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For a generation or more, the mass spectrometry that developed at the frontier of molecular biology was worlds apart from isotope ratio mass spectrometry, a label-free approach done on optimized gas-source magnetic sector instruments. Recent studies show that electrospray-ionization Orbitraps and other mass spectrometers widely used in the life sciences can be fine-tuned for high-precision isotope ratio analysis. Since isotope patterns form everywhere in nature based on well-understood principles, intramolecular isotope measurements allow unique insights into a fascinating range of research topics. This Perspective introduces a wider readership to current topics in stable isotope research with the aim of discussing how soft-ionization mass spectrometry coupled with ultrahigh mass resolution can enable long-envisioned progress. We highlight novel prospects of observing isotopes in intact polar compounds and speculate on future directions of this adventure into the overlapping realms of biology, chemistry, and geology.

Japanese flounder (Paralichthys olivaceus) is an important marine fish species of both fisheries and aquaculture in Northeast Asia. The commercial interest for all-female progenies due to several sex-related traits has prompted basic research on the mechanisms of sex determination in this species. By conducting a linkage analysis of the sex-determining locus, we initially identified 12 microsatellite markers linked to sex in 11 scaffolds, whose localization was restricted to a specific region of linkage group 9. Sequence analysis of this region identified 181 genes based on the UniProt database annotations. Among them, the amh gene was considered a potential candidate for sex determination because this gene is known to have taken over the role of sex determination in many teleosts. An in-depth sequence analysis of both the coding and non-coding regions of amh in XX and XY individuals detected nine SNPs linked with maleness. However, because these substitutions were synonymous, the upstream and downstream regions of amh were also investigated and a male-specific variant with deletions in the promoter region was detected. This truncated Y-specific amh variant was named amhy, and the amh shared by both sexes was named amhx. The association analysis using both females and males of the genotypic sex inferred by the presence/absence of amhy found complete association with phenotypic sex and genotype. Gene expression analysis in larvae derived from a single-pair progeny by quantitative real-time PCR detected amhy transcripts in the larval trunks between 20 and 100 days after hatching only in XY larvae. Localization of amhy by in situ hybridization was detected in presumptive Sertoli cells of XY gonads. Expression of amhx was almost undetectable in both XX and XY genotypes. Loss of Amh function by CRISPR-Cas9 induced male-to-female sex reversal, indicating that this gene was necessary for the masculinization of XY individuals. In conclusion, the complete linkage of amhy with males, its early expression in XY gonads before testicular differentiation, and the induction of sex reversal by loss-of-function mutation support the view that amhy is the sex-determining gene in this species.

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International audience; 17O-excess (Δ17O = δ17O − 0.52 × δ18O) of sulfate trapped in Antarctic ice cores has been proposed as a potential tool for assessing past oxidant chemistry, while insufficient understanding of atmospheric sulfate formation around Antarctica hampers its interpretation. To probe influences of regional specific chemistry, we compared year-round observations of Δ17O of non-sea-salt sulfate in aerosols (Δ17O(SO42−)nss) at Dome C and Dumont d'Urville, inland and coastal sites in East Antarctica, throughout the year 2011. Although Δ17O(SO42−)nss at both sites showed consistent seasonality with summer minima (∼1.0‰) and winter maxima (∼2.5‰) owing to sunlight-driven changes in the relative importance of O3 oxidation to OH and H2O2 oxidation, significant intersite differences were observed in austral spring–summer and autumn. The cooccurrence of higher Δ17O(SO42−)nss at inland (2.0‰ ± 0.1‰) than the coastal site (1.2‰ ± 0.1‰) and chemical destruction of methanesulfonate (MS–) in aerosols at inland during spring–summer (October–December), combined with the first estimated Δ17O(MS–) of ∼16‰, implies that MS– destruction produces sulfate with high Δ17O(SO42−)nss of ∼12‰. If contributing to the known postdepositional decrease of MS– in snow, this process should also cause a significant postdepositional increase in Δ17O(SO42−)nss over 1‰, that can reconcile the discrepancy between Δ17O(SO42−)nss in the atmosphere and ice. The higher Δ17O(SO42−)nss at the coastal site than inland during autumn (March–May) may be associated with oxidation process involving reactive bromine and/or sea-salt particles around the coastal region.

