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In traditional understanding, P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP) are regarded as efflux transporters that can decrease the concentration of their substrates in the testis, thereby reducing reproductive toxicity in males (RTM) and protecting spermatogenesis. However, there is currently no direct pharmacological evidence demonstrating that P-gp and BCRP can reduce the occurrence of drug-induced RTM. In this study, we chose small molecule targeted anti-tumor agents as model drugs and systematically retrieved and collected information on the transporters and RTM for these drugs, followed by correlation analysis. The results showed a lower incidence of RTM for P-gp substrate drugs, which aligns with previous knowledge. Surprisingly, BCRP substrate drugs exhibited higher rates of RTM in various dimensions, contradicting previous notions. This discrepancy may be attributed to the differential distribution and transport directions of P-gp and BCRP on the blood-testis barrier (BTB). For the first time, this study may provide clues that BCRP may facilitate the passage of exogenous compounds across the BTB, increasing the occurrence of RTM, rather than protecting spermatogenesis as traditionally believed. Furthermore, this study provides the first direct verification of the role of P-gp in reducing RTM and protecting spermatogenesis.

Understanding the relationship between activity over the entire lifespan and longevity is an important facet of aging research. We present a comprehensive framework for the statistical analysis of longitudinal activity and behavioral monitoring and their relationship with age-at-death at the individual level, highlighting the importance of advanced methodological approaches in aging research. The focus is on animal models, where continuous monitoring activity in terms of movement, reproduction and behaviors over the entire lifespan is feasible at the individual level. We specifically demonstrate the methodology with data on activity monitoring for Mediterranean fruit flies. Advanced statistical methodologies to explore the interface between activity and age-at-death include functional principal component analysis, concurrent regression, Fréchet regression and point processes. While the focus of this perspective is on relating age-at-death with data on movement, reproduction, behavior and nutrition of Mediterranean fruit flies, the methodology equally pertains to data from other species, including human data.

The fundamental trade-off between current and future reproduction has long been considered to result in a tendency for species that can grow large to begin reproduction at a larger size. Due to the prolonged time required to reach maturity, estimates of tree maturation size remain very rare and we lack a global view on the generality and the shape of this trade-off. Using seed production from five continents, we estimate tree maturation sizes for 486 tree species spanning tropical to boreal climates. Results show that a species' maturation size increases with maximum size, but in a non-proportional way: the largest species begin reproduction at smaller sizes than would be expected if maturation were simply proportional to maximum size. Furthermore, the decrease in relative maturation size is steepest in cold climates. These findings on maturation size drivers are key to accurately represent forests' responses to disturbance and climate change.

Infertility affects ∼12 % of couples, with environmental chemical exposure as a potential contributor. Of the chemicals that are actively manufactured, very few are assessed for reproductive health effects. Rodents are commonly used to evaluate reproductive effects, which is both costly and time consuming. Thus, there is a pressing need for rapid methods to test a broader range of chemicals. Here, we developed a strategy to evaluate large numbers of chemicals for reproductive toxicity via a yeast, S. cerevisiae high-throughput assay to assess gametogenesis as a potential new approach method (NAM). By simultaneously assessing chemicals for growth effects, we can distinguish if a chemical affects gametogenesis only, proliferative growth only or both. We identified a well-known mammalian reproductive toxicant, bisphenol A (BPA) and ranked 19 BPA analogs for reproductive harm. By testing mixtures of BPA and its analogs, we found that BPE and 17 β-estradiol each together with BPA showed synergistic effects that worsened reproductive outcome. We examined an additional 179 environmental chemicals including phthalates, pesticides, quaternary ammonium compounds and per- and polyfluoroalkyl substances and found 57 with reproductive effects. Many of the chemicals were found to be strong reproductive toxicants that have yet to be tested in mammals. Chemicals having affect before meiosis I division vs. meiosis II division were identified for 16 gametogenesis-specific chemicals. Finally, we demonstrate that in general yeast reproductive toxicity correlates well with published reproductive toxicity in mammals illustrating the promise of this NAM to quickly assess chemicals to prioritize the evaluation for human reproductive harm.

During the last decade, the spotted wing drosophila, Drosophila suzukii, has spread from eastern Asia to the Americas, Europe, and Africa. This fly attacks many species of cultivated and wild fruits with soft, thin skins, where its serrated ovipositor allows it to lay eggs in undamaged fruit. Parasitoids from the native range of D. suzukii may provide sustainable management of this polyphagous pest. Among these parasitoids, host-specificity testing has revealed a lineage of Ganaspis near brasiliensis, referred to in this paper as G1, that appears to be a cryptic species more host-specific to D. suzukii than other parasitoids. Differentiation among cryptic species is critical for introduction and subsequent evaluation of their impact on D. suzukii. Here, we present results on divergence in genomic sequences and architecture and reproductive isolation between lineages of Ganaspis near brasiliensis that appear to be cryptic species. We studied five populations, two from China, two from Japan, and one from Canada, identified as the G1 vs G3 lineages based on differences in cytochrome oxidase l sequences. We assembled and annotated the genomes of these populations and analyzed divergences in sequence and genome architecture between them. We also report results from crosses to test reproductive compatibility between the G3 lineage from China and the G1 lineage from Japan. The combined results on sequence divergence, differences in genome architectures, ortholog divergence, reproductive incompatibility, differences in host ranges and microhabitat preferences, and differences in morphology show that these lineages are different species. Thus, the decision to evaluate the lineages separately and only import and introduce the more host-specific lineage to North America and Europe was appropriate.

Age and longevity are key parameters for demography and life-history evolution of organisms. In clonal species, a widespread life history among animals, plants, macroalgae and fungi, the sexually produced offspring (genet) grows indeterminately by producing iterative modules, or ramets, and so obscure their age. Here we present a novel molecular clock based on the accumulation of fixed somatic genetic variation that segregates among ramets. Using a stochastic model, we demonstrate that the accumulation of fixed somatic genetic variation will approach linearity after a lag phase, and is determined by the mitotic mutation rate, without direct dependence on asexual generation time. The lag phase decreased with lower stem cell population size, number of founder cells for the formation of new modules, and the ratio of symmetric versus asymmetric cell divisions. We calibrated the somatic genetic clock on cultivated eelgrass Zostera marina genets (4 and 17 years respectively). In a global data set of 20 eelgrass populations, genet ages were up to 1,403 years. The somatic genetic clock is applicable to any multicellular clonal species where the number of founder cells is small, opening novel research avenues to study longevity and, hence, demography and population dynamics of clonal species.

