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Stephanorhynchus White, 1846 is a eugnomine weevil genus endemic to New Zealand, with 18 nominal taxa described within the genus. Examination of the type specimens of these taxa with greater understanding of related genera has led to the distinction of four well-defined genera from the species ascribed to the genus. These are the monotypic genus Pittosporobiusgen. nov., with type species P. crassus (Broun, 1880) comb. nov.; Moanusgen. nov., with type species M. lawsoni (Sharp, 1876) comb. nov., and including M. brevipennis (Pascoe, 1876) comb. nov. (= Stephanorhynchus griseipictus Broun, 1886 syn. nov.), M. nigrosparsus (Broun, 1893) comb. nov. (= Stephanorhynchus pygmaeus Broun, 1903 - syn. nov.) and M. tumulus Mazur and Brown sp. nov. (type locality Mt Dick, Otago Lakes, South Island, New Zealand); Glabrorhynchusgen. nov., with type species G. costifer (Broun, 1893) comb. nov., and including G. insolitus (Broun, 1893) comb. nov., G. purus (Pascoe, 1876) comb. nov., and G. halli (Broun, 1914) comb. nov. A reduced concept of Stephanorhynchus White, 1846 contains now four species: S. curvipes White, 1846, S. tuberosus Broun, 1881, S. attelaboides (Fabricius, 1775), S. aper Sharp, 1886. All species within the complex have been redescribed, with details provided of their external morphology and terminal structure and supported by drawings and colour photographs. Keys to genera and species are also provided as well as distribution maps and information about host plants and biology. The systematic position of these genera within the Eugnomini and their similarity with the genus Callistomorphus Perroud, 1865 from New Caledonia are discussed.Article registered number New taxa Glabrorhynchus gen. nov. Moanus gen. nov. Moanus tumulus sp. nov.Pittosporobius gen. nov. [ABSTRACT FROM AUTHOR]

Simple Summary: The programmed grooming model is an evolutionary hypothesis for the regulation of ectoparasite-defense grooming behavior. It proposes that grooming to remove ectoparasites such as ticks is regulated by a type of internal biological clock that has evolved to pre-emptively remove parasites before they can blood feed. Programmed grooming contrasts with the stimulus-driven model, in which grooming is stimulated by direct peripheral irritation from ectoparasites. Since programmed grooming was first proposed in 1992, 26 studies have provided robust support for the model with ungulate hosts and ticks. Additional studies from unaffiliated investigators have evaluated the predictions of the model in different host systems (including rodents and primates) and in a variety of ectoparasites (fleas, lice, and keds). After reviewing the current evidence, I conclude that (1) tests of the programmed grooming model should utilize the established protocol, so that the results can be compared and assessed in light of previous studies; (2) the model predictions should be tailored to the host biology under investigation; and (3) the model predictions should be tailored to the ectoparasite biology, since the efficacy of grooming depends on the parasite. It is hoped that future studies will reveal much more about how grooming helps wild animals to defend themselves against the threat of parasites. In 1992, an evolutionary model for the endogenous regulation of parasite-defense grooming was first proposed for African antelope by Ben and Lynette Hart. Known as the programmed grooming model, it hypothesized that a central control mechanism periodically evokes grooming so as to remove ectoparasites before they blood feed. The programmed grooming model contrasts with a stimulus-driven mechanism, in which grooming is stimulated by direct peripheral irritation from ectoparasite bites. In the 30+ years since the seminal 1992 paper, 26 studies have provided robust support for the programmed grooming model in ungulate hosts and ticks. In addition, multiple studies from unaffiliated investigators have evaluated the predictions of the model in different host systems (including rodents and primates) and in a variety of other ectoparasites (fleas, lice, and keds). I conducted a tricennial review of these studies to assess the current evidence and arrived at the following three conclusions: (1) tests of the programmed grooming predictions should use a similar methodology to the well-established protocol, so that the results are comparable and can be properly assessed; (2) the predictions used to test the model should be tailored to the biology of the host taxa under investigation; and (3) the predictions should likewise be tailored to the biology of the ectoparasites involved, bearing in mind that grooming has varying degrees of effectiveness, depending on the parasite. Further research is warranted to enhance our understanding of the role of grooming in maintaining the health of wild animals in the face of parasite attacks. [ABSTRACT FROM AUTHOR]

Invasive fungal infections are a growing threat to human health. Secreted effector proteins are a ubiquitous strategy used by diverse microbial pathogens to manipulate host biology and enable pathogen replication. Recent work has revealed secreted protein effectors produced by human fungal pathogens. Secreted fungal effectors target apoptosis, myeloid cell polarization, Toll-like receptor signaling, and phagosome action. Despite lacking specialized secretion systems, fungi have evolved secreted effectors that subvert many host pathways targeted by highly host-adapted bacteria and parasites. Invasive fungal infections pose a major threat to human health. Bacterial and protozoan pathogens secrete protein effectors that overcome innate immune barriers to promote microbial colonization, yet few such molecules have been identified in human fungal pathogens. Recent studies have begun to reveal these long-sought effectors and have illuminated how they subvert key cellular pathways, including apoptosis, myeloid cell polarization, Toll-like receptor signaling, and phagosome action. Thus, despite lacking the specialized secretion systems of bacteria and parasites, it is increasingly clear that fungi independently evolved effectors targeting pathways often subverted by other classes of pathogens. These findings demonstrate the remarkable power of convergent evolution to enable diverse microbes to infect humans while also setting the stage for detailed dissection of fungal disease mechanisms. [ABSTRACT FROM AUTHOR]

The subgenus Anicla, commonly known as green cutworms, harbours some of the owlet moths (Lepidoptera: Noctuinae), whose larvae are notable for their economic importance. Knowledge of the immature stages for this group is available for three of the nine described species. Anicla infecta Ochsenheimer, 1816 is widely distributed in the Americas and is especially abundant in agricultural ecosystems. However, in the Neotropics, its economic damage can be confused with sympatric species, including Anicla ignicans (Guenée, 1852), whose distributions overlap in most parts of the American continent. In this sense, here, the identity of A. ignicans is investigated through its geographical distribution, based on molecular and morphological data. Additionally, the morphological and behavioural traits of immature stages were described in detail, information about its geographical distribution and larval host plants was gathered, and the species' biological parameters from larvae reared on an artificial diet were determined. Anicla ignicans is distributed throughout the Neotropical region, preferably in areas with xeric and/or grass‐dominated ecosystems. The eggs present valuable characters to distinguish A. ignicans from other owlet moth species, such as the reduced number of ribs, the way the micropyle openings are arranged and the shape of the aeropyles. However, the larvae show very similar chromatic polymorphisms to other Anicla species. Although A. ignicans prefer to feed on grasses, it was observed that more than 85% of the larvae that were fed with a modified bean‐based Greene diet survived. Additionally, the percentage of time for each phase of development obtained here is very similar for the different species of Anicla, regardless of the temperature or feeding of the larvae. [ABSTRACT FROM AUTHOR]

The persistence of the latent viral reservoir is the main hurdle to curing HIV-1 infection. SIV infection of non-human primates (NHPs), namely Indian-origin rhesus macaques, is the most relevant and widely used animal model to evaluate therapies that seek to eradicate HIV-1. The utility of a model ultimately rests on how accurately it can recapitulate human disease, and while reservoirs in the NHP model behave quantitatively very similar to those of long-term suppressed persons with HIV-1 (PWH) in the most salient aspects, recent studies have uncovered key nuances at the clonotypic level that differentiate the two in qualitative terms. In this review, we will highlight differences relating to proviral intactness, clonotypic structure, and decay rate during ART between HIV-1 and SIV reservoirs and discuss the relevance of these distinctions in the interpretation of HIV-1 cure strategies. While these, to some degree, may reflect a unique biology of the virus or host, distinctions among the proviral landscape in SIV are likely to be shaped significantly by the condensed timeframe of NHP studies. ART is generally initiated earlier in the disease course, and animals are virologically suppressed for shorter periods before receiving interventions. Because these are experimental variables dictated by the investigator, we offer guidance on study design for cure-related studies performed in the NHP model. Finally, we highlight the case of GS-9620 (Vesatolimod), an antiviral TLR7 agonist tested in multiple independent pre-clinical studies in which virological outcomes may have been influenced by study-related variables. [ABSTRACT FROM AUTHOR]