Significance Carbonyl sulfide (OCS) is a key proxy of the global photosynthesis rate, but the greatest uncertainty in the OCS cycle is its missing source. Our unique method of measuring sulfur isotope ratios (34S/32S) of OCS was used in this study to distinguish oceanic and anthropogenic OCS sources. A north–south latitudinal gradient in the 34S/32S ratio of OCS was found, corresponding to OCS concentrations during wintertime within eastern Asia, providing evidence of the importance of anthropogenic OCS emissions from China. Sulfur isotopic constraints of the atmospheric OCS budget revealed that anthropogenic OCS sources, and not only oceanic OCS sources, are likely to be major constituents of the missing source of atmospheric OCS., Carbonyl sulfide (OCS), the most abundant sulfur-containing gas in the atmosphere, is used as a proxy for photosynthesis rate estimation. However, a large missing source of atmospheric OCS has been inferred. Sulfur isotope measurements (34S/32S ratio and δ34S) on OCS are a feasible tool to distinguish OCS sources from oceanic and anthropogenic emissions. Here we present the latitudinal (north–south) observations of OCS concentration and δ34S within Japan. The observed δ34S of OCS of 9.7 to 14.5‰ reflects source and sink effects. Particularly in winter, latitudinal decreases in δ34S values of OCS were found to be correlated with increases in OCS concentrations, resulting an intercept of (4.7 ± 0.8)‰ in the Keeling plot approach. This result implies the transport of anthropogenic OCS emissions from the Asian continent to the western Pacific by the Asian monsoon outflow. The estimated background δ34S of OCS in eastern Asia is consistent with the δ34S of OCS previously reported in Israel and the Canary Islands, suggesting that the background δ34S of OCS in the Northern Hemisphere ranges from 12.0 to 13.5‰. Our constructed sulfur isotopic mass balance of OCS revealed that anthropogenic sources, not merely oceanic sources, account for much of the missing source of atmospheric OCS.

The exposure of adult fish to warm or high temperatures is known to impair reproduction, yet the long-term reproductive impacts for treatments at early life are not well clarified. This study aimed to evaluate the effects of warm temperature (WT) during juvenile stage on gonad maturation, gamete quality, and offspring thermotolerance in rainbow trout. While the comparison of basic reproductive parameters in WT females did not reveal any kind of impairment, many WT males showed an atrophied, undeveloped gonad, or a smaller testis with lower milt volume; sperm quality parameters in WT males and deformity rates in the respective progeny were also highly affected. However, despite of such negative effects, many of the remaining progeny presented better rates of survival and growth when exposed to the same conditions as those of parental fish (WT), suggesting that thermal stress in parr stage males elicited intergenerational thermotolerance after a single generation. The present results support that prolonged warming stress during early life stages can adversely affect key reproductive aspects, but contrastingly increase offspring performance at upper thermal ranges. These findings have implications on the capacity of fish to adapt and to cope with global warming. Fil: Butzge, Arno Juliano. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Yoshinaga, Tulio Teruo. Universidade de Sao Paulo; Brasil Fil: Moreno Acosta, Omar David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Fernandino, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Sanches, Eduardo Antônio. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Tabata, Yara Aiko. Salmonid Experimental Station At Campos Do Jordão; Brasil Fil: de Oliveira, Claudio. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Takahashi, Neuza Sumico. Centro de Pesquisa de Aquicultura; Brasil Fil: Hattori, Ricardo Shohei. Salmonid Experimental Station at Campos do Jordão; Brasil

Environmentally favorable conditions the sustainability of spermatogenesis is brought about by a balance between two types of division, the self-renewal division for the maintenance of the stem cell pool and the differentiation division for continuous production of spermatozoa. The production of gametes under unfavorable, stressful conditions can decrease or even be interrupted, compromising fertility parameters. Thus, the survival of spermatogonial stem cells (SSCs) is crucial for the recovery of spermatogenesis after stressful situations (e.g. high temperature). Here, we show that the Notch pathway protects the spermatogonial stem cells against thermal stress, ensuring reproductive success after normal conditions are restored. First, presenilin enhancer-2 (pen-2), the catalytic subunit of γ-secretase complex, was localized in SSCs of the medaka testis. The exposure of adult males to thermal stress condition induced apoptosis in all spermatogenics cells, with the exception of SSCs. Concomitantly, the Notch pathways was up-regulated, including the pen-2, its ligands (dll4, jag1-2) and its receptors (notch1a-3); pen-2 expression was restricted to the SSCs during thermal stress. The importance of this pathway was further supported by an ex vivo approach, in which the inhibition of Notch activity induced a loss of SSCs. Overall, this study demonstrates that the Notch pathways activity is necessary for the protection of SSCs under chronic thermal stress.

After the 1980s, atmospheric sulfate reduction is slower than the dramatic reductions in sulfur dioxide (SO2) emissions. However, a lack of observational evidence has hindered the identification of causal feedback mechanisms. Here, we report an increase in the oxygen isotopic composition of sulfate ([Formula: see text]) in a Greenland ice core, implying an enhanced role of acidity-dependent in-cloud oxidation by ozone (up to 17 to 27%) in sulfate production since the 1960s. A global chemical transport model reproduces the magnitude of the increase in observed [Formula: see text] with a 10 to 15% enhancement in the conversion efficiency from SO2 to sulfate in Eastern North America and Western Europe. With an expected continued decrease in atmospheric acidity, this feedback will continue in the future and partially hinder air quality improvements.

