Female Reproduction Research Articles

1α,25(OH)2D3 improves 17β-estradiol secretion and potentially alleviates endoplasmic reticulum stress in muskrat granulosa cells.

Vitamin D3 plays an essential regulatory role in female reproduction. However, the studies on the correlation between vitamin D3 and muskrat reproduction are limited. This study aims to determine the role of the active form of vitamin D3, 1α,25-dihydroxytamin D3 [1α,25(OH)2D3], on muskrat ovarian granulosa cells (MGCs). The results showed that vitamin D receptor (VDR) was prominently localized in MGCs and 1α,25(OH)2D3 supplementation increased VDR signaling of MGCs. Meanwhile, 10nM of 1α,25(OH)2D3 stimulated MGCs to secrete 17β-estradiol and enhanced the mRNA expression of steroidogenic enzymes. 1α,25(OH)2D3 also remarkably down-regulated MGCs endoplasmic reticulum stress according to the expression of GRP78, p-PERK, ATF4, and CHOP. In addition, RNA-seq analysis revealed that 10nM of 1α,25(OH)2D3 activated the PI3K/Akt/mTOR and TNF pathways that contributed to the inhibition of MGCs apoptosis. Taken together, these findings suggest that 1α,25(OH)2D3-induced VDR signaling improves 17β-estradiol secretion and potentially alleviate MGCs endoplasmic reticulum stress through the PERK-ATF4-CHOP pathway.

Reduced Water Availability to Mothers and Embryos Has Little Effect on Offspring Phenotypes in an Invasive Lizard.

Water availability has critical impacts on numerous physiological functions in all organisms and can have different effects across life stages. For example, water available to reproductive females can influence offspring production, and has the potential to influence how early-stage offspring (e.g., embryos) respond to moisture in their developmental environment. In this study, we use the brown anole lizard (Anolis sagrei) to examine the effects of water availability on reproductive investment. We tested the hypothesis that water available to mothers influences embryonic development under different levels of moisture in their incubation environment. We demonstrate that a substantial reduction in water availability to mothers (~70% reduction) has no observable effect on fecundity, egg size, or egg hydration. We also provide evidence that our water restriction to mothers does not influence how embryos respond to moisture conditions during egg incubation. However, moisture in the egg incubation substrate positively affected egg water uptake, egg hatching success and hatchling body size (but not hatchling hydration). Overall, our study shows that reproduction in adult female A. sagrei is robust to variation in water availability, but survival during early life stages is sensitive to this variable. Thus, the effect of water availability on different fitness components varies between life stages.

The effects of parasitism on sex allocation of a hermaphroditic acorn barnacle.

Sex allocation theory predicts the adaptive allocation of resources to male versus female reproduction in simultaneous hermaphrodites in response to individual characteristics or environmental factors. Because parasites uptake resources from their hosts, their presence could affect the sex allocation of the hosts. We investigated the effects of infestation status and infestation intensity by the rhizocephalan barnacle Boschmaella japonica on reproduction, including sex allocation, of the host intertidal barnacle Chthamalus challengeri. Feeding activity was also examined as a factor related to resource intake. Both male and female reproductive investment decreased with increasing parasite infestation, and the sex allocation of large infested hosts was more male-biased than that of large uninfested hosts. Moreover, in contrast to the model prediction that male investment does not change under resource limitation, male investment decreased in infested hosts whose resources were taken by parasites. This reduction in male investment could be explained by changes in mating group size, since infested hosts have shorter penises and consequently are able to access fewer mating partners.

Effects, Mechanisms of Action and Application of Vitex agnus-castus for Improvement of Health and Female Reproduction.