Microbiota in intermediate hosts of human schistosomes play a significant role in various aspects of snail biology, such as growth and development. Understanding the potential impact of microbiota on snail–schistosome interactions and snail competence is crucial for future research and requires omics-based approaches. Successfully developing axenic and gnotobiotic models is a significant step that involves proper isolation of snail eggs, effective sterilization methods, suitable nutrition, and husbandry practices. And more axenic snail species are needed to cover diverse schistosome species. Advancing axenic and gnotobiotic snail systems and combining them with advanced technologies can offer insights into the role of snail microbiota and uncover intricate microbiota–snail and snail–parasite interactions, leading to the development of new strategies for controlling schistosomiasis. The microbiota in the intermediate snail hosts of human schistosomes can significantly affect host biology. For decades, researchers have developed axenic snails to manipulate the symbiotic microbiota. This review summarizes the characteristics of symbiotic microbes in intermediate snail hosts and describes their interactions with snails, affecting snail growth, development, and parasite transmission ability. We focus on advances in axenic and gnotobiotic technologies for studying snail–microbe interactions and exploring the role of microbiota in snail susceptibility to Schistosoma infection. We discuss the challenges related to axenic and gnotobiotic snails, possible solutions to address these challenges, and future research directions to deepen our understanding of snail–microbiota interactions, with the aim to develop microbiota-based strategies for controlling snail populations and reducing their competence in transmitting parasites. [ABSTRACT FROM AUTHOR]

A recent increase in the number of high-quality genome sequences and assemblies facilitates systematic screening of vertebrate DNA, better reflecting endogenous retrovirus (ERV) variability across wildlife and providing a means for evaluating historic and contemporary retrovirus transmission. In contrast to commonly studied laboratory and domestic animals, recent studies of wildlife ERVs and exogenous retroviruses (XRVs) offer insights into historic and contemporary retrovirus activities in hosts undergoing natural selection. Wildlife host populations under natural selection provide insights into ERV variation that segregates at various frequencies in host populations and highlight limitations of ERV detection relying on reference genome assemblies derived from one or a few individuals alone. Phylogenetic differences between ERVs and contemporary XRVs suggest that XRVs are prone to extinction over evolutionary timescales, while the ERV record persists, or that many retroviruses remain to be discovered. Large-scale phylogenomic screening for coopted ERV functions suggest that the frequency of coopted genes is underestimated. Endogenous retroviruses (ERVs) are inherited genomic remains of past germline retroviral infections. Research on human ERVs has focused on medical implications of their dysregulation on various diseases. However, recent studies incorporating wildlife are yielding remarkable perspectives on long-term retrovirus–host interactions. These initial forays into broader taxonomic analysis, including sequencing of multiple individuals per species, show the incredible plasticity and variation of ERVs within and among wildlife species. This demonstrates that stochastic processes govern much of the vertebrate genome. In this review, we elaborate on discoveries pertaining to wildlife ERV origins and evolution, genome colonization, and consequences for host biology. [ABSTRACT FROM AUTHOR]

Background: Tsetse flies (Glossina spp.) are the definitive biological vectors of African trypanosomes in humans and animals. Controlling this vector is the most promising method of preventing trypanosome transmission. This requires a comprehensive understanding of tsetse biology and host preference to inform targeted design and management strategies, such as the use of olfaction and visual cues in tsetse traps. No current review exists on host preference and blood meal analyses of tsetse flies. Methods: This review presents a meta-analysis of tsetse fly blood meal sources and the methodologies used to identify animal hosts from 1956 to August 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRIMA-ScR) was applied. This focused on tsetse-endemic countries, blood meal analysis methodologies and the blood meal hosts identified. The articles were retrieved and screened from databases using predetermined eligibility criteria. Results: Only 49/393 of the articles retrieved matched the inclusion criteria. Glossina's main hosts in the wild included the bushbuck, buffalo, elephant, warthog, bushpig and hippopotamus. Pigs, livestock and humans were key hosts at the domestic interface. The least studied species included Glossina fuscipleuris, G. fusca, G. medicorum, G. tabaniformis and G. austeni. In the absence of preferred hosts, Glossina fed opportunistically on a variety of hosts. Precipitin, haemagglutination, disc diffusion, complement fixation, ELISA and PCR-based assays were used to evaluate blood meals. Cytochrome b (Cyt b) was the main target gene in PCR to identify the vertebrate hosts. Conclusions: Tsetse blood meal sources have likely expanded because of ecological changes that could have rendered preferred hosts unavailable. The major approaches for analysing tsetse fly blood meal hosts targeted Cyt b gene for species identification by Sanger sequencing. However, small-fragment DNAs, such as the mammalian 12S and 16S rRNA genes, along with second- and third-generation sequencing techniques, could increase sensitivity for host identification in multiple host feeders that Sanger sequencing may misidentify as "noise". This review of tsetse fly blood meal sources and approaches to host identification could inform strategies for tsetse control. [ABSTRACT FROM AUTHOR]

Organismal divergence can be driven by differential resource use and adaptation to different trophic niches. Variation in diet is a major factor shaping the gut microbiota, which is crucial for many aspects of their hosts' biology. However, it remains largely unknown how host diet diversity affects the gut microbiota, and it could be hypothesized that trophic niche width is positively associated with gut microbiota diversity. To test this idea, we sequenced the 16S ribosomal RNA gene from intestinal tissue of 14 threespine stickleback populations from lakes of varying size on Vancouver Island, Canada, that have been shown to differ in trophic niche width. Using lake size as a proxy for trophic ecology, we found evidence for higher gut microbiota uniqueness among individuals from populations with broader trophic niches. While these results suggest that diet diversity might promote gut microbiota diversity, additional work investigating diet and gut microbiota variation of the same host organisms will be necessary. Yet our results motivate the question of how host population diversity (e.g., ecological, morphological, genetic) might interact with the gut microbiota during the adaptation to ecological niches. [ABSTRACT FROM AUTHOR]

The intestinal microbiota, an invisible organ supporting a host's survival, has essential roles in metabolism, immunity, growth, and development. Since intestinal microbiota influences a host's biology, application of such data to wildlife conservation has gained interest. There are standard protocols for studying the human intestinal microbiota, but no equivalent for wildlife. A major challenge is sampling the intestinal microbiota in an effective, unbiased way. Fecal samples are a popular proxy for intestinal microbiota because collection is non‐invasive and allows for longitudinal sampling. Yet it is unclear whether the fecal microbiota is representative of the intestinal microbiota. In wildlife studies, research on the sampling methodology is limited. In this study focusing on amphibians, we characterize and compare the microbiota (small intestine, large intestine, and feces) of two Hong Kong stream‐dwelling frog species: Lesser Spiny Frog (Quasipaa exilispinosa) and Hong Kong Cascade Frog (Amolops hongkongensis). We found that the microbiota of both species are similar at the level of phylum and family, but diverge at the level of genus. When we assessed the performance of fecal microbiota in representing the intestinal microbiota in these two species, we found that (1) the microbiota of the small and large intestine differs significantly, (2) feces are not an appropriate proxy of either intestinal sections, and (3) a set of microbial taxa significantly differs between sample types. Our findings raise caution equating fecal and intestinal microbiota in stream‐dwelling frogs. Sampling feces can avoid sacrifice of an animal, but researchers should avoid over‐extrapolation and interpret results carefully. [ABSTRACT FROM AUTHOR]