As microplastics may bring about adverse effects on living organisms, it is important to establish more precise quantification approaches to better understand their dynamics.One method to determine the concentration of microplastics is to estimate their mass using three-dimensional (3D) models, but its accuracy is not well known.In this study, we evaluated the shape of the particles and verified the accuracy of a 3D model-based mass estimation using samples from a tidal flat facing Tokyo Bay.The particle shape evaluation suggested that the microplastics were flat and irregular in shape; based on these data, we created two types of models to estimate their mass.As a result, an accuracy of mass estimation by our model was higher than other models that consider the slenderness and flatness of particles.The optimization of mass estimation methods based on 3D models may improve the reliability of microplastic evaluation in monitoring studies., 公開日: 2023-08-05

Marine biogenic sulphur affects Earth’s radiation budget and may be an indicator of primary productivity in the Southern Ocean, which is closely related to atmospheric CO2 variability through the biological pump. Previous ice-core studies in Antarctica show little climate dependence of marine biogenic sulphur emissions and hence primary productivity, contradictory to marine sediment records. Here we present new 720,000-year ice core records from Dome Fuji in East Antarctica and show that a large portion of non-sea-salt sulphate, which was traditionally used as a proxy for marine biogenic sulphate, likely originates from terrestrial dust during glacials. By correcting for this, we make a revised calculation of biogenic sulphate and find that its flux is reduced in glacial periods. Our results suggest reduced dimethylsulphide emissions in the Antarctic Zone of the Southern Ocean during glacials and provide new evidence for the coupling between climate and the Southern Ocean sulphur cycle., Ice core derived marine biogenic sulphate does not agree with marine sediment records. Here based on new ice core records spanning the past 720,000 years obtained from Dome Fuji the authors propose that dust contributed a higher percentage of sulphate aerosols than previously thought.

This paper presents isotopic compositions (δ15N and Δ17O values) of atmospheric particulate nitrate (p-NO3−) collected over the Pacific Ocean between 40°S and 68°N on two cruises using the Research Vessel Hakuho Maru. Six marine regions over the Pacific Ocean were categorized using backward trajectory analysis, and various ion concentrations were employed to assess the dominance of anthropogenic or non-anthropogenic sources. The δ15N(p-NO3−) values ranged from −15.4‰ to 2.5‰ over the Pacific Ocean between 40°S and 68°N. The range of the source δ15N(NOx) values were calculated for each sample based on isotopic exchange/fractionation during oxidation from NOx (NO and NO2) to HNO3, and a range of −14.1 to 6.9‰ was yielded over the Pacific Ocean. Compared to other regions, extremely low δ15N(NOx) values of −14.1‰ to −7.3‰ were found over the equatorial Pacific, and such values cannot be matched using conventional NOx apportionment. Emissions of specific oceanic nitrogen emissions of NH3 and alkyl nitrate are thus proposed for the equatorial Pacific. Results demonstrate the importance of the nitrogen recycling process between the ocean and lower atmosphere in the equatorial Pacific. Δ17O(p-NO3−) values and light flux were found to be generally well-correlated in most Pacific Ocean regions, and this result is consistent with the importance of photolysis for OH radical concentrations relative to the contribution of O3 in producing HNO3 from NOx. In contrast, Δ17O(p-NO3−) values for the eastern North Pacific region were higher than in other regions with similar light fluxes, which implies a contribution from halogens to p-NO3− formation.

Surrogate broodstock technology is emerging as a promising biotechnology for xenogeneic production of gametes of highly valuable fish species. In this study, we produced gametes of landlocked Atlantic salmon using triploid rainbow trout as recipient through germ cell transplantation technique in embryos. Spermatogonial cells were obtained from Atlantic salmon juveniles and transplantation conducted into the coelomic cavity of 150 mixed-sex triploid embryos of rainbow trout. Colonization efficiency assessed in larvae four weeks post-transplantation showed presence of PKH-26-labeled cells in 61.1% of individuals. Analysis in sexually mature adults revealed presence of donor-derived sperm in four transplanted males (10%), whereby one of them reached sexual maturity in the first year. Transplanted females became mature after the second year and donor-derived oocytes were detected in four individuals (12.1%). Milt produced by transplanted triploid males were used for artificial insemination. Genetic analysis of hatchlings revealed that progeny was composed by pure Atlantic salmon and therefore were donor-derived. In conclusion, this study shows that surrogate broodstock can be used to produce oocytes and spermatozoa using species from different genus. The production of surrogate gametes using species with a shorter life cycle represents an efficient approach to streamline the development of improved strains in aquaculture industry.

Made available in DSpace on 2019-10-04T12:33:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-12-18 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundacao Araucaria (Fundacao Araucaria de Apoio ao Desenvolvimento Cientifico e Tecnologico do Estado do Parana) Astyanax is an abundant fish genus in South America. Some species of this group are characterized by the presence of B chromosomes and absence of morphologically differentiated sex chromosomes. In this study, we used quantitative real-time polymerase chain reaction to characterize mRNA expression of dmrt1 in Astyanax scabripinnis gonads. Maturing gonads of males with the B chromosome overexpressed dmrt1. Our findings suggest that B chromosomes may have an adaptive role in A. scabripinnis sex determination and maintenance. Univ Fed Sao Carlos, Dept Genet & Evolucao, Programa Posgrad Biol Evolut & Genet Mol, Sao Carlos, SP, Brazil UPD CJ APTA SAA, Estacao Expt Salmonicultura Campos do Jordao, Sao Paulo, Brazil Univ Sao Paulo, Fac Med Vet & Zootecnia, Dept Cirurgia, Sao Paulo, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Morfol, Botucatu, SP, Brazil Univ Estadual Ponta Grossa, Dept Biol Estrutural Mol & Genet, Programa Posgrad Biol Evolut, Ave Carlos Cavalcanti 4748, BR-84030900 Ponta Grossa, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Morfol, Botucatu, SP, Brazil CNPq: 407187/2016-2 CAPES: 001 Fundacao Araucaria (Fundacao Araucaria de Apoio ao Desenvolvimento Cientifico e Tecnologico do Estado do Parana): 16174