This narrative review describes the provenance and chemical composition of Vitex agnus-castus, as well as the currently available knowledge concerning its action. To search the related articles, Cochrane Library, PubMed, Web of Science, SCOPUS databases between the years 1995 and 2024, and the keywords "Vitex," "review," "fertility," "ovarian" and "mechanisms" were used in various combinations. The data listed in this review demonstrate that Vitex agnus-castus and its constituents (isoflavones and essential oils) affect a number of physiological actions via multiple extra- and intracellular mechanisms of action. This makes it an efficient drug in both traditional and modern medicine for the treatment of a number of illnesses. The main described target of Vitex agnus-castus is female reproduction. It can up-regulate ovarian cycle and fecundity via a wide spectrum of mediators from hypothalamic, pituitary and ovarian hormones up to intracellular regulators of proliferation, apoptosis, oxidation and dopamine receptors. These effects determine its potential action as protector and medicine against a number of female reproductive disorders and reproduction-related health problems including menstrual disorders, premenstrual syndrome, cyclic mastalgia, corpus luteum insufficiency, abnormal production of progesterone and prolactin, low fertility and infertility, hyperandrogenism and polycystic ovarian syndrome. Nevertheless, further high-quality studies are needed to firmly establish the biological and clinical efficacy of this plant.

Inter-organelle communication dynamically orchestrates juvenile hormone biosynthesis and female reproduction

Inter-organelle communication dynamically orchestrates juvenile hormone biosynthesis and female reproduction

Factors associated with the discontinuation of modern contraceptive methods among lactating women in nine West African high-fertility countries: findings of the most recent demographic and health surveys

IntroductionContraception discontinuation is a concern, especially if it occurs in breastfeeding women, thereby exposing them to a high risk of close and unwanted pregnancies. Our study aimed to measure the prevalence and identify the individual and community-level factors associated with the discontinuation of modern contraceptives among breastfeeding women.MethodsThis was a secondary analysis of retrospective data of the most recent Demographic and Health Surveys (DHS) data from nine high-fertility rate countries, conducted mostly between 2018–2021. We reported weighted frequencies of modern contraceptives discontinuation (binary variable, coded 1 and 0). The independent variables included individual-level variables, including sociodemographic characteristics, female reproduction and family planning history, the women and their households exposure to media, and community-level ones such as place of residence (urban and rural) and country. Multilevel-modified Poisson regression was used to identify associated factors at the 5% threshold.ResultsThe overall prevalence of modern contraceptives discontinuation was 13.1% among 5,599 lactating mothers, with wide variations between countries (prevalence ranging from 8.2% in Sierra Leone to 33.6% in Guinea). Women were more likely to discontinue contraception if they were the head of the household (adjusted prevalence ratio (aPR) = 1.71; 95% CI [1.17–2.50]; p = 0.006). In addition, compared to implant users, women using pills (aPR = 3.06; 95% CI [2.24–4.16]; p < 0.001), those using injectables (aPR = 2.80; 95% CI [2.16–3.62]; p < 0.001), and women whose partners used condoms (aPR = 2.30; 95% CI [1.47–3.59]; p < 0.001) were more likely to discontinue contraception. Moreover, women who were not sexually active (aPR = 2.11; 95% CI [1.75–2.54]; p < 0.001) and those who wanted children within two subsequent years (aPR = 1.84; 95% CI [1.36–2.48]; p < 0.001) were more likely to discontinue contraception. Finally, method discontinuation varied by country, with women in Gambia, Guinea, Mauritania, and Mali more likely to discontinue a modern contraceptive method than those living in Burkina Faso.ConclusionTo improve the retention of women using contraceptive, high-fertility rate countries need to focus on contraceptive education, communication about side effects, dissemination of family planning messages through the media, and regular monitoring of women taking contraceptives.

Ustiloxin A impairs oocyte quality by disrupting organelles function.

