonization. The existence of different environmental conditions among basins and/or density-depend processes could explain this lack of recruitment from distant areas. The positive correlation between clonal richness and heterozygote excess suggests that most genetic diversity is retained within individuals in the form of heterozygosity in clonal populations, which might increase their resilience., (© 2021. The Author(s).)

A diverse array of sex determination ( SD ) mechanisms, encompassing environmental to genetic, have been found to exist among vertebrates, covering a spectrum from fixed SD mechanisms (mammals) to functional sex change in fishes (sequential hermaphroditic fishes). A major landmark in vertebrate SD was the discovery of the SRY gene in 1990. Since that time, many attempts to clone an SRY ortholog from nonmammalian vertebrates remained unsuccessful, until 2002, when DMY/dmrt1by was discovered as the SD gene of a small fish, medaka. Surprisingly, however, DMY/dmrt1by was found in only 2 species among more than 20 species of medaka, suggesting a large diversity of SD genes among vertebrates. Considerable progress has been made over the last 3 decades, such that it is now possible to formulate reasonable paradigms of how SD and gonadal sex differentiation may work in some model vertebrate species. This review outlines our current understanding of vertebrate SD and gonadal sex differentiation, with a focus on the molecular and cellular mechanisms involved. An impressive number of genes and factors have been discovered that play important roles in testicular and ovarian differentiation. An antagonism between the male and female pathway genes exists in gonads during both sex differentiation and, surprisingly, even as adults, suggesting that, in addition to sex-changing fishes, gonochoristic vertebrates including mice maintain some degree of gonadal sexual plasticity into adulthood. Importantly, a review of various SD mechanisms among vertebrates suggests that this is the ideal biological event that can make us understand the evolutionary conundrums underlying speciation and species diversity.

In the early fetal stage, the gonads are bipotent and only later become the ovary or testis, depending on the genetic sex. Despite many studies examining how sex determination occurs from biopotential gonads, the spatial and temporal organization of bipotential gonads and their progenitors is poorly understood. Here, using lineage tracing in mice, we find that the gonads originate from a T + primitive streak through WT1 + posterior intermediate mesoderm and appear to share origins anteriorly with the adrenal glands and posteriorly with the metanephric mesenchyme. Comparative single-cell transcriptomic analyses in mouse and cynomolgus monkey embryos reveal the convergence of the lineage trajectory and genetic programs accompanying the specification of biopotential gonadal progenitor cells. This process involves sustained expression of epithelial genes and upregulation of mesenchymal genes, thereby conferring an epithelial-mesenchymal hybrid state. Our study provides key resources for understanding early gonadogenesis in mice and primates., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: The role of miRNA as endocrine regulators is emerging, and microRNA mir-30b has been reported to repress Mkrn3. However, the expression of miR-30b during male puberty has not been studied., Design and Methods: Circulating relative miR-30b expression was assessed in sera of 26 boys with constitutional delay of growth and puberty (CDGP), treated with low-dose testosterone (T) (n =11) or aromatase inhibitor letrozole (Lz) (n =15) for 6 months and followed up to 12 months (NCT01797718). The associations between the relative expression of miR-30b and hormonal markers of puberty were evaluated., Results: During the 12 months of the study, circulating miR-30b expression increased 2.4 ± 2.5 (s.d.) fold (P = 0.008) in all boys, but this change did not correlate with corresponding changes in LH, testosterone, inhibin B, FSH, or testicular volume (P = 0.25-0.96). Lz-induced activation of the hypothalamic-pituitary-gonadal (HPG) axis was associated with more variable miR-30b responses at 3 months (P < 0.05), whereas those treated with T exhibited significant changes in relative miR-30b levels in the course the study (P < 0.01-0.05)., Conclusions: Circulating miR-30b expression in boys with CDGP increases in the course of puberty, and appears to be related to the activity of the HPG axis.

