Anti-müllerian hormone and anti-müllerian hormone type II receptor messenger ribonucleic acid expression in rat ovaries during postnatal development, the estrous cycle, and gonadotropin-induced follicle growth

Effect of serum anti-Müllerian hormone levels on the superovulation response in Holstein heifers

BACKGROUND

Anti-Müllerian hormone (AMH) holds potential as a biomarker for assessing the superovulation (SO) response in cattle. Nonetheless, there exists scant information regarding this aspect in the literature concerning dairy heifers. Given this gap, our objective is to explore the viability of AMH as an indicator for gauging the SO response specifically in Holstein heifers. Furthermore, our aim encompasses examining the variations in AMH levels within the same individuals before and after undergoing SO.

METHODS

The study included 41 Holstein heifers. All heifers were superovulated and blood samples were taken both before and after the SO protocol.

RESULTS

The findings revealed that the mean values of serum AMH concentrations before and after SO were 0.122 ng/mL (0.093-0.248 ng/mL) and 0.119 ng/mL (0.084-0.170 ng/mL), respectively. AMH concentrations in heifers were stratified into low (<0.106 ng/mL), medium (0.107-0.126 ng/mL) and high (>0.127 ng/mL) categories both before and after SO.

CONCLUSIONS

There was no significant correlation between AMH levels in the heifers both before and after SO treatment with the number of follicles, corpora lutea, total embryos collected or embryos transferred (p > 0.05). Furthermore, this study showed that serum AMH concentrations in Holstein heifers did not change after SO treatment. In this study, as AMH levels in Holstein heifers were in a narrow range, a relationship between AMH and SO response could not be determined. In future studies, we believe that it would be more useful to plan more studies in Holstein donor heifers, taking into account the number of animals and AMH levels.

Role of Anti-Müllerian Hormone in Male Reproduction and Sperm Motility

Anti-Müllerian hormone (AMH) is secreted by Sertoli cells and is responsible for the regression of Müllerian ducts in the male fetus as part of the sexual differentiation process. Serum AMH concentrations are at their lowest levels in the first days after birth but increase after the first week, likely reflecting active Sertoli cell proliferation. AMH rises rapidly in concentration in boys during the first month, reaching a peak level at ∼6 months of age, and it remains high during childhood, then they will slowly decline during puberty, falling to low levels in adulthood. Serum AMH measurement is used by pediatric endocrinologist as a specific marker of immature Sertoli cell number and function during childhood. After puberty, AMH is released especially by the apical pole of the Sertoli cells toward the lumen of the seminiferous tubules, resulting in higher levels in the seminal plasma than in the serum. Recently, AMH has received increasing attention in research on male fertility-related disorders. This article reviews and summarizes the potential contribution of serum AMH measurement in different male fertility-related disorders.

Reduced anti-Müllerian hormone action in cumulus-oocyte complexes is beneficial for oocyte maturation without affecting oocyte competence

Anti-Müllerian hormone (AMH) is a key paracrine/autocrine factor regulating folliculogenesis in the postnatal ovary. As antral follicles mature to the preovulatory stage, AMH production tends to be limited to cumulus cells. Therefore, the present study investigated the role of cumulus cell-derived AMH in supporting maturation and competence of the enclosed oocyte. Cumulus-oocyte complexes (COCs) were isolated from antral follicles of rhesus macaque ovaries for in vitro maturation with or without AMH depletion. Oocyte meiotic status and embryo cleavage after in vitro fertilization were assessed. In vitro maturation with AMH depletion was also performed using COCs from antral follicles of human ovarian tissue. Oocyte maturation and morphology were evaluated. The direct AMH action on mural granulosa cells of the preovulatory follicle was further assessed using human granulosa cells cultured with or without AMH supplementation. More macaque COCs produced metaphase II oocytes with AMH depletion than those of the control culture. However, preimplantation embryonic development after in vitro fertilization was comparable between oocytes derived from COCs cultured with AMH depletion and controls. Oocytes resumed meiosis in human COCs cultured with AMH depletion and exhibited a typical spindle structure. The confluency and cell number decreased in granulosa cells cultured with AMH supplementation relative to the control culture. AMH treatment did not induce cell death in cultured human granulosa cells. Data suggest that reduced AMH action in COCs could be beneficial for oocyte maturation. Cumulus cell-derived AMH is not essential for supporting oocyte competence or mural granulosa cell viability.