A large and increasing body of evidence has demonstrated that hosts often need microbial symbionts to perform essential functions. Deficiencies of microbe-free hosts are usually attributed to the lack of microbial benefits, but the field has neglected evolutionary addiction, where dependencies evolve without benefits. Evolutionary addiction is a general process that could operate in any host system evolving in the continual presence of symbionts, from the human gut to plant roots to microbial hosts of other microbes. Evolutionary addiction helps explain the broad extent to which microbes impact host biology. Microbes are widely recognized to be vital to host health. This new consensus rests, in part, on experiments showing how hosts malfunction when microbes are removed. More and more microbial dependencies are being discovered, even in fundamental processes such as development, immunity, physiology, and behavior. But why do they exist? The default explanation is that microbes are beneficial; when hosts lose microbes, they also lose benefits. Here I call attention to evolutionary addiction, whereby a host trait evolves a need for microbes without having been improved by them. Evolutionary addiction should be considered when interpreting microbe-removal experiments, as it is a distinct and potentially common process. Further, it may have unique implications for the evolution and stability of host–microbe interactions. [ABSTRACT FROM AUTHOR]

Invasive fungal diseases (IFDs) play an important role in the supportive care of paediatric patients with acute leukaemia and those undergoing allogeneic haematopoietic cell transplantation, and they are associated with significantly decreased overall survival rates in affected individuals. Relative to adults, children and adolescents are distinct in terms of host biology, predisposing conditions, presentation and epidemiology of fungal diseases, and in the pharmacology of antifungal agents. The paediatric development of antifungal agents has moved forward in a coordinated manner, and major advances have been made regarding concepts and recommendations for the prevention and treatment of IFDs. However, antifungal therapy is increasingly complex, and a solid knowledge of the available options is needed more than ever for successful management. This narrative review provides a summary of the paediatric development of agents that have been recently approved (anidulafungin, posaconazole) or are in advanced stages of development (isavuconazole). It also reviews the emerging evidence for the efficacy of echinocandins for prophylaxis of invasive aspergillosis, presents new data on alternative dosing regimens of echinocandins and voriconazole, and provides a brief overview of new antifungal agents in clinical development that are expected to be developed for paediatric patients. [ABSTRACT FROM AUTHOR]

With the advent of high-throughput sequencing, large sets of insect-infecting RNA viruses producing apparent asymptomatic infections are being discovered. In the Mediterranean fruit fly (medfly) Ceratitis capitata, an agricultural key pest of a wide range of fruits, 13 different RNA viruses have been described so far. Recent analysis demonstrated a wide distribution of these viruses in different medfly strains collected worldwide, but little is known about the interactions between those viruses and the medfly host. Previous studies suggested that a higher abundance of Ceratitis capitata nora virus (CcaNV) correlated with a shorter lifespan in adults. Here, we investigated the effect of CcaNV on a broad range of parameters related to host fitness and its interaction with other trophic levels. CcaNV purified from a naturally infected medfly strain was added to the larval diet. Pupal weight, adult emergence, flying ability, and longevity were monitored after oral infections. Our results revealed detrimental effects associated with a CcaNV infection in the medfly, in terms of reduced pupal weight and reduced adult longevity. Moreover, we tested the influence of a CcaNV infection in medflies on the parasitism performance of Aganaspis daci, an endoparasitoid used in biological control programs against medflies. Our results showed that A. daci progeny increased when parasitizing on CcaNV-infected larvae. Overall, we proved that covert RNA viruses can impact the insect ecology, directly affecting its insect host biology and indirectly influencing multitrophic interactions. [ABSTRACT FROM AUTHOR]

The parasitoid way of life (parasitizing and finally killing a single arthropod host) is one of the most successful lifeways in the animal kingdom, sparking an explosive diversification and accompanying numerous parasitoid strategies in insects, especially in the order Hymenoptera. Amongst parasitoid wasps, the Polysphincta group of genera has evolved a highly distinctive parasitoid mode of life, as solitary koinobiont ectoparasitoids of spiders (Chelicerata: Araneae). Some species of polysphinctine wasps have a remarkable ability to control spiders' web-building behaviour (host web manipulation) to protect the vulnerable wasp cocoons. The group currently consists of 25 genera and 294 extant species worldwide, with 14 genera known to manipulate their host spiders. This study reviews the current species composition, distribution, host utilization and biology of all genera belonging to the Polysphincta group and their ancestral genera of spider egg mass pseudo-parasitoids, highlighting specific offensive approaches for subjugating spider hosts for oviposition and web manipulation against specific spider hosts. There must still be many more unique behaviours to be discovered, given that the life histories of several polysphinctine genera are poorly known or unknown. A tidy correspondence between lineages of polysphinctines and host spiders was recognized, implying the evolutionary history of polysphinctines. Based on the integrated information on behavioural data and host utilization, we suggest some hypotheses determining triggers for host shifts and discuss the possibility of adaptive radiation driven by divergent natural selection on host differentiation. One new taxonomic change is proposed: Zaglyptus idukkiensis (Manjusha, Sudheer & Ghosh, 2019), comb. nov., is transferred from Polysphincta. [ABSTRACT FROM AUTHOR]

The large American liver fluke (Fascioloides magna) is considered an invasive trematode parasite in Europe. Its origin dates back before the Cretaceous-Paleogene Mass Extinction, after which it survived at least three population bottlenecks and successful host switches before it arrived in Europe. The authors review the evolutionary history of F. magna, the distribution by its ancient proboscidean hosts, and the probable drivers of the switch to the white-tailed deer (Odocoileus virginianus). The review collects knowledge on the biology of intermediate hosts, which helps understand the factors that influence the epidemiology of F. magna in aquatic ecosystems. The authors demonstrate the adaptation potential of the parasite using data from both North American and European endemics. Finally, the study calls attention to the epidemiological risk of human-induced global change, with a special interest in the invasive snail species Pseudosuccinea columella. [ABSTRACT FROM AUTHOR]

Symbiotic bacteria can alter host biology by providing protection from natural enemies, or alter reproduction or vectoral competence. Symbiont‐linked control of vector‐borne disease in Anopheles has been hampered by a lack of symbioses that can establish stable vertical transmission in the host. Previous screening found the symbiont 'Candidatus Tisiphia' in Anopheles plumbeus, an aggressive biter and potential secondary vector of malaria parasites and West Nile virus. We screened samples collected over 10‐years across Germany and used climate databases to assess environmental influence on incidence. We observed a 95% infection rate, and that the frequency of infection did not fluctuate with broad environmental factors. Maternal inheritance is indicated by presence in the ovaries through FISH microscopy. Finally, we assembled a high‐quality 1.6 Mbp draft genome of 'Ca. Tisiphia' to explore its phylogeny and potential metabolic competence. The infection is closely related to strains found in Culicoides biting midges and shows similar patterns of metabolism, providing no evidence of the capacity to synthesize B‐vitamins. This infection offers avenues for onward research in anopheline mosquito symbioses. Additionally, it provides future opportunity to study the impact of 'Ca. Tisiphia' on natural and transinfected hosts, especially in relation to reproductive fitness and vectorial competence and capacity. [ABSTRACT FROM AUTHOR]

The occurrence of plant disease is determined by interactions among host, pathogen, and environment. Air humidity shapes various aspects of plant physiology and high humidity has long been known to promote numerous phyllosphere diseases. However, the molecular basis of how high humidity interferes with plant immunity to favor disease has remained elusive. Here we show that high humidity is associated with an "immuno‐compromised" status in Arabidopsis plants. Furthermore, accumulation and signaling of salicylic acid (SA), an important defense hormone, are significantly inhibited under high humidity. NPR1, an SA receptor and central transcriptional co‐activator of SA‐responsive genes, is less ubiquitinated and displays a lower promoter binding affinity under high humidity. The cellular ubiquitination machinery, particularly the Cullin 3‐based E3 ubiquitin ligase mediating NPR1 protein ubiquitination, is downregulated under high humidity. Importantly, under low humidity the Cullin 3a/b mutant plants phenocopy the low SA gene expression and disease susceptibility that is normally observed under high humidity. Our study uncovers a mechanism by which high humidity dampens a major plant defense pathway and provides new insights into the long‐observed air humidity influence on diseases. Synopsis: Many plant diseases are more severe when air humidity is high; however, the effect of air humidity on host plant biology remains obscure. This report shows that, in very humid conditions, key salicylic acid‐mediated plant defenses are suppressed, making plants more vulnerable to infection. High humidity triggers a range of plant physiological responses.Investigating the effects of high humidity on individual plant immune pathways revealed a significant suppression of salicylic acid (SA) accumulation and signaling.Cellular ubiquitination pathways are suppressed in high humidity, including the ubiquitination and activity of the SA receptor NPR1. [ABSTRACT FROM AUTHOR]

