Female Reproduction Research Articles

The JNK signalling pathway gene BmJun is involved in the regulation of egg quality and production in the silkworm, Bombyx mori.

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.

Linking proximate drivers and fitness returns of vigilance in a large ungulate

Vigilance allows animals to quickly detect threats from conspecifics and predators to avoid or minimize costly encounters. Time spent vigilant is usually traded‐off against other fitness‐enhancing activities, such that fitness returns are expected when allocation to vigilance increases. We assessed the proximate factors influencing vigilance and investigated whether vigilance correlates with fitness in wild mountain goats. We first studied which extrinsic and intrinsic factors influenced alert duration and frequency using focal observations recorded over 12 years on individually‐marked adult females. We found that females increased vigilance in forested areas compared with open areas and were less vigilant when they were surrounded by conspecific neighbours. Reproductive females were more frequently vigilant and for longer periods compared with females without offspring. Mothers also tended to perform longer alerts when their offspring was > 10 m away than at shorter distances, suggesting that variation in offspring's vulnerability to predation influences mother's vigilance. Thus, predation risk and offspring vulnerability were the main mechanisms driving variation in vigilance. To assess fitness returns, we then used a joint modelling framework to estimate the latent correlations at the individual level among vigilance traits (alert duration, alert frequency, and total time spent vigilant) and fitness components (adult female survival and offspring survival) while accounting for the drivers observed to influence vigilance. Contrary to expectations, we found no evidence that vigilance is associated with fitness returns, with only some traits being at best weakly positively correlated with survival of offspring and adult females. This might arise because vigilance incurs costs that outweighs its potential benefits, or because vigilance metrics are not repeatable due to their high plasticity, challenging the commonly assumed positive relationship between vigilance and fitness.

Association of a non-synonymous variant of MLH3 gene involved in meiotic recombination with conception rate of Japanese Black cattle

Context Conception rate, which is an important parameter to evaluate female fertility, has been gradually decreasing in Japanese Black cattle during the past decades. Meiosis is an essential biological process in gamete formation and meiotic failure could be a cause of infertility or reduced fertility in mammals. Of note, single nucleotide polymorphisms (SNPs) in the MLH3 gene involved in meiotic recombination were reported to affect the genome-wide recombination rate of meiosis in cattle. Aims The present study was conducted to investigate the association of SNPs in the MLH3 gene with conception rate in Japanese Black cattle. Methods On the basis of the reproductive data of 2045 Japanese Black cattle born from 1990 to 2009, we selected two groups of the reproductive females with high conception rate (n = 103) and low conception rate (n = 109). Then, we genotyped the SNPs in MLH3 gene in both reproductive groups by sequencing and polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). The significant association of SNPs with conception rate in Japanese Black cattle was estimated by Fisher’s exact test, by using R commander. Key results We found the presence of five SNPs of MLH3 gene in Japanese Black cattle, including non-synonymous variants of MLH3 N408S that has been reported to be involved in meiotic recombination rate and MLH3 S591G newly identified in the present study. Comparison of genotype distributions and allele frequencies of the MLH3 N408S between high and low conception-rate groups indicated a significant difference between these groups, suggesting that this SNP is associated with conception rate. However, there is no significant difference between MLH3 S591G with conception rate in Japanese Black cattle. Conclusions We found a significant association between a non-synonymous variant of MLH3 N408S and conception rate, suggesting that this SNP can be a potential marker for selecting the Japanese Black cattle for improving fertility. We also identified a novel non-synonymous variant of MLH3 S591G in Japanese Black cattle. Implications These findings will be informative for future marker-assisted selection to improve the fertility of Japanese Black cattle. This is the first report of a genetic variant implicated in meiotic recombination being linked to female fertility in cattle.

The Effects of Bisphenol A and its Analogs on Steroidogenesis in MA-10 Leydig Cells and KGN Granulosa Cells†.