In group-living species, reproductive variation among individuals of the same sex is widespread. By identifying the mechanisms underlying this reproductive skew, we gain fundamental insights into the evolution and maintenance of sociality. A common mechanism, social control, is typically studied by quantifying dominance, which is one of many attributes of sociality that describes how individuals exert influence on others and is an incomprehensive measure of social control as it accounts only for direct relationships. Here, we use the global reaching centrality (GRC), which quantifies the degree of hierarchy in a social network by accounting for both direct and indirect social relationships. Using a wild, free-living population of adult female yellow-bellied marmots (Marmota flaviventris), we found a positive relationship between the reproductive skew index and GRC: more despotic social groups have higher reproductive skew. The GRC was stronger predictor for skew than traditional measures of social control (i.e. dominance). This allows deeper insights into the diverse ways individuals control other group members reproduction, a core component in the evolution of sociality. Future studies of skew across taxa may profit by using more comprehensive, network-based measures of social control.

Reproduction is a functional outcome that relies on complex cellular, tissue, and organ interactions that span the developmental period to adulthood. Thus, the assessment of its disruption by environmental chemicals would benefit significantly from scalable and innovative approaches to testing using functionally comparable reproductive models such as the nematode C. elegans. We adapted a previously described low-throughput in vivo chromosome segregation assay using C. elegans predictive of reproductive toxicity and leveraged available public data sources (ToxCast, ICE) to screen and characterize 133 physiologically-relevant chemicals in a high-throughput manner. The screening outcome was further validated in a second, independent in vivo assay assessing embryonic viability. In total, 13 chemicals were classified as reproductive toxicants with the two most active chemicals belonging to the large family of Quaternary Ammonium Compounds (QACs) commonly used as disinfectants but with limited available reproductive toxicity data. We compared the results from the C. elegans assay with ToxCast in vitro data compiled from 700+ cell response assays and 300+ signaling pathways-based assays. We did not observe a difference in the bioactivity or in the average potency (AC50) between the top and bottom chemicals. However, the intended target categories were significantly different between the classified chemicals with, in particular, an over-representation of steroid hormone targets for the high Z-score chemicals. Taken together, these results point to the value of in vivo models that scale to high-throughput level for reproductive toxicity assessment and to the need to prioritize the assessment of QACs impacts on reproduction.

Many animals and plants have species-typical annual cycles, but individuals vary in their timing of life-history events. Individual variation in fur replacement (moult) timing is poorly understood in mammals due to the challenge of repeated observations and longitudinal sampling. We examined factors that influence variation in moult duration and timing among elephant seals (Mirounga angustirostris). We quantified the onset and progression of fur loss in 1178 individuals. We found that an exceptionally rapid visible moult (7 days, the shortest of any mammals or birds), and a wide range of moult start dates (spanning 6-10× the event duration) facilitated high asynchrony across individuals (only 20% of individuals in the population moulting at the same time). Some of the variation was due to reproductive state, as reproductively mature females that skipped a breeding season moulted a week earlier than reproductive females. Moreover, individual variation in timing and duration within age-sex categories far outweighed (76-80%) variation among age-sex categories. Individuals arriving at the end of the moult season spent 50% less time on the beach, which allowed them to catch up in their annual cycles and reduce population-level variance during breeding. These findings underscore the importance of individual variation in annual cycles.

Data from Bering-Chukchi-Beaufort Seas bowhead whales (Balaena mysticetus), harvested during 1973–2021 by aboriginal subsistence hunters, were used to estimate reproductive parameters: length at sexual maturity (LSM), age at sexual maturity (ASM), pregnancy rate (PR), and calving interval. Sexual maturity (N = 187 females) was determined from the presence/absence of corpora in the ovaries, or a fetus. Using sampling bias-corrected logistic regression, LSM was estimated at 13.5 m, 95% CI [13.0, 13.8]. There was a downward trend in LSM over time, statistically significant with one method but marginal with another. A growth model translated this estimate to an ASM estimate of 23.5 years, 95% CI [20.4, 26.7]. Pregnancy rate was determined from mature females (N = 125), and from a subset limited to certain autumn-caught whales (n = 37) to reduce bias. The PR was estimated at 0.46 globally, 95% CI [0.36, 0.55] and 0.38 for the autumn sample, 95% CI [0.20, 0.51]. Both estimated PRs are consistent with a 3-year calving interval, because the larger estimate includes two cohorts of pregnant whales harvested in spring, and bowhead whale gestation is longer than 12 months. These analyses represent the most conclusive empirical estimates of ASM, LSM, and PR for this bowhead whale stock from the largest available data sets to date.

The fundamental goal of a rare plant translocation is to create self-sustaining populations with the evolutionary resilience to persist in the long term. Yet, most plant translocation syntheses focus on a few factors influencing short-term benchmarks of success (e.g., survival and reproduction). Short-term benchmarks can be misleading when trying to infer future growth and viability because the factors that promote establishment may differ from those required for long-term persistence. We assembled a large (n = 275) and broadly representative data set of well-documented and monitored (7.9 years on average) at-risk plant translocations to identify the most important site attributes, management techniques, and species' traits for six life-cycle benchmarks and population metrics of translocation success. We used the random forest algorithm to quantify the relative importance of 29 predictor variables for each metric of success. Drivers of translocation outcomes varied across time frames and success metrics. Management techniques had the greatest relative influence on the attainment of life-cycle benchmarks and short-term population trends, whereas site attributes and species' traits were more important for population persistence and long-term trends. Specifically, large founder sizes increased the potential for reproduction and recruitment into the next generation, whereas declining habitat quality and the outplanting of species with low seed production led to increased extinction risks and a reduction in potential reproductive output in the long-term, respectively. We also detected novel interactions between some of the most important drivers, such as an increased probability of next-generation recruitment in species with greater seed production rates, but only when coupled with large founder sizes. Because most significant barriers to plant translocation success can be overcome by improving techniques or resolving site-level issues through early intervention and management, we suggest that by combining long-term monitoring with adaptive management, translocation programs can enhance the prospects of achieving long-term success.