The epoxiconazole and tebuconazole fungicides impair granulosa cells functions partly through the aryl hydrocarbon receptor (AHR) signalling with contrasted effects in obese, normo-weight and polycystic ovarian syndrome (PCOS) patients

Polycystic ovarian syndrome (PCOS), frequently associated to obesity, is the main reproductive disorder in women in age to procreate. Some evidence suggests that pesticides can result in alterations of the female reproductive system, including polycystic ovary syndrome (PCOS). Here, we detected two fungicides, Tebuconazole (Tb) and Epoxiconazole (Epox) in the soils and waters of French area. Our hypothesis is that these two triazoles could be associated to the etiology of PCOS. We used the human KGN cell line and primary human granulosa cells (hGCs) from different group of patients: normal weight non PCOS (NW), normal weight PCOS (PCOS NW), obese (obese) and obese PCOS (PCOS obese). We exposed in vitro these cells to Tb and Epox from 0 up to 10 mM for 24 and 48 h and analysed cell viability and steroidogenesis. In hGCs NW, cell viability was reduced from 12.5 µM for Tb and 75 µM for Epox. In hGCs NW, Epox decreased progesterone (Pg) and estradiol (E2) secretions and inhibited STAR, HSD3B and CYP19A1 mRNA expressions from 25 µM and increased AHR mRNA expression from 75 µM. Tb exposure also reduced steroid secretion and STAR and CYP19A1 mRNA expressions and increased AHR mRNA expression but at cytotoxic concentrations. Silencing of AHR in KGN cells reduced inhibitory effects of Tb and Epox on steroid secretion. Tb and Epox exposure decreased more steroid secretion in hGCs from obese, PCOS NW and PCOS obese groups than in NW group. Moreover, we found a higher gene expression of AHR within these three groups. Taken together, both Epox and Tb reduced steroidogenesis in hGCs through partly AHR and Tb was more cytotoxic than Epox. These triazoles alter more strongly PCOS and/or obese hGCs suggesting that human with reproductive disorders are more sensitive to triazoles exposure.

The Role of Anti-Müllerian Hormone in Ovarian Function

Anti-Müllerian hormone (AMH) is a member of the transforming growth factor β (TGFβ) superfamily, whose actions are restricted to the endocrine-reproductive system. Initially known for its role in male sex differentiation, AMH plays a role in the ovary, acting as a gatekeeper in folliculogenesis by regulating the rate of recruitment and growth of follicles. In the ovary, AMH is predominantly expressed by granulosa cells of preantral and antral follicles (i.e., post primordial follicle recruitment and prior to follicle-stimulating hormone (FSH) selection). AMH signals through a BMP-like signaling pathway in a manner distinct from other TGFβ family members. In this review, the latest insights in AMH processing, signaling, its regulation of spatial and temporal expression pattern, and functioning in folliculogenesis are summarized. In addition, effects of AMH variants on ovarian function are reviewed.

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.