Knowledge related to sulfur isotope ratios of carbonyl sulfide (OCS or COS), the most abundant atmospheric sulfur species, remains scarce. An earlier method developed for sulfur isotopic analysis for OCS using S + fragmentation by an isotope ratio mass spectrometer is inapplicable for ambient air samples because of the large samples required (approx. 500 L of 500 pmol mol −1 OCS). To overcome this difficulty, herein we present a new sampling system for collecting approximately 10 nmol of OCS from ambient air coupled with a purification system. Salient system features are (i) accommodation of samples up to 500 L (approx. 10 nmol) of air at 5 L min −1 ; (ii) portability of adsorption tubes ( 1∕4 in. (0.64 cm) outer diameter, 17.5 cm length, approximately 1.4 cm 3 volume) for preserving the OCS amount and δ34 S(OCS) values at − 80 ∘ C for up to 90 days and 14 days; and (iii) purification OCS from other compounds such as CO2 . We tested the OCS collection efficiency of the systems and sulfur isotopic fractionation during sampling. Results show precision (1 σ ) of δ34 S(OCS) values as 0.4 ‰ for overall procedures during measurements for atmospheric samples. Additionally, this report presents diurnal variation of δ34 S(OCS) values collected from ambient air at the Suzukakedai campus of the Tokyo Institute of Technology located in Yokohama, Japan. The observed OCS concentrations and δ34 S(OCS) values were, respectively, 447–520 pmol mol −1 and from 10.4 ‰ to 10.7 ‰ with a lack of diurnal variation. The observed δ34 S(OCS) values in ambient air differed greatly from previously reported values of δ34 S(OCS) = ( 4.9±0.3 ) ‰ for compressed air collected at Kawasaki, Japan, presumably because of degradation of OCS in cylinders and collection processes for that sample. The difference of atmospheric δ34 S(OCS) values between 10.5 ‰ in Japan (this study) and ∼13 ‰ recently reported in Israel or the Canary Islands indicates that spatial and temporal variation of δ34 S(OCS) values is expected due to a link between anthropogenic activities and OCS cycles. The system presented herein is useful for application of δ34 S(OCS) for investigation of OCS sources and sinks in the troposphere to elucidate its cycle.

Sex determination in pejerrey is genetically prescribed by the Y chromosome-linked anti-müllerian hormone amhy but is also strongly influenced by water temperature during the critical period of sex determination. Its gonadal differentiation is characterized by a cephalocaudal and left-to-right histological gradient in both sexes that presumably helps prevent discrepant intersex development in different regions of the gonads in response to ambiguous thermal and genetic stimuli, but the relation of this gradient to molecular processes of sex differentiation is unknown. In this study, we investigated the spatiotemporal expression patterns of amh, gonadal aromatase (cyp19a1a), and apoptosis in relation to the histological gradient in ovaries and testes at an intermediate, sexually neutral temperature. The location and timing of expression of amh, cyp19a1a, and apoptosis seemed to be highly coordinated with the time of gonadal sex differentiation and the histological gradient of gonadal sex differentiation. Apoptosis occurred predominantly in the anterior region of the right gonads and is surmised to be a process to delay differentiation in this area compared to the left gonad, possibly as a means to ensure uniform development in both gonads. Aromatase expression early during development was noted even in putative XY males, supporting the notion of primacy of female development in pejerrey gonads. Thus, apoptosis may be particularly important to prevent discrepant gonadal differentiation in XY individuals where genetic pro-male (amhy), pro-female (cyp19a1a), and thermal stimuli may antagonize.

Oxygen-17 anomaly (Δ17O) has been used as a probe to constrain the relative importance of different pathways leading to sulfate formation. Here, we report the Δ17O values in atmospheric sulfate collected at a remote site in the Mt. Everest region to decipher the possible formation mechanisms of sulfate in such a pristine environment. The Δ17O in non-dust sulfate show higher values than most existing data in modern atmospheric sulfate. The seasonality of Δ17O in non-dust sulfate exhibits high values in the pre-monsoon and low values in the monsoon, opposite to the seasonality in Δ17O for both sulfate and nitrate (i.e., minima in warm season and maxima in cold season) observed from diverse geographic sites. This high Δ17O in non-dust sulfate found in this region clearly indicates the important role of the S(IV) + O3 pathway in atmospheric sulfate formation promoted by high cloud water pH conditions. In turn, this study highlights observational evidence that atmospheric acidity plays an important role in controlling sulfate formation pathways particularly for dust-rich environments.