Bisphenols are a family of chemicals used in the manufacture of consumer products containing polycarbonate plastics and epoxy resins. Studies have shown that exposure to bisphenol A (BPA) may disrupt steroidogenesis and induce adverse effects on male and female reproduction, but little is known about BPA replacements. We determined the effects of six bisphenols on the steroidogenic function of MA-10 Leydig cells and KGN granulosa cells by measuring the levels of progesterone and estradiol produced by these cells as well as the expression of transcripts involved in steroid and cholesterol biosynthesis. MA-10 and KGN cells were exposed for 48hours to one of six bisphenols (0.01-50μM): BPA, bisphenol F, bisphenol S, bisphenol AF, bisphenol M, or bisphenol TMC under both basal and dibutyryl cAMP (Bu2cAMP)-stimulated conditions. In MA-10 cells, most bisphenols increased the Bu2cAMP-stimulated production of progesterone. In KGN cells, there was a general decrease in progesterone production, while estradiol levels were increased following exposure to many bisphenols. qRT-PCR analyses revealed that all six bisphenols (≥1μM) upregulated the expression of STAR, a cholesterol transporter, in both cell lines after stimulation. Key transcripts directly involved in steroid and cholesterol biosynthesis were significantly altered in a cell line, chemical, and concentration-dependent manner. The expression of upstream genes was also differentially affected. Thus, BPA and five of its analogs can disrupt steroid production in two steroidogenic cell lines and alter the levels of transcripts involved in this process. Importantly, BPA replacements do not appear to have fewer effects than BPA.

Chorus Organization in a Neotropical Forest Cicada

In many species of animals, males aggregate in particular locations and produce calls to attract searching females for reproduction. One striking feature of such choruses is synchronization. On a scale of hours, choruses are often concentrated at particular times of day, such as dawn or dusk. On a scale of seconds, males may also synchronize the rhythm of their calls with one another. While synchronized calling at this scale suggests benefits acting at the collective level, competitive interactions between males to attract females can also lead to synchronized calling as an epiphenomenon. Why males in some species synchronize the rhythm of their calls is still debated, and more work is needed to understand the evolution of this behavior. I investigated chorus organization in the Emerald cicada (Zammara smaragdula), a Neotropical forest cicada in southern Belize, to explore these issues. Choruses in this species occurred at dawn and dusk and, occasionally, during daytime. There was no evidence for synchronization in the rhythm of calls among males, as bouts of collective calling occurred after quiet intervals of variable rather than fixed durations. The temporal aggregation of calls in this species thus probably emerged from competitive interactions among males to attract females. The degree of temporal overlap in the calls of males during a chorus varied as a function of chorus phase and time of day, suggesting flexibility in chorus organization, perhaps in relation to temporal variations in factors such as the number of calling cicadas, the number of predators present or ambient temperature during a chorus.

Thyroid hormones in female and male reproduction with special reference to dogs and cats

Thyroid hormones have an important function in numerous physiological processes in humans and animals, including the regulation of metabolism, growth and development of individual and reproductive function. The thyroid hormones, triiodothyronine (T3) and thyroxine (T4), have a direct effect on the reproductive organs and an indirect effect in interaction with other hormones. Thyroid hormones influence the reproductive system by regulating metabolism and tissue development of the ovaries, uterus and placenta. Changes in the serum concentrations of T3 and T4 lead to disturbances in overall body function. Thyroid dysfunction, including hypothyroidism and hyperthyroidism, can lead to significant reproductive problems. The aim of this review was to describe the functions of thyroid hormones and the effects of hypothyroidism and hyperthyroidism on the animal reproductive system. Hypothyroidism is often caused by autoimmune diseases such as lymphocytic thyroiditis, and is associated with later puberty, reduced fertility and abnormalities in reproductive organ development. Hypothyroidism can lead to a prolonged interval, absent cycles, silent oestrus cycles, prolonged oestrus bleeding, and a lack of libido, with the occurrence of infertility, miscarriages, stillbirths and mummified foetuses. In males, hypothyroidism leads to a decrease in libido, semen quality, ejaculate volume, testicular atrophy, hypospermia and azoospermia. Hyperthyroidism, on the other hand, is usually the result of thyroid cancer, which produces excessive amounts of thyroid hormones. Increased concentrations of thyroid hormones lead to disturbances in the physiological balance of reproductive hormones, irregular oestrus cycles, anovulation and reduced fertility, as well as a decrease in the weight of the ovaries and the number of healthy follicles, with a simultaneous increase in the number of atretting follicles. The effects of hyperthyroidism on male fertility include disorders of spermatogenesis, changes in sex hormone levels and changes in sperm quality, such as hypospermia, oligozoospermia, asthenozoospermia and teratozoospermia. It is important to diagnose and treat thyroid disorders in time in order to prevent negative effects on fertility and reproduction in animals.