Oocyte quality is pivotal for fertilization and early embryonic development. Ustiloxin A (UA), is an emerging mycotoxin that has been frequently detected in rice and paddy. Because UA has been reported to be phytotoxic and cytotoxic, it poses a potential hazard to human and animal health. However, the effects of UA on oocyte maturation remain unknown. Here, we investigated the effects of acute UA exposure on mouse oocyte maturation. First, UA exposure inhibited oocyte maturation in a concentration-dependent manner and induced meiotic arrest by disrupting spindle assembly and reducing actin density. Moreover, mitochondrial function was substantially disrupted in oocytes upon UA exposure. Aberrant mitochondrial distribution, substantial downregulation of mitochondrial dynamics-associated genes Mfn1, Mfn2 and Fis1, decreased membrane potential and TOM20 expression were observed in UA-exposed oocytes; these effects further led to oxidative stress and DNA damage. Furthermore, UA induced ER and Golgi dysfunction and triggered ER stress by increasing GRP78 expression, which ultimately resulted in autophagy and early apoptosis in oocytes. Therefore, these results demonstrate that UA impairs oocyte quality by disrupting organelles function, providing new insight into the influence of UA on female reproduction in mammals.

Genetic parameters and genome-wide association studies including the X chromosome for various reproduction and semen quality traits in Nellore cattle

BackgroundThe profitability of the beef industry is directly influenced by the fertility rate and reproductive performance of both males and females, which can be improved through selective breeding. When performing genomic analyses, genetic markers located on the X chromosome have been commonly ignored despite the X chromosome being one of the largest chromosomes in the cattle genome. Therefore, the primary objectives of this study were to: (1) estimate variance components and genetic parameters for eighteen male and five female fertility and reproductive traits in Nellore cattle including X chromosome markers in the analyses; and (2) perform genome-wide association studies and functional genomic analyses to better understand the genetic background of male and female fertility and reproductive performance traits in Nellore cattle.ResultsThe percentage of the total direct heritability (h2total) explained by the X chromosome markers (h2x) ranged from 3 to 32% (average: 16.4%) and from 9 to 67% (average: 25.61%) for female reproductive performance and male fertility traits, respectively. Among the traits related to breeding soundness evaluation, the overall bull and semen evaluation and semen quality traits accounted for the highest proportion of h2x relative to h2total with an average of 39.5% and 38.75%, respectively. The total number of significant genomic markers per trait ranged from 7 (seminal vesicle width) to 43 (total major defects). The number of significant markers located on the X chromosome ranged from zero to five. A total of 683, 252, 694, 382, 61, and 77 genes overlapped with the genomic regions identified for traits related to female reproductive performance, semen quality, semen morphology, semen defects, overall bulls’ fertility evaluation, and overall semen evaluation traits, respectively. The key candidate genes located on the X chromosome are PRR32, STK26, TMSB4X, TLR7, PRPS2, SMS, SMARCA1, UTP14A, and BCORL1. The main gene ontology terms identified are “Oocyte Meiosis”, “Progesterone Mediated Oocyte Maturation”, “Thermogenesis”, “Sperm Flagellum”, and “Innate Immune Response”.ConclusionsOur findings indicate the key role of genes located on the X chromosome on the phenotypic variability of male and female reproduction and fertility traits in Nellore cattle. Breeding programs aiming to improve these traits should consider adding the information from X chromosome markers in their genomic analyses.

The ecdysone-induced bZIP transcription factor MafB establishes a positive feedback loop to enhance vitellogenesis and reproduction in the Aedes aegypti mosquito

Female mosquitoes require a vertebrate blood meal to activate reproduction, transmitting numerous devastating human diseases. Vitellogenesis is a central event of female reproduction that involves the massive production of vitellogenin (Vg) in the fat body and the maturation of ovaries. This process is controlled by the steroid hormone 20-hydroxyecdysone (20E); however, its molecular regulatory basis remains not completely understood. We found that the expression of Aedes aegypti muscle aponeurosis fibromatosis B (AaMafB), coding for a basic leucine zipper (bZIP) transcription factor, was significantly up-regulated after a blood meal. The 20E-bound ecdysone receptor-ultraspiracle heterodimer directly targeted the ecdysone response element in the promoter of AaMafB, activating its transcription. Coimmunoprecipitation assays illustrated the interaction between AaMafB and Cap "n" collar C (AaCncC), another bZIP transcription factor. RNA interference-mediated depletion of AaMafB or AaCncC led to impaired ovarian growth, decreased expression of AaVg and Halloween genes, and reduced 20E levels. The AaMafB-AaCncC heterodimer directly activated the transcription of AaVg and AaShade by targeting the antioxidant response element in their promoters. Together, our results indicate that AaMafB functions as an early 20E response gene, the product of which heterodimerizes with AaCncC to maintain high 20E levels and facilitates activation of AaVg in mosquitoes after a blood meal.