17O-excess (Δ17O = δ17O − 0.52 × δ18O) of sulfate trapped in Antarctic ice cores has been proposed as a potential tool for assessing past oxidant chemistry, while insufficient understanding of atmospheric sulfate formation around Antarctica hampers its interpretation. To probe influences of regional specific chemistry, we compared year-round observations of Δ17O of non-sea-salt sulfate in aerosols (Δ17O(SO42−)nss) at Dome C and Dumont d’Urville, inland and coastal sites in East Antarctica, throughout the year 2011. Although Δ17O(SO42–)nss at both sites showed consistent seasonality with summer minima (~1.0 ‰) and winter maxima (~2.5 ‰) owing to sunlight-driven changes in the relative importance of O3-oxidation to OH- and H2O2-oxidation, significant inter-site differences were observed in austral spring–summer and autumn. The co-occurrence of higher Δ17O(SO42–)nss at inland (2.0 ± 0.1 ‰) than the coastal site (1.2 ± 0.1 ‰) and chemical destruction of methanesulfonate (MS–) in aerosols at inland during spring–summer (October to December), combined with the first estimated Δ17O(MS–) of ~16 ‰, implies that MS– destruction produces sulfate with high Δ17O(SO42–)nss of ~12 ‰. If contributing to the known post-depositional decrease of MS– in snow, this process should also cause a significant post-depositional increase in Δ17O(SO42–)nss over 1 ‰, that can reconcile the discrepancy between Δ17O(SO42–)nss in the atmosphere and ice.

The exposure of adult fish to warm or high temperatures is known to impair reproduction, yet the long-term reproductive impacts for treatments at early life are not well clarified. This study aimed to evaluate the effects of warm temperature (WT) during juvenile stage on gonad maturation, gamete quality, and offspring thermotolerance in rainbow trout. While the comparison of basic reproductive parameters in WT females did not reveal any kind of impairment, many WT males showed an atrophied, undeveloped gonad, or a smaller testis with lower milt volume; sperm quality parameters in WT males and deformity rates in the respective progeny were also highly affected. However, despite of such negative effects, many of the remaining progenies presented better rates of survival and growth when exposed to the same conditions as those of parental fish (WT), suggesting that thermal stress in parr stage males elicited intergenerational thermoresistance after a single generation . The present results support that prolonged warming stress during early life stages can adversely affect key reproductive aspects, but constrastingly increase offspring performance at upper thermal ranges. These findings have implications on the capacity of fish to adapt and to cope with global warming.

The 11th Symposium on Polar Science/Special session: [S] Accelerating Arctic research: Recent progress and future prospect of Arctic research, Poster presentations, Mon. 16 Nov. - Fri. 18 Dec.

Atheriniform fishes have recently emerged as attractive models for evolutionary, ecological, and molecular/physiological studies on sex determination. Many species in this group have marked temperature-dependent sex determination (TSD) and yet many species also have a sex determinant gene that provides a strong drive for male differentiation. Thus, in these species the 2 forms of sex determination that were once considered to be mutually exclusive, environmental (ESD) and genotypic (GSD) sex determination, can coexist at environmentally relevant conditions. Here, we review the current knowledge on sex determination in atheriniform fishes with emphasis on the molecular and physiological mechanisms of ESD and GSD, the coexistence and cross-talk between these 2 mechanisms, the possibility of extragonadal transduction of environmental information and/or extragonadal onset of sex determination, and the results of field studies applying novel tools such as otolith increment analysis and molecular markers of genetic sex developed for selected New World and Old World atheriniform species. We also discuss the existence of molecular and histological mechanisms to prevent the discrepant differentiation in parts of the gonads because of ambiguous or conflicting environmental and genetic signals and particularly the possibility that the female is the default state in these species.

The production of an adequate number of gametes is necessary for normal reproduction, for which the regulation of proliferation from early gonadal development to adulthood is key in both sexes. Cystic proliferation of germline stem cells is an especially important step prior to the beginning of meiosis; however, the molecular regulators of this proliferation remain elusive in vertebrates. Here, we report that ndrg1b is an important regulator of cystic proliferation in medaka. We generated mutants of ndrg1b that led to a disruption of cystic proliferation of germ cells. This loss of cystic proliferation was observed from embryogenic to adult stages, impacting the success of gamete production and reproductive parameters such as spawning and fertilization. Interestingly, the depletion of cystic proliferation also impacted male sexual behavior, with a decrease of mating vigor. These data illustrate why it is also necessary to consider gamete production capacity in order to analyze reproductive behavior. Fil: Arias Padilla, Luisa Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Castañeda Cortés, Diana C.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Rosa, Ivana F. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Moreno Acosta, Omar David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Hattori, Ricardo S.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Nóbrega, Rafael H.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Fernandino, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina

After the 1980s, atmospheric sulfate reduction is slower than the dramatic reductions in sulfur dioxide (SO