Investigating the role of non-helpers in group living thrips.

Behavioural variation among individuals is a hallmark of cooperative societies, which commonly contain breeders and non-breeders, helpers and non-helpers. In some cases, labour is divided with non-breeders "helping." Conversely, in some societies, subordinate non-breeders may not help. These individuals may be (i) an insurance workforce ensuring continuity of help for breeders when other helpers are lost, (ii) conserving energy while waiting to breed themselves or (iii) simply of too poor physiological quality either to help or breed. In the Australian Outback, Acacia thrips Dunatothrips aneurae (Thysanoptera) glue Acacia phyllodes into "domiciles" using silk-like secretions, either alone or cooperatively. Domicile maintenance is important for humidity, so repair can be interpreted as helping. I found that not all females helped to repair damage; some repaired partially or not at all ("non-helpers"). At the same time, some co-foundresses are non- or partially reproductive ("non-breeders"), and their role is currently unknown. I first tested the possibility that helping and breeding are divided, with non-helping females breeding, and non-breeders helping. In a lab experiment, I rejected this idea. Experimentally damaged domiciles were typically repaired by reproductive females, and less so by non- or partially reproductive individuals. To test whether non-helpers are an insurance workforce, I successively removed repairing females and found that non-helping females from the same domicile did not increase effort as a result, rejecting this hypothesis. Then I tested whether non-helpers were conserving energy waiting to breed. In a field experiment, I removed all other females, allowing either a helpful female or a non-helper to "inherit" her domicile. Isolated like this, non-helpers laid very few eggs compared to helpers or naturally occurring single foundresses, despite similar ovarian development. My findings show that labour was not divided: reproduction and helping covaried positively, probably depending on individual variation in female quality and intra-domicile competition. Non-helping females were neither an insurance workforce nor conserving energy waiting to breed. They are likely simply of poor quality, freeloading by benefiting from domicile maintenance by others. I hypothesize they are tolerated because of selection for indiscriminate communal brood care in the form of domicile repair.

Stem cell transplantation extends the reproductive life span of naturally aging cynomolgus monkeys

The ovary is crucial for female reproduction and health, as it generates oocytes and secretes sex hormones. Transplantation of mesenchymal stem cells (MSCs) has been shown to alleviate pathological ovarian aging. However, it is unclear whether MSCs could benefit the naturally aging ovary. In this study, we first examined the dynamics of ovarian reserve of Chinese women during perimenopause. Using a naturally aging cynomolgus monkey (Macaca fascicularis) model, we found that transplanting human embryonic stem cells-derived MSC-like cells, which we called M cells, into the aging ovaries significantly decreased ovarian fibrosis and DNA damage, enhanced secretion of sex hormones and improved fertility. Encouragingly, a healthy baby monkey was born after M-cell transplantation. Moreover, single-cell RNA sequencing analysis and in vitro functional validation suggested that apoptosis, oxidative damage, inflammation, and fibrosis were mitigated in granulosa cells and stromal cells following M-cell transplantation. Altogether, these findings demonstrate the beneficial effects of M-cell transplantation on aging ovaries and expand our understanding of the molecular mechanisms underlying ovarian aging and stem cell-based alleviation of this process.

The Sex Dependent and Independent Effects of Dietary Whey Proteins Are Passed from the Mother to the Offspring.

The study assesses the metabolic impact of dietary whey proteins across generations. Virgin females are fed 20% energy whey proteins with 70% energy carbohydrates, which reduces body weight gain and visceral adipose compared to controls fed dietary casein. In contrast, the males are unresponsive. The effect is accentuated in reproductive females that also have reduced plasma levels of glucose. The responsive females have increased cecal levels of pyruvic and lactic acid, suggesting a greater catabolism of carbohydrates in the gut. While the male and female offspring born to mothers on whey proteins continue to reduce body weight gain, the female offspring further decreases the visceral and subcutaneous tissues and increases the gut capacity to breakdown dietary carbohydrates and proteins, whereas the male offspring are able to only decrease the visceral and increase protein catabolism in the gut. The ileum of male mice responded by reducing the gene expression for fibroblast growth factor 15 and increasing the expression of chymotrypsinogen B1. The effect of whey proteins on growth can be passed from the mother to the offspring without a sex preference, whereas the transmission of gut activity and adiposity are dependent on the sex of the offspring.