The Balbiani body is formed by microtubule-controlled molecular condensation of Buc in early oogenesis.

Vertebrate oocyte polarity has been observed for two centuries and is essential for embryonic axis formation and germline specification, yet its underlying mechanisms remain unknown. In oocyte polarization, critical RNA-protein (RNP) granules delivered to the oocyte's vegetal pole are stored by the Balbiani body (Bb), a membraneless organelle conserved across species from insects to humans. However, the mechanisms of Bb formation are still unclear. Here, we elucidate mechanisms of Bb formation in zebrafish through developmental biomolecular condensation. Using super-resolution microscopy, live imaging, biochemical, and genetic analyses invivo, we demonstrate that Bb formation is driven by molecular condensation through phase separation of the essential intrinsically disordered protein Bucky ball (Buc). Live imaging, molecular analyses, and fluorescence recovery after photobleaching (FRAP) experiments invivo reveal Buc-dependent changes in the Bb condensate's dynamics and apparent material properties, transitioning from liquid-like condensates to a solid-like stable compartment. Furthermore, we identify a multistep regulation by microtubules that controls Bb condensation: first through dynein-mediated trafficking of early condensing Buc granules, then by scaffolding condensed granules, likely through molecular crowding, and finally by caging the mature Bb to prevent overgrowth and maintain shape. These regulatory steps ensure the formation of a single intact Bb, which is considered essential for oocyte polarization and embryonic development. Our work offers insight into the long-standing question of the origins of embryonic polarity in non-mammalian vertebrates, supports a paradigm of cellular control over molecular condensation by microtubules, and highlights biomolecular condensation as a key process in female reproduction.

Mycotoxin toxicity and its alleviation strategy on female mammalian reproduction and fertility.

Mycotoxin, a secondary metabolite of fungus, found worldwide and concerning in crops and food, causing multiple acute and chronic toxicities. Its toxic profile includes hepatotoxicity, carcinogenicity, teratogenicity, estrogenicity, immunotoxicity, and neurotoxicity, leading to deleterious impact on human and animal health. Emerging evidence suggests that it adversely affects perinatal health, progeny by its ability to cross placental barriers. Due to its wide occurrence and potential toxicity on reproductive health, it is essential to understand the mechanisms of mycotoxin-related reproductive toxicity. This review summarizes the toxicities and mechanisms of mycotoxin on maternal and offspring reproduction among mammalian species. Approaches for effective mycotoxin alleviation are also discussed, providing strategies against mycotoxin contamination. The profound mycotoxin toxicities in female mammalian reproduction affect follicle assembly, embryo development, and fetus growth, thereby decreasing offspring fertility. Factors from endocrine system such as hypothalamic-pituitary-gonadal axis and gut-ovarian axis, placenta ABC transporters, organelle and cytoskeleton dynamics, cell cycle control, genomic stability, and redox homeostasis are found to be closely related to mycotoxin toxicities. Approaches from physical, chemical, biological, and supplementation of natural antioxidants are discussed for the mycotoxin elimination, while their applications are not widespread. Available ways for mycotoxin and its toxicities alleviation need further study. Since a species-, time-, and dose-specific response might exist in mycotoxin toxicities, more consideration should be given to the protocols for mycotoxin toxicity studies, such as experimental animal models, exposure duration, and dosage. Specific mechanism for mycotoxin, especially form a molecular biology perspective, could be investigated with multi-omics technologies and advanced imaging techniques. Mass spectrometry with algorithms may provide more accurate exposure assessments, and be further helpful to identify the high-risk individuals in the future.