Serum anti-Müllerian hormone concentrations are related to embryo development: lessons from time-lapse imaging

Our objective was to study whether serum anti-Müllerian hormone (AMH) concentrations were associated with embryo morphokinetic events. This retrospective cohort study was performed in a private university-affiliated in vitro fertilization centre between March 2019 and December 2020 and included 902 oocytes cultured in a time-lapse imaging incubator, obtained from 114 intracytoplasmic sperm injection cycles performed. The relationship between AMH concentrations and morphokinetic events was investigated by considering the clustering of data (multiple embryos/patient). Evaluated kinetic markers were time to pronuclei appearance (tPNa) and fading (tPNf), time to two (t2), three (t3), four (t4), five (t5), six (t6), seven (t7), and eight cells (t8), (tSB) and time to the start of blastulation (tSB) and to blastulation (tB). Significant inverse relationships were observed between serum AMH concentrations and tPNf, t3, t4, t5, t6, t7, t8, and tB. The AMH was positively correlated with the KIDScore and implantation rate. Increased serum AMH concentrations correlated with faster embryo development. The clinical implications of this effect on embryo development warrant further investigation.

Transcriptome Signature of Immature and In Vitro-Matured Equine Cumulus-Oocytes Complex

Maturation is a critical step in the development of an oocyte, and it is during this time that the oocyte advances to metaphase II (MII) of the meiotic cycle and acquires developmental competence to be fertilized and become an embryo. However, in vitro maturation (IVM) remains one of the limiting steps in the in vitro production of embryos (IVP), with a variable percentage of oocytes reaching the MII stage and unpredictable levels of developmental competence. Understanding the dynamics of oocyte maturation is essential for the optimization of IVM culture conditions and subsequent IVP outcomes. Thus, the aim of this study was to elucidate the transcriptome dynamics of oocyte maturation by comparing transcriptomic changes during in vitro maturation in both oocytes and their surrounding cumulus cells. Cumulus-oocyte complexes were obtained from antral follicles and divided into two groups: immature and in vitro-matured (MII). RNA was extracted separately from oocytes (OC) and cumulus cells (CC), followed by library preparation and RNA sequencing. A total of 13,918 gene transcripts were identified in OC, with 538 differentially expressed genes (DEG) between immature OC and in vitro-matured OC. In CC, 13,104 genes were expressed with 871 DEG. Gene ontology (GO) analysis showed an association between the DEGs and pathways relating to nuclear maturation in OC and GTPase activity, extracellular matrix organization, and collagen trimers in CC. Additionally, the follicle-stimulating hormone receptor gene (FSHR) and luteinizing hormone/choriogonadotropin receptor gene (LHCGR) showed differential expressions between CC-MII and immature CC samples. Overall, these results serve as a foundation to further investigate the biological pathways relevant to oocyte maturation in horses and pave the road to improve the IVP outcomes and the overall clinical management of equine assisted reproductive technologies (ART).

Anti-Müllerian Hormone levels after metformin treatment in polycystic ovary syndrome: A systematic review and meta-analysis

This systematic review and meta-analysis aim to evaluate whether treatment with metformin would reduce Anti-Müllerian Hormone levels in patients with polycystic ovary syndrome. A search was performed in Medline, Embase, Web of Science, and Cochrane Library databases and grey literature (Google Scholar). The following keywords were used in the search strategy: "Polycystic Ovary Syndrome", "Anti-Mullerian Hormone", "Metformin". The search was limited to human studies, with no language restriction. 328 studies were found, 45 studies were selected for full-text reading and 16 of those studies, six randomized controlled trial and 10 non-randomized studies were included. The synthesis of randomized controlled trials, metformin showed a reduction in serum levels of Anti-Müllerian Hormone compared to control groups (SMD - 0.53, 95 %CI - 0.84 to - 0.22, p < 0.001, I2 = 0 %, four studies, 171 participants, high quality of evidence). Six non-randomized studies evaluated data before and after the metformin intervention. The synthesis showed that using metformin reduced serum Anti-Müllerian Hormone values (SMD - 0.79, 95 %CI - 1.03 to - 0.56, p < 0.001, I2 = 0 %, six studies, 299 participants, low quality of evidence). Metformin administration in women with polycystic ovary syndrome is associated significantly with reduced Anti-Müllerian Hormone serum levels.

