Functional characterization of follicle-stimulating hormone and luteinizing hormone receptors in cloudy catshark, Scyliorhinus torazame

The follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in cloudy catshark were cloned, and recombinant FSHR and LHR were expressed for characterization. Ventral lobe extract (VLE) from the pituitary contains homologous FSH and LH, and it stimulated the cAMP signaling of FSHR and LHR dose-dependently. Two transcript variants of LHR (LHR-L with exon 10 and LHR-S without) were identified, and LHR-S was the dominant form with higher basal cAMP activity without VLE stimulation. Among various developmental stages of follicles, FSHR expression was mainly associated with the pre-vitellogenic and early white follicles. When follicles were recruited into vitellogenesis, the expression of FSHR decreased while of LHR was upregulated reciprocally, suggesting that LHR may also be responsible for the control of vitellogenesis in chondrichthyans. The expression of LHR-L was upregulated among maturing follicles before ovulation, indicating LHR-L could have a specific role in receiving the LH surge signal for final maturation. Plasma LH-like activity was transiently increased prior to the progesterone (P4)-surge and testosterone-drop at the beginning of P4-phase, supporting a pituitary control of follicle-maturation via LH signaling in chondrichthyans. The expression of follicular LHR was downregulated during the P4-phase when LH-like activity was high, indicating that the LH-dependent downregulation of LHR is conserved in chondrichthyans as it is in other vertebrate lineages. (213 words).

Melatonin protects oogenesis from hypobaric hypoxia-induced fertility damage in mice

Environmental hypoxia adversely affects reproductive health in humans and animals at high altitudes. Therefore, how to alleviate the follicle development disorder caused by hypoxia exposure and to improve the competence of fertility in plateau non-habituated female animals are important problems to be solved urgently. In this study, a hypobaric hypoxic chamber was used for 4 weeks to simulate hypoxic conditions in female mice, and the effects of hypoxia on follicle development, proliferation and apoptosis of granulosa cells, reactive oxygen species (ROS) levels in MII oocyte and 2-cell rate were evaluated. At the same time, the alleviating effect of melatonin on hypoxic exposure-induced oogenesis damage was evaluated by feeding appropriate amounts of melatonin daily under hypoxia for 4 weeks. The results showed that hypoxia exposure significantly increased the proportion of antral follicles in the ovary, the number of proliferation and apoptosis granulosa cells in the follicle, and the level of ROS in MII oocytes, eventually led to the decline of oocyte quality. However, these defects were alleviated when melatonin was fed under hypoxia conditions. Together, these findings suggest that hypoxia exposure impaired follicular development and reduced oocyte quality, and that melatonin supplementation alleviated the fertility reduction induced by hypoxia exposure.

Investigations of the function of AMH in granulosa cells in hens

Anti-mullerian hormone (AMH) plays a crucial role in follicle regulation in mammals by preventing premature primordial follicle activation and restricting follicle development through reduction of FSH sensitivity and inhibition of FSH-induced increase of steroidogenic enzymes. AMH is produced by granulosa cells from growing follicles and expression declines at the time of selection in both mammalian and avian species. The role of AMH in chicken granulosa cells remains unclear, as research is complicated because mammalian AMH is not bioactive in chickens and there is a lack of commercially available chicken AMH. In the current experiments, we used RNA interference to study the role of AMH on markers of follicle development in the presence and absence of FSH. Cultured chicken granulosa cells from 3-5 mm follicles and 6-8 mm follicles, the growing pool from which follicle selection is thought to occur, were used. Transfection with an AMH-specific siRNA significantly reduced AMH mRNA expression in granulosa cells from 3-5 mm and 6-8 mm follicles. Genes of interest were only measured in granulosa cells of 3-5 mm follicles due to low expression of AMH mRNA at the 6-8 mm follicle stage. Knockdown of AMH mRNA did not affect markers of follicle development (follicle stimulating hormone receptor, FSHR; steroidogenic acute regulatory protein, STAR; cytochrome P450 family 11 subfamily A member 1, CYP11A1; bone morphogenetic protein receptor type 2, BMPR2) or FSH responsiveness in granulosa cells from 3-5 mm follicles, indicating that AMH does not regulate follicle development directly by affecting markers of steroidogenesis, FSHR or BMPR2 at this follicle stage in chickens.

Ulipristal (UPA) effects on rat ovaries: Unraveling follicle dynamics, ovulation inhibition, and safety implications for prolonged use

Ulipristal (UPA), a selective progesterone receptor modulator, has both agonistic and antagonistic effects on progesterone receptors. UPA suppresses ovulation by inhibiting the luteinizing hormone (LH) surge from the pituitary gland; however, the direct effect of UPA on ovarian tissue remains poorly studied. In the present study, we examined the effects of UPA on the ovaries of rats. Rats were treated for 28 days with UPA, and the effects of UPA on ovarian tissue were examined histologically and the expression of antioxidant genes and cell death markers were also investigated. UPA treatment increased the number of primordial follicles at each treatment group, primordial follicles increased at all dose levels, but the size/magnitude of the effect decreased with the increasing dose. The number of primary and antral follicles tended to increase with increasing UPA levels. Furthermore, the decrease in primary follicle number could be attributed to the exhaustion of follicles, but the examination of proliferation markers, oxidative stress markers, and cell death markers revealed no remarkable toxic effects on ovarian tissues. These results suggest that UPA treatment promotes follicle development at each stage but inhibits ovulation by suppressing the LH surge, resulting in an increase in atretic follicles or unruptured luteinized cysts. These results suggest that UPA may not have both toxic effects on the ovary and a direct local effect on ovarian follicles, but we should be careful about the effects of prolonged UPA treatment in patients with uterine fibroids on their future fecundity.

The neuroendocrine system of Ciona intestinalis Type A, a deuterostome invertebrate and the closest relative of vertebrates

Deuterostome invertebrates, including echinoderms, hemichordates, cephalochordates, and urochordates, exhibit common and species-specific morphological, developmental, physiological, and behavioral characteristics that are regulated by neuroendocrine and nervous systems. Over the past 15 years, omics, genetic, and/or physiological studies on deuterostome invertebrates have identified low-molecular-weight transmitters, neuropeptides and their cognate receptors, and have clarified their various biological functions. In particular, there has been increasing interest on the neuroendocrine and nervous systems of Ciona intestinalis Type A, which belongs to the subphylum Urochordata and occupies the critical phylogenetic position as the closest relative of vertebrates. During the developmental stage, gamma-aminobutylic acid, D-serine, and gonadotropin-releasing hormones regulate metamorphosis of Ciona. In adults, the neuropeptidergic mechanisms underlying ovarian follicle growth, oocyte maturation, and ovulation have been elucidated. This review article provides the most recent and fundamental knowledge of the neuroendocrine and nervous systems of Ciona, and their evolutionary aspects.