AbstractAlthough numerous studies have demonstrated the impact of microbiome manipulation on human health, research on the microbiome's influence on female health remains relatively limited despite substantial disease burden. In light of this, we present a selected review of clinical trials and preclinical studies targeting both the vaginal and gut microbiomes for the prevention or treatment of various gynecologic conditions. Specifically, we explore studies that leverage microbiota transplants, probiotics, prebiotics, diet modifications, and engineered microbial strains. A healthy vaginal microbiome for females of reproductive age consists of lactic acid-producing bacteria predominantly of the Lactobacillus genus, which serves as a protective barrier against pathogens and maintains a balanced ecosystem. The gut microbiota's production of short-chain fatty acids, metabolism of primary bile acids, and modulation of sex steroid levels have significant implications for the interplay between host and microbes throughout the body, ultimately impacting reproductive health. By harnessing interventions that modulate both the vaginal and gut microbiomes, it becomes possible to not only maintain homeostasis but also mitigate pathological conditions. While the field is still working toward making broad clinical recommendations, the current studies demonstrate that manipulating the microbiome holds great potential for addressing diverse gynecologic conditions.Lay summaryManipulating the microbiome has recently entered popular culture, with various diets thought to aid the microbes that live within us. These microbes live in different locations of our body and accordingly help us digest food, modulate our immune system, and influence reproductive health. The role of the microbes living in and influencing the female reproductive tract remains understudied despite known roles in common conditions such as vulvovaginal candidiasis (affecting 75% of females in their lifetime), bacterial vaginosis (25% of females in their lifetime), cervical HPV infection (80% of females in their lifetime), endometriosis (6-10% of females of reproductive age), and polycystic ovary syndrome (10-12% of females of reproductive age). Here, we review four different approaches used to manipulate the female reproductive tract and gastrointestinal system microbiomes: microbiota transplants, probiotics, prebiotics, and dietary interventions, and the use of engineered microbial strains. In doing so, we aim to stimulate discussion on new ways to understand and treat female reproductive health conditions.

The relationship between the early-age activity of Mediterranean fruit flies (medflies) or other fruit flies and their lifespan has not been much studied, in contrast to the connections between lifespan and diet, sexual signaling, and reproduction. The objective of this study is to assess intra-day and day-to-day activity profiles of female Mediterranean fruit flies and their role as biomarker of longevity as well as to explore the relationships between these activity profiles, diet, and age-at-death throughout the lifespan. We use advanced statistical methods from functional data analysis (FDA). Three distinct patterns of activity variations in early-age activity profiles can be distinguished. A low-caloric diet is associated with a delayed activity peak, while a high-caloric diet is linked with an earlier activity peak. We find that age-at-death of individual medflies is connected to their activity profiles in early life. An increased risk of mortality is associated with increased activity in early age, as well as with a higher contrast between daytime and nighttime activity. Conversely, medflies are more likely to have a longer lifespan when they are fed a medium-caloric diet and when their daily activity is more evenly distributed across the early-age span and between daytime and nighttime. The before-death activity profile of medflies displays two characteristic before-death patterns, where one pattern is characterized by slowly declining daily activity and the other by a sudden decline in activity that is followed by death.

INTRODUCTION: Increasing the midwifery workforce has been identified as an evidence-based approach to decrease maternal mortality and reproductive health disparities worldwide. Concurrently, the profession of midwifery, as with all healthcare professions, has undergone a significant shift in practice with acceleration of telehealth use to expand access. We conducted a systematic literature review to identify and synthesize the existing evidence regarding how midwives experience, perceive and accept providing sexual and reproductive healthcare services at a distance with telehealth. METHODS: Five databases were searched, PubMed, CINHAL, PsychInfo, Embase and the Web of Science, using search terms related to midwives, telehealth and experience. Peer-reviewed studies with quantitative, qualitative or mixed methods designs published in English were retrieved and screened. Studies meeting the inclusion criteria were subjected to full-text data extraction and appraisal of quality. Using a convergent approach, the findings were synthesized into major themes and subthemes. RESULTS: After applying the inclusion/exclusion criteria, 10 articles on midwives experience of telehealth were reviewed. The major themes that emerged were summarized as integrating telehealth into clinical practice; balancing increased connectivity; challenges with building relationships via telehealth; centring some patients while distancing others; and experiences of telehealth by age and professional experience. CONCLUSIONS: Most current studies suggest that midwives experience of telehealth is deeply intertwined with midwives experience of the response to COVID-19 pandemic in general. More research is needed to understand how sustained use of telehealth or newer hybrid models of telehealth and in-person care are perceived by midwives.

Bioenergetic constraints are the ultimate determinant of the timing of reproduction, and seasonal breeding is consequently a widely observed trait. Consistent with this, attention has focused on plasticity in reproductive phenology conceptualized as a response to concomitant advances in the phenology of the environmental energy supply caused by climate change. Few studies, however, have directly compared timing of reproduction with energetic status in free-living wild animals. Here we demonstrate that neither body mass nor adiposity are strong proximate predictors of date of conception in wild reindeer (Rangifer tarandus). Weak coupling between energetic status and the phenology of reproduction accounts for the increasing discrepancy between the phenology of forage (energy supply) and the phenology of reproduction (energy demand) observed across the last 2-4 decades in two populations of this species. The results emphasise that phenological plasticity is not a passive response to changes in energy supply but derives from the way in which environmental factors interact with the core control mechanisms that govern timing. Central in this respect is integration, within the rheostatic centres of the hypothalamus, of information on nutritional status with the circannual life-history calendar.

BACKGROUND AND AIMS: The increased likelihood and severity of storm events has brought into focus the role of coastal ecosystems in provision of shoreline protection by attenuating wave energy. Canopy-forming kelps, including giant kelp (Macrocystis pyrifera), are thought to provide this ecosystem service, but supporting data are extremely limited. Previous in situ examinations relied mostly on comparisons between nominally similar sites with and without kelp. Given that other factors (especially seafloor bathymetry and topographic features) often differ across sites, efforts to isolate the effects of kelp on wave energy propagation confront challenges. In particular, it can be difficult to distinguish wave energy dissipation attributable to kelp from frictional processes at the seabed that often covary with the presence of kelp. Here, we use an ecological transition from no kelp to a full forest, at a single site with static bathymetry, to resolve unambiguously the capacity of giant kelp to damp waves. METHODS: We measured waves within and outside rocky reef habitat, in both the absence and the presence of giant kelp, at Marguerite Reef, Palos Verdes, CA, USA. Nested within a broader kelp restoration project, this site transitioned from a bare state to one supporting a fully formed forest (density of 8 stipes m-2). We quantified, as a function of incident wave conditions, the decline in wave energy flux attributable to the presence of kelp, as waves propagated from outside and into reef habitat. KEY RESULTS: The kelp forest damped wave energy detectably, but to a modest extent. Interactions with the seabed alone reduced wave energy flux, on average, by 12 ± 1.4 % over 180 m of travel. The kelp forest induced an additional 7 ± 1.2 % decrease. Kelp-associated declines in wave energy flux were slightly greater for waves of longer periods and smaller wave heights. CONCLUSIONS: Macrocystis pyrifera forests have a limited, albeit measurable, capacity to enhance shoreline protection from nearshore waves. Expectations that giant kelp forests, whether extant or enhanced through restoration, have substantial impacts on wave-induced coastal erosion might require re-evaluation.