Demography leads to more conservative European societies

ABSTRACT Using the Survey of Health, Ageing and Retirement in Europe (a total of 66,188 participants from 15 European countries) and the European Gender and Generation Survey (a total of 121,248 participants from 12 countries), we investigated i) whether differences in political attitudes and attitudes toward family values (i.e. attitudes toward homosexual couples, attitudes toward female reproduction) are associated with differences in the average number of children, and ii) whether such an association between fertility and attitudes affects the population share of these attitudes in subsequent generations. We found that in most of the countries analyzed, right-wing (conservative) individuals have, on average, more children and grandchildren than left-wing (liberal) individuals. We also found that the proportion of right-wing individuals increases from generation to generation. Since political attitudes are presumably evolved traits that are socially and genetically transmitted from one generation to the next, these findings may suggest that demographic differences can lead to shifts in prevailing political attitudes. Thus, to some extent, demography may explain longer-term political trends.

Advances in PIWI-piRNA function in female reproduction in mammals.

PIWI-interacting RNAs (piRNAs), which associate with PIWI clade Argonaute proteins to form piRNA-induced silencing complexes (piRISCs) in germline cells, are responsible for maintaining genomic integrity and reproductive function through transcriptional or post-transcriptional suppression of transposable elements and regulation of protein-coding genes. Recent discoveries of crucial PIWI-piRNA functions in oogenesis and embryogenesis in golden hamsters suggest an indispensable role in female fertility that has been obscured in the predominant mouse model of PIWI-piRNA pathway regulation. In particular, studies of piRNA expression dynamics, functional redundancies, and compositional variations across mammal species have advanced our understanding of piRNA functions in male and, especially, female reproduction. These findings further support the use of hamsters as a more representative model of piRNA biology in mammals. In addition to discussing these new perspectives, the current review also covers emerging directions for piRNA research, its implications for female fertility, and our fundamental understanding of reproductive mechanisms.

Domestic violence against women in rural areas of Saharanpur: A population-based study on prevalence and risk factors

ABSTRACT Background: Domestic violence (DV) against women is a global problem and is present in every country. It is a matter of serious concern in most communities and cultures and has consequences on women’s mental, physical, reproductive, and sexual health. The study aimed to determine the prevalence and pattern of DV among married women. Materials and Methods: A community-based, cross-sectional study was conducted among 400 reproductive age group females in the rural area of district Saharanpur for a period of six months using multistage random sampling. Results: The prevalence of DV was found to be 21%. The most common type of DV was physical violence (18%) followed by psychological violence (12.8%), financial violence (5.5%), and sexual violence (2.3%). The major perpetrators of DV were the husbands in 79% of the cases. Regression analysis depicted a significant association between age, education of husband, husband’s addiction, and depression of study participants with events of DV. Multivariate analysis shows only the addictions of husbands and the depression status of study participants to be significantly associated with DV. Conclusion: The prevalence of DV was 21% which is still high and appropriate measures should be taken to strengthen the laws for women and to empower them.

Antibody Preparation, Protein Expression, and Function Analysis of Cyp19a1b in Ovarian Differentiation in a Natural Triploid Teleost Qi River Crucian Carp (Carassius auratus)

Estrogen is an essential sex steroid that functions in numerous biological systems including female reproduction, neuroendocrine, vascular, skeletal, and immune systems. The synthesis of estrogen is controlled by the rate-limiting enzyme, which has been confirmed to exist in two different forms, named brain aromatase and ovary aromatase, and encoded by cyp19a1a and cyp19a1b respectively in teleosts. However, existing studies have primarily focused on the expression and function of cyp19a1b in the brain and cyp19a1a in the gonad, the roles of cyp19a1b in the female gonad of teleosts are largely unknown. In our previous study, we cloned the full length of the cyp19a1b gene from a natural triploid teleost Qi River crucian carp (Carassius auratus), andthe spatial and temporal expression patterns of cyp19a1b mRNA were detected. To further clarify the roles of cyp19a1b in the ovarian differentiation of Qi River crucian carp, we produced a polyclonal antibody of Cyp19a1b in this study. Western blotting results showed that Cyp19a1b was mainly expressed in the brain and then in the ovary, heart, liver, and muscle. During embryogenesis, Cyp19a1b was abundantly expressed in the neurula stage. Immunohistochemistry demonstrated that Cyp19a1b was expressed in the radioactive glial cells (RGCs) of the brain from 20 days after hatching (dah) and the somatic cells of the ovaries from 30 dah, the critical period of ovarian differentiation in Qi River crucian carp. With the treatment of letrozole, an inhibitor of the aromatase, the expression of Cyp19a1b was downregulated both in the brain and gonad. Our results suggested that Cyp19a1b might be involved in the development of the nervous system and also participate in the ovarian differentiation of Qi River crucian carp.