Global warming is predicted to have major effects on the annual time windows during which species may successfully reproduce. At the organismal level, climatic shifts engage with the control mechanism for reproductive seasonality. In mammals, laboratory studies on neuroendocrine mechanism emphasize photoperiod as a predictive cue, but this is based on a restricted group of species. In contrast, field-oriented comparative analyses demonstrate that proximate bioenergetic effects on the reproductive axis are a major determinant of seasonal reproductive timing. The interaction between proximate energetic and predictive photoperiodic cues is neglected. Here, we focused on photoperiodic modulation of postnatal reproductive development in common voles (Microtus arvalis), a herbivorous species in which a plastic timing of breeding is well documented. We demonstrate that temperature-dependent modulation of photoperiodic responses manifest in the thyrotrophin-sensitive tanycytes of the mediobasal hypothalamus. Here, the photoperiod-dependent expression of type 2 deiodinase expression, associated with the summer phenotype was enhanced by 21°C, whereas the photoperiod-dependent expression of type 3 deiodinase expression, associated with the winter phenotype, was enhanced by 10°C in spring voles. Increased levels of testosterone were found at 21°C, whereas somatic and gonadal growth were oppositely affected by temperature. The magnitude of these temperature effects was similar in voles photoperiodical programmed for accelerated maturation (ie, born early in the breeding season) and in voles photoperiodical programmed for delayed maturation (ie, born late in the breeding season). The melatonin-sensitive pars tuberalis was relatively insensitive to temperature. These data define a mechanistic hierarchy for the integration of predictive temporal cues and proximate thermo-energetic effects in mammalian reproduction., (© 2021 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Bone is emerging as a versatile endocrine organ and its interactions with apparently unrelated organs are being more widely recognized. Osteocalcin (OCN), a polypeptide hormone secreted by osteoblasts, has been found to exert multiple endocrine functions through its metabolically active form, uncarboxylated OCN (uOCN). Mounting evidence has shown that following its binding to G-protein coupled receptor 6a (Gprc6a) in the peripheral tissues, uOCN acts on pancreatic β cells to increase insulin secretion, and on muscle and white adipose tissue to promote glucose and lipid metabolism. More strikingly, researchers have found a surprising role of uOCN in testicular function to facilitating testosterone biosynthesis and regulating male fertility via a pancreas-bone-gonadal axis. However, the detailed functional mechanisms of uOCN on the hypothalamic-pituitary-gonadal axis or the pancreas-bone-gonadal axis are not fully understood. Besides highlighting the regulatory mechanisms of uOCN in the hypothalamus and pituitary, we also discuss its role in male as well as female fertility and its potential clinical implications in some reproductive endocrine diseases and pubertal developmental disorders.

The European sea bass (Dicentrarchus labrax) exhibits female-biased sexual size dimorphism (SSD) early in development. New tagging techniques provide the opportunity to monitor individual sex-related growth during the post-larval and juvenile stages. We produced an experimental population through artificial fertilization and followed a rearing-temperature protocol (~16°C from hatching to 112 days post-hatching, dph; ~20°C from 117 to 358 dph) targeting a roughly balanced sex ratio. The fish were tagged with microchips between 61 and 96 dph in five tagging trials of 50 fish each; individual standard length (SL) was recorded through repeated biometric measurements performed between 83 to 110 dph via image analyses. Body weight (BW) was modelled using the traits measured on the digital pictures (i.e. area, perimeter and volume). At 117 dph, the fish were tagged with microtags and regularly measured for SL and BW until 335 dph. The experiment ended at 358 dph with the sexing of the fish. The sex-ratio at the end of the experiment was significantly in favor of the females (65.6% vs. 34.4%). The females were significantly longer and heavier than the males from 103 dph (~30 mm SL, ~0.44 g BW) to 165 dph, but the modeling of the growth curves suggests that differences in size already existed at 83 dph. A significant difference in the daily growth coefficient (DGC) was observed only between 96 and 103 dph, suggesting a physiological or biological change occurring during this period. The female-biased SSD pattern in European sea bass is thus strongly influenced by very early growth differences between sexes, as already shown in previous studies, and in any case long before gonadal sex differentiation has been started, and thus probably before sex has been determined. This leads to the hypothesis that early growth might be a cause rather than a consequence of sex differentiation in sea bass., Competing Interests: The authors declare that they have no competing interests.