The ca. 74 ka BP ‘‘super-eruption’’ of Toba volcano in Sumatra is the largest known Quaternary eruption. It expelled an estimated of 2800 km3 of dense rock equivalent, creating a caldera of 100 x 30 km. The eruption is estimated to have been 3500 greater than the Tambora eruption that created the “year without summer” in 1816 in Europe (Oppenheimer, 2002). However, the consequences of this “mega-eruption” on the climate and human evolution that could be expected for such eruption are still debated and uncertain. There is no evidence that this eruption has triggered any catastrophic climate change such as a “nuclear winter”. One of such lack of evidence lies in the ice.In the ice core community, this eruption still remains a mystery. Indeed, the estimated size of the eruption should have left a gigantic mark in the ice, at least in the form of a huge sulfuric acid layer but none of the ice records covering this period show any such singularity. The sulfate record seems so common that it is in fact difficult to allocate a specific sulfate peak to this event.In an effort to synchronize the Vostok ice core and the EPICA Dome C core, (Svensson et al., 2013) have identified three possible sulfuric acid layers for the Toba eruption in the Vostok ice core. In order to see if one of such event could have been the Toba eruption, we have performed the sulfur & oxygen isotope analysis of these three sulfuric acid layers in the hope that it could reveal some particularity. The sulfur results show that 1- all these three events have injected their products in the stratosphere and 2- the sulfur isotopic compositions of these three events share a common array, array that is in lines with other stratospheric eruptions, however one of the three acid layers shows an extremely and unusual weak oxygen anomaly, potentially indicating a major eruption. In order to remove the last doubts about the existence or not of one or a series of eruptions related to TOBA, the geochemical analysis of volcanic glasses trapped in the ice will be performed and presented.

Made available in DSpace on 2020-12-10T19:59:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-27 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Albinism is the most common color variation described in fish and is characterized by a white or yellow phenotype according to the species. In rainbow trout Oncorhynchus mykiss, aside from yellow-albino phenotypes, cobalt blue variants with autosomal, recessive inheritance have also been reported. In this study, we investigated the inheritance pattern and chromatophores distribution/abundance of cobalt blue trouts obtained from a local fish farm. Based on crosses with wild-type and dominant yellow-albino lines, we could infer that cobalt blue are dominant over wild-type and co-dominant in relation to yellow-albino phenotype, resulting in a fourth phenotype: the white-albino. Analysis of chromatophores revealed that cobalt blue trouts present melanophores, as the wild-type, and a reduced number of xanthophores. As regards to the white-albino phenotype, they were not only devoid of melanophores but also presented a reduced number of xanthophores. Cobalt blue and white-albino trouts also presented reduced body weight and a smaller pituitary gland compared to wild-type and yellow-albino phenotypes. The transcription levels of tshb and trh were up regulated in cobalt blue compared to wild type, suggesting the involvement of thyroid hormone in the expression of blue color. These phenotypes represent useful models for research on body pigmentation in salmonids and on the mechanisms behind endocrine control of color patterning. Agencia Paulista Tecnol Agronegocios, Secretaria Agr, Unidade Pesquisa & Desenvolvimento Campos Jordao, Salmonid Expt Stn Campos Jordao, Sao Paulo, Brazil Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Surg, Sao Paulo, Brazil Sao Paulo State Univ, Grad Program Biol Sci Genet, Inst Biosci Botucatu, Botucatu, SP, Brazil Tokyo Univ Marine Sci & Technol, Dept Marine Biosci, Tokyo, Japan Puriaqua Limitada, Sao Paulo, Brazil Agencia Paulista Tecnol Agronegocios, Secretaria Agr, Sao Paulo Fisheries Inst, Sao Paulo, Brazil Sao Paulo State Univ, Grad Program Biol Sci Genet, Inst Biosci Botucatu, Botucatu, SP, Brazil FAPESP: 2013/17612-9 FAPESP: 2014/00569-6

To shed light on the mechanisms of and interactions of GSD and TSD in pejerrey, we investigated how the transcriptional profiles of amhy and amha are affected by feminizing (17 °C) and masculinizing (29 °C) temperatures during the critical period of sex determination/differentiation and their relation with the expression profiles of AMH receptor type II ( amhrII ), gonadal aromatase ( cyp19a1a ), and 11 beta-hydroxysteroid dehydrogenase 2 ( hsd11b2 ). Careful consideration of the results of this study and all information currently available for this species, including similar analyzes for an intermediate, mixed-sex promoting temperature (25 °C), suggests a model for genotypic/temperature-dependent sex determination and gonadal sex differentiation that involves a) cyp19a1a -dependent, developmentally-programmed ovarian development as the default state that becomes self-sustaining in the absence of a potent and timely masculinizing stimulus, b) early, developmentally-programmed amhy expression and high temperature as masculinization signals that antagonize the putative female pathway by suppressing cyp19a1a expression, c) increasing stress response, cortisol, and the synthesis of the masculinizing androgen 11-keto-testosterone via hsd11b2 with increasing temperature that is important for masculinization in both genotypes but particularly so in XX individuals, and d) an endocrine network with positive/negative feedback mechanisms that ensure fidelity of the male/female pathway once started. The proposed model, albeit tentative and non-all inclusive, accounts for the continuum of responses, from all-females at low temperatures to all-males at high temperatures and for the balanced-, genotype-linked sex ratios obtained at intermediate temperatures, and therefore supports the coexistence of TSD and GSD in pejerrey across the range of viable temperatures for this species.