Deciphering the Roles & Regulation of Estradiol Signaling during Female Mini-Puberty: Insights from Mouse Models

Mini-puberty of infancy is a short developmental phase occurring in humans and other mammals after birth. In females, it corresponds to transient and robust activation of the hypothalamo-pituitary-ovarian (HPO) axis revealed by high levels of gonadotropin hormones, follicular growth, and increased estradiol production by the ovary. The roles of estradiol signaling during this intriguing developmental phase are not yet well known, but accumulating data support the idea that it aids in the implementation of reproductive function. This review aims to provide in-depth information on HPO activity during this particular developmental phase in several mammal species, including humans, and to propose emerging hypotheses on the putative effect of estradiol signaling on the development and function of organs involved in female reproduction.

Hormone concentrations of dominant follicles in the TALES randomized controlled trial comparing letrozole with tamoxifen

BACKGROUND

In this secondary analysis of the TAmoxifen or Letrozole in Estrogen Sensitive tumors (TALES) trial, we aimed to investigate if concurrent administration of letrozole vs. tamoxifen vs. no added treatment affects hormonal composition and size of stimulated ovarian follicles.

METHODS

TALES is a randomized controlled trial of IVF stimulation for estrogen receptor (ER)-positive breast cancer patients stimulated with gonadotropins and administered concurrent tamoxifen 20 mg or letrozole 5 mg. We analyzed estradiol (E2), testosterone (T), progesterone (P4), follicle stimulating hormone (FSH), luteinizing hormone (LH), and anti-Mullerian hormone (AMH). We used ANOVA/Kruskal-Wallis, logistic, and linear regression models to examine differences in follicular hormone levels, size, and mature oocyte yield between trial arm.

RESULTS

We included data from total 246 follicles (94 letrozole, 82 tamoxifen, and 70 control) from 123 unique participants. E2 was lower (letrozole 187.4, tamoxifen 1026.0, control 821.5 ng/mL, p < 0.01) and T was higher (letrozole 2489, tamoxifen 571, and control 504 ng/mL, p < 0.03) in the letrozole group compared to tamoxifen and control groups, while other hormone levels and follicle size were similar across groups. There were no significant differences in hormone concentrations within the follicle between tamoxifen and control arms. On multivariate logistic regression, there was no significant association of mature oocyte yield by follicle size, hormone levels, or trial arm.

CONCLUSIONS

Concurrent administration of letrozole with gonadotropins affects follicular E2 and T concentrations compared to tamoxifen/control. Tamoxifen was not associated with any differences in hormone concentrations within the follicle. Mature oocyte yield was similar across groups.

Anti-Müllerian hormone-mediated preantral follicle atresia is a key determinant of antral follicle count in mice

STUDY QUESTION

Does anti-Müllerian hormone (AMH) induce preantral follicle atresia in mice?

SUMMARY ANSWER

The present findings suggest that AMH-mediated follicle atresia only occurs in early follicles before they become sensitive to FSH.

WHAT IS KNOWN ALREADY

Most prior studies have investigated the ability of AMH to inhibit primordial follicle activation. Our previous study showed that AMH-overexpressing mice had fewer preantral follicles than expected after accounting for primordial follicle inhibition but the reason for this was not determined.

STUDY DESIGN, SIZE, DURATION

Cross-sectional-control versus transgenic/knockout mouse studies were carried out.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Studies were conducted on female wild-type (Amh+/+), AMH-knockout (Amh-/-) and AMH overexpressing (Thy1.2-AMHTg/0) mice on a C57Bl/6J background (age: 42-120 days). The follicle counts were conducted for primordial, transitioning, primary, secondary and antral follicles in Amh-/- and Amh+/+ mice. After confirming that follicle development speeds were identical (proliferating cell nuclear antigen immunohistochemistry), the ratio of follicles surviving beyond each stage of folliculogenesis was determined in both genotypes. Evidence for increased rates of preantral follicle atresia was assessed by active caspase-3 immunohistochemistry in wild-type and Thy1.2-AMHTg/0 mice.