Objective: To investigate the incidence of hypothalamus-pituitary-gonadal (HPG) axis initiation/recovery after treatment and to identify predictive risk factors for noninitiation/recovery., Methods: A total of 127 consecutive suprasellar germ cell tumor (GCT) patients managed at Peking Union Medical College Hospital (2006-2019) were retrospectively analyzed. Prepubertal patients (followed up until 13 years of age for girls and 14 years of age for boys) and patients with HPG dysfunction (followed up for 2 years) were divided into the initiation/recovery and noninitiation/recovery groups., Results: Of the 127 suprasellar GCT patients, 75 met the follow-up criteria, 28 (37.3%) of whom experienced HPG axis initiation/recovery. Compared to the noninitiation/recovery group, the initiation/recovery group included more males and had shorter delayed diagnosis times, smaller tumor sizes, lower panhypopituitarism rates, thinner pituitary stalk widths, lower visual deficit rates, and higher serum testosterone and estradiol levels. The cutoff values of pituitary stalk width, tumor size, and delayed diagnosis time used to predict noninitiation/recovery were 6.9 mm, 6.9 mm and 1.7 years, respectively. Tumor size ≥6.9 mm (odds ratio (OR) = 7.5, 95% CI: 2.2-25.8, P = 0.001), panhypopituitarism (OR = 5.0, 95% CI: 1.4-17.6, P = 0.013), and delayed diagnosis time ≥1.7 years (OR = 5.7, 95% CI: 1.5-20.7, P = 0.009) were risk factors for noninitiation/recovery., Conclusions: Among suprasellar GCT patients, nearly one-third of prepubertal patients and patients with HPG dysfunction experience HPG axis initiation/recovery after treatment. Tumor size ≥6.9 mm, panhypopituitarism, and delayed diagnosis time ≥1.7 years were identified as predictive risk factors for noninitiation/recovery.