High-quality dietary protein (essential amino acids matched to reproductive needs) partially breaks the lifespan and reproduction trade-off in lubber grasshoppers.

Finding interventions to break the trade-off between reproduction and lifespan can provide insight into physiological limitations of animals. Effects of dietary protein quality on the trade-off are currently unclear, but clarity could lead to better designed diets that match animal needs. Dietary amino acid blends matching yolk proteins support reproduction and extend lifespan in fruit flies. To test if this is conserved across species, we matched dietary amino acids to vitellogenin to test reproduction and lifespan in adult females of the lubber grasshopper. Specifically, we compared varying degrees of protein quality by manipulating dietary essential amino acids. We identified a high-quality protein diet (amino acids matched to vitellogenin, or reproductive needs) that increased reproduction and matched lifespan in comparison to diets that differed only in the ratios of essential amino acids (i.e., were isocaloric and isonitrogenous). All these diets had longer lifespan but lower reproductive output than fully fed controls. In a separate experiment, full reproduction was possible on the high-quality artificial diet when offered at a 78% higher protein quantity and with a larger lettuce supplement (~ 17% of ad libitum). Additionally, we observed that as dietary protein quality was decreased (i.e., diets were less matched to vitellogenin), reproduction was reduced, and lifespan was extended in the more extreme scenarios. Taken together, these results indicate that the balance of dietary essential amino acids plays an important role in the lifespan and reproduction trade-off, while more work needs to be conducted to find the optimal diet mix for this species.

No evidence hunting bait increases American black bear population growth in Maine, USA

AbstractAmerican black bear (Ursus americanus) populations are increasing throughout much of North America. Use of multiple harvest methods, including hunting over bait, is intended to increase harvest success rates to meet harvest and population management objectives. However, black bear population growth can be influenced by food availability, and some speculate the use of bait may inadvertently increase bear abundance through food resource supplementation. We collected hair from black bears captured from 2005–2019 and a selection of potential food items, including those used as bait from 3 study areas in Maine, USA, with different levels of human influence. We used stable isotope analysis of the black bear hair and food item samples to evaluate the contribution of different identified food groups to the diet of individual bears. We found no evidence that greater contribution of human food resources, including bait, increased the number of cubs per litter for reproductive females or that human foods comprised a greater part of the diet in years when natural food resources were less abundant. Approximately 69% of black bear harvest occurred over bait. We found the probability of reproductive‐age females to be harvested increased with average representation of human foods with high carbon enrichment (including bait) in their diet, but the relationship was weak, likely because of sampling constraints. Additionally, the probability of being harvested was greater in years when natural food resources were scarce. We conclude that bait is not available on the landscape in large enough amounts or for a sufficient amount of time in Maine to substantially influence female reproduction. Our results indicate hunting over bait is an effective tool in a state that is attempting to maintain a stable bear population via harvest, and dispels conjecture that hunting over bait may increase cub production and offset the intention of harvest.

Importance and variability of the paternal component in sow reproductive traits.