Thiol-yne click crosslink hyaluronic acid/chitosan hydrogel for three-dimensional in vitro follicle development

There is a great deal of potential for in vitro follicle growth to provide an alternative approach to fertility preservation. This strategy reduces the possibility of cancer cells re-exposure after transplantation, and it does not require hormone stimulation. Adopting a three-dimensional (3D) culture method helps preserve the architecture of the follicle and promotes the maturity of oocytes. In order to maintain follicle morphology, enhance the quality of mature oocytes, and facilitate meiotic spindle assembly, the current work aimed to develop the 3D in vitro preantral mouse follicle culture method. Thiolated chitosan-co-thiolated hyaluronic (CSHS) hydrogel was designed to evaluate the effects of biomaterials on ovarian follicle development. Isolated follicles from mouse ovaries were randomly divided into alginate (Alg) as a 3D control, thiolated hyaluronic acid (HASH), and CSHS groups. Single follicle was encapsulated in each hydrogel, and performed for 10 days and subsequently ovulated to retrieve mature oocytes on day 11. CSHS hydrogel promoted follicle survival and oocyte viability with maintained spherical morphology of follicle. Matured oocytes with normal appearance of meiotic spindle and chromosome alignment were higher in the CSHS group compared with those in the Alg and HASH groups. Furthermore, CSHS increased expression level of folliculogenesis genes (TGFβ-1, GDF-9) and endocrine-related genes (LHCGR, and FSHR). With various experimental setups and clinical applications, this platform could be applied as an alternative method to in vitro follicle culture with different experimental designs and clinical applications in the long-term period.

HucMSC-EVs Facilitate In Vitro Development of Maternally Aged Preantral Follicles and Oocytes

Follicle developmental capacity and oocyte quality decline with advanced maternal age. Extracellular vesicles from human umbilical cord mesenchymal stem cells (HucMSC-EVs) act as a potential therapeutic product in the treatment of age-related ovarian dysfunction. In vitro culture (IVC) of preantral follicles is a useful method for understanding the mechanism of follicle development and is a promising means for improving female fertility. However, whether HucMSC-EVs have beneficial effects on aged follicle development during IVC has not yet been reported. Our research demonstrated that follicular development with single-addition withdrawal of HucMSC-EVs was better than that with continuous treatment with HucMSC-EVs. HucMSC-EVs facilitated the survival and growth of follicles, promoted the proliferation of granulosa cells (GCs), and improved the steroid hormone secretion of GCs during IVC of aged follicles. Both GCs and oocytes could uptake HucMSC-EVs. Moreover, we observed elevated cellular transcription in GCs and oocytes after treatment with HucMSC-EVs. The RNA sequencing (RNA-seq) results further validated that the differentially expressed genes are related to the promotion of GC proliferation, cell communication, and oocyte spindle organization. Additionally, the aged oocytes displayed a higher maturation rate, presented less aberrant spindle morphology, and expressed a higher level of the antioxidant protein Sirtuin 1 (SIRT1) after treatment with HucMSC-EVs. Our findings suggested that HucMSC-EVs can improve the growth and quality of aged follicles and oocytes in vitro through the regulation of gene transcription, which provides evidence for HucMSC-EVs as potential therapeutic reagents to restore female fertility with advanced age.

Design and Application Strategies of Natural Polymer Biomaterials in Artificial Ovaries

For certain types of cancer patients, ovarian transplantation has a risk of malignant cancer cell infection. However, the autologous transplantation of an artificial ovary is safe and effective, guarantees the normal development of isolated follicles, regular oocyte maturation, and ovulation, partially restores endocrine function, and enables the patient to regain reproductive ability. Despite the complexity of the natural ovary, some progress has been made in the repair or replacement of reproductive tissues with the use of various biomaterials. This article reviews the physical structure, biomechanical properties, design elements, preparation routes, construction and practical use of natural polymer materials, usually hydrogel scaffolds, such as alginate, fibrin, gelatin, collagen, agarose, and acellular ovarian matrix in the preparation of artificial ovaries. We summarize how these materials can be made into artificial ovaries to achieve the conditions for fertility through follicle and oocyte development and identify several major issues to overcome for the future development of artificial ovaries, including how to establish blood recirculation, and how to establish hormone synthesis and release channels. This review is intended to provide a reference for the use of natural polymer biomaterials in reproductive clinics.

Altrenogest treatment during the last week of lactation on ovarian traits and subsequent reproductive performance of primiparous and multiparous sows

High-quality follicles result in larger corpora lutea (CL), producing more progesterone, and having a fundamental role in pregnancy maintenance. For some sows, follicular growth takes place during lactation, and follicle selection occurs under a catabolic environment. As altrenogest inhibits follicular development, this study aimed to evaluate follicular growth, CL size, estrus expression, and subsequent reproductive performance of sows treated with altrenogest during the last seven days of a three-week lactation. A total of 81 primiparous and 319 multiparous sows were allocated to two treatments: CONT (control group) and ALT (20 mg of altrenogest/day during the last seven days of lactation). Subsamples of 20 primiparous sows and 97 multiparous were randomly selected to evaluate follicular growth and 26 multiparous sows for serum progesterone analysis at day 21 of gestation. On day 21 of pregnancy, CL measurement was performed by ultrasound. Once in estrus, sows were post-cervically inseminated with pooled semen doses with 1.5 × 10⁹ sperm cells at estrus onset and every 24 h during the standing reflex period. Sows not showing estrus until 10 days after weaning were considered in anestrus. The variables weaning-to-estrus interval, CL size, litter size in the subsequent cycle, and piglet birth weight were evaluated using the GLIMMIX procedure and compared using the Tukey-Kramer test. Anestrus, pregnancy, farrowing, and adjusted farrowing rate were evaluated as binary responses using logistic regression. Follicular size was analyzed as a repeated measure during treatment and after weaning. Treatment was considered as a fixed effect. During the treatment period, follicular size was smaller in ALT sows than CONT sows (3.29 vs. 3.52 mm; P < 0.001). However, after treatment, ALT sows showed a larger follicular size than CONT sows (5.30 vs. 5.03 mm; P ≤ 0.01). There were less ALT sows showing estrus than CONT sows on days three (1.03 vs. 4.57%) and four (55.38 vs. 68.02%) after weaning (P ≤ 0.05), respectively. At 21 days after insemination, ALT sows showed larger CL size and lower CL size variation (P < 0.01) than CONT sows. Anestrus rate, pregnancy rate, farrowing rate, adjusted farrowing rate, litter size in the subsequent cycle, piglet birth weight, litter birth weight, and birth weight variation did not differ between treatments (P ≥ 0.14). In conclusion, altrenogest treatment during the last week of lactation concentrated estrus expression on day five after weaning, larger follicle and CL sizes; however, with no improvement in reproductive performance.