Across internally fertilising species, males transfer ejaculate proteins that trigger wide-ranging changes in female behaviour and physiology. Much theory has been developed to explore the drivers of ejaculate protein evolution. The accelerating availability of high-quality genomes now allows us to test how these proteins are evolving at fine taxonomic scales. Here, we use genomes from 264 species to chart the evolutionary history of Sex Peptide (SP), a potent regulator of female post-mating responses in Drosophila melanogaster. We infer that SP first evolved in the Drosophilinae subfamily and has since followed markedly different evolutionary trajectories in different lineages. Outside of the Sophophora-Lordiphosa, SP exists largely as a single-copy gene with independent losses in several lineages. Within the Sophophora-Lordiphosa, the SP gene family has repeatedly and independently expanded. Up to seven copies, collectively displaying extensive sequence variation, are present in some species. Despite these changes, SP expression remains restricted to the male reproductive tract. Alongside, we document considerable interspecific variation in the presence and morphology of seminal microcarriers that, despite the critical role SP plays in microcarrier assembly in D. melanogaster, appears to be independent of changes in the presence/absence or sequence of SP. We end by providing evidence that SP's evolution is decoupled from that of its receptor, Sex Peptide Receptor, in which we detect no evidence of correlated diversifying selection. Collectively, our work describes the divergent evolutionary trajectories that a novel gene has taken following its origin and finds a surprisingly weak coevolutionary signal between a supposedly sexually antagonistic protein and its receptor.

The Varroa destructor mite is a parasitic threat to managed and feral honey bee colonies around the world. Beekeepers use miticides to eliminate Varroa in commercial hives, but these chemicals can diminish bee health and increase miticide resistance. In contrast, feral honey bees have developed multiple ways to counteract mites without chemical treatment. We compared mite levels, grooming habits, and mite-biting behavior between feral Africanized honey bees (genomically verified Apis mellifera scutellata hybrids) and managed Italian honey bees (A. mellifera ligustica). Surprisingly, there was no difference in mite infestation levels between scutellata-hybrids and managed bees over one year despite the regular use of miticides in managed colonies. We also found no differences in the social immunity responses of the two groups, as measured by their hygienic habits (through worker brood pin-kill assays), self-grooming, and mite-biting behavior. However, we provide the first report that both scutellata-hybrids and managed honey bees bite off mite chemosensory forelegs, which the mites use to locate brood cells for reproduction, to a significantly greater degree than other legs (a twofold greater reduction in foreleg length relative to the most anterior legs). Such biting may impair mite reproduction.

Understanding the evolutionary mechanisms underlying the maintenance of individual differences in behavior and physiology is a fundamental goal in ecology and evolution. The pace-of-life syndrome hypothesis is often invoked to explain the maintenance of such within-population variation. This hypothesis predicts that behavioral traits are part of a suite of correlated traits that collectively determine an individual's propensity to prioritize reproduction or survival. A key assumption of this hypothesis is that these traits are underpinned by genetic trade-offs among life-history traits: genetic variants that increase fertility, reproduction and growth might also reduce lifespan. We performed a systematic literature review and meta-analysis to summarize the evidence for the existence of genetic trade-offs between five key life-history traits: survival, growth rate, body size, maturation rate, and fertility. Counter to our predictions, we found an overall positive genetic correlation between survival and other life-history traits and no evidence for any genetic correlations between the non-survival life-history traits. This finding was generally consistent across pairs of life-history traits, sexes, life stages, lab vs. field studies, and narrow- vs. broad-sense correlation estimates. Our study highlights that genetic trade-offs may not be as common, or at least not as easily quantifiable, in animals as often assumed.

Understanding species distributions and predicting future range shifts requires considering all relevant abiotic factors and biotic interactions. Resource competition has received the most attention, but reproductive interference is another widespread biotic interaction that could influence species ranges. Rubyspot damselflies (Hetaerina spp.) exhibit a biogeographic pattern consistent with the hypothesis that reproductive interference has limited range expansion. Here, we use ecological niche models to evaluate whether this pattern could have instead been caused by niche differentiation. We found evidence for climatic niche differentiation, but the species that encounters the least reproductive interference has one of the narrowest and most peripheral niches. These findings strengthen the case that reproductive interference has limited range expansion and also provide a counterexample to the idea that release from negative species interactions triggers niche expansion. We propose that release from reproductive interference enables species to expand in range while specializing on the habitats most suitable for breeding.

Infertility is a condition where a male or female is unable to achieve pregnancy through at least 1 year of regular, unprotected sexual intercourse. There are several known causes and risk factors associated with infertility. The gut microbiota is a complex community of trillions of microorganisms living in the gut. Due to modern lifestyle changes, such as dietary habits, physical inactivity, and increasing antibiotic use, the diversity and composition of these microbes may change in a detrimental manner. Dysbiosis or an imbalance of the gut microbiota compared to a normal composition can lead to various abnormalities, such as obesity, Alzheimer's, metabolic disorders, and infertility. This review will cover the factors influencing gut microbiota composition, the mechanisms by which gut microbiota contributes to infertility in men and women, the effects of gut microbiota on problems that may arise during pregnancy, and therapeutic methods for diseases caused by dysbiosis of the gut microbiota. [ABSTRACT FROM AUTHOR]