Copulation interruption decreases female reproductive success in a false widow spider

Copulation is essential for transferring sperm from males to females in most animals. During copulation, males and females are often static and thus prone to predation or other threats. Its duration should therefore be reduced to minimize costs but sufficient to ensure the fertilization of eggs. Here, we investigated reproductive behavior and success in the false widow spider, Steatoda grossa (Araneae: Theridiidae), when copulation was interrupted after 1, 3, 5, 10, or 20 min or was not experimentally interrupted (control). Copulation duration in this study is defined as the total duration of insertions of male pedipalps into a female’s copulatory openings. In S. grossa, uninterrupted copulations typically last 40 to 60 min. We found that within the first 5 min, copulation interruption negatively affected reproductive success (i.e., number of egg sacs, their total mass, and number of spiderlings), and delayed production of the first egg sac within the first 10 min (in some extreme instances by over 200 days). However, when copulation duration was 10 min or longer, reproductive outcome was unaffected. In the 1-min treatment, the number of egg sacs and their mass varied greatly, which indicates considerable variation among males with respect to the speed and efficiency of sperm transfer. We discuss the costs and benefits of extended copulation duration on female reproduction and on male and female fitness.

Comparative biology of chlorantraniliprole selected and unselected Chrysoperla carnea (Stephens) populations: Stability of resistance, inheritance mode, and realized heritability.

Insecticide resistance in natural enemies can be used as a positive trait in integrated pest management programs by increasing the compatibility of two important tools; biological and chemical control. In this experiment, a field population of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) was selected with chlorantraniliprole for 35 generations (Chlor-Sel) developed a 100.32-fold resistance level compared to an unselected population (Unsel). The dominance values of resistance for reciprocal crosses confirmed incomplete dominance inheritance of chlorantraniliprole resistance. The results on projected rate of chlorantraniliprole resistance showed that at 10% to 90% survival in each selection and a realized heritability value of 0.19, the Chlor-Sel will require only 3 to 26 generations (Slope=1.15) to increase a 10-fold level of resistance. The results of the age-stage life table experiment showed that fecundity, oviposition days, male and female longevity, net reproductive rate (Ro), and gross reproductive rate (GRR) of both crosses were significantly increased compared to their parents. The fecundity of reproductive females, male and female longevity, Ro, generation time (T), and GRR of Chlor-Sel were not significantly different than that of the Unsel strain of C. carnea. In conclusion, chlorantraniliprole resistance in C. carnea has an autosomal, polygenic, and incompletely dominant inheritance mode and C. carnea has potential to develop resistance that leads to fitness benefits. This information will help in management of insect pests by deploying resistant strains with selected insecticides and conservation of these natural enemies in fields with sustaining resistance genes.

In Vitro Toxicity of a DEHP and Cadmium Mixture on Sheep Cumulus-Oocyte Complexes.

Di-(2-ethylhexyl) phthalate (DEHP) and Cadmium (Cd) affect female reproduction. To date, toxicological research has focused on the effects of individual contaminants, whereas living beings are exposed to mixtures. This study analyzed the effects of a DEHP/Cd mixture on nuclear and cytoplasmic maturation of sheep cumulus-oocyte complexes (COCs) compared with single compounds. COCs recovered from slaughterhouses-derived sheep ovaries were in vitro exposed to 0.5 μM DEHP, 0.1 μM Cd, or DEHP/Cd mixture at the same concentrations during 24 h of in vitro maturation (IVM). After IVM, oocyte nuclear chromatin configuration was evaluated, and bioenergetic/oxidative parameters were assessed on expanded cumulus cells (CCs) and matured oocytes (chi-square test and one-way ANOVA; p < 0.05). Under examined conditions, oocyte nuclear maturation was never impaired. However, COC bioenergetics was affected with stronger effects for the mixture than single compounds. Indeed, the percentages of matured oocytes with healthy mitochondrial distribution patterns were reduced (p < 0.001 and p < 0.05 for mixture and single compounds, respectively). Oocyte mitochondrial membrane potential, intracellular ROS levels, and mitochondria/ROS co-localization were reduced, with the same significance level, in all contaminated conditions. CCs displayed increased ROS levels only upon mixture exposure (p < 0.001). In conclusion, in vitro exposure to the DEHP/Cd mixture affected COC quality in the sheep to a greater extent than separate compounds.