Two forms of G protein-coupled estrogen receptor 1 in the ricefield eel: Expression and functional characterization in relation to ovarian follicle development

G protein-coupled estrogen receptor 1 (Gper1) mediates many rapid, non-genomic estrogenic effects in vertebrates, and plays an important reproductive role in the maintenance of oocyte meiotic arrest in teleost fishes. In the present study, two genes for Gper1, namely gper1a and gper1b, were identified in the genome of a teleost fish, the ricefield eel (Monopterus albus) through Blast and syntenic analysis. Although genes neighboring gper1b are of high synteny, ricefield eel Gper1b shares very low (around 15) percent identities with Gper1 homologues of other vertebrates. In transiently transfected HEK293T cells, both ricefield eel Gper1a and Gper1b responded to estradiol (E₂) and estradiol-BSA (E₂-BSA) challenges by activating pCRE but not pSRE luciferase reporters, which were abolished by G-15 and NF-449. The production of cAMP was also increased in HEK293T cells transfected with Gper1a or Gper1b expression construct after E₂-BSA challenge, which was also abolished by G-15. Surprisingly, both Gper1a and Gper1b showed ligand-independent effects on pCRE luciferase reporters at higher transfected doses (10 ng). RT-PCR analysis showed that the transcript of gper1a is broadly expressed in tissues of both female and male fish while the expression of gper1b in tissues demonstrates obvious sexual dimorphism, with transcripts detected in all tissues examined in female whereas they were barely detectable in some peripheral tissues of male including the testis. In the ovary, the expression of both gper1a and gper1b was detected in the oocyte but not the follicular layer, with the mRNA levels increased during vitellogenesis, peaked at the late vitellogenic stage, and decreased precipitously at the full-grown and germinal vesicle breakdown (GVBD) stages. Moreover, E₂ and E₂-BSA induced cAMP production in the in vitro incubated follicles at mid-vitellogenic stage but not the GVBD stage, and the induction could be completely abolished by G-15, a Gper1 inhibitor. Taken together, these results suggest that both Gper1a and Gper1b may play important roles in the development and maturation of ovarian follicles in ricefield eels, possibly through inhibition of oocyte meiotic resumption.

The function of Wls in ovarian development

WNT ligand transporter Wls is essential for the WNT dependent developmental and pathogenic processes. The spatiotemporal expression pattern of Wls was investigated in this study. Immature female mice (21-22 days old) were treated with 5 IU, pregnant mare's serum gonadotrophin (PMSG) to stimulate follicular development, followed 48 h later by injection with 5 IU, human chorionic gonadotrophin (hCG) to induce ovulation. The expression of Wls was stimulated in granulosa cells and the forming corpus luteum after hCG administration. To study the function of Wls, the Amhr2tm3(cre)Bhr strain was used to target deletion of Wls in granulosa cells. The deletion of Wls caused a significant decrease in the fertility of WlsAmhr2-Cre female mice. In female WlsAmhr2-Cre mice, decreased ovarian size and number of antral follicles were found. The number of corpus luteum in immature PMSG/hCG primed WlsAmhr2-Cre mice was much less than that in the control group. Compared with control animals, WlsAmhr2-Cre mice have lower serum progesterone levels. RNA sequencing was used to identify genes regulated by Wls after hCG treatment. Several genes known to be critical for follicle development and steroidogenesis were significantly down-regulated, such as Fshr, Lhcgr, Sfrp4, Inhba, Cyp17a1, Hsd3b1, and Hsd17b7. The expression of WNT signaling downstream target genes, Bmp2 and Cyp19a1, also decreased significantly in WlsAmhr2-Cre ovary. In summary, the findings of this study suggest that Wls is critical for female fertility and luteinization.

Coping with large litters: the management of neonatal piglets and sow reproduction

As a result of intensive breeding, litter size has considerably increased in pig production over the last three decades. This has resulted in an increase in farrowing complications. Prolonged farrowing will shorten the window for suckling colostrum and reduce the chances for high-quality colostrum intake. Studies also agree that increasing litter sizes concomitantly resulted in decreased piglet birth weight and increased within-litter birth weight variations. Birth weight, however, is one of the critical factors affecting the prognosis of colostrum intake, and piglet growth, welfare, and survival. Litters of uneven birth weight distribution will suffer and lead to increased piglet mortality before weaning. The proper management is key to handle the situation. Feeding strategies before farrowing, management routines during parturition (e.g., drying and moving piglets to the udder and cross-fostering) and feeding an energy source to piglets after birth may be beneficial management tools with large litters. Insulin-like growth factor 1 (IGF-1)-driven recovery from energy losses during lactation appears critical for supporting follicle development, the viability of oocytes and embryos, and, eventually, litter uniformity. This paper explores certain management routines for neonatal piglets that can lead to the optimization of their colostrum intake and thereby their survival in large litters. In addition, this paper reviews the evidence concerning nutritional factors, particularly lactation feeding that may reduce the loss of sow body reserves, affecting the growth of the next oocyte generation. In conclusion, decreasing birth weight and compromised immunity are subjects warranting investigation in the search for novel management tools. Furthermore, to increase litter uniformity, more focus should be placed on nutritional factors that affect IGF-1-driven follicle development before ovulation.

miRNA expression profile in chicken ovarian follicles throughout development and miRNA-mediated MMP expression