MAIN RESULTS AND THE ROLE OF CHANCE

Amh -/- mice at 100-120 days of age had lower primordial follicle counts but higher primordial follicle activation rates compared to Amh+/+ mice. These counteracting effects led to equivalent numbers of primordial follicles transitioning to the primary stage in Amh+/+ and Amh-/- mice. Despite this, Amh+/+ mice had fewer primary, secondary, small antral and medium antral follicles than Amh-/- mice indicating differing rates of developing follicle atresia between genotypes. Cleaved caspase-3 immunohistochemistry in Thy1.2-AMHTg/0 ovaries revealed high rates of granulosa cell and oocyte apoptosis in late primary/early secondary follicles of Thy1.2-AMHTg/0 mice.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

The findings were shown only in one species and additional research will be required to determine generalizability to other species.

WIDER IMPLICATIONS OF THE FINDINGS

This study is consistent with prior studies showing that Amh-/- mice have increased primordial follicle activation but these new findings demonstrate that AMH-mediated preantral follicle atresia is a predominant cause of the increased small antral follicle counts in Amh-/- mice. This suggests that the role of AMH is not to conserve the ovarian reserve to prolong fertility, but instead to prevent the antral follicle pool from becoming too large. While this study may demonstrate a new function for AMH, the biological purpose of this function requires further investigation, particularly in mono-ovulatory species.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Health Research Council of New Zealand and the University of Otago. No competing interests to declare.

Knock-down of amh transcription by antisense RNA reduces FSH and increases follicular atresia in female Oreochromis niloticus

Anti-Müllerian hormone (Amh) plays an important role in regulating gonad development in teleosts. However, little is known about the effects of Amh on follicle development. In this study, we transfected the vector containing antisense RNA fragments of the amh gene to produce Nile tilapia, Oreochromis niloticus, with knocked-down Amh function in vivo. The results confirmed that the antisense RNA effectively inhibited amh transcription and Amh protein expression in female tilapia ovarian tissue. At 180 days of age, compared with control fish, female tilapia with knocked-down Amh function showed significantly increased growth and significantly decreased ovary weight and gonadosomatic index (P < 0.05). Female fish in the control group had ruddy-colored external genitalia, eggs extruded from the abdomen when gently squeezed, and most oocytes were developmental stage V. In contrast, the external genitalia of female fish with knocked-down Amh function did not have the ruddy color, no eggs extruded from the abdomen when squeezed, most oocytes were at developmental stages II and III, and considerable follicular atresia was apparent. At 180 days of age, the transcript levels of amhrII, cyp19a1a, foxl2 and sox9b in ovarian tissue, and the titers of luteinizing hormone, follicle stimulating hormone, and estradiol in the serum, were significantly lower in fish with knocked-down Amh function than in control fish (P < 0.05). We concluded that decreased serum hormone levels and an abnormal AMH signal delayed development and caused follicular degeneration in Nile tilapia with knocked-down Amh function. These findings show that antisense RNA is a feasible approach for gene silencing in fish, and represents an accurate and effective strategy to study gene function.

Key signalling pathways underlying the aetiology of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine condition characterised by a range of reproductive, endocrine, metabolic and psychological abnormalities. Reports estimate that around 10% of women of reproductive age are affected by PCOS, representing a significant prevalence worldwide, which poses a high economic health burden. As the origin of PCOS remains largely unknown, there is neither a cure nor mechanism-based treatments leaving patient management suboptimal and focused solely on symptomatic treatment. However, if the underlying mechanisms underpinning the development of PCOS were uncovered then this would pave the way for the development of new interventions for PCOS. Recently, there have been significant advances in our understanding of the underlying pathways likely involved in PCOS pathogenesis. Key insights include the potential involvement of androgens, insulin, anti-Müllerian hormone and transforming growth factor beta in the development of PCOS. This review will summarise the significant scientific discoveries on these factors that have enhanced our knowledge of the mechanisms involved in the development of PCOS and discuss the impact these insights may have in shaping the future development of effective strategies for women with PCOS.