The gut microbiota is crucial for many aspects of their hosts' biology, and it has been characterized for many species across the animal kingdom. Yet, we still don't have a good understanding of whether non-lethal sampling can accurately capture the diversity of gut-associated bacterial communities, as estimated from lethal sampling of intestinal tissue. We further lack knowledge on whether non-lethal sampling methods are suitable for detecting gut microbiota shifts associated with changes in environmental factors (e.g., diet). We addressed these questions in threespine stickleback fish, a model system for evolutionary ecology, by comparing bacterial communities from intestinal tissue and feces. Despite some differences in community composition between the two sample types and considerable temporal variation among fecal samples, bacterial communities appear to largely overlap. Further, we detected consistent and significant changes of fecal bacterial communities associated with an experimental diet manipulation. This suggests that fecal sampling can represent an adequate non-lethal method to characterize the gut microbiota of threespine stickleback, but additional studies will be necessary before drawing general conclusions regarding the validity of fecal sampling for gut microbiota studies. To this end, we give recommendations to improve the characterization of the gut microbiota via fecal sampling. Fecal sampling allows studying temporal gut microbiota shifts associated with environmental change at the individual level, which increases opportunities for future experimental gut microbiota research. [ABSTRACT FROM AUTHOR]

Plant parasites take advantage of host developmental plasticity to elicit profound developmental and physiological changes. In the case of plant-parasitic nematodes (PPNs), these changes can result in the development of new plant organs. Despite the importance of the development- and physiology-altering abilities of these parasites in pathology, research has historically focused on their abilities to suppress immunity. We argue that, given the dramatic changes involved in feeding site establishment, it is entirely possible that development- and physiology-altering abilities of PPNs may, in fact, dominate effector repertoires – highlighting the need for novel high-throughput screens for development- and physiology-altering 'tools'. Uncovering this portion of the nematode 'toolbox' can enable biotechnology, enhance crop protection, and shed light on fundamental host biology itself. Plant-parasitic nematodes (PPNs) profoundly alter plant development, but there is a paucity of information about nematode effectors that alter development and physiology. The recent advances in gland-cell-specific transcriptomics have allowed us to access the full effector repertoire of PPNs. The development of a novel, reproducible, high-throughput screen for development- and physiology-altering effector function will be essential to accelerate the field. [ABSTRACT FROM AUTHOR]

Ecological interactions between parasites and their hosts play a fundamental role in evolutionary processes. Selection pressures are exerted on parasites and their hosts, usually resulting in high levels of specificity. Such is the case of ectoparasitic bat‐flies, but how large‐scale spatial gradients affect the dynamics of their interactions with their bat hosts is still unknown. In the present study, we investigated interaction patterns between bats and their ectoparasitic flies (Streblidae and Nycteribiidae), both presenting their peak of diversity in the Neotropical region, along a latitudinal gradient. Using network analyses and parasitic indices, grounded on the latitudinal diversity gradient pattern, we evaluated how spatial gradients affect species interactions and parasitic indices at the biogeopraphic scale, with increasing species richness in interaction networks closer to the tropics, leading to increases in network modularity, size, and specialization, and to a decrease in nesting and connectivity. We conducted a literature review, focusing on studies done in the Neotropical region, and own data. We obtained a bat richness of 97 species parasitized by 128 species of ectoparasitic flies, distributed into 57 interaction networks between latitudes 29° S and 19° N in the Neotropic. Network metrics and parasitic indices varied along the latitudinal gradient, with changes in the richness of bats and their ectoparasitic flies and in the structure of their interactions; network specialization, modularity, and connectance increase with latitude, while network size decreases with latitude. Regions closer to the equator had higher parasite loads. Our results show that interaction network metrics present a latitudinal gradient and that such interactions, when observed at a local scale, hide variations that only become perceptible at larger scales. In this way, ectoparasites such as bat flies are not only influenced by the ecology and biology of their hosts, but also by other environmental factors acting directly on their distribution and survival. [ABSTRACT FROM AUTHOR]

Transposable elements (TEs) are DNA sequences that can transpose and replicate within the genome, leading to genetic changes that affect various aspects of host biology. Evolutionarily, hosts have also developed molecular mechanisms to suppress TEs at the transcriptional and post-transcriptional levels. Recent studies suggest that stress-induced formation of ribonucleoprotein (RNP) granules, including stress granule (SG) and processing body (P-body), can play a role in the sequestration of TEs to prevent transposition, suggesting an additional layer of the regulatory mechanism for TEs. RNP granules have been shown to contain factors involved in RNA regulation, including mRNA decay enzymes, RNA-binding proteins, and noncoding RNAs, which could potentially contribute to the regulation of TEs. Therefore, understanding the interplay between TEs and RNP granules is crucial for elucidating the mechanisms for maintaining genomic stability and controlling gene expression. In this review, we provide a brief overview of the current knowledge regarding the interplay between TEs and RNP granules, proposing RNP granules as a novel layer of the regulatory mechanism for TEs during stress. [ABSTRACT FROM AUTHOR]

Food has long been known to perform dual functions of nutrition and medicine, but mounting evidence suggests that complex host‐pathogen dynamics can emerge along continuous resource gradients. Empirical examples of nonmonotonic responses of infection with increasing host resources (e.g., low prevalence at low and high resource supply but high prevalence at intermediate resources) have been documented across the tree of life, but these dynamics, when observed, often are interpreted as nonintuitive, idiosyncratic features of pathogen and host biology. Here, by developing generalized versions of existing models of resource dependence for within‐ and among‐host infection dynamics, we provide a synthetic view of nonmonotonic infection dynamics. We demonstrate that where resources jointly impact two (or more) processes (e.g., growth, defense, transmission, mortality, predation), nonmonotonic infection dynamics, including alternative states, can emerge across a continuous resource supply gradient. We review the few empirical examples that concurrently measured resource effects on multiple rates and pair this with a wide range of examples in which resource dependence of multiple rates could generate nonmonotonic infection outcomes under realistic conditions. This review and generalized framework highlight the likely generality of such resource effects in natural systems and point to opportunities ripe for future empirical and theoretical work. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fine detail of gene expression in each cell is achievable by single-cell (sc)RNA-seq. • scRNA-seq has generated gene expression cell atlases for helminth species. • Host cell responses to infection can be profiled at the single-cell level. • Organoids provide an in vitro system for helminth research. How parasites develop and survive, and how they stimulate or modulate host immune responses are important in understanding disease pathology and for the design of new control strategies. Microarray analysis and bulk RNA sequencing have provided a wealth of data on gene expression as parasites develop through different life-cycle stages and on host cell responses to infection. These techniques have enabled gene expression in the whole organism or host tissue to be detailed, but do not take account of the heterogeneity between cells of different types or developmental stages, nor the spatial organisation of these cells. Single-cell RNA-seq (scRNA-seq) adds a new dimension to studying parasite biology and host immunity by enabling gene profiling at the individual cell level. Here we review the application of scRNA-seq to establish gene expression cell atlases for multicellular helminths and to explore the expansion and molecular profile of individual host cell types involved in parasite immunity and tissue repair. Studying host-parasite interactions in vivo is challenging and we conclude this review by briefly discussing the applications of organoids (stem-cell derived mini-tissues) to examine host-parasite interactions at the local level, and as a potential system to study parasite development in vitro. Organoid technology and its applications have developed rapidly, and the elegant studies performed to date support the use of organoids as an alternative in vitro system for research on helminth parasites. [ABSTRACT FROM AUTHOR]