Context: Testosterone (T) or estradiol (E2) are administered to suppress gonadal function in female-to-male (FTM) and male-to-female (MTF) transgender patients. How often sex steroids cause adequate suppression without GnRH agonist (GnRHa) or progestin therapy has not been reported., Objectives: (1) To determine how often T and E2 therapy alone can effectively suppress gonadal function in MTF and FTM transgender patients, and (2) to determine the frequency and range of serum E2 levels above the normal male range in FTM patients receiving T therapy., Design: Retrospective cohort study., Setting: Outpatient reproductive endocrinology clinic at an academic medical center., Patients: A total of 65 FTM and 33 MTF patients were included who were > 18 years of age and not receiving progestin or GnRHa therapy., Intervention: Female-to-male patients were receiving T through injections or gel. Male-to-female patients were receiving oral or subcutaneous E2., Main Outcome Measurements: In FTM patients the indicator of ovary suppression was amenorrhea. In MTF patients, the indicator of testes suppression was T levels <50 ng/dL., Results: Median serum total T level for FTM patients was 712 ng/dL (range, 370-1164 ng/dL). On T therapy alone, 90.8% of patients achieved amenorrhea and 49.2% of patients had serum E2 levels above the normal range for women. For MTF patients, the median serum E2 level was 129.2 pg/mL (range, 75-197 pg/mL). On E2 therapy alone, 84.8% of MTF patients had adequate suppression of testicular function., Conclusions: Testosterone and E2 therapy are usually effective without progestin or GnRHa therapy to suppress gonadal function in transgender patients. Progestin and/or GnRHa therapy should only be initiated in those patients who do not have adequate gonadal suppression on optimized doses of T or E2 alone., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Steroidogenic factor 1 (NR5A1) is essential for gonadal development. To study the importance of NR5A1 during early gonadal sex differentiation, we generated Sox9-Cre-Nr5a1 conditional knockout (cKO) mice: Sox9-Cre;Nr5a1 flox/flox and Sox9-Cre;Nr5a1 flox/- mice. Double-immunostaining for NR5A1 and AMH revealed silenced NR5A1 in Sertoli cells and reduced AMH + cells in the gonads of XY Sox9-Cre-Nr5a1 cKO mice between embryonic days 12.5 (E12.5) and E14.5. Double-immunostaining for SOX9 and FOXL2 further indicated an early block in Sertoli cells and ectopic granulosa cell differentiation. The number of cells expressing the Leydig cell marker 3βHSD obviously reduced in the gonads of XY Sox9-Cre;Nr5a1 flox/- but not Sox9-Cre;Nr5a1 flox/flox mice at E15.5. The presence of STRA8 + cells indicated that germ cells entered meiosis in the gonads of XY Sox9-Cre-Nr5a1 cKO mice. The results of qRT-PCR revealed remarkably reduced and elevated levels of testis and ovary markers, respectively, in the gonads of XY Sox9-Cre-Nr5a1 cKO mice at E12.5‒E13.5. These data suggested that the loss of Nr5a1 abrogates the testicular pathway and induces the ectopic ovarian pathway, resulting in postnatal partial/complete male-to-female gonadal sex reversal. Our findings provide evidence for the critical role of NR5A1 in murine gonadal sex determination in vivo.

Nutrition affects multiple aspects of insect physiology such as body size and fecundity, but we lack a detailed understanding of how nutrition influences the reproductive physiology of male insects such as mosquitoes. Given that female mosquitoes are vectors of many deadly diseases and can quickly proliferate, understanding how male nutrition impacts female fecundity could be of critical importance. To uncover the relationship between nutrition in adult male mosquitoes and its impacts on reproductive physiology, we reared larvae of the Northern house mosquito, Culex pipiens, on a standard lab diet and divided adult males among three different dietary treatments: low (3%), moderate (10%), and high (20%) sucrose. We found that although overall body size did not differ among treatments, one-week-old males raised on the 3% sucrose diet had significantly smaller male accessory glands (MAGs) compared to males that consumed the 10% and the 20% sucrose diets. Diet affected whole-body lipid content but did not affect whole-body protein content. Using nuclear magnetic resonance (NMR) spectroscopy, we found that diet altered the metabolic composition of the MAGs, including changes in lactic acid, formic acid, and glucose. We also observed changes in protein and lipid abundance and composition in MAGs. Females who mated with males on the 3% diet were found to produce significantly fewer larvae than females who had mated with males on the 10% diet. Taken together, our results demonstrate that the diet of adult male mosquitoes clearly affects male reproductive physiology and female fecundity., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Recent data argue for a pro-inflammatory role of CAMP (cathelicidin antimicrobial peptide) in adipocytes and adipose tissue (AT) and for regulatory circuits involving TLRs. In order to investigate regulatory effects of TLR2 and TLR4, 3T3-L1 adipocytes were stimulated with TLR2 agonistic lipopeptide MALP-2 and with TLR4 agonist LPS in presence or absence of signal transduction inhibitors. CAMP gene expression was analysed by quantitative real-time PCR in adipocytes and in murine AT compartments and cellular subfractions. CAMP expression was higher in gonadal than in subcutaneous AT and there was a gender-specific effect with higher levels in males. Adipocytes had higher CAMP expression than the stroma-vascular cell (SVC) fraction. MALP-2 up-regulated CAMP expression significantly, mediated by STAT3 and PI3K and potentially (non-significant trend) by NF-κB and MAPK, but not by raf-activated MEK-1/-2. Moreover, LPS proved to act as a potent inducer of CAMP via NF-κB, PI3K and STAT3, whereas specific inhibition of MAPK and MEK-1/-2 had no effect. In conclusion, activation of TLR2 and TLR4 by classical ligands up-regulates adipocyte CAMP expression involving classical signal transduction elements. These might represent future drug targets for pharmacological modulation of CAMP expression in adipocytes, especially in the context of metabolic and infectious diseases.