The hypothalamus is the coordination center of the sheep (Ovis aries) endocrine system and plays an important role in the reproductive processes of sheep. However, the specific mechanism by which the hypothalamus affects sheep reproductive performance remains unclear. In this study, the hypothalamus tissues of high-reproduction small-tailed Han sheep and low-reproduction Wadi sheep were collected, and full-length transcriptome sequencing by Oxford Nanopore Technologies (ONT) was performed to explore the key functional genes associated with sheep fecundity. The differentially expressed genes (DEGs) were screened and enriched using DESeq2 software through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Approximately 41.75 million clean reads were obtained from the hypothalamus tissues of high- and low-reproduction sheep, after quality control, 32,194,872 high-quality full-length sequences and 2,114 DEGs were obtained, including 1,247 upregulated genes and 867 downregulated genes (P adjust < 0.05, |log2FC|>1). Some DEGs were enriched in oocyte meiosis, progesterone-mediated oocyte maturation, estrogen signaling pathway, GnRH signaling pathway and other development-related signaling pathways. The constructed protein-protein interaction (PPI) networks identified the reproduction-related genes, such as GSK3B, PPP2R1B, and PPP2CB. The results of this study will enrich and supplement the genomic information available for small-tailed Han sheep and Wadi sheep, as well as expand the understanding of the molecular mechanisms underlying the regulation of animal reproduction by the hypothalamus, and they also provided reference data for further investigations on the mechanism of high reproduction in sheep. [ABSTRACT FROM AUTHOR]

Thermal bleaching, or the loss of symbiotic algae that provide most energetic resources for the coral host, is an increasing threat to reefs worldwide and is projected to worsen with climate change. While bleaching is a well-recognized threat, the impact on the process of reproduction in bleaching survivors is not well resolved, despite being central to coral resilience. Montipora capitata can survive bleaching while completing a full gametogenic cycle, offering an ideal system to study gametogenic resilience and physiological tradeoffs. We experimentally bleached fragments of M. capitata colonies and followed their gametogenesis and physiological responses for 10 months (six time points). All bleached colonies produced gametes at the same time as controls, suggesting that reproductive processes were energetically prioritized. However, proteomic analysis revealed tradeoffs and delays in activating key physiological processes earlier in gametogenesis in areas such as skeletal growth and reproductive hormone synthesis. Tradeoffs during the gametogenic cycle, likely a direct response to thermal bleaching, resulted in smaller oocytes from bleached colonies, potentially indicating decreased transfer of parental resources to gametes. While gametogenesis is likely to continue in this species, it is unknown how the fecundity, synchrony of spawning, viability and success of future offspring may be impacted by future bleaching events. [ABSTRACT FROM AUTHOR]

ABSTRACT Hormones mediate life‐history trade‐offs. In female mammals, such trade‐offs have been studied predominantly in the contexts of oestrogen, progesterone and prolactin. We evaluate the hypothesis that prenatal and postnatal testosterone levels structure and regulate trade‐offs in females involving components of reproduction and survival. This hypothesis is predicated on the observation that testosterone confers competition‐related and survival‐related benefits, but also reproduction‐related costs, to female mammals. The hypothesis is supported by field and laboratory data from diverse non‐human animals, and data from healthy women. Most broadly, relatively low testosterone level in females has been associated with earlier, faster and higher offspring production, greater attractiveness to males, and reduced dominance or competitiveness, whereas higher testosterone level is associated with delayed and reduced reproduction but increased dominance, status, aggression, and resource accrual. The magnitude of testosterone‐mediated trade‐offs is expected to depend upon the strength of female–female competition, which represents some function of species‐specific ecology, behaviour and mating system. Testosterone‐associated trade‐offs have, until now, been virtually ignored in studies of female life history, reproductive physiology, evolutionary endocrinology, and female‐limited disease, probably due to researcher biases towards conceptualizing androgens as hormones with effects mainly restricted to males. [ABSTRACT FROM AUTHOR]

The Jun N‐terminal kinase (JNK) signalling pathway has a key role in tissue remodelling during insect metamorphosis by regulating programmed cell death. However, multiple members of the JNK pathway in Lepidoptera remain uncharacterized. In this study, two key genes of the JNK pathway, BmJun and BmFos, were cloned from the silkworm Bombyx mori, a lepidopteran model insect, and their effects on reproductive development were investigated. BmJun and BmFos encode 239 and 380 amino acids, respectively. Both proteins have typical basic leucine zipper domains and form a BmJUN‐BmFOS dimer activator protein to exert transcriptional regulation. During the wandering stage of silkworm development, interference in BmJun expression had no effect on pupation, whereas B. mori vitellogenin (BmVg) expression, which is essential for egg development, was suppressed in the fat body and egg laying was significantly reduced. Additionally, numerous eggs appeared shrivelled and deformed, suggesting that they were nutritionally stunted. Inhibition of the JNK pathway caused abnormal pupal metamorphosis, an increase in shrivelled, unfertilized eggs, a decrease in fat body synthesis, and accumulation of BmVg in the ovaries of female B. mori. The results indicated that BmJUN and BmFOS can form an AP‐1 dimer. Interfering with BmJun or inhibiting the phosphorylation of BmJUN leads to a reduction in the synthesis of BmVg in the fat body and its accumulation in the ovaries, thereby affecting the quality and production of the progeny eggs. These findings suggest that regulating Jun in the JNK pathway could be a potential way to inhibit female reproduction in Lepidoptera. [ABSTRACT FROM AUTHOR]

The plastic nutritional foundations of growth and reproduction are crucial in mediating animal (insect) life histories but remain largely unexplored. Here, we investigate how the nutritional quality of dung during larval feeding affects subsequent (adult) life history traits of a coexisting guild of four closely related European sepsid dung fly species: Sepsis cynipsea (L.), Sepsis fulgens (Meigen), Sepsis punctum (Fabricius), and Sepsis thoracica (Robineau‐Desvoidy) (all Diptera: Sepsidae). Larvae were raised in standard cow dung, protein‐rich (yeast‐supplemented) dung, microbe‐depleted (autoclaved) dung, and in a combined treatment of autoclaved dung with yeast enrichment. Responses of egg‐to‐adult survival, total development time, final adult body size, and female reproductive potential in terms of age at first reproduction and offspring number were assessed. Overall survival was lower in autoclaved dung, but also tended to be reduced rather than enhanced by potentially artificial microbial additives such as supplemental yeast, which apparently cannot be metabolized effortlessly by the fly larvae. The only trait positively affected was adult body size, for which we observed an increase in three of four species when larvae were raised in yeast‐supplemented dung. Flies emerged smaller when reared in autoclaved dung, and the addition of yeast to autoclaved dung partly compensated the negative effect of autoclaving to result in a body size similar to control dung. Our results thus indicate that larval growth is likely reduced by autoclaving‐induced killing of nutritional microorganisms in the dung, which however may recolonize. Whereas for some model insects nutrition is well‐understood, more research is necessary to unravel the diverse effects of natural and artificial stressors on the nutrition of non‐model insects, such as these dung‐decomposing flies providing important ecosystem services in human‐mediated grasslands. [ABSTRACT FROM AUTHOR]