Animals, including humans, with chronic Trypanosoma cruzi infection can be successfully treated and cured using existing FDA-approved drugs and newly discovered compounds. T. cruzi and Chagas disease offer unequalled model systems and highly accessible host species for efficient drug discovery and for determining drug efficacy. New understanding of T. cruzi biology and infection characteristics identify potential new directions, assays, and approaches for streamlining drug discovery for T. cruzi. Currently licensed compounds can be more effectively dosed to achieve a higher frequency of parasitological cures. There appears to be limited risk of development and spread of drug resistance in T. cruzi using currently available and highly effective 'in-development' compounds. The Chagas field has gone >50 years without tangible progress toward new therapies. My colleagues and I have recently reported on a benzoxaborole compound that achieves consistent parasitological cure in experimentally infected mice and in naturally infected non-human primates (NHPs). While these results do not assure success in human clinical trials, they significantly de-risk this process and form a strong justification for such trials. Highly effective drug discovery depends on a solid understanding of host and parasite biology and excellent knowledge in designing and validating chemical entities. This opinion piece seeks to provide perspectives on the process that led to the discovery of AN15368, with the hope that this will facilitate the discovery of additional clinical candidates for Chagas disease. [ABSTRACT FROM AUTHOR]

The invasive South American Leaf miner, Phthorimaea (=Tuta) absoluta Meyrick (Lepidoptera: Gelechiidae) is now getting a status of key pest in India. Biology studies carried out on tomato revealed that the P. absoluta had four larval instars. The total life cycle of P. absoluta lasted for 20.62 ± 0.66 days with an egg, larval and pupal periods of 2.54 ± 0.15, 9.54 ± 0.31 days and 8.54 ± 0.20 days, respectively. The longevity of female (40.00 ± 0.49 days) was found longer than the males which lasted for 36.45 ± 0.21 days. The biology studies carried out at different temperature conditions revealed the lowest egg (3.00 ± 0.24), larval (10.00 ± 0.27), pupal (9.00 ± 0.27) period, high fecundity (211.00 ± 2.54/female), highest female (40.00 ± 0.49) and male (36.45 ± 0.21) longevity at 30oC. Studies on the spatial distribution of eggs by P. absoluta revealed that the P. absoluta adults mostly preferred to lay the eggs on upper leaf surface (6.07 eggs) followed by lower surface of leaves (5.79 eggs). Ovipositional preference studies on different solanaceous crops viz., tomato, brinjal, potato, chilli and European black nightshade revealed that the adults of P. absoluta highly preferred tomato (233.70 and 326.00 eggs plant-1) followed by potato (95.90 and 143.20 eggs plant-1) both under free and no choice conditions, respectively. Biology of P. absoluta on other solanaceous crops revealed that the total life cycle was the shortest on tomato (22.00 ± 0.61) followed by European black nightshade (27.75 ± 0.84 days). However, no eggs hatched on chilli. [ABSTRACT FROM AUTHOR]

Background: The mosquito microbiota impacts different parameters in host biology, such as development, metabolism, immune response and vector competence to pathogens. As the environment is an important source of acquisition of host associate microbes, we described the microbiota and the vector competence to Zika virus (ZIKV) of Aedes albopictus from three areas with distinct landscapes. Methods: Adult females were collected during two different seasons, while eggs were used to rear F1 colonies. Midgut bacterial communities were described in field and F1 mosquitoes as well as in insects from a laboratory colony (>30 generations, LAB) using 16S rRNA gene sequencing. F1 mosquitoes were infected with ZIKV to determine virus infection rates (IRs) and dissemination rates (DRs). Collection season significantly affected the bacterial microbiota diversity and composition, e.g., diversity levels decreased from the wet to the dry season. Field-collected and LAB mosquitoes' microbiota had similar diversity levels, which were higher compared to F1 mosquitoes. However, the gut microbiota composition of field mosquitoes was distinct from that of laboratory-reared mosquitoes (LAB and F1), regardless of the collection season and location. A possible negative correlation was detected between Acetobacteraceae and Wolbachia, with the former dominating the gut microbiota of F1 Ae. albopictus, while the latter was absent/undetectable. Furthermore, we detected significant differences in infection and dissemination rates (but not in the viral load) between the mosquito populations, but it does not seem to be related to gut microbiota composition, as it was similar between F1 mosquitoes regardless of their population. Conclusions: Our results indicate that the environment and the collection season play a significant role in shaping mosquitoes' bacterial microbiota. [ABSTRACT FROM AUTHOR]

Background: The question of which ecological and evolutionary processes structure the distribution of biodiversity has intrigued scientists for centuries, and historically, inferences have been gained predominantly by studying animals and plants. Although substantial progress has been made towards understanding the multitude of factors that shape host‐associated microbial communities (i.e., microbiomes), it remains largely unknown whether large‐scale geographical patterns in diversity observed for macroorganisms also apply for their microbiomes and whether microbiomes are shaped by the same processes that appear key for determining biogeographical patterns in their hosts. The geographical distribution of microbiome diversity: We discuss challenges and potential approaches for studying microbiome biogeography, with the goal of inspiring future lines of research that can stimulate the development of new ecological and evolutionary theory in the microbiome field. The theory and examples presented here focus specifically on bacterial microbiomes, and we give an overview of host‐associated bacterial microbiome research beginning to examine some of the classic biodiversity patterns central to the fields of ecology and evolution. Potential impacts of microbiome variation for host ecology and evolution: Microbiome diversity patterns are particularly important to consider because microbes are crucial for many aspects of the biology of their hosts. We discuss how more comprehensive knowledge of the geographical variation of microbiome diversity at the host individual and population levels might be crucial for understanding host ecology and evolution. [ABSTRACT FROM AUTHOR]

Wolbachia is a maternally transmitted endosymbiotic bacteria that infects a wide variety of arthropod and nematode hosts. The effects of Wolbachia on host biology are far-reaching and include changes in host gene expression. However, previous work on the host transcriptional response has generally been investigated in the context of a single host genotype. Thus, the relative effect of Wolbachia infection versus vs. host genotype on gene expression is unknown. Here, we explicitly test the relative roles of Wolbachia infection and host genotype on host gene expression by comparing the ovarian transcriptomes of 4 strains of Drosophila melanogaster (D. melanogaster) infected and uninfected with Wolbachia. Our data suggest that infection explains a small amount of transcriptional variation, particularly in comparison to variation in gene expression among strains. However, infection specifically affects genes related to cell cycle, translation, and metabolism. We also find enrichment of cell division and recombination processes among genes with infection-associated differential expression. Broadly, the transcriptomic changes identified in this study provide novel understanding of the relative magnitude of the effect of Wolbachia infection on gene expression in the context of host genetic variation and also point to genes that are consistently differentially expressed in response to infection among multiple genotypes. [ABSTRACT FROM AUTHOR]

My goal in writing this is to increase awareness of the roles played by microbial symbionts in eukaryote ecology and evolution. Most eukaryotes host one or more species of symbiotic microorganisms, including prokaryotes and fungi. Many of these have profound impacts on the biology of their hosts. For example, microbial symbionts may expand the niches of their hosts, cause rapid adaptation of the host to the environment and re-adaptation to novel conditions via symbiont swapping, facilitate speciation, and fundamentally alter our concept of the species. In some cases, microbial symbionts and multicellular eukaryote hosts have a mutual dependency, which has obvious conservation implications. Hopefully, this contribution will stimulate a reevaluation of important ecological and evolutionary concepts including niche, adaptation, the species, speciation, and conservation of multicellular eukaryotes. [ABSTRACT FROM AUTHOR]