Effects of home range size and burrow fidelity on survival and reproduction in eastern chipmunks (Tamias striatus) across different environmental contexts.

Survival and reproductive success are greatly influenced by how an individual uses its surrounding environment, which can differ across spatial scales. To better understand the habitat-fitness relationships of animals, it is essential to study space use at multiple spatial scales. Here, we used 13years of capture-mark-recapture and burrow location data to investigate how two different aspects of space use influence the survival and female reproduction in a wild population of eastern chipmunks (Tamias striatus) in southern Québec. We quantified home range size and site fidelity in a population experiencing massive inter-annual variations in food availability due to the masting of American beech trees (Fagus grandifolia). We found that site fidelity tended to increase the probability of reproduction but that this effect was strongly dependent on the context of beech seed production: probability of reproduction was higher for females that were faithful from a mast year to the following non-mast year. Site fidelity was not related to survival and we found no significant effect of home range size on either fitness trait. Our results indicate that, in our study system, different aspects of space use affect fitness traits in different ways. We emphasize the importance of examining multiple spatial scales in related analyses.

Expression and functional analysis of adipokinetic hormone reveal its different roles in larval development and female fecundity in Panonychus citri (McGregor) (Acari: Tetranychidae).

Adipokinetic hormone (AKH), a crucial neuropeptide, participates in the important physiological processes by specially binding to its receptor to activate the AKH signalling pathway. AKH regulates energy metabolism. However, it remains unknown whether AKH affects larval development and adult reproduction by influencing energy metabolism. In the present study, the AKH was identified from Panonychus citri and contained the conserved functional domain 'Q-[LIV]-[NT]-F-[ST]-X (2)-W' that characterises the AKH family. The relative expression levels of PcAKH revealed different patterns of AKH expression at different developmental stages of P. citri. Feeding of double-standard RNA against PcAKH induced decreased fecundity and reduced survival, which was accompanied by the down-regulation of vitellogenin gene expression. In addition, after silencing the PcAKH, lipid metabolism and carbohydrate homeostasis were disrupted, manifested by increased body width and weight, and fasting phenomenon. Further investigation found that compared with the control, physiological changes in trehalose and triglyceride contents were accompanied by variations in the mRNA expression levels of genes related to lipid metabolism and carbohydrate metabolism. The disorder of lipid and carbohydrate metabolism may affect adult female reproduction, which may lead to insufficient vitellogenin deposition. Moreover, the silencing of PcAKH seriously affected the growth and development of larvae, which was manifested as delayed development period and difficulty in moulting. Conclusively, all these results in current study demonstrated that double-stranded RNA silencing system targeting PcAKH effectively inhibited larval development and female fecundity by disturbing lipid and carbohydrate metabolism, and PcAKH is a specific RNAi target for control of P. citri in the design and development of biopesticide in sustainable agriculture.

Morphological characteristics, developmental dynamics, and gene temporal expressions across various development stages of Aphis gossypii sexual female