Accumulating evidence has demonstrated the role of microRNAs (miRs) in the avian ovary. In this study, high-throughput transcriptome analyses were employed to study the differential miR expression profiles in the chicken ovary, aiming to reveal miR-targeting matrix metalloproteinase (MMP) expression during follicular growth, maturation, and atresia. Using tissues of chicken ovarian follicles at key steps of development (slow growing - white, the most recently recruited - small yellow, and preovulatory - F2) and regression (the third postovulatory), 14 small RNA (sRNA) libraries were constructed. The 25 most highly expressed known miRs were identified along with eight significantly differentially expressed (DE) miRs (gga-miR-let-7d, gga-miR-31-3p, gga-miR-138-1-3p, gga-miR-1552-5p, gga-miR-92-3p, gga-miR-31-5p, gga-miR-202-3p, and gga-miR-6648-3p) which were further examined by quantitative real time-PCR (qRT-PCR) in white, yellowish, small yellow, and atretic follicles as well as in the granulosa and theca layer of yellow preovulatory F3-F1 follicles (n = 6 hens). These miRs were mainly associated with four pathways: inhibition of MMPs, axonal guidance signaling, HIF1α signaling, and GP6 signaling. Four predicted target genes (i.e. MMP-16, ADAM10, COL4A2, and COL4A5) were examined by qRT-PCR and negatively correlated with DE miRs. The identified candidate miR:mRNA target pairs include gga-miR-31-5p or gga-miR-92-3p:MMP-16, gga-miR-31-5p or gga-miR-92-3p:ADAM10, let-7d:COL4A2, and gga-miR-138-1-3p:COL4A5 are potentially associated with MMP modulation in the hen ovary, mostly in the granulosa and theca cells of the largest preovulatory follicles. These results provide a novel insight to the role of miRs in follicle development by identifying a miR target network that is putatively engaged in remodeling of the extracellular matrix during ovarian follicle development in chickens.

Identification of Potential Biomarkers of Polycystic Ovary Syndrome via Integrated Bioinformatics Analysis

Polycystic ovary syndrome (PCOS) is a life-long reproductive, endocrine, and metabolic disorder that affects up to 17% of women of reproductive age. However, the effect of granulosa cells (GCs) transcriptome changes on oocyte capacity and follicular development in patients with PCOS has not been elucidated. This study aims to analyze transcriptome changes in GCs of PCOS from different perspectives and explore potential biomarkers for the diagnosis and treatment of PCOS. The gene expression profiles of GSE34526 and GSE107746 were obtained from the GEO database. Differentially expressed genes (DEGs) and key signaling pathways were identified. Gene Set Enrichment Analysis (GSEA) revealed that Toll-like receptors, NOD-like receptors, and NOTCH signaling pathways were obviously enriched in GCs of PCOS. We further analyzed DEGs from three aspects: transcription factors (TFs), secreted proteins, and follicular development. Compared with normal GCs, the DEGs encoding TFs and secretory proteins in GCs of PCOS remarkably changed. Besides, HAS2 and CBLN1, which are highly expressed in preovulatory follicular GCs and may trigger ovulation, were significantly decreased in GCs of PCOS. This study found candidate genes and signaling pathways in PCOS, providing new insights and foundations for the etiology of PCOS. Besides, HSA2 and CBLN1 may be potential therapeutic biomarkers for ovulation disorders in PCOS.

Dynamic characteristics of lipid metabolism in cultured granulosa cells from geese follicles at different developmental stages

Previous studies have shown that lipid metabolism in granulosa cells (GCs) plays a vital role during mammalian ovarian follicular development. However, little research has been done on lipid metabolism in avian follicular GCs. The goal of the present study was to investigate the dynamic characteristics of lipid metabolism in GCs from geese pre-hierarchical (6–10 mm) and hierarchical (F4-F2 and F1) follicles during a 6-day period of in vitro culture. Oil red O staining showed that with the increasing incubation time, the amount of lipids accumulated in three cohorts of GCs increased gradually, reached the maxima after 96 h of culture, and then decreased. Moreover, the lipid content varied among these three cohorts, with the highest in F1 GCs. The qPCR results showed genes related to lipid synthesis and oxidation were highest expressed in pre-hierarchical GCs, while those related to lipid transport and deposition were highest expressed in hierarchical GCs. These results suggested that the amount of intracellular lipids in GCs increases with both the follicular diameter and culture time, which is accompanied by significant changes in expression of genes related to lipid metabolism. Therefore, it is postulated that the lipid accumulation capacity of geese GCs depends on the stage of follicle development and is finely regulated by the differential expression of genes related to lipid metabolism.

Determination of the roles of GREM1 gene in granulosa cell proliferation and steroidogenesis of hen ovarian prehierarchical follicles

Gremlin genes are known members of the DAN family of bone morphogenetic protein (BMP) antagonists, but their functions and regulatory mechanisms in ovarian follicular development of chicken remain unknown. The current study was designed to investigate the mRNA expression patterns of gremlin1 gene (GREM1) and its protein location in the follicles sampled, and to explore the biological effect of GREM1 on the prehierarchical follicular development. This work revealed that chicken GREM1 mRNA exhibits a constant expression level across all the prehierarchical follicles (PFs) from 1-4 mm to 7-8 mm in diameter, and the preovulatory follicles (from F6 to F1) by using RT-qPCR (P > 0.05). The GREM1 protein is predominantly expressed in the oocytes and granulosa cells (GCs) of the PFs by immunohistochemistry. Furthermore, our data demonstrated that siRNA-mediated knockdown of GREM1 in the GCs resulted in a significant reduction in cell proliferation (P < 0.001); conversely, overexpression of GREM1 in the GCs led to a remarkable increase in cell proliferation (P < 0.001). Interestingly, the expression levels of proliferating cell nuclear antigen (PCNA) and cyclin D2 (CCND2) mRNA and proteins were notably increased when GREM1 expression was upregulated in the GCs (P < 0.01), however, the expression levels of CYP11A1 and StAR were markedly downregulated (P < 0.01). The current results showed that GREM1 gene plays a stimulatory role in GC proliferation during growth and development of the prehierarchical follicles in vitro but an inhibitory role in GC differentiation and steroidogenesis of the hen ovary follicles.