Correlation of serum anti-Mullerian hormone with hormonal and environmental parameters in Brazilian climacteric women

This study aimed to identify the correlation among anti-Mullerian Hormone serum levels and 25-OH-D, obesity, metabolic syndrome (MetS), and sexual hormones in climacteric women classified according to stages of reproductive aging (SRA). A cross-sectional study was conducted with a total of 177 Brazilian climacteric women between 40 and 64 years old. Concentrations of AMH were measured using the Access 2 Immunoassay System. A multiple linear regression analysis was used to identify the relationship among AMH, 25-OH-D, obesity, MetS, sexual hormones, sociodemographic and lifestyle factors. AMH levels decreased with increased age (B = - 0.059; p < 0.001), and reproductive aging (B = - 0.483; p < 0.001). Obesity indicators, lifestyle characters, 25-OH-D levels and MetS were not significantly associated with AMH serum concentration. Negative correlation was found for FSH (B = - 0.009; p < 0.001) and LH (B = - 0.006; p = 0.004); positive correlation for E2 (B = 0.001; p = 0.011), DHEAS (B = 0.003; p < 0.001) and SHBG (B = 0.003; p = 0.005). In the model adjusted for SRA, FSH levels (p < 0.001) and DHEAS (p = 0.014) were associated with AMH. Although, with the adjustment for age, only FSH remained with a significant association (p = 0.001). Of the other analytes, none was associated with AMH, regardless of the model fit. Our findings confirm that serum AMH level decreased with age and FSH levels, but there is no correlation between AMH with obesity, 25-OH-D, MetS or other sexual hormones in Brazilian climacteric women.

The effect of medication on serum anti-müllerian hormone (AMH) levels in women of reproductive age: a meta-analysis

OBJECTIVE

The study aims to address whether serum anti-müllerian hormone (AMH) levels fluctuate in the short term after medication application, including oral contraceptives (OCs), metformin (MET), Gonadotropin-releasing hormone agonist (GnRH-a), dehydroepiandrosterone (DHEA), vitamin D (VD), clomiphene citrate (CC), and letrozole (LET).

METHODS

Published literature from PubMed, Embase, and Cochrane central was retrieved up until 19 September 2021. A total of 51 self-control studies with an average Newcastle-Ottawa quality assessment scale (NOS) score of 6.90 were analyzed. The extracted data were entered into Stata software, and the weighted mean difference/standardized mean difference (WMD/SMD) and 95% confidence interval (CI) were used for data analysis.

RESULTS

After OCs treatment the AMH level showed a significant decline in women with normal ovarian function, which was significant within 3 months (WMD = -1.43, 95% CI: -2.05 to -0.80, P < 0.00001). After MET treatment, the serum AMH decreased in polycystic ovary syndrome (PCOS) patients (WMD = -1.79, 95% CI: -2.32 to -1.26, P < 0.00001), in both obese and non-obese patients. GnRH-a treatment in endometriosis patients led to dynamic changes in the serum AMH levels, that is, ascent at 1 month (P = 0.05), and descent at 3 months (P = 0.02). After DHEA treatment the serum AMH increased in diminished ovarian reserve (DOR) / poor ovarian response (POR) patients (WMD = 0.18, 95% CI: 0.09 to 0.27, P < 0.0001). After VD treatment the serum AMH increased, and it was obvious in non-PCOS patients (WMD = 0.78, 95% CI: 0.34 to 1.21, P = 0.0004). After CC treatment the serum AMH decreased significantly in PCOS patients, specifically in non-obese patients (WMD = -1.24, 95% CI: -1.87 to -0.61, P = 0.0001).