BackgroundAphis gossypii (Hemiptera: Aphididae) is a worldwide polyphagous phloem-feeding agricultural pest, and it can produce offspring by sexual or asexual reproduction. Compared with dozens of generations by parthenogenesis, sexual reproduction is performed in only one generation within one year, and little is known about the sexual reproduction of A. gossypii. In this study, sexual females of A. gossypii were successfully obtained through a previously established induction platform, and the morphological characteristics, developmental dynamics, and temporal gene expression were examined. Subsequently, signaling pathways potentially involved in regulating the growth, development, and reproduction of sexual females were investigated.ResultsThe morphological observation showed that from the 1st instar nymph to adult, sexual females exhibited a gradually deepened body color, an enlarged body size, longer antennae with a blackened end, and obviously protruding cauda (in adulthood). The anatomy found that the ovaries of sexual females developed rapidly from the 2nd instar nymph, and the embedded oocytes matured in adulthood. In addition, time-course transcriptome analysis revealed that gene expression profiles across the development of sexual females fell into 9 clusters with distinct patterns, in which gene expression levels in clusters 1, 5, and 8 peaked at the 2nd instar nymphal stage with the largest number of up-regulated genes, suggesting that the 2nd instar nymph was an important ovary development period. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that a large number of genes in the sexual female adult were enriched in the TGF-beta signaling pathway and Forkhead box O (FoxO) signaling pathway, highlighting their important role in sexual female adult development and reproduction.ConclusionThe morphological changes of the sexual female at each developmental stage were revealed for the first time. In addition, time-course transcriptomic analyses suggest genes enriched in the TGF-beta signaling pathway and FoxO signaling pathway probably contribute to regulating the development and oocyte maturation of sexual females. Overall, these findings will facilitate the regulating mechanism research in the growth and development of sexual females by providing candidate genes.

Quaternary ammonium compound exposure causes infertility by altering endocrine signaling and gametogenesis.

Quaternary ammonium compounds (QACs) are common substances utilized in cleaners, ophthalmic solutions, swimming pool treatments, cosmetics, and other consumer goods. Previous studies have shown that QAC exposure causes infertility in both male and female mice. Based on these studies, we hypothesized that oral QAC exposure negatively impacts male and female reproduction through changes in physiologic and endocrine mechanisms rather than direct toxicity to gametes. Endocrine disruption was assessed by evaluating luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations in male and female mice exposed orally throughout gestation and lactation, and by changes in estrogen and progesterone in in orally exposed females throughout pregnancy. Sperm functionality and spermatogenesis were assessed by in vitro fertilization; while Sertoli cell homeostasis was evaluated by determining cellular metabolism, cell cycle progression and blood-testes barrier (BTB) permeability. QAC exposure decreased LH, and FSH concentrations in both males and females, and decreased progesterone and estrogen concentrations during pregnancy. QACs significantly decreased Sertoli cell metabolism at 0.0005 % ADBAC+DDAC well before disruption of the BTB at 0.01 %. Fertilization was not affected 24 h after exposure but was decreased after a 10 day rest period suggesting a disruption in spermatogenesis rather than direct toxicity to sperm. Lastly, QAC exposure altered Sertoli cell cycling with a G2/M cycle arrest. While the effect of QAC exposure on humans is unknown, implications from the in vivo and in vitro studies are concerning given the rise in infertility rates and increased reliance on assisted reproductive technologies along with ubiquitous exposure to QACs.

Developmental expression patterns of gonadal hormone receptors in arcuate kisspeptin and GABA neurons of the postnatal female mouse.