Intrafollicular injection of nonesterified fatty acids impaired dominant follicle growth in cattle

Dairy cows frequently undergo a state of negative energy balance (NEB) after parturition and some have impaired ovarian functions that result in delayed resumption of estrous cyclicity and development of follicles without ovulation occurring. During the postpartum period, cows undergo body-fat store losses, hormonal changes, fat mobilization and increases in nonesterified fatty acid (NEFAs) concentrations in blood and follicular fluid. The effect of NEFAs on follicular development and function of follicular cells, however, is not fully understood. The aim of this study, therefore, was to study the effect of an intrafollicular injection of a mixture of oleic, stearic and palmitic NEFAs on dominant follicle development and function of granulosa cells in cows that were not in a NEB state. Follicular size was less at 24 and 48 h after administration of NEFAs compared to that of control follicles injected with vehicle only. At 24 h after intrafollicular injection, the relative mRNA transcript abundance for proteins involved in steroidogenesis (CYP19A1, 3BHSD, STAR, FSHR), metabolism (GLUT1, GLUT3, INSR, IRS1, IRS2, SLC27A1, PPARG), and cell proliferation and apoptosis (CCND2; XIAP) in granulosa cells, as well as estradiol concentrations in follicular fluid were similar in control and NEFA-treated follicles. In conclusion, the results of this study indicate increased intrafollicular concentrations of NEFAs in cows that are not in a NEB state has a detrimental effect on follicle development. We propose intrafollicular injection is a useful approach to further investigate the local effects of NEFAs on the function of follicular cells.

Nodal regulates ovarian functions in zebrafish

Nodal, a member of the transforming growth factor-β (TGF-β) superfamily, plays critical roles during embryo development. Several studies suggest that Nodal also regulates reproduction. The objective of this study was to investigate if Nodal is expressed in zebrafish ovary and if it is involved in the regulation of ovarian functions. Using real-time PCR, we detected two Nodal homologs, nodal-related (ndr)1, and ndr2 in zebrafish ovarian follicles. We further compared the mRNA levels of ndr1, ndr2, and their receptors between maturational incompetent early vitellogenic follicles (stage IIIa) and mid- to late-vitellogenic follicles (stage IIIb) which are capable of undergoing maturation when they are induced by hormones. We found that mRNAs for ndr1 and ndr2, as well as a type I receptor, acvr1ba, were significantly increased in follicular cells isolated from stage IIIb follicles. In primary cultures of ovarian follicular cells, treatment with recombinant human Nodal inhibited cell proliferation. On the other hand, Nodal increased the mRNA levels of two steroidogenic enzymes hsd3b2 and cyp17a1, as well as paqr8, which encodes the membrane progestin receptor-β (mPR-β). Conversely, knockdown of ndr1 and ndr2 using siRNAs decreased the mRNA levels of hsd3b2, cyp17a1, and paqr8. Finally, treatment of Nodal significantly induced oocyte maturation. Taken together, these findings suggest that Nodal exerts multiple effects on zebrafish ovary to regulate follicle growth, steroidogenesis, and oocyte maturation.

CFP1-dependent histone H3K4 trimethylation in murine oocytes facilitates ovarian follicle recruitment and ovulation in a cell-nonautonomous manner

CxxC-finger protein 1 (CFP1)-mediated trimethylated histone H3 at lysine-4 (H3K4me3) during oocyte development enables the oocyte genome to establish the competence to generate a new organism. Nevertheless, it remains unclear to which extent this epigenetic modification forms an instructive component of ovarian follicle development. We investigated the ovarian functions using an oocyte-specific Cxxc1 knockout mouse model, in which the H3K4me3 accumulation is downregulated in oocytes of developing follicles. CFP1-dependent H3K4 trimethylation in oocytes was necessary to maintain the expression of key paracrine factors and to facilitate the communication between an oocyte and the surrounding granulosa cells. The distinct gene expression patterns in cumulus cells within preovulatory follicles were disrupted by the Cxxc1 deletion in oocytes. Both follicle growth and ovulation were compromised after CFP1 deletion, because Cxxc1 deletion in oocytes indirectly impaired essential signaling pathways in granulosa cells that mediate the functions of follicle-stimulating hormone and luteinizing hormone. Therefore, CFP1-regulated epigenetic modification of the oocyte genome influences the responses of ovarian follicles to gonadotropin in a cell-nonautonomous manner.

[Effect of electroacupuncture at different acupoints on follicle development and related factors in serum and ovary tissues of PCOS rats]

OBJECTIVE

To observe the effect of electroacupuncture (EA) at different acupoints on follicle development, expression of gonadotropins and their receptors and anti-Müllerian hormone(AMH), inhibin B(INHB) in polycystic ovarian syndrome (PCOS) rats, so as to explore its mechanisms underlying improvement of PCOS.

METHODS

Sixty female SD rats were randomized into six groups: control, model, Zusanli(ST36), Sanyinjiao(SP6), Guanyuan(CV4) and combination (ST36+SP6+CV4, n=10 rats/group). The PCOS model was established by gavage of Letrozole solution (1.0 mg/kg) once daily for 21 consecutive days. Rats of the control group were given 1% Carboxymethyl Cellulose (CMC, 1 mg/kg). EA (2 Hz) was applied to ST36, SP6, or/and CV4 for 20 min, once daily for 14 consecutive days. The number of follicles was counted, and the ovarian structure and follicular development were observed under light microscope after H.E. stain, and the contents of serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), AMH, and INHB were assayed by enzyme-linked immunosorbent assay, and the ratio of LH/FSH was calcula-ted. The immunoactivity of LH receptor (LHR) and FSH receptor (FSHR) proteins was detected by immunohistochemistry.

RESULTS

After modeling, the number of follicles at the growth stage, contents of serum LH, AMH and INHB, and ratio of LH/FSH were significantly increased, and serum FSH level and FSHR, LHR immunoactivity were remarkably decreased in the model group relevant to the control group (P<0.05, P<0.01). Following EA intervention, the number of follicles at the growth stage in the SP6, CV4 and combination groups, LH/FSH ratio and serum AMH levels in the 4 EA groups, INHB contents in the ST36, CV4 and combination groups were significantly reduced (P<0.05, P<0.01), while serum FSH contents in the 4 EA groups, FSHR immunoactivity at the early stage in the ST36 group and LHR immunoactivity at both early and late stages in the ST36 and CV4 groups were considerably increased in comparison with those of the model group (P<0.01, P<0.05). The therapeutic effect of SP6 was significantly superior to that of CV4 in down-regulating serum LH level (P<0.01), but significantly inferior to that of CV4 in up-regulating serum FSH content and in down-regulating LH/FSH ratio and serum AMH and INHB levels (P<0.05, P<0.01). The effect of CV4 was comparable to that of ST36 in up-regulating serum FSH, and in down-regulating serum LH/FSH ratio, AMH and INHB levels (P>0.05).