The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Wed. 4 Dec. / 2F Auditorium, National Institute of Polar Research

Made available in DSpace on 2021-06-25T15:01:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Germ cell transplantation and testis graft represent promising biotechnologies that can be applied for the reproduction of commercial or endangered species. However, mechanisms of rejection from the host immune system might remove the transplanted donor cells/tissues and limit the surrogate production of gametes. In this work, we administered emulsion containing-immunosuppressants to verify whether they are capable to prevent immune rejection and promote survival of testis allografts in rainbow trout. In the first part of this study, we demonstrated in vitro that tacrolimus and cyclosporine were able to affect viability, inhibit leucocyte proliferation, and suppress il2 expression in vitro. In in vivo experiments, both doses of tacrolimus (0.5 and 1.5 mg/kg) and the lower dose of cyclosporine (20 mg/kg) significantly inhibited the expression of il2 in head kidney, three days post-injection. A higher dose of cyclosporine (40 mg/kg) was able to inhibit il2 expression for up to seven days post-injection. In the second part, testis allografts were conducted in fish treated weekly with emulsion containing-tacrolimus. Immunohistochemical, conventional histology, and qRT-PCR (vasa) analysis demonstrated the presence of spermatogonial cells by the fifth week, in animals treated with 0.5 mg/kg of tacrolimus similar as found in autografted group. In the group treated with the highest tacrolimus dose (1.5 mg/kg) and in the non-treated group (without immunosuppressant), no germ cells or their respective markers were detected. il2 expression in head kidney was also suppressed in grafted animals treated with tacrolimus compared to nontreated group. These results suggest that tacrolimus may be a promising immunosuppressant for testis allografts or germ cell transplantation in rainbow trout. Co-administration combining tacrolimus (at lower dose) with other immunosuppressive drugs for inhibiting other activation pathways of the immune system, as performed in human organ transplantation, could be an alternative approach to optimize the immunosuppressive effects in host organisms. Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Surg, BR-05508270 Sao Paulo, Brazil Sao Paulo State Univ, Inst Biosci Botucatu, Dept Morphol, BR-18618689 Botucatu, SP, Brazil Univ Sao Paulo, Biomed Sci Inst, Interunit Biotechnol Program, BR-05508900 Sao Paulo, Brazil Univ Sao Paulo, Cell & Mol Therapy Ctr, Sch Med, Internal Med Dept,NUCEL, BR-05360130 Sao Paulo, Brazil Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Pathol, BR-05508270 Sao Paulo, Brazil UPD CJ APTA SAA, Salmonid Expt Stn Campos do Jordao, BR-12460000 Campos Do Jordao, Brazil Sao Paulo State Univ, Inst Biosci Botucatu, Dept Morphol, BR-18618689 Botucatu, SP, Brazil FAPESP: 2013/17612-9 FAPESP: 2015/20762-8 CNPq: 404583/2016-4 CAPES: 001

The Tenth Symposium on Polar Science/Special session: [S] Future plan of Antarctic research: Towards phase X of the Japanese Antarctic Research Project (2022-2028) and beyond, Tue. 3 Dec. / Entrance Hall (1st floor) at National Institute of Polar Research (NIPR)

In South America, the order Atheriniformes includes the monophyletic genus Odontesthes with 20 species that inhabit freshwater, estuarine and coastal environments. Pejerrey Odontesthes argentinensis is widely distributed in coastal and estuarine areas of the Atlantic Ocean and is known to foray into estuaries of river systems, particularly in conditions of elevated salinity. However, to our knowledge, a landlocked self‐sustaining population has never been recorded. In this study, we examined the pejerrey population of Salada de Pedro Luro Lake (south‐east of Buenos Aires Province, Argentina) to clarify its taxonomic identity. An integrative taxonomic analysis based on traditional meristic, landmark‐based morphometrics and genetic techniques suggests that the Salada de Pedro Luro pejerrey population represents a novel case of physiological and morphological adaptation of a marine pejerrey species to a landlocked environment and emphasises the environmental plasticity of this group of fishes Fil: Colautti, Dario César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentina Fil: Miranda, Leandro Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: González Castro, M.. Universidad Nacional de Mar del Plata; Argentina Fil: Villanova, Vanina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Strüssmann, Carlos A.. Tokyo University Of Marine Science And Technology; Japón Fil: Mancini, Miguel Alberto. Universidad Nacional de Río Cuarto; Argentina Fil: Maiztegui, Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentina Fil: Berasain, Gustavo. Provincia de Buenos Aires. Ministerio de Asuntos Agrarios; Argentina Fil: Hattori, Ricardo Shohei. Tokyo University of Marine Science and Technology; Japón Fil: Grosman, Manuel Fabián. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina Fil: Sanzano, Pablo Miguel. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina Fil: Lozano, I.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Llamazares Vegh, Sabina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Salinas, V.. Universidad Nacional de Río Cuarto; Argentina Fil: Del Ponti, O.. Universidad Nacional de La Pampa; Argentina Fil: Fresno, P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Minotti, Priscilla Gail. Universidad Nacional de San Martín; Argentina Fil: Yamamoto, Y.. Tokyo University Of Marine Science And Technology; Japón Fil: Baigún, C.. Universidad Nacional de San Martín; Argentina