Common carp, Cyprinus carpio, is a global invasive species illegally introduced into the Groenvlei system, South Africa, in the 1990s for recreational angling. To manage this population effectively, basic information is needed on its biology including growth and reproduction. This study examined the growth trends of C. carpio using otolith growth zone deposition rates which were validated using a chemical mark–recapture experiment (n = 16). From a total of 140 C. carpio, length-at-age was best described using the Von Bertalanffy growth model for males and females. The average lengths-at-50% maturity were estimated at 314 mm FL (males) and 262 mm FL (females). Compared with other South African C. carpio populations, the Groenvlei population is relatively fast growing and long lived, with the oldest female aged 20 years and the oldest male aged 18 years, likely facilitated by relatively favourable environmental conditions at Groenvlei. Data from this study provide a baseline at the commencement of C. carpio management interventions at Groenvlei and an opportunity to monitor changes in population dynamics facilitated by these efforts. [ABSTRACT FROM AUTHOR]

Corals and gorgonians play an important role as ecosystem engineers in many sublittoral communities worldwide. However, coral populations are being increasingly impacted by human activities. Active ecological restoration is a popular conservation tool nowadays, widely used to revert degradation in natural populations. Several studies have reported survival and growth success in actively restored corals, but few have studied the long‐term effect of transplantation on coral reproduction. We investigated survival and sexual reproduction of transplanted colonies of the Mediterranean gorgonian Eunicella singularis up to 3 years after being recovered from fishery bycatch and transplanted back to their habitat. Three different colony sizes were tested to explore possible effects of fragmentation on survival and reproduction. Results showed that transplanted colonies suffered a significant mortality during the first 4–5 months (30–35%), independently of fragment size. However, larger fragments showed high survival despite other disturbances, as a bloom of ephemerons filamentous algae occurred during the study. Results also showed that reproductive capacity is negatively affected by transplantation in female colonies. Conversely, male colonies were not directly affected by transplantation but showed an unexpectedly reduced number of spermary sacs both in transplanted and natural control colonies. The trade‐off between investment in reproduction and mortality of transplants highlights that large colony size could be the most appropriate for the active restoration of E. singularis. This study emphasizes the need to explore the long‐term viability and the reproduction investment in transplanted corals as indicators of restoration success, whose populations are sustained by sexual reproduction. [ABSTRACT FROM AUTHOR]

Background and Research Aims: The natural habitats of aphyllous vanillas in Madagascar have been extensively degraded by human activities. The implications of this degradation are complex given their intricate interactions with other organisms. This study highlights possible approaches to the conservation of aphyllous vanillas after examining the impact of forest degradation on phorophyte diversity, reproductive modes, and genetic diversity. Methods: We conducted comparative studies of conserved and degraded forests in two contrasting bioclimatic zones. We characterized the changes in horizontal and vertical forest structures and assessed the ecological importance of the tree species. We identified the preferred phorophytes of two aphyllous Vanilla species, Vanilla madagascariensis and Vanilla decaryana, and investigated their population genetics. Results and Conclusions: Our findings confirmed a declining trend in tree diversity, number of trees, and cover rate in degraded forests. Canopy openness is associated with an increase in the number of phorophytes and the asexual reproductive mode of Vanilla species. Dominant tree species were more likely to become phorophytes, and there was a positive correlation between phorophyte diameter and number of hosted vanilla individuals. Significant deviations from the Hardy-Weinberg equilibrium were observed in each population, particularly in the dry forest and degraded sites, compared with the conserved sites. Additionally, slight differentiation was observed between vanilla populations in conserved and degraded forests, with an alarming effective population size (Ne) that did not exceed 13 individuals. Conservation Implications: We recommend the introduction of new genotypes to promote genetic enrichment, the ban on logging potential phorophytes, and the inclusion of some degraded forests comprising Vanilla species in conservation. [ABSTRACT FROM AUTHOR]

The world is currently facing a biodiversity crisis and for many species, this is exacerbated by historic exploitation. Monitoring programs provide an integral tool to understand changes in abundance and the impact of threats informing conservation actions. However, measures of absolute abundance for management can be misleading, particularly when there is a biased sex ratio. Here we recommend focusing on the rate‐limiting cohort for management actions using the case of North Atlantic right whales. The North Atlantic right whale has a male‐biased sex ratio, with reproductively active females making up less than a fifth of the species. We highlight the importance of understanding and incorporating reproductive potential into management actions to provide species with the best chance of recovery. [ABSTRACT FROM AUTHOR]

Background: Embryonic genome activation (EGA) is a critical step in early embryonic development, as it marks the transition from relying on maternal factors to the initiation of transcription from embryo's own genome. The factors associated with EGA are not well understood and need further investigation. PRD-like (PRDL) homeodomain transcription factors (TFs) are considered to play crucial roles in this early event during development but these TFs have evolved differently, even within mammalian lineages. Different numbers of PRDL TFs have been predicted in bovine (Bos taurus); however, their divergent evolution requires species-specific confirmation and functional investigations. Results: In this study, we conducted molecular cloning of mRNAs for the PRDL TFs ARGFX, DUXA, LEUTX, NOBOX, TPRX1, TPRX2, and TPRX3 in bovine oocytes or in vitro fertilized (IVF) preimplantation embryos. Our results confirmed the expression of PRDL TF genes in early bovine development at the cDNA level and uncovered their structures. For each investigated PRDL TF gene, we isolated at least one homeodomain-encoding cDNA fragment, indicative of DNA binding and thus potential role in transcriptional regulation in developing bovine embryos. Additionally, our cDNA cloning approach allowed us to reveal breed-related differences in bovine, as evidenced by the identification of a high number of single nucleotide variants (SNVs) across the PRDL class homeobox genes. Subsequently, we observed the prediction of the 9aa transactivation domain (9aaTAD) motif in the putative protein sequence of TPRX3 leading us to conduct functional analysis of this gene. We demonstrated that the TPRX3 overexpression in bovine fibroblast induces not only protein-coding genes but also short noncoding RNAs involved in splicing and RNA editing. We supported this finding by identifying a shared set of genes between our and published bovine early embryo development datasets. Conclusions: Providing full-length cDNA evidence for previously predicted homeobox genes that belong to PRDL class improves the annotation of the bovine genome. Updating the annotation with seven developmentally-important genes will enhance the accuracy of RNAseq analysis with datasets derived from bovine preimplantation embryos. In addition, the absence of TPRX3 in humans highlights the species-specific and TF-specific regulation of biological processes during early embryo development. [ABSTRACT FROM AUTHOR]