The biology of the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae), on various plant parts was studied under laboratory conditions. The hosts used were maize cob, maize leaves, sorghum leaves, cowpea leaves, castor leaves, banana leaves and marigold flowers. Differences were observed across the hosts with respect to the growth and development of FAW. The shortest larval duration was found in larvae that consumed maize cob, but marigold flowers increased the larval duration. The pupal duration did not differ between hosts, but the pupal weight was greatest when reared on castor leaves. Fecundity, hatchability and survivability were recorded highest when reared on maize leaves, followed by maize cob. Therefore, maize cob was the best suited host of FAW, helping in the completion of the life cycle within a short duration with higher fecundity. [ABSTRACT FROM AUTHOR]

Host cells sense and respond to pathogens by dynamically regulating cell signaling. The rapid modulation of signaling pathways is achieved by post‐translational modifications (PTMs) that can alter protein structure, function, and/or binding interactions. By using chemical probes to broadly profile changes in enzyme function or side‐chain reactivity, activity‐based protein profiling (ABPP) can reveal PTMs that regulate host–microbe interactions. While ABPP has been widely utilized to uncover microbial mechanisms of pathogenesis, in this review, we focus on more recent applications of this technique to the discovery of host PTMs and enzymes that modulate signaling within infected cells. Collectively, these advances underscore the importance of ABPP as a tool for interrogating the host response to infection and identifying potential targets for host‐directed therapies. [ABSTRACT FROM AUTHOR]

Introduction: Host-microbe interactions are pivotal in host biology, ecology, and evolution. Recent developments in sequencing technologies have provided newer insights into the same through the hologenome concept. Methods: We report here the study on metagenome-assembled genomes (MAGs) associated with Candida tropicalis (studied through shotgun metagenome sequencing), adding to the knowledge about endomicrobiomes of yeast. De novo assembly and binning recovered two partial archaeal genomes, taxonomically belonging to the phylum Asgardarchaeota. Results and Discussion: The phylogenomic analysis based on the core genes revealed that both the binned genomes cladded separately with the less studied and uncultivated 'Candidatus' superphylum, designated as Asgard archaea (the nearest known relative of eukaryotes). Between the two binned genomes, the average nucleotide index (ANI) was 71.2%. The average nucleotide identities (ANI) of the two binned genomes with 'Candidatus Heimdallarchaeota' were 60.4-61.2%. The metabolic pathways of both the binned genomes predicted genes belonging to sulfur reduction, Kreb's pathway, glycolysis, and C1 carbon metabolism. Further, both the binned genomes were predicted to support autotrophic as well as the heterotrophic mode of growth, which might probably help the host in its nutritional requirements also. Further, the genomes showed few eukaryotic signature proteins (ESPs) and SNARE proteins indicating that members of Asgardarchaeota are the closest relatives of eukaryotes. The gaps present in the metabolic potential of the MAGs obtained and the absence of a few essential pathways shows that they are probably in a symbiotic relationship with the host. The present study, reports for the first-time endosymbiosis of Asgard archaea with yeast. It also provides insights into the metabolic potential, ecology, evolutionary history, and endosymbiotic nature of the important but 160 poorly studied Asgard archaea. [ABSTRACT FROM AUTHOR]

Enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) are gastrointestinal pathogens responsible for severe diarrheal illness. EHEC and EPEC form "attaching and effacing" lesions during colonization and, upon adherence, inject proteins directly into host intestinal cells via the type III secretion system (T3SS). Injected bacterial proteins have a variety of functions but generally alter host cell biology to favor survival and/or replication of the pathogen. Non‐LEE‐encoded effector A (NleA) is a T3SS‐injected effector of EHEC, EPEC, and the related mouse pathogen Citrobacter rodentium. Studies in mouse models indicate that NleA has an important role in bacterial virulence. However, the mechanism by which NleA contributes to disease remains unknown. We have determined that the following translocation into host cells, a serine and threonine‐rich region of NleA is modified by host‐mediated mucin‐type O‐linked glycosylation. Surprisingly, this region was not present in several clinical EHEC isolates. When expressed in C. rodentium, a non‐modifiable variant of NleA was indistinguishable from wildtype NleA in an acute mortality model but conferred a modest increase in persistence over the course of infection in mixed infections in C57BL/6J mice. This is the first known example of a bacterial effector being modified by host‐mediated O‐linked glycosylation. Our data also suggests that this modification may confer a selective disadvantage to the bacteria during in vivo infection. [ABSTRACT FROM AUTHOR]

Insect eggs are exposed to a plethora of abiotic and biotic threats. Their survival depends on both an innate developmental program and genetically determined protective traits provided by the parents. In addition, there is increasing evidence that (a) parents adjust the egg phenotype to the actual needs, (b) eggs themselves respond to environmental challenges, and (c) egg-associated microbes actively shape the egg phenotype. This review focuses on the phenotypic plasticity of insect eggs and their capability to adjust themselves to their environment. We outline the ways in which the interaction between egg and environment is two-way, with the environment shaping the egg phenotype but also with insect eggs affecting their environment. Specifically, insect eggs affect plant defenses, host biology (in the case of parasitoid eggs), and insect oviposition behavior. We aim to emphasize that the insect egg, although it is a sessile life stage, actively responds to and interacts with its environment. [ABSTRACT FROM AUTHOR]

Unravelling the structure-function variation of phycospheric microorganisms and its ecological correlation with harmful macroalgal blooms (HMBs) is a challenging research topic that remains unclear in the natural dynamic process of HMBs. During the world's largest green tide bloom, causative macroalgae Ulva prolifera experienced dramatic changes in growth state and environmental conditions, providing ideal scenarios for this investment. Here, we assess the phycospheric physicochemical characteristics, the algal host's biology, the phycospheric bacterial constitutive patterns, and the functional potential during the U. prolifera green tide. Our results indicated that (i) variation in the phycosphere nutrient structure was closely related to the growth state of U. prolifera; (ii) stochastic processes govern phycospheric bacterial assembly, and the contribution of deterministic processes to assembly varied among phycospheric seawater bacteria and epiphytic bacteria; (iii) phycospheric seawater bacteria and epiphytic bacteria exhibited significant heterogeneity variation patterns in community composition, structure, and metabolic potential; and (iv) phycospheric bacteria with carbon or nitrogen metabolic functions potentially influenced the nutrient utilization of U. prolifera. Furthermore, the keystone genera play a decisive role in the structure-function covariation of phycospheric bacterial communities. Our study reveals complex interactions and linkages among environment-algae-bacterial communities which existed in the macroalgal phycosphere and highlights the fact that phycospheric microorganisms are closely related to the fate of the HMBs represented by the green tide. [ABSTRACT FROM AUTHOR]

Despite their diversity, global distribution, and apparent effects on host biology, the rules of life that govern variation in microbiomes among host species remain unclear, particularly in freshwater organisms. In this study, we sought to assess whether geographic location, taxonomy (order, family, and genus), or functional feeding group (FFG) designations would best explain differences in the gut microbiome composition among macroinvertebrates sampled across 10 National Ecological Observatory Network's (NEON) freshwater stream sites in the United States. Subsequently, we compared the beta diversity of microbiomes among locations, taxonomy (order, family, and genus), and FFGs in a single statistical model to account for variation within the source microbial community and the types of macroinvertebrates sampled across locations. We determined significant differences in community composition among macroinvertebrate orders, families, genera, and FFGs. Differences in microbiome compositions were underscored by different bacterial ASVs that were differentially abundant among variables (four bacterial ASVs across the 10 NEON sites, 43 ASVs among the macroinvertebrate orders, and 18 bacterial ASVs differing among the five FFGs). Analyses of variations in microbiome composition using the Bray–Curtis distance matric revealed FFGs as the dominant source of variation (mean standard deviation of 0.8), followed by stream site (mean standard deviation of 0.5), and finally family and genus (mean standard deviation of 0.3 each). Our findings revealed a principal role for FFG classification in insect gut microbiome beta diversity with additional roles for geographic distribution and taxonomy. [ABSTRACT FROM AUTHOR]