Puberty is a complex process that culminates in the acquisition of psychophysical maturity and reproductive capacity. This elaborate and fascinating process marks the end of childhood. Behind it lies a complex, genetically mediated neuroendocrine mechanism through which the gonads are activated thanks to the fine balance between central inhibitory and stimulating neuromodulators and hormones with both central and peripheral action. The onset of puberty involves the reactivation of the hypothalamic-pituitary-gonadal (HPG) axis, supported by the initial "kiss" between kisspeptin and the hypothalamic neurons that secrete GnRH (the GnRH "pulse generator"). This pulsatile production of GnRH is followed by a rise in LH and, consequently, in gonadal steroids. The onset of puberty varies naturally between individuals, and especially between males and females, in the latter of whom it is typically earlier. However, pathological variations, namely precocious and delayed puberty, are also possible. This article reviews the scientific literature on the physiological mechanisms of puberty and the main pathophysiological aspects of its onset., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In 2012, after the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) that followed the Tohoku earthquake and tsunami in March 2011, no rock shell (Thais clavigera; currently recognized as Reishia clavigera; Gastropoda, Neogastropoda, Muricidae) specimens were found near the plant from Hirono to Futaba Beach (a distance of approximately 30 km). In July 2016, however, rock shells were again found to inhabit the area. From April 2017 to May 2019, we collected rock shell specimens monthly at two sites near the FDNPP (Okuma and Tomioka) and at a reference site ~ 120 km south of the FDNPP (Hiraiso). We examined the gonads of the specimens histologically to evaluate their reproductive cycle and sexual maturation. The gonads of the rock shells collected at Okuma, ~ 1 km south of the FDNPP, exhibited consecutive sexual maturation during the 2 years from April 2017 to May 2019, whereas sexual maturation of the gonads of specimens collected at Hiraiso was observed only in summer. The consecutive sexual maturation of the gonads of the specimens collected at Okuma might not represent a temporary phenomenon but rather a site-specific phenotype, possibly caused by specific environmental factors near the FDNPP.

Transgenic zebrafish in which the germline is specifically labeled with enhanced green fluorescent protein (eGFP) can be used for continuous observation of germline development during the lifetime, from the primordial germ cells (PGCs) in the early embryo to the gametes in the mature gonad. In this chapter, we describe a procedure for the generation of transgenic fish Tg(piwil1:egfp-UTRnanos3), the sample preparation for live imaging of PGCs, for high-resolution imaging of germ cells in developing gonads, and quantifying PGC numbers. The methods described in this chapter are not only applicable to the study of germ cells, but also provide general advices for researchers who are willing to generate transgenic zebrafish and do observation on live embryos as well as on fixed tissues.