Background: The age of Danish women giving birth to their first child has risen throughout the last 50 years, and the number of women and men who are having their first child when they are at advanced maternal or paternal age is increasing worldwide. Postponing parenthood is not unique to Denmark, as the same pattern is seen especially in other European and Western countries. The aim of this study was in a social media setting to explore reflections on the timing of motherhood among Danish women of reproductive age who not yet had children. Method: This study was a qualitative study based on three online focus groups on Facebook. Twenty-six women of reproductive age discussed the timing of motherhood for three days in January 2020. Data were analyzed using Systematic Text Condensation. Results: Three main themes were identified: 'Life before parenthood', 'To plan for a child' and 'A life without children'. Several external and internal conditions influence whether and if so when women consider becoming mothers. Regarding the biological capacity for having children, women compare themselves with their female relatives and friends and colleagues regarding the social norms surrounding motherhood. Women with no children often experience either positive or negative pressure from family, friends, and colleagues regarding when to have children. Conclusion: Several internal and external considerations influence when and if women become mothers. Social surroundings such as family, friends, and colleagues have an impact on women's reproductive considerations in terms of pressure to have children in the future. Danish women tend to compare their reproductive capacity to their female relatives and compare the social norms surrounding motherhood to their female friends. Women in this study were positive towards discussing the timing of motherhood with other women of reproductive age on social media. Plain english summary: The age of women giving birth to their first child has risen throughout the last 50 years, and the number of Danish women and men having their first child when they are at advanced maternal or paternal is increasing. Postponing motherhood is not unique to Denmark, as the same pattern is seen especially in other European and Western countries. In this study, we explored the reflections on the timing of motherhood among Danish women of reproductive age who had not yet had children. Using a novel approach, we conducted three online focus groups on the social media platform Facebook. Twenty-six women aged 18–43 years without children, regardless of whether they wanted to have children in the future, were included. The study revealed several internal and external considerations influencing when and if women establish a family. Regarding their biological capacity for having children, women tend to compare themselves to their female relatives and their friends and colleagues regarding the social norms surrounding motherhood. Women with no children often experience pressure from family, friends, and colleagues about when to have children, which can be perceived as unfavorable while at the same time being experienced as motivating for planning future motherhood. Women in this study were positive towards discussing the timing of motherhood with other women of reproductive age on social media. [ABSTRACT FROM AUTHOR]

We chose the "natural laboratory" provided by high-altitude native ethnic Tibetan women who had completed childbearing to examine the hypothesis that multiple oxygen delivery traits were associated with lifetime reproductive success and had genomic associations. Four hundred seventeen (417) women aged 46 to 86 y residing at =3,500 m in Upper Mustang, Nepal, provided information on reproductive histories, sociocultural factors, physiological measurements, and DNA samples for this observational cohort study. Simultaneously assessing multiple traits identified combinations associated with lifetime reproductive success measured as the number of livebirths. Women with the most livebirths had distinctive hematological and cardiovascular traits. A hemoglobin concentration near the sample mode and a high percent of oxygen saturation of hemoglobin raised arterial oxygen concentration without risking elevated blood viscosity. We propose ongoing stabilizing selection on hemoglobin concentration because extreme values predicted fewer livebirths and directional selection favoring higher oxygen saturation because higher values had more predicted livebirths. EPAS1, an oxygen homeostasis locus with strong signals of positive natural selection and a high frequency of variants occurring only among populations indigenous to the Tibetan Plateau, associated with hemoglobin concentration. High blood flow into the lungs, wide left ventricles, and low hypoxic heart rate responses aided effective convective oxygen transport to tissues. Women with physiologies closer to unstressed, low altitude values had the highest lifetime reproductive success. This example of ethnic Tibetan women residing at high altitudes in Nepal links reproductive fitness with trait combinations increasing oxygen delivery under severe hypoxic stress and demonstrates ongoing natural selection. [ABSTRACT FROM AUTHOR]

Hipposideros spp. are insectivorous bats and karst cave dwellers. This study aimed to study the roosting ecology, reproduction, and population fluctuations of three species H. diadema, H. larvatus, and H. ater in Gunung Sewu Karst region, Indonesia. Age and reproductive status of individuals were identified and analyzed using a combination of forearm length (FA) and body mass grades (W). Multiple regression analysis was used to determine the correlation between population size, rainfall and population structure based on FA, reproductive status, and W. Crude birth rate (CBR) and general fertility rate (GFR) were used to determine the population’s birth rate and female fertility. The results showed that the population of the three Hipposideros species were quite stable over the year with a peak in January which classified them as monoestrous, with mating, pregnancy, and lactation occurring once a year with no delay between mating and pregnancy. Pregnancy lasted 8–12 weeks and lactation 4–5 weeks. The population structure of the three species tended to be stable over the year. The CBR and GFR values can be used for rapid assessment guidelines in an area. [ABSTRACT FROM AUTHOR]

1. Monitoring behavioural dynamics in complex animal environments, such as poultry breeding facilities, poses a challenge. Utilising technological approaches, such as accelerometers, offers a solution to assess long-term changes in reproductive activity at an individual bird level. Specifically, these sensors measure acceleration associated with the position and movements of the body over time. However, it is important to assess the most suitable method for attaching accelerometer tags to ensure they do not negatively impact behaviour and yield high-quality data.2. The potential of tri-axial accelerometer tags for assessing reproductive behaviour in Japanese quail was evaluated. Two attachment methods – a backpack (plastic platform with elastic bands near wing bases) and a patch (accelerometer on fabric glued to the synsacrum region) – were compared. Controls were handled similarly but without tags. Eighteen pairs of females were housed in pens and assessed immediately and 24 h after handling. After a week of habituation, a male from the same treatment group was introduced into each pen on d 8. The reproductive behaviour of the males was recorded using accelerometers and video recordings.3. The results showed that birds with patches were able to remove their conspecific’s accelerometer and displayed an increased initial immobility response compared to the control and backpack groups. The presence of accelerometer tags did not impact male/female reproductive interactions nor fear responses to a novel object. From accelerometer recordings, male reproductive behaviour was easily identified as high amplitude fluctuations in the three axial components of the acceleration vectors, which was reflected as large values of dynamic body acceleration (VeDBA).4. In conclusion, the use of backpacks with accelerometers is a useful strategy to address highly relevant and difficult to tackle behavioural topics such as the temporal dynamic of male reproductive behaviour within breeding groups. [ABSTRACT FROM AUTHOR]