Integrative and conjugative elements (ICEs) are major drivers of horizontal gene transfer in bacteria. They mediate their own transfer from host cells (donors) to recipients and allow bacteria to acquire new phenotypes, including pathogenic and metabolic capabilities and drug resistances. Streptococcus mutans, a major causative agent of dental caries, contains a putative ICE, TnSmu1, integrated at the 3′ end of a leucyl tRNA gene. We found that TnSmu1 is a functional ICE, containing all the genes necessary for ICE function. It excised from the chromosome and excision was stimulated by DNA damage. We identified the DNA junctions generated by excision of TnSmu1, defined the ends of the element, and detected the extrachromosomal circle. We found that TnSmu1 can transfer from S. mutans donors to recipients when co‐cultured on solid medium. The presence of TnSmu1 in recipients inhibited successful acquisition of another copy and this inhibition was mediated, at least in part, by the likely transcriptional repressor encoded by the element. Using microscopy to track individual cells, we found that activation of TnSmu1 caused an arrest of cell growth. Our results demonstrate that TnSmu1 is a functional ICE that affects the biology of its host cells. [ABSTRACT FROM AUTHOR]

Microbiomes affect many aspects of host biology, but the eco‐evolutionary forces that shape their diversity in natural populations remain poorly understood. Geographical gradients, such as latitudinal clines, generate predictable patterns in biodiversity at macroecological scales, but whether these macroscale processes apply to host–microbiome interactions is an open question. To address this question, we sampled the microbiomes of 13 natural populations of Drosophila melanogaster along a latitudinal cline in the eastern United States. The microbiomes were surprisingly consistent across the cline, as latitude did not predict either alpha or beta diversity. Only a narrow taxonomic range of bacteria were present in all microbiomes, indicating that strict taxonomic filtering by the host and neutral ecological dynamics are the primary factors shaping the fly microbiome. Our findings reveal the complexity of eco‐evolutionary interactions shaping microbial variation in D. melanogaster and highlight the need for additional sampling of the microbiomes in natural populations along environmental gradients. [ABSTRACT FROM AUTHOR]

Background Food processing alters diet digestibility and composition, thereby influencing interactions between host biology, diet, and the gut microbiota. The fecal metabolome offers insight into those relations by providing a readout of diet–microbiota interactions impacting host health. Objectives The aims were to determine the effects of consuming a processed diet on the fecal metabolome and to explore relations between changes in the fecal metabolome with fecal microbiota composition and gastrointestinal health markers. Methods This was a secondary analysis of a randomized controlled trial wherein healthy adults [94% male; 18–61 y; BMI (kg/m2): 26 ± 3] consumed their usual diet [control (CON), n  = 27] or a Meal, Ready-to-EatTM (Ameriqual Packaging) military ration diet composed of processed, shelf-stable, ready-to-eat items for 21 d (MRE; n  = 27). Fecal metabolite profiles, fecal microbiota composition, biomarkers of intestinal barrier function, and gastrointestinal symptoms were measured before and after the intervention. Between-group differences and associations were assessed using nonparametric t tests, partial least-squares discriminant analysis, correlation, and redundancy analysis. Results Fecal concentrations of multiple dipeptides [Mann-Whitney effect size (ES) = 0.27–0.50] and long-chain SFAs (ES = 0.35–0.58) increased, whereas plant-derived compounds (ES = 0.31–0.60) decreased in MRE versus CON (P  < 0.05; q  < 0.20). Changes in dipeptides correlated positively with changes in fecal concentrations of Maillard-reaction products (ρ = 0.29–0.70; P  < 0.05) and inversely with changes in serum prealbumin (ρ = −0.30 to −0.48; P  ≤ 0.03). Multiple bile acids, coffee and caffeine metabolites, and plant-derived compounds were associated with both fecal microbiota composition and gastrointestinal health markers, with changes in fecal microbiota composition explaining 26% of the variability within changes in gastrointestinal health–associated fecal metabolites (P  = 0.001). Conclusions Changes in the fecal metabolomes of adults consuming a Meal, Ready-to-EatTM diet implicate interactions between diet composition, diet digestibility, and the gut microbiota as contributing to variability within gastrointestinal responses to the diet. Findings underscore the need to consider both food processing and nutrient composition when investigating the impact of diet–gut microbiota interactions on health outcomes. This trial was registered at www.clinicaltrials.gov as NCT02423551. [ABSTRACT FROM AUTHOR]

Ovaustra aurantia Tetley, Glatz & Fagan‐Jeffries, gen. et sp. nov. (Mesostoinae) is described from Kangaroo Island. South Australia, Australia, and is a solitary, koinobiont, egg‐larval parasitoid of the enigma moth, Aenigmatinea glatzella Kristensen & Edwards, 2015, in the monotypic family Aenigmatineidae Kristensen & Edwards, 2015 (Lepidoptera). Female parasitoids oviposit into the eggs of A. glatzella soon after female moths place them beneath minute adpressed leaves at the growing foliar tips of the larval host plant Callitris gracilis R.T. Baker (Cupressaceae). Adult parasitoids emerge from A. glatzella larval chambers located directly beneath the bark of small branches, some way from the growing tip. Adults can be seen on or near foliage of C. gracillis primarily during October and coinciding with the presence of adult host moths. Morphological and preliminary molecular evidence place Ovaustra Glatz, Fagan‐Jeffries & Tetley, gen. nov. within Mesostoinae s.l. and indicate that its closest relatives are likely to reside within a group of genera from Australia and New Zealand whose hosts and biology are not well defined but are apparently quite broad, including lepidopteran, coleopteran and dipteran larvae, as well as primary plant gall induction. [ABSTRACT FROM AUTHOR]

This article is a Commentary on McCombe et al. (2023), 239: 222–239. [ABSTRACT FROM AUTHOR]

Transposable elements are known by many names, including 'transposons', 'interspersed repeats', 'selfish genetic elements', 'jumping genes', and 'parasitic DNA', but here we will refer to them simply as transposable elements. Many biologists will have heard of transposable elements and their ability to transpose (change position) within the genome. But fewer may be aware of their varied influences on host biology, including contributions to the evolution of diverse host traits such as internal gestation, memory, colouration, and adaptive immunity. Transposable elements are a near ubiquitous feature of eukaryotic genomes, and they often comprise a substantial proportion of total genomic content. Consequently, transposable element genes are considered among the most abundant coding sequences in nature. Recent advances in genome sequencing have ushered in a golden age for transposable-element research, providing opportunities to greatly improve our understanding of the effects of transposable elements on host evolution and disease. However, our ability to detect and analyse transposable elements still faces significant challenges, impairing efforts to decipher their evolution, characterise their diversity, and elucidate their myriad host influences. Below, we summarise key aspects of transposable element biology in eukaryotes and discuss major outstanding research questions. Transposable elements are a near ubiquitous feature of eukaryotic genomes, and they are among the most abundant coding sequences in nature. In this Primer, Hayward and Gilbert discuss key aspects of transposable element biology and highlight major outstanding research questions. [ABSTRACT FROM AUTHOR]

Endogenous retroviruses (ERVs), deriving from exogenous retroviral infections of germ line cells occurred millions of years ago, represent ~8% of human genome. Most ERVs are highly inactivated because of the accumulation of mutations, insertions, deletions, and/or truncations. However, it is becoming increasingly apparent that ERVs influence host biology through genetic and epigenetic mechanisms under particular physiological and pathological conditions, which provide both beneficial and deleterious effects for the host. For instance, certain ERVs expression is essential for human embryonic development. Whereas abnormal activation of ERVs was found to be involved in numbers of human diseases, such as cancer and neurodegenerative diseases. Therefore, understanding the mechanisms of regulation of ERVs would provide insights into the role of ERVs in health and diseases. Here, we provide an overview of mechanisms of transcriptional regulation of ERVs and their dysregulation in human diseases. [ABSTRACT FROM AUTHOR]