The evolution of social behavior depends on genetic changes, yet, how genomic variation manifests itself in behavioral diversity is still largely unresolved. Chromosomal inversions can play a pivotal role in producing distinct behavioral phenotypes, in particular, when inversion genes are functionally associated with hormone synthesis and signaling. Male ruffs exhibit alternative reproductive tactics (ARTs) with an autosomal inversion determining two alternative morphs with clear behavioral and hormonal differences from the ancestral morph. We investigated hormonal and transcriptomic differences in the pituitary and gonads. Using a GnRH challenge, we found that the ability to synthesize testosterone in inversion carriers is severely constrained, whereas the synthesis of androstenedione, a testosterone precursor, is not. Inversion morphs were able to produce a transient increase in androstenedione following the GnRH injection, supporting the view that pituitary sensitivity to GnRH is comparable to that of the ancestral morph. We then performed gene expression analyses in a second set of untreated birds and found no evidence of alterations to pituitary sensitivity, gonadotropin production or gonad sensitivity to luteinizing hormone or follicle-stimulating hormone across morphs. Inversion morphs also showed reduced progesterone receptor expression in the pituitary. Strikingly, in the gonads, inversion morphs over-expressed STAR, a gene that is located outside of the inversion and responsible for providing the cholesterol substrate required for the synthesis of sex hormones. In conclusion, our results suggest that the gonads determine morph-specific differences in hormonal regulation., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The reproductive neuroendocrine axis, or hypothalamo-pituitary-gonadal (HPG) axis, is a paragon of complex biological system involving numerous cell types, spread over several anatomical levels communicating through entangled endocrine feedback loops. The HPG axis exhibits remarkable dynamic behaviors on multiple time and space scales, which are an inexhaustible source of studies for mathematical and computational biology. In this review, we will describe a variety of modeling approaches of the HPG axis from a cellular endocrinology viewpoint. We will in particular investigate the questions raised by some of the most striking features of the HPG axis: (i) the pulsatile secretion of hypothalamic and pituitary hormones, and its counterpart, the cell signaling induced by frequency-encoded hormonal signals, and (ii) the dual, gametogenic and glandular function of the gonads, which relies on the tight control of the somatic cell populations ensuring the proper maturation and timely release of the germ cells., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The agenesis of the gonads and adrenal gland in revealed by knockout mouse studies strongly suggested a crucial role for Nr5a1 (SF-1 or Ad4BP) in organ development. In relation to these striking phenotypes, NR5A1/Nr5a1 has the potential to reprogram cells to steroidogenic cells, endow pluripotency, and regulate cell proliferation. However, due to limited knowledge regarding NR5A1 target genes, the mechanism by which NR5A1/Nr5a1 regulates these fundamental processes has remained unknown. Recently, newlyestablished technologies have enabled the identification of NR5A1 target genes related to multiple metabolic processes, as well as the aforementioned biological processes. Considering that active cellular processes are expected to be accompanied by active metabolism, NR5A1 may act as a key factor for processes such as cell differentiation, proliferation, and survival by coordinating these processes with cellular metabolism. A complete and definite picture of the cellular processes coordinated by NR5A1/Nr5a1 could be depicted by accumulating evidence of the potential target genes through whole genome studies.

The hypothalamic-pituitary axis (HP axis) plays a critical and integrative role in the endocrine system control to maintain homeostasis. The HP axis is responsible for the hormonal events necessary to regulate the thyroid, adrenal glands, gonads, somatic growth, among other functions. Endocrine-disrupting chemicals (EDCs) are a worldwide public health concern. There is growing evidence that exposure to EDCs such as bisphenol A (BPA), some phthalates, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and biphenyls (PBBs), dichlorodiphenyltrichloroethane (DDT), tributyltin (TBT), and atrazine (ATR), is associated with HP axis abnormalities. EDCs act on hormone receptors and their downstream signaling pathways and can interfere with hormone synthesis, metabolism, and actions. Because the HP axis function is particularly sensitive to endogenous hormonal changes, disruptions by EDCs can alter HP axis proper function, leading to important endocrine irregularities. Here, we review the evidence that EDCs could directly affect the mammalian HP axis function., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Precocious puberty (PP) is a common reason for referral to pediatric endocrinology clinics, with a strong female predominance. PP is a broad term encompassing benign variants of normal development, gonadotropin-dependent precious puberty (GDPP), and gonadotropin-independent precocious puberty (GIPP). This article reviews the definitions, physiology, clinical presentation, evaluation and treatment of these conditions.