Reproductive traits are an integral part of the goals of the breeding programs that contribute to the economic success of production. Reproductive phenotypes such as litter size, number of piglets born alive, or litter weight at birth are mainly attributed to females. Thus, the maternal components can be found by default in quantitative genetics' animal models. Still, paternal contribution to variance components should not be discarded. In this review, we indicate the importance of paternal effects in pig breeding by describing both the biology and genetics of boars' traits, the use of (non-)genetic service sire effects in quantitative genetic models for traits measured on females, and genes involved in male reproduction. We start by describing the important biological traits of boars that have the most important effect on their reproductive abilities, i.e., sexual maturity, sperm quality, and testes parameters. Then we move to the possible environmental effects that could affect those traits of boars (e.g., feed, temperature). The main part of the review in detail describes the genetics of boars' reproductive traits (i.e., heritability) and their direct effect on reproductive traits of females (i.e., genetic correlations). We then move to the use of both genetic and non-genetic service sire effects in quantitative models estimated as their percentage in the total variance of traits, which vary depending on the breed from 1 to 4.5% or from 1 to 2%, respectively. Finally, we focus on the description of candidate genes and confirmed mutations affecting male reproduction success: IGF2, Tgm8, ESR1, ZSWIM7, and ELMO1. In conclusion, the observed variance of paternal effects in female reproduction traits might come from various attributes of boars including biological and genetic aspects. Those attributes of boars should not be neglected as they contribute to the success of female reproductive traits.

Growth, reproduction and resource allocation in the Norwegian lemming Lemmus lemmus (L.) under controlled conditions

Lemmings from a laboratory colony did not show statistically significant differences in growth between the sexes up to an age of 50 days. After this, growth slowed down, but adult individuals continued to gain weight, some reaching more than 100 g. Reproductive females gained more weight than non-reproductive. Maximal longevity was between 2 and 3 years. The Norwegian lemming has high reproductive potentials. Females became sexually mature at about 3 weeks of age, even down to two weeks, and remained sexually active until the last periods of life. With 8 mammae and an average litter size of 4, our material confirmed the one-half rule. Litter size up to 16 was recorded. With post-partum oestrus, litters were born at 21 day intervals. Pregnancy and lactation therefore overlapped. Resource allocation between the mother’s demands and those of the two sets of progeny, is achieved partly because the lactation period is so much shorter than the gestation period. Thus competition for energy is reduced. We did not observe any negative effects of the presence of sucklings on the ensuing litter. Even with concurrency in pregnancy and lactation the female herself gained some weight. The Norwegian lemming is thus capable of rapid population growth.

Effect of Gossypol on Gene Expression in Swine Granulosa Cells.

Gossypol (GP), a polyphenolic compound in cottonseed, has notable effects on female reproduction and the respiratory system in pigs. This study aimed to discern the alterations in gene expression within swine granulosa cells (GCs) when treated with two concentrations of GP (6.25 and 12.5 µM) for 72 h, in vitro. The analysis revealed significant changes in the expression of numerous genes in the GP-treated groups. A Gene Ontology analysis highlighted that the differentially expressed genes (DEGs) primarily pertained to processes such as the mitotic cell cycle, chromosome organization, centromeric region, and protein binding. Pathway analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated distinct impacts on various pathways in response to different GP concentrations. Specifically, in the GP6.25 group, pathways related to the cycle oocyte meiosis, progesterone-mediated oocyte maturation, and p53 signaling were prominently affected. Meanwhile, in the GP12.5 group, pathways associated with PI3K-Akt signaling, focal adhesion, HIF-1 signaling, cell cycle, and ECM-receptor interaction showed significant alterations. Notably, genes linked to female reproductive function (CDK1, CCNB1, CPEB1, MMP3), cellular component organization (BIRC5, CYP1A1, TGFB3, COL1A2), and oxidation-reduction processes (PRDX6, MGST1, SOD3) exhibited differential expression in GP-treated groups. These findings offer valuable insights into the changes in GC gene expression in pigs exposed to GP.

Prenatal phthalate exposure and pubertal development in 16-year-old daughters: reproductive hormones and number of ovarian follicles.