CONCLUSION

EA of CV4, SP6, ST36 and ST36+CV4+SP6 can reduce the number of follicles at the growth stage and regulate the expression levels of gonadotropins in PCOS rats. The effects of EA of CV4 and ST36 are evidently better than those of EA of SP6 in up-regulating serum FSH content and in down-regulating LH/FSH ratio, and serum AMH and INHB levels, and EA of SP6 is evidently superior to EA of CV4 down-regulating LH level, but without synergistic effect among the 3 acupoints.

High copper levels in follicular fluid affect follicle development in polycystic ovary syndrome patients: Population-based and in vitro studies

Although the adverse effects of copper overexposure on the liver, kidney, spleen and intestinal organs are well known, information about the impact of copper toxicity on human reproduction is limited. A total of 348 infertile patients were enrolled in our present study, including 89 with polycystic ovary syndrome (PCOS), 145 with fallopian tube obstruction and 114 controls. The follicular fluid concentrations of 22 trace elements were measured by inductively coupled plasma mass spectrometry (ICP-MS). Principal component analysis was used to identify trace element profile alterations in different groups. The mRNA levels of steroidogenesis-related genes were measured by real-time PCR. Our results showed that the trace element profile in follicular fluid was obviously altered in PCOS patients. Copper concentrations were significantly (p < .05) higher in the PCOS group than in the other two groups. Increased copper levels in follicular fluid were associated with a higher number of retrievable oocytes in the PCOS group (B = 1.785, p = .001) but a lower rate of high-quality embryos (B = -6.360, p = .050). Moreover, follicular fluid copper levels were positively correlated with follicular fluid progesterone levels (r = 0.275, p = .010) and testosterone levels (r = 0.250, p = .022). Cultured human granulosa cells overexposed to copper showed significantly (p < .05) increased estradiol secretion and decreased testosterone levels. Real-time quantitative PCR revealed a significant (p < .05) increase in CYP19A1 and HSD3b mRNA expression. Our results indicate that increased copper levels in follicular fluid could affect follicle development in PCOS patients, and the mechanism may be related to copper-induced abnormalities in steroidogenesis.

Taurine Promotes In-vitro Follicle Development, Oocyte Maturation, Fertilization and Cleavage of rats

It is well known that a large quantity of taurine is present in mammalian ovaries. Taurine reportedly promotes the secretion of female reproductive hormones by stimulating hypothalamus-pituitary-gonadal axis function. Therefore, we speculated that taurine may have beneficial effects on follicle growth, oocyte maturation, fertilization and cleavage. Here, we cultured rat follicles, immature oocytes and sperms in vitro and treated with taurine to observe the changes in follicle diameter, estradiol concentration as well as the rate of oocytes maturation, fertilization and cleavage using an inverted microscope. The results showed that taurine can elevate ovarian follicles growth and oocyte maturation, fertilization, and cleavage rates in vitro, which may be attributed to its osmoregulation and stimulation on the estradiol secretion. Our results provide important insights into taurine application in female production, although the underlying mechanism need to be further addressed.

Treatment of female rhesus macaques with a somatostatin receptor antagonist that increases oocyte fertilization rates without affecting post-fertilization development outcomes

PURPOSE

To determine the effects of PGL1001, a somatostatin receptor isoform-2 (SSTR-2) antagonist, on ovarian follicle development, oocyte fertilization, and subsequent embryo developmental potential in the rhesus macaque.

METHODS

Cycling female rhesus macaques (N = 8) received vehicle through one menstrual (control) cycle, followed by daily injections of PGL1001, a SSTR-2 antagonist, for three menstrual (treatment) cycles. Main endpoints include overall animal health and ovarian hormones (e.g., estradiol [E2], progesterone [P4], and anti-Müllerian hormone [AMH]), ovarian circumference, numbers of oocytes and their maturation status following controlled ovarian stimulation (COS), as well as oocyte fertilization and subsequent blastocyst rates that were assessed in control and PGL1001 treatment cycles. Circulating PGL1001 levels were assessed at baseline as well as 6, 60, and 90 days during treatment.

RESULTS

PGL1001 treatment did not impact overall animal health, menstrual cycle length, or circulating levels of ovarian hormones (E2, P4, and AMH) in comparison to vehicle treatment during natural cycles. PGL1001 treatment increased (p ˂ 0.05) ovarian circumference and the day 8 to day 1 ratio of AMH levels (p ˂ 0.05) during a COS protocol, as well as oocyte fertilization rates compared to the vehicle treatment interval. Blastocyst development rates were not significantly different between vehicle and PGL1001 treatment groups.

CONCLUSION

Prolonged treatment with PGL1001 appears to be safe and does not affect rhesus macaque general health, menstrual cycle length, or ovarian hormone production. Interestingly, PGL1001 treatment increased the fertilization rate of rhesus macaque oocytes collected following ovarian stimulation.

Different patterns of ovarian recovery after cancer treatment suggest various individual ovarian susceptibilities to chemotherapy

The relationship between early recovery of menstrual activity and blood anti-Müllerian hormone (AMH) concentrations were investigated within the first year post-chemotherapy in 32 young patients with breast cancer. All were treated by surgery and the same chemotherapy protocol (three cycles of FEC100 plus three cycles of taxanes). Menstrual activity, blood AMH (using picoAMH ELISA) and FSH concentrations were measured longitudinally before, during and up to 12 months after the end of chemotherapy (six samples per patient). Among the cohort, 17 patients recovered spontaneous cycles at +6 months (fast recovery) whereas the remaining 15 patients were still amenorrheic at that time (slow recovery). Blood AMH differed between these two subgroups at each time of the recovery phase starting at 3 months post-chemotherapy. The AMH patterns were also different: rapid and large increase in the fast recovery versus slow and partial increase in the slow recovery subgroup. No difference in ovarian recovery was observed between patients with a hormone positive or negative tumour. In conclusion, studying the post-chemotherapy patterns of menstrual activity and AMH, two paces of early ovarian recovery are distinguishable in young breast cancer patients who received the same chemotherapy protocol. This suggests different individual ovarian susceptibilities to chemotherapy.