The arcuate nucleus of the hypothalamus (ARC) is central in the neuronal regulation of fertility and reproduction through translating gonadal steroid hormone cues into the GnRH signaling pathway in the brain. Evidence suggests that circulating gonadal steroids play an important role in modulating female reproduction via kisspeptin and γ-aminobutyric acid (GABA) neurons in the ARC in both development and adulthood. However, the temporal onset of these ARC neurons' sensitivity to gonadal steroids is unknown. Using RNAscope® in situ hybridization, we localized androgen receptor (Ar), estrogen receptor alpha (Esr1), and progesterone receptor (Pgr) expression in ARC kisspeptin or GABA neurons of female mice at postnatal day (P)4, P8, P12, P20, and P60. A probe that binds to kiss1 mRNA or vGat mRNA was used to produce signal in kisspeptin or GABA neurons, respectively. In adult, we identified that the vast majority of kisspeptin neurons coexpressed Esr1 (95%) and Pgr (93%), while a smaller proportion coexpressed Ar (66%). Similar proportions of Ar- or Esr1-positive kisspeptin neurons were seen from P4, suggesting that kisspeptin neurons develop adult-like sensitivity to androgen and estrogen in early postnatal life. In contrast, the proportion of Pgr-positive kisspeptin cells in early life was significantly lower than in adulthood, suggesting that progesterone sensitivity develops over time in the ARC kisspeptin population. ARC GABA neurons also colocalized with Ar (70%), Esr1 (64%), or Pgr (85%) in adulthood. GABA neurons continuously expressed Esr1 or Pgr from the postnatal stages to adulthood, while the proportion of Ar-positive GABA neurons gradually increased from P4 (24%) to P20 (59%). These results suggest that while ARC GABA neurons can respond to circulating estrogen and progesterone from early postnatal ages, this same population may become more sensitive to androgens during later postnatal life. Our findings identified the expression patterns of Ar, Esr1, and Pgr by ARC kisspeptin and GABA neurons during early postnatal life. These data provide the understanding for the hormone sensitivity of these populations during early postnatal life, the critical time for the formation and regulation of female reproductive physiology.Esr1 (95%) and Pgr (93%), while a smaller proportion coexpressed Ar (66%). Similar proportions of Ar- or Esr1-positive kisspeptin neurons were seen from P4, suggesting that kisspeptin neurons develop adult-like sensitivity to androgen and estrogen in early postnatal life. In contrast, the proportion of Pgr-positive kisspeptin cells in early life was significantly lower than in adulthood, suggesting that progesterone sensitivity develops over time in the ARC kisspeptin population. ARC GABA neurons also colocalized with Ar (70%), Esr1 (64%), or Pgr (85%) in adulthood. GABA neurons continuously expressed Esr1 or Pgr from the postnatal stages to adulthood, while the proportion of Ar-positive GABA neurons gradually increased from P4 (24%) to P20 (59%). These results suggest that while ARC GABA neurons can respond to circulating estrogen and progesterone from early postnatal ages, this same population may become more sensitive to androgens during later postnatal life. Our findings identified the expression patterns of Ar, Esr1, and Pgr by ARC kisspeptin and GABA neurons during early postnatal life. These data provide the understanding for the hormone sensitivity of these populations during early postnatal life, the critical time for the formation and regulation of female reproductive physiology.

Exposure of Porcine Oocytes to Methylparaben During InVitro Maturation Alters the Expression of Genes Involved in Cumulus Cell Expansion and Steroidogenesis, Decreasing Hyaluronic Acid and Progesterone Synthesis.

Parabens are widely used because of their antimicrobial properties in drugs, cosmetics, and food; however, it has been reported that methylparaben may adversely influence female reproduction. Methylparaben decreases oocyte invitro maturation at a maturation inhibition concentration 50 of 780.31 μM but also decreases oocyte viability at a lethal concentration 50 of 2028.38 μM. Additionally, parabens are endocrine disruptors, affecting steroidogenesis as well as cumulus cell expansion. Therefore, the aim of this study was to elucidate some of the mechanisms by which methylparaben alters cumulus cell expansion and decreases oocyte maturation through the evaluation of gene expression related to cumulus cell expansion, hyaluronic acid, and progesterone synthesis. For this, oocytes were exposed to different methylparaben concentrations of 0 (control), 650, 780, and 1000 μM for 20 and 44 h of invitro maturation. The cumulus cell expansion rates, maturation rates, gene expression rates, and hyaluronic acid and progesterone concentrations were revaluated after 20 and 44 h of culture. At sublethal concentrations, methylparaben decreased invitro maturation as well as cumulus cell expansion at 44 h. Additionally, methylparaben decreased the expression of Has2 and Cd44 at 20 and 44 h of maturation. The expression levels of Stard1, Cyp11a1, and Hsd3b1 were also altered by methylparaben exposure at 20 and 44 h of maturation, suggesting its role as an endocrine disruptor. Hyaluronic acid and progesterone concentrations in the culture medium decreased at 20 and 44 h. These findings could partially explain some of the mechanisms by which methylparaben alters female fertility.