Is there a possible association between prenatal phthalate exposure and late effects in teenage daughters with respect to reproductive hormone levels, uterine volume, and number of ovarian follicles? Our study showed subtle associations between phthalate metabolite concentrations in maternal serum from pregnancy or cord blood and LH and insulin-like growth factor 1 (IGF-1) levels as well as uterine volume in their daughters 16 years later. Endocrine-disrupting environmental chemicals may adversely affect human reproductive health, and many societies have experienced a trend toward earlier puberty and an increasing prevalence of infertility in young couples. The scientific evidence of adverse effects of foetal exposure to a large range of chemicals, including phthalates, on male reproductive health is growing, but very few studies have explored effects on female reproduction. This follow-up study included 317 teenage daughters who were part of the Copenhagen Mother-Child Cohort, a population-based longitudinal birth cohort of 1210 females born between 1997 and 2002. A total of 317 female participants (median age 16 years) were examined for weight, height, and menstrual pattern. A serum sample was analysed for concentrations of reproductive hormones, and trans-abdominal 3D ultrasonography was performed to obtain the number of ovarian follicles, ovarian and uterine size. Prenatal maternal serum samples were available for 115 females, and cord blood samples were available for 118 females. These were analysed for concentrations of 32 phthalate metabolites. Weighted quantile sum regression was used for modelling associations of combined prenatal phthalate exposure with the reproductive outcomes in post-menarcheal females. In bivariate correlation analyses, negative significant associations were found between several prenatal phthalate metabolite concentrations and serum hormone concentrations (testosterone, 17-OH-progesterone, and IGF-1) as well as number of ovarian follicles in puberty. Positive significant correlations were found between prenatal phthalate exposure and FSH and sex hormone-binding globulin concentrations. Combined analyses of phthalate exposure (weighted quantile sums) showed significant negative associations with IGF-1 concentration and uterine volume as well as a significant positive association with LH concentration. Phthalate metabolites were measured in serum from single prenatal maternal blood samples and cord blood samples. Potential concomitant exposure to other endocrine-disrupting environmental chemicals before or after birth was not controlled for. The study population size was limited. Our results support the need for further research into possible adverse effects of environmental chemicals during foetal development of the female reproductive system. The work was supported by The Center on Endocrine Disruptors (CeHoS) under The Danish Environmental Protection Agency and The Ministry of Environment and Food (grant number: MST-621-00 065). No conflicts of interest are declared. N/A.

7954 Vitamin D Deficiency Underlies Defective Endometrial Decidualization In Vivo and In Vitro

Abstract Disclosure: M. Yi: None. T. Wang: None. A. Jukic: None. F.J. DeMayo: None. Several epidemiologic studies have reported associations between vitamin D and both menstrual cycles and fertility. Vitamin D signaling occurs most often through the interaction of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) with its cognate receptor, the transcription factor vitamin D receptor (VDR). This study aims to define the role of vitamin D and VDR on female reproduction and identify vitamin D-mediated signaling. In our studies, preliminary results demonstrate mice on a vitamin D-deficient diet showed a significantly impaired uterine decidualization reaction in response to exogenous hormones. To knockdown VDR expression, human endometrial stroma cells (THESCs) were transfected with either non-targeting control (siNT) or VDR siRNA (siVDR) for 48 h. And, to perform the in vitro decidualization, the cell culture media was replaced to differentiate the cells by treatment with 17β-estradiol (E), medroxyprogesterone acetate (P), and db-cAMP (C) for 72 h. At the 48 h exposure of EPC, the decidual media was replaced with containing 1,25(OH)2D3 or vehicle and cultured for 24 h additionally. Treatment of 1,25(OH)2D3 (ligand) and knockdown of VDR (receptor) in THESCs resulted in an increased expression of the decidualization markers, PRL and IGFBP1. Transcriptomic analysis was then conducted to identify the biological networks regulated by the ligand and receptor in THESCs. THESCs were transfected with either siNT or siVDR for 48 h, and the culture media was replaced with either treatment of 2 nM of 1,25(OH)2D3 or vehicle for an additional 24 h. Differentially expressed genes (DEGs) were affected by the ligand and receptor (N = 626 and 1499, respectively) based on a three-way ANOVA filtered with false discovery rate (FDR)-adjusted p-value<0.05 and fold-change (FC)≥|1.4|. Pathway analyses and predicted upstream regulators were analyzed by Ingenuity Pathways Analysis (IPA), and among the predicted upstream regulators of the DEGs, β-estradiol was predicted as an activator for both. Thus, to test the role of vitamin D in estrogen signaling, THESCs were treated with either EPC or PC for 72 h in total, and at the 48 h exposure, the decidual media was replaced with 1,25(OH)2D3 or vehicle and cultured for 24 h additionally. Removal of estrogen (PC) caused loss of the enhanced expression of decidual markers by 1,25(OH)2D3 that was observed in control EPC-treated cells. In conclusion, Vitamin D signaling modulates human and mouse uterine stromal cell differentiation by modulating the ability of estrogen to stimulate decidualization in endometrial stromal cells, a process critical to establishing pregnancy. Presentation: 6/2/2024