The stalk-eyed fruit flies, with their eyes borne at the ends of long stalks, are distinctly different from all other members of the family Tephritidae (Diptera). They resemble stalk-eyed flies (Diptera, Diopsidae) but they are much larger and their antennae are located in the middle of the head instead of on the eye stalks. The stalk-eyed fruit flies are represented by two genera (Pelmatops Enderlein and Pseudopelmatops Shiraki) mainly found in the Oriental tropics and subtropics, but their basic biology remains poorly documented. Here, we describe the life history, reproductive biology, and host use patterns of Pelmatops spp. (mainly P. ichneumoneus (Westwood)). These flies used two local brambles, Rubus setchuenensis and R. multibracteatus (Rosales, Rosaceae), as hosts, with females laying eggs below the epidermal tissue. The larvae bore into the stem, where they feed, eventually dropping to the ground to pupate in the soil. We describe the pupal morphology and eclosion, including the elongation of their eye stalks, feeding, mating, and agonistic behavior in adults. We observed mating between female P. ichneumoneus and male P. tangliangi and tentatively suggest that the two species could be conspecific. Our work presents the first detailed report on the biology of stalk-eyed fruit flies and it lays a significant foundation for future studies on the ecology and evolution of this group. [ABSTRACT FROM AUTHOR]

The maternally inherited endosymbiont, Wolbachia, is known to alter the reproductive biology of its arthropod hosts for its own benefit and can induce both positive and negative fitness effects in many hosts. Here, we describe the effects of the maintenance of two distinct Wolbachia infections, one each from supergroups A and B, on the parasitoid host Nasonia vitripennis. We compare the effect of Wolbachia infections on various traits between the uninfected, single A‐infected, single B‐infected, and double‐infected lines with their cured versions. Contrary to some previous reports, our results suggest that there is a significant cost associated with the maintenance of Wolbachia infections where traits such as family size, fecundity, longevity, and rates of male copulation are compromised in Wolbachia‐infected lines. The double Wolbachia infection has the most detrimental impact on the host as compared to single infections. Moreover, there is a supergroup‐specific negative impact on these wasps as the supergroup B infection elicits the most pronounced negative effects. These negative effects can be attributed to a higher Wolbachia titer seen in the double and the single supergroup B infection lines when compared to supergroup A. Our findings raise important questions on the mechanism of survival and maintenance of these reproductive parasites in arthropod hosts. [ABSTRACT FROM AUTHOR]

Disease-transmitting vectors are living organisms that pass infectious agents from one animal/human to another. The epidemiologically important vectors are usually hematophagous arthropods, including mosquitoes, ticks, triatome bugs, sand flies, and tsetse flies. All of them harbor an endogenous microbiota that functionally complements their host's biology. Different arthropod vectors are ecologically and behaviorally distinct, and as such, their relationships with symbiotic microbes vary. In this review, we summarize the recent discoveries that reveal how bacterial metabolic activities influence development, nutrition, and pathogen defense in mosquitoes, ticks, triatome bugs, and sand flies. These studies provide a foundation for a systematic understanding of vector–microbiota interactions and for the development of integrated approaches to control vector-borne diseases. Vectors transmit a variety of infectious pathogens that threaten animal and human health. The different life cycles, feeding habits, and habitats of these vectors lead to their association with diverse symbiotic microorganisms. Metabolic interactions between symbiotic microbes and vectors profoundly influence multiple aspects of vector biology. Harnessing and manipulating vector–microbe symbioses can provide potential targets for vector control. [ABSTRACT FROM AUTHOR]

Mammalian orthoreovirus (reovirus) is a double-stranded RNA (dsRNA) virus which encapsidates its 10 genome segments within a double-layered viral particle. Reovirus infection triggers an antiviral response in host cells which serves to limit viral replication. This antiviral response is initiated by recognition of the incoming viral genome by host sensors present in the cytoplasm. However, how host sensors gain access to the reovirus genome is unclear, as this dsRNA is protected by the viral particle proteins throughout infection. To initiate infection, reovirus particles are endocytosed and the outer viral particle layer is disassembled through the action of host proteases. This disassembly event is required for viral escape into the cytoplasm to begin replication. We show that endosomal proteases are required even late in infection, when disassembly is complete, to induce an immune response to reovirus. Additionally, counter to dogma, our data demonstrate that at least some viral dsRNA genome is exposed and detectable during entry. We hypothesize that some proportion of reovirus particles remain trapped within endosomes, allowing for the breakdown of these particles and release of their genome. We show that rapidly uncoating mutants escape the endosome more rapidly and induce a diminished immune response. Further, we show that particles entering through dynamin-independent pathways evade detection by host sensors. Overall, our data provide new insight into how genomes from entering reovirus particles are detected by host cells. IMPORTANCE Viruses must infect host cells to replicate, often killing the host cell in the process. However, hosts can activate defenses to limit viral replication and protect the organism. To trigger these host defenses to viral infections, host cells must first recognize that they are infected. Mammalian orthoreovirus (reovirus) is a model system used to study host-virus interactions. This study identifies aspects of host and virus biology which determine the capacity of host cells to detect infection. Notably, entry of reovirus into host cells plays a critical role in determining the magnitude of immune response triggered during infection. Mutants of reovirus which can enter cells more rapidly are better at avoiding detection by the host. Additionally, reovirus can enter cells through multiple routes. Entry through some of these routes also helps reovirus evade detection. [ABSTRACT FROM AUTHOR]

Insights into interactions between viral factors and the cellular machinery usually lead to discoveries concerning host cell biology. Thus, the gene expression field has historically relied on viral model systems to discover mechanisms underlying different cellular processes. In recent years, the functional characterization of the small nuclear noncoding RNAs expressed by the oncogenic Herpesvirus saimiri, called HSURs, resulted in the discovery of two mechanisms for the regulation of gene expression. HSUR1 and HSUR2 associate with host microRNAs, which are small noncoding RNAs that broadly regulate gene expression by binding to messenger RNAs. HSUR1 provided the first example of a process known as target-directed miRNA degradation that operates in cells to regulate miRNA populations. HSUR2 functions as a miRNA adaptor, uncovering an entirely new, indirect mechanism by which miRNAs can inhibit mRNA function. Here, I review the path that led to these discoveries and their implications and postulate new exciting questions about the functions of these fascinating viral noncoding RNAs. [ABSTRACT FROM AUTHOR]

The rabies virus (RABV) phosphoprotein (P protein) is expressed as several isoforms, which differ in nucleocytoplasmic localization and microtubule (MT) association, mediated by several sequences, including nuclear localization (NLS) and export (NES) sequences. This appears to underpin a functional diversity enabling multiple functions in viral replication and modulation of host biology. Mechanisms regulating trafficking are poorly defined, but phosphorylation by protein kinase C (PKC) in the P protein C-terminal domain (PCTD) regulates nuclear trafficking, mediated by PCTD-localized NLS/NES sequences, indicating that phosphorylation contributes to functional diversity. The molecular mechanism underlying the effects of PKC, and potential roles in regulating other hostcell interactions are unresolved. Here, we assess effects of phosphorylation on the P3 isoform, which differs from longer isoforms through an ability to localize to the nucleus and associate with MTs, which are associated with antagonism of interferon (IFN) signaling. We find that phosphomimetic mutation of the PKC site S210 inhibits nuclear accumulation and MT association/bundling. Structural analysis indicated that phosphomimetic mutation induces no significant structural change to the NLS/NES but results in the side chain of N226 switching its interactions from E228, within the NES, to E210. Intriguingly, N226 is the sole substituted residue between the PCTD of the pathogenic IFN-resistant RABV strain Nishigahara and a derivative attenuated IFN-sensitive strain Ni-CE, inhibiting P3 nuclear localization and MT association. Thus, S210 phosphorylation appears to impact on N226/E228 to regulate P protein localization, with N226 mutation in Ni-CE mimicking a constitutively phosphorylated state resulting in IFN sensitivity and attenuation. [ABSTRACT FROM AUTHOR]