Toxaphene is an organochlorine pesticide and environmental contaminant that is concerning due to its atmospheric transport and persistence in soil. In Florida, toxaphene and other organochlorine pesticides were used heavily in agriculture on the north shore of Lake Apopka and they are still detectable in soil. Wild largemouth bass that inhabit the lake and the marshes along the north shore have been exposed to a variety of organochlorine pesticides including dieldrin, methoxychlor, and p,p'-DDE, among others. While these other organochlorine pesticides have been studied for their endocrine disrupting effects in largemouth bass, there is little information for toxaphene. In this study, male and female largemouth bass were given food containing 50 mg/kg toxaphene for almost 3 months, to achieve tissue levels similar to those found in fish at Lake Apopka. Sex-specific toxicity was then evaluated by measuring various reproductive endpoints and transcriptomic changes. In females, gonadosomatic index showed a trend towards reduction (p = 0.051) and plasma vitellogenin was reduced by ~40% relative to controls. However plasma levels of 17β-estradiol and testosterone were not perturbed by toxaphene exposure. These data suggest that toxaphene does not act as a weak estrogen as many other organochlorine pesticides do, but rather appears to be acting as an antiestrogen in female fish. There were no obvious changes in the gonadosomatic index and plasma hormones in male bass. However, ex vivo explant experiments revealed that toxaphene prevented human chorionic gonadotropin-stimulated testosterone production in the testis. This suggested that toxaphene had anti-androgenic effects in males. Subsequent transcriptomic analyses of the testis revealed that androgen receptor/beta-2-microglobulin signaling was up-regulated while insulin-related pathways were suppressed with toxaphene, which could be interpreted as a compensatory response to androgen suppression. In the male liver, the transcriptome analysis revealed an overwhelming suppression in immune-related signaling cascades (e.g. lectin-like receptor and ITSM-Containing Receptor signaling, CD16/CD14 Proinflammatory Monocyte Activation, and CD38/CD3-JUN/FOS/NF-kB Signaling in T-cell Proliferation). Overall, this study showed that toxaphene induced sex-specific effects. The transcriptomic and physiological responses observed can contribute to the development of adverse outcome pathways for toxaphene exposure in fish., (Copyright © 2020. Published by Elsevier Inc.)

Fibroblast growth factor 9 (FGF9) is an autocrine/paracrine growth factor that plays critical roles in embryonic and organ developments and is involved in diverse physiological events. Loss of function of FGF9 exhibits male-to-female sex reversal in the transgenic mouse model and gain of FGF9 copy number was found in human 46, XX sex reversal patient with disorders of sex development. These results suggested that FGF9 plays a vital role in male sex development. Nevertheless, how FGF9/Fgf9 expression is regulated during testis determination remains unclear. In this study, we demonstrated that human and mouse SRY bind to -833 to -821 of human FGF9 and -1010 to -998 of mouse Fgf9, respectively, and control FGF9/Fgf9 mRNA expression. Interestingly, we showed that mouse SRY cooperates with SF1 to regulate Fgf9 expression, whereas human SRY-mediated FGF9 expression is SF1 independent. Furthermore, using an ex vivo gonadal culture system, we showed that FGF9 expression is sufficient to switch cell fate from female to male sex development in 12-16 tail somite XX mouse gonads. Taken together, our findings provide evidence to support the SRY-dependent, fate-determining role of FGF9 in male sex development., (© The Author(s) 2020. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The assumption for hermaphroditic fish species that mature individuals of the terminal sex arise directly from mature individuals of the primary sex has led to the use of sex ratios as a proxy for age at maturity (A 50 ). The timing of transition and deficient energy reserves, however, can result in a delay between transition and spawning. To test the assumption of female maturity and investigate the relationship between maturation and energy reserves, common snook, Centropomus undecimalis, a protandrous hermaphrodite, were collected from rivers, estuaries, inlets and offshore habitats on the east coast of Florida during 2010-2015. Immature females were observed every month, with lowest proportions during the peak spawning months of July and August. When calculated based on sex ratio, A 50 (8.1 years) overestimated the age at which 50% of the female population was, in fact, mature (4.1-4.9 years). Best-fit models indicate that mesenteric fat index (I F ) and hepato-somatic index (I H ) were significantly affected by gonad phase, month and size and weakly by habitat. In post hoc analysis, immature female I F did not differ significantly from developing and regenerating females, but immature female I H was significantly lower than that for all mature phases except animals in the regressing phase. Although immature females may have sufficient energy in terms of fat, it appears that energy is not allocated to reproductive processes, as evidenced by lower I H . Nonetheless, approximately 95% of females were spawning-capable during peak spawning months, suggesting that the energy threshold at which immature females reach maturity is met by most females each spawning cycle., (© 2020 Fisheries Society of the British Isles.)