Cadmium exposure in newborn rats ovary induces developmental disorders of primordial follicles and the differential expression of SCF/c-kit gene

Since the 1990s, the rising problem that gonad reproductive toxicity on adult female after exposing to cadmium (Cd), an environmental endocrine disruptor, has attracted high attention at home and abroad,and was systematically studied. Our research focuses on a further problem is that early cadmium exposure (during birth to before puberty) impact on development and function of ovarian cells and its possible mechanism. Our research focuses on the changes of ovarian cells growth and development after the newborn rat ovaries with cadmium exposure in vitro, and different expression of ovarian cells development-related factors, SCF/c-kit and changes of their DNA methylation status. We obtained ovaries from 4-day-old SD rats and cultured them in DMEM/F12 mixed with α-MEM media in vitro. Different doses of cadmium were designed as control, 0.5, 5, 10 and 50μM, and then the constituent ratio of ovarian follicle and follicular oocytes diameter were observed with microscope after 4-h exposure. We found that the increased constituent ratio of original follicle and decreased diameter of all levels of follicular oocytes(compared with control, with statistically significant differences, P<0.01).After the measurement of expression of SCF/c-kit by qRT-PCR and Western Blotting, the mRNA and protein expression of SCF/c-kit in ovarian were both decreased. We further found that the increased constituent ratio of growth follicle and increased diameter of oocytes under the treatment of adding SCF in cell culture media. Finally, MALDI-TOF-MS method showed DNA-low methylation status of SCF/c-kit promoter region after Cd exposure. Overall, we concluded that the exposure of cadimium (5-50μM) on newborn rats ovaries could inhibit follicle development.SCF/c-kit system might mediate follicle development damage caused by cadmium, which is associated with DNA hypomethylation of SCF/c-kit promoter region may be worthy of further study.

Dose dependent effect of resveratrol in preventing cisplatin-induced ovarian damage in rats: An experimental study

This study aimed to evaluate the effect of resveratrol in preventing cisplatin (CP) induced ovarian damage in rats. Twenty-eight female Wistar albino rats were separated into four groups. No medication was given to group 1. Over the 21-day study period, low-dose resveratrol was given to group 2, high-dose resveratrol was given to group 3, and saline was administered to group 4. On the 15th day of medication, all groups except for group 1 were treated with a single dose of CP. Serum levels of anti-Mullerian hormone (AMH) were tested at baseline and on the 15th and 21st days. All rats underwent oophorectomy one week after CP application. Primordial, primary, secondary, and tertiary follicles were counted microscopically. No significant difference was observed among the groups in mean AMH levels according to follow-up time. The numbers of primary and primordial follicles were statistically significantly higher in group 2 than in group 4 (p<0.05). The number of tertiary follicles was statistically significantly higher in group 1 than in groups 3 and 4 (p<0.05), but it was not statistically significantly different than in group 2. Resveratrol, particularly at low-doses, can prevent CP induced ovarian damage by maintaining the numbers of primordial and primary follicles. Further studies are needed to study the effect of resveratrol on human ovaries.

Thyroid peroxidase identified in human granulosa cells: another piece to the thyroid-ovary puzzle?

Thyroid hormones seemingly influence the maturation of the human oocyte. Thyroid hormone receptors have been isolated in granulosa mural and cumulus cells and the mature oocyte of the human ovarian follicle. Thyroid hormones are present in follicular fluid in concentrations similar to those in serum. Most importantly, enzymes involved in the chain that regulate the generation of thyroid hormones have been found in granulosa cells. For the first time, we have isolated thyroid peroxidase by immunocytochemistry in the granulosa cumulus cells of the human ovarian follicle, thereby supporting the hypothesis that the human ovarian follicle may be an independent thyroid-hormone producing unit.

Transcriptome analysis of the potential roles of FOXL2 in chicken pre-hierarchical and pre-ovulatory granulosa cells

Forkheadbox L2 (FOXL2) is a transcription factor involved in mammalian ovarian development, especially in granulosa cell differentiation. However, this factor's function in mature chicken ovary is unclear. To explore the function of FOXL2 in chicken granulosa cells, we performed RNA-seq to compare the transcriptomes of pre-hierarchical (phGCs) and pre-ovulatory granulosa cells (poGCs) by FOXL2 overexpression. We observed that focal adhesion might be one of the key pathways activated during the differentiation of granulosa cells, and FOXL2 might be involved in follicle selection by regulating the expression of cytokines and the concentration of cyclic adenosine monophosphate (cAMP). Interestingly, we observed that FOXL2 played different roles in phGCs and poGCs, which might contribute to homeostasis in the chicken follicle by inducing differentiation of granulosa cells in pre-hierarchal follicles and preventing premature ovulation in pre-ovulatory follicles. Taken together, the results of our study establish a framework for understanding the potential functions of FOXL2 in the chicken granulosa cell.

Expression and regulation of prolactin-like protein messenger RNA in undifferentiated chicken granulosa cells

Prolactin-like protein (PRL-L; LOC417800) is a homolog of PRL in non-mammalian vertebrates and can act as a functional ligand of PRL receptor (PRLR). Despite its widespread expression in extrapituitary tissues, mechanisms of regulation of PRL-L in the chicken ovary remain unknown. In this study, we first examined PRL-L expression in chicken ovarian developing follicles. PRL-L transcript levels were highest (P<0.05) in follicular walls of <2mm follicles and progressively declined during follicle maturation. Undifferentiated granulosa cells of 6-8mm follicles had higher (P<0.05) PRL-L mRNA levels than differentiated granulosa cells of F3, F2 or F1 follicles. In cultured undifferentiated granulosa cells, levels of PRL-L transcript were increased (P<0.05) by follicle stimulating hormone (FSH) treatment while were not altered by the addition of luteinizing hormone (LH). In addition, 10ng/ml non-glycosylated (NG-) and 1ng/ml glycosylated (G-) PRL increased (P<0.05) but at higher levels (100 or 1000ng/ml) both showed no effects on PRL-L expression. Furthermore, 100ng/ml NG-PRL enhanced (P<0.05) FSH-induced PRL-L expression, whereas the effects of G-PRL were not significant. These results suggest that PRL-L mRNA is differentially expressed in the follicular hierarchy and its high abundance in undifferentiated granulosa cells is under the regulation of FSH or PRL variants independently or in combination. Moreover, in undifferentiated granulosa cells we also provide evidence for a positive role for PKA, PKC and PI3K signaling while a negative role for ERK2 in mediating FSH stimulation of PRL-L transcription.