Made available in DSpace on 2020-12-10T19:43:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundacao Araucaria (Fundacao Araucaria de Apoio ao Desenvolvimento Cientifico e Tecnologico do Estado do Parana) The species complex Astyanax scabripinnis is one of the most studied with respect to origin, distribution, and frequency of B chromosomes, and is considered a model organism for evolutionary studies. Research using population inferences about the occurrence and frequency of the B chromosome shows seasonal variation between sexes, which is associated with the presence of this supernumerary element. We hypothesized that the B chromosome could influence the sex ratio of these animals. Based on this assumption, the present work aimed to investigate if differences exist among levels of gene expression with qRT-PCR of the amh (associated with testicular differentiation) and foxl2a (associated with ovarian differentiation) genes between B-carrier and non-B-carrier individuals. The results showed that for the amh gene, the difference in expression between animals with B chromosomes was not accentuated compared to that in animals without this chromosome. Expression of foxl2a in B-carrier females, however, was reduced by 73.56% compared to females that lacked the B chromosome. Males had no difference in expression of the amh and foxl2a genes between carriers and non-carriers of the B chromosome. Results indicate that the presence of B chromosomes is correlated with the differential expression of sex-associated genes. An analysis of these results integrated with data from other studies on the reproductive cycle in the same species reveals that this difference in expression may be expanding the reproductive cycle of the species. Univ Fed Sao Carlos, Dept Genet & Evolucao, Programa Posgrad Biol Evolut & Genet Mol, Rodovia Washington Luis,Km 235, BR-13565905 Sao Carlos, SP, Brazil UPD CJ APTA SAA, Estacao Expt Salmonicultura Campos do Jordao, BR-12460000 Sao Paulo, SP, Brazil Univ Sao Paulo, Fac Med Vet & Zootecnia, Dept Cirurgia, Rua Prof Orlando Marque Paiva, BR-05508270 Sao Paulo, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Morfol, Dist Rubiao Jr S-N, BR-18618970 Botucatu, SP, Brazil Uppsala Univ, Evolutionary Biol Ctr, Dept Ecol & Genet, SE-75236 Uppsala, Sweden Univ Estadual Ponta Grossa, Dept Biol Estrutural Mol & Genet, Programa Posgrad Biol Evolut, Ave Carlos Cavalcanti 4748, BR-84030900 Ponta Grossa, PR, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Morfol, Dist Rubiao Jr S-N, BR-18618970 Botucatu, SP, Brazil CNPq: 407187/2016-2 CAPES: 001 Fundacao Araucaria (Fundacao Araucaria de Apoio ao Desenvolvimento Cientifico e Tecnologico do Estado do Parana): 16174

The pejerrey possesses a genotypic sex determination system driven by the amhy gene and yet shows marked temperature‐dependent sex determination. Sex‐reversed XY females have been found in a naturally breeding population established in Lake Kasumigaura, Japan. These females could mate with normal XY males and generate YY “supermale” individuals that, if viable and fertile, would sire only genotypic male offspring. This study was conducted to verify the viability, gender, and fertility of YY pejerrey and to develop a molecular method for their identification. Production of YY fish was attempted by crossing a thermally sex‐reversed XY female and an XY male, and rearing the progeny until sexual maturation. To identify the presumable YY individuals, we first conducted a PCR analysis using amhy‐specific primers to screen only amhy‐positive (XY and YY) fish. This screening showed that 60.6% of the progeny was amhy‐positive, which suggested the presence of YY fish. We then conducted a second screening by qPCR in order to identify the individuals with two amhy copies in their genome. This screening revealed 13 individuals, all males, with values twice higher than the other 30 amhy‐positive fishes, suggesting they have a YY complement. This assumption as well as the viability, fertility, and “supermale” nature of these individuals was confirmed in progeny tests with XX females that yielded 100% amhy‐positive offspring. These results demonstrate that qPCR can obviate progeny test as a means to identify the genotypic sex and therefore may be useful for the survey of all three possible genotypes in wild populations.

The species complex Astyanax scabripinnis is one of the most studied with respect to origin, distribution, and frequency of B chromosomes, and is considered a model organism for evolutionary studies. Research using population inferences about the occurrence and frequency of the B chromosome shows seasonal variation between sexes, which is associated with the presence of this supernumerary element. We hypothesized that the B chromosome could influence the sex ratio of these animals. Based on this assumption, the present work aimed to investigate if differences exist among levels of gene expression with qRT-PCR of the amh (associated with testicular differentiation) and foxl2a (associated with ovarian differentiation) genes between B-carrier and non-B-carrier individuals. The results showed that for the amh gene, the difference in expression between animals with B chromosomes was not accentuated compared to that in animals without this chromosome. Expression of foxl2a in B-carrier females, however, was reduced by 73.56% compared to females that lacked the B chromosome. Males had no difference in expression of the amh and foxl2a genes between carriers and non-carriers of the B chromosome. Results indicate that the presence of B chromosomes is correlated with the differential expression of sex-associated genes. An analysis of these results integrated with data from other studies on the reproductive cycle in the same species reveals that this difference in expression may be expanding the reproductive cycle of the species.

Estimates of biogeochemical processes and the proportion of N2O production in the aquatic system of impoundments are important to quantify nitrogen cycling, particularly during stratification perio...