At a length of 27 mm and greater, each subsequent varices of Pteropurpura macroptera (Deshayes, 1838) represents one year of growth. Among snails still growing, a single varix is added most frequently during August or September. Reproduction occurs from April to early July. The growth rate in situ and in culture were similar. Egg capsules, embryos and the average number of each per cluster are provided. The diet in culture was exclusively bivalves. [ABSTRACT FROM AUTHOR]

Background: Voluntary waiting period (VWP), housing systems and the presence of a veterinarian are effective factors on reproductive performance of a dairy farm. Objectives: This study aimed to investigate the management practices associated with VWP and its effects on reproductive performance. Methods: A total of 136,943 records of 21,756 cows that calved between 1990 and 2013 were used. A questionnaire was also conducted with the farms involved to determine if they adjust the timing of insemination based on the body condition score (BCS) of the cows, postpartum health situation (PPHS) or environmental factors such as heat stress and season. The impact of changing the VWP selectively, the presence of a veterinarian and the type of barn on reproductive outcomes like days open (DO), number of services per conception (NSPC) and days to first service (DFS) was examined using a linear mixed model. This model considered animals and herds as random factors and management practices as fixed factors in the analysis. Results: Among herds that reported altering the VWP based on heat stress, DFS significantly increased (61.68 ± 0.68 vs. 58.4 ± 0.83) while DO (119.70 ± 1.86 vs. 126.9 ± 2.29) and NSPC (1.98 ± 0.04 vs. 2.48 ± 0.05) reduced compared to herds that did not alter the VWP. Our results showed that farms with a full‐time veterinarian had a better reproductive performance than those with part‐time care (p < 0.05). Housing system was significantly associated with fertility traits, so that cows in free‐stall barns were more fertile than those kept in open‐shed barns. Conclusions: The obtained results from this study indicated that management decisions to selectively altering the VWP led to difference in DFS and improved reproductive performance. [ABSTRACT FROM AUTHOR]

Climate change is increasing mean temperatures, and intensifying heatwaves. Natural populations may respond to stress through shorter-term acclimation via plasticity and/or longer-term inter-generational evolution. However, if the pace and/or extent of thermal change is too great, local extinctions occur; one potential cause in ectotherms is identified to be the heat-liability of male reproductive biology. Recent data from several species, including the beetle Tribolium castaneum , confirmed that male reproductive biology is vulnerable to heatwaves, which may constrain populations. However, such reproductive-damage may be overestimated, if there is potential to adapt to elevated mean temperatures associated with climate change via evolution and/or acclimation. Here, we tested this to evaluate whether pre-exposures could improve heatwave tolerance (adaptation or acclimation), by experimentally evolving Tribolium castaneum populations to divergent thermal regimes (30 °C vs. 38 °C). Findings across assays revealed that relative to 30 °C-regime males, males from the 38 °C regime, maintained constantly at 8 °C warmer for 25 generations, displayed an increase; (i) in post heatwave (42 °C) reproductive fitness by 55%, (ii) survival by 33%, and (iii) 32% larger testes volumes. Unexpectedly, in the acclimation assay, warm-adapted males' post-heatwave survival and reproduction were best if they experienced cool developmental acclimation beforehand, suggesting a cost to adapting to 38 °C. These results help progress knowledge of the potential for survival and reproduction to adapt to climate change; trait specific adaptation to divergent thermal regimes can occur over relatively few generations, but this capacity depended on the interaction of evolutionary and thermal acclimatory processes. [ABSTRACT FROM AUTHOR]

This essay is part of a Thematic Collection of Science, Technology & Human Values on the work of Adele E. Clarke (1945–2024). [ABSTRACT FROM AUTHOR]

Demographic parameters are key to understanding population dynamics. Here, we analyse the survival and reproduction of the German wolf population in the 20 years following recolonization. Specifically, we analysed the effects of environmental, ecological and individual characteristics on 1) survival probability of the population; 2) annual survival rates of age classes; 3) reproduction probability; and 4) reproductive output, measured as the number of detected pups/juveniles. Using Cox proportional hazards model, we estimated a median survival time of circa three years for wolves. Annual survival probabilities were found to be 0.75 for juveniles, 0.75 for subadults and 0.88 for adults. Survival was lower for juveniles in winter and for subadult males in summer, probably associated with dispersal events. Low habitat suitability was clearly associated with lower survival in juveniles and subadults, but not in adults. Local territory density was related to increased survival. Reproduction probability within a territory was 0.88, but explanatory variables had no effect. Reproductive output was four pups/juveniles on average, positively related to habitat suitability and female experience, but negatively related to territory density. Survival values were very high for the species when compared to other regions. We hypothesize that carrying capacity has not been reached in the study area, thus the survival may decrease in the future if the landscape becomes saturated. Furthermore, our results highlight a spatial pattern in survival and reproduction, with area of better habitat suitability favouring faster population growth. Thus, targeting conservation measures to low habitat suitability areas will have a strong population effect on the short term by boosting survival and reproduction of the individuals, while long‐term viability should be carefully planned with high suitability areas in mind, as those contain the territories with higher survival and reproduction potential. [ABSTRACT FROM AUTHOR]

Simvastatin (SIM), a commonly prescribed drug for lowering serum-lipid, has been detected in many aquatic environments. Exposure to high concentrations of SIM in rats and aquatic organisms resulted in toxicity to hepatocytes and negative effects on development. However, there is a paucity of studies on the effects of long-term exposure to low concentrations of SIM on aquaculture species. This study aimed to analyze the effects of environmentally relevant concentrations (0.1 µg/L and 1 µg/L) of SIM exposure for two months on developing Mozambique tilapias. Surprisingly, the growth of male tilapias was enhanced after a 2-month SIM exposure. The analysis of testis histology revealed that after the SIM exposure, the development of the testis was delayed, and sperm production was reduced. Sequencing of testis transcriptomes showed that the exposure to SIM altered the expression of many genes related to the development of testes and spermatogenesis. These data suggest that a 2-month exposure to environmentally relevant concentrations of increases the growth of male tilapias by inhibiting sexual development of males. [ABSTRACT FROM AUTHOR]