Anti-Müllerian hormone (AMH) receptor type II expression and AMH activity in bovine granulosa cells

Anti-Müllerian hormone (AMH) produced by granulosa cells has previously been proposed to play a role in regulating granulosa cell differentiation and follicle selection. Although AMH receptor type II (AMHR2) dimerizes with a type I receptor to initiate AMH signaling, little is known about the regulation of AMHR2 expression in bovine granulosa cells and the role of AMH in follicle development. The primary objectives of this study were to: (1) characterize AMHR2 expression in granulosa cells during follicle development; (2) identify factors that regulate AMHR2 mRNA expression in granulosa cells; and (3) examine the role of AMH signaling in granulosa cell differentiation and proliferation. Bovine granulosa cells were isolated from 5- to 8-mm follicles before selection and deviation, as well as from 9- to 12-mm and 13- to 24-mm follicles after selection. Analyses revealed that expression of AMHR2 was greater in 5- to 8-mm follicles compared with 13- to 24-mm follicles (P < 0.05). Granulosa cells treated with bone morphogenetic protein 6 (BMP6) or BMP15, but not BMP2, significantly increased AMHR2 expression when compared with control cultured cells (P < 0.05). In addition, expression of AMH was greater in granulosa cells cultured with BMP2, BMP6, or BMP15 when compared with controls (P < 0.05). Finally, treatment with recombinant human AMH, in vitro, inhibited CYP19A1 expression in a dose-related (10-100 ng/mL) fashion, and reduced granulosa cell proliferation at 48 and 72 hours (P < 0.05). Results from these studies indicate that AMH signaling plays a role in both regulating granulosa cell proliferation and preventing granulosa cells from 5- to 8-mm follicles from undergoing premature differentiation before follicle selection.

Balance of insulin and FSH concentrations improves the in vitro development of isolated goat preantral follicles in medium containing GH

The aim of this study was to evaluate the effect of different combinations of insulin and FSH concentrations in culture media containing GH on the in vitro follicle morphology, antrum formation, growth rates, estradiol (E2) production, oocyte viability and maturation as well as gene expression for FSHR, GHR, INSR, CYP19A1, CYP17, 3ßHSD. Secondary follicles were individually cultured for 18 days in a basic medium containing 50ng/mL GH supplemented with low insulin concentration (INS-LW: 10ng/mL) or high insulin concentration (INS-HG: 10μg/mL) alone or with a fixed FSH concentration (FSH100: 100ng/mL) or with increasing FSH concentrations (FSH-SEQ: 100ng/mL, days 0-6; 500ng/mL, days 6-12; 1000ng/mL days 12-18). In the INS-LW treatment was observed a higher (P<0.05) incidence of normal follicles at day 18 of culture. However, overall higher (P<0.05) follicular growth, oocyte diameter and meiotic resumption rates were obtained using INS-HG+FSH 100. The INS-HG and INS-HG+FSH100 treatments showed higher E2 production and mRNA levels for CYP19A1, CYP17, 3βHSD when compared to INS-LW and INS-LW+FSH100. However, the addition of increasing FSH concentration, regardless of insulin concentration, did not improve the follicular growth, meotic resumption, E2 production or gene expression of steroidogenic enzymes when compared with INS-HG+FSH100. In conclusion, in presence of GH, a basic medium supplemented with 10μg/mL insulin and 100μg/mL FSH throughout the culture period, improves follicular and oocyte growth, oocyte meiotic resumption and E2 production from isolated preantral caprine follicles cultured in vitro.

Proteomic analysis of human follicular fluid from fertile women

Background

Follicular fluid is a unique biological fluid in which the critical events of oocyte and follicular maturation and somatic cell-germ cell communication occur. Because of the intimate proximity of follicular fluid to the maturing oocyte, this fluid provides a unique window into the processes occurring during follicular maturation. A thorough identification of the specific components within follicular fluid may provide a better understanding of intrafollicular signaling, as well as reveal potential biomarkers of oocyte health for women undergoing assisted reproductive treatment. In this study, we used high and low pH HPLC peptide separations followed by mass spectrometry to perform a comprehensive proteomic analysis of human follicular fluid from healthy ovum donors. Next, using samples from a second set of patients, an isobaric mass tagging strategy for quantitative analysis was used to identify proteins with altered abundances after hCG treatment.

Results

A total of 742 follicular fluid proteins were identified in healthy ovum donors, including 413 that have not been previously reported. The proteins belong to diverse functional groups including insulin growth factor and insulin growth factor binding protein families, growth factor and related proteins, receptor signaling, defense/immunity, anti-apoptotic proteins, matrix metalloprotease related proteins, and complement activity. In a quantitative analysis, follicular fluid samples from age-matched women undergoing in vitro fertilization oocyte retrieval were compared and 17 follicular fluid proteins were found at significantly altered levels (p < 0.05) between pre-hCG and post-hCG samples. These proteins belong to a variety of functional processes, including protease inhibition, inflammation, and cell adhesion.

Conclusions

This database of FF proteins significantly extends the known protein components present during the peri-ovulatory period and provides a useful basis for future studies comparing follicular fluid proteomes in various fertility, disease, and environmental exposure conditions. We identified 17 differentially expressed proteins after hCG treatment and together these data showed the feasibility for defining biomarkers that illuminate how the ovarian follicle microenvironment is altered in various infertility-related conditions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12014-015-9077-6) contains supplementary material, which is available to authorized users.

Diet-induced maternal obesity alters ovarian morphology and gene expression in the adult mouse offspring

OBJECTIVE

To examine the effects of high-fat (HF) diet-induced maternal obesity on follicular population and gene expression in adult offspring ovaries.

DESIGN

Experimental mouse study.

SETTING

Laboratory.

ANIMAL(S)

Mice on HF diet.

INTERVENTION(S)

Female C57BL/6J mice were fed an HF or standard chow (C) diet 6 weeks before conception, through pregnancy and lactation. Offspring were fed the C or HF diet from weaning, creating the HF/HF, HF/C, C/HF, C/C offspring groups.

MAIN OUTCOME MEASURE(S)

Follicular counts and gene expression in adult offspring ovaries.

RESULT(S)

Prenatal exposure to maternal HF nutrition resulted in the reduction of primordial, antral, and Graafian follicle numbers in offspring ovaries (both HF/C and HF/HF). Expression levels of genes involved in apoptosis (FoXO3a), follicular growth and development (Gdf9), and circadian rhythms generation (Clock and Bmal1) were elevated in the ovaries of HF/C and HF/HF offspring, while expression of the circadian clock genes Cry1 and Per1 were lower in HF/HF ovaries.

CONCLUSION(S)

Maternal obesity during pregnancy has long-term deleterious consequences on follicular growth and development in the adult offspring ovaries, which may impact their reproductive potential.