Sex change was induced in Epinephelus marginatus juveniles using a nonsteroidal aromatase inhibitor (AI), a synthetic androgen (17α-methyltestosterone; MT), and a combination of both (MT + AI) in a 90-day experiment. A detailed remodeling of the gonads, the plasma level of gonadal steroids, and immunostaining of pituitary follicle-stimulating hormone (FSH), luteinizing hormone (LH), and somatolactin (SL) cells were analyzed. Sex inversion reached the final spermatogenesis stages using MT, while AI triggered spermatogenesis, but reaching only the spermatid stage. Estradiol (E 2 ) levels did not change in fish treated with AI but decreased throughout the experimental period in animals treated with MT and MT + AI. Testosterone (T) levels increased in animals treated with MT during the first 60 days (and combined with AI in the first 30 days), decreasing in all experimental groups at 90 days, while AI-treated animals had increased plasma 11-ketotestosterone (11-KT) levels after 90 days. In control fish, FSH- and SL-producing cells (ir-FSH and ir-SL) were restricted to pars intermedia (PI) of the adenohypophysis. Pituitary ir-FSH cells were decreased at the end of the experimental period in all treatments compared with the CT animals. LH-producing cells (ir-LH) were present in proximal pars distalis (PPD) and pars intermedia (PI) of adenohypophysis and did not change after the experimental period. The decreased number of ir-FSH cells at the end of the experiment in all treatments could be related to the negative feedback loop triggered by the increase in natural and/or synthetic androgens.

Women acquire cocaine habits faster and are more motivated to obtain drug than men. In general, female rodents acquire intravenous cocaine self-administration (SA) faster and show greater locomotor responses to cocaine than males. Sex differences are attributed to differences in circulating estradiol. We used the four core genotype (FCG) mouse to ask whether sex chromosome complement influences vulnerability to cocaine's reinforcing and/or locomotor-activating effects. The FCG cross produces ovary-bearing mice with XX or XY genotypes (XXF, XYF) and testes-bearing mice with XX or XY genotypes (XXM, XYM). A greater percentage of gonadal females acquired cocaine SA via infusions into jugular catheters as compared with XYM mice, but XXM mice were not significantly different than any other group. Discrimination of the active versus inactive nose poke holes and cocaine intake were in general greater in gonadal females than in gonadal males. Progressive ratio tests for motivation revealed an interaction between sex chromosomes and gonads: XYM mice were more motivated to self-administer cocaine taking more infusions than mice in any other group. Locomotor responses to cocaine exposure revealed effects of sex chromosomes. After acute exposure, activity was greater in XX than in XY mice and the reverse was true for behavioral sensitization. Mice with XY genotypes displayed more activity than XX mice when given cocaine after a 10-day drug-free period. Our data demonstrate that sex chromosome complement alone and/or interacting with gonadal status can modify cocaine's reinforcing and locomotor-activating effects. These data should inform current studies of sex differences in drug use., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier Inc. All rights reserved.)