CONCLUSIONS

Serum AMH levels may be affected in the short term after drug application. Specifically, OC, MET and CC lead to decreased AMH level, DHEA and VD lead to increased AMH level, and GnRH-a leads to dynamic variation, which is correlated with PCOS, obesity, age, and duration of medication. The impacts of these medications should be taken into consideration when AMH is used as a marker of ovarian reserve.

Knockout of cyclin B1 in granulosa cells causes female subfertility

In mammalian cells, cyclin B1 plays a pivotal role in mitotic and meiotic progression. It has been reported that infertility occurs after disruption of cyclin B1 (Ccnb1) in male germ cells and oocytes. However, it remains to be elucidated whether the specific disruption of Ccnb1 in granulosa cells influences the reproductive activity of female mice. Amhr2 is expressed in granulosa cells (GCs) of the ovary. Here, we mated Ccnb1^Flox/Flox mice with a transgenic mouse strain expressing Amhr2-Cre to generate GC-specific Ccnb1 knockout mice. The results showed that Ccnb1 ^Flox/Flox, Amhr2-Cre (Ccnb1 cKO) mice were subfertile but had normal oocyte meiotic progress, spindle shape and protein levels of cohesin subunits REC8 and SMC3 on arm chromosomes during meiosis I. A further study found that 32.4% of oocytes from Ccnb1 cKO mice exhibited chromosome condensation and spindle disassembly after the first polar body extrusion and failed to undergo second meiosis, which was never found in oocytes from Ccnb1^Flox/Flox mice. In addition, the percentages of 2-cell embryos, morulas, and blastocysts in the Ccnb1 mutant group were all dramatically decreased compared to those in the Ccnb1^Flox/Flox group (39.2% vs. 86.8%, 26.0% vs. 85.0%, 19.1% vs. 85.8%, respectively). Therefore, GC-specific Ccnb1 deletion in mice could cause fewer and poor-quality blastocysts and subsequent subfertility, which plays an important role in understanding the function of cyclin B1 in reproduction.

Anti-Müllerian Hormone Inhibits FSH-Induced Cumulus Oocyte Complex In Vitro Maturation and Cumulus Expansion in Mice

Anti-Müllerian hormone (AMH) is secreted by the ovaries of female animals and exerts its biological effects through the type II receptor (AMHR2). AMH regulates follicular growth by inhibiting the recruitment of primordial follicles and reducing the sensitivity of antral follicles to FSH. Despite the considerable research on the actions of AMH in granulosa cells, the effect of AMH on the in vitro maturation of oocytes remains largely unknown. In the current study, we showed that AMH is only expressed in cumulus cells, while AMHR2 is produced in both cumulus cells and oocytes. AMH had no significant effect on COCs nuclear maturation, whereas it inhibited the stimulatory effects of FSH on COCs maturation and cumulus expansion. Moreover, AMH treatment effectively inhibited the positive effect of FSH on the mRNA expressions of Hyaluronan synthase 2 (Has2), Pentraxin 3 (Ptx3), and TNF-alpha-induced protein 6 (Tnfaip 6) genes in COCs. In addition, AMH significantly decreased the FSH-stimulated progesterone production, but did not change estradiol levels. Taken together, our results suggest that AMH may inhibit the effects of FSH-induced COCs in vitro maturation and cumulus expansion. These findings increase our knowledge of the functional role of AMH in regulating folliculogenesis.

Cadmium disrupts mouse embryonic stem cell differentiation into ovarian granulosa cells through epigenetic mechanisms

Cadmium (Cd) can influence germ cell development, and epigenetic events may be involved. However, there is no study on whether Cd can influence germ cells differentiation into ovarian granulosa cells (GCs), and more insight into the molecular mechanism of the effect of Cd on germ cell development from mouse embryonic stem (ES) cells into ovarian granulosa cells and investigation of appropriate epigenetic factors are of great importance. In this study, mouse ES cell differentiation into GCs was established in an in vitro model. Subsequently, different Cd concentrations of 0, 0.1, 0.3, and 1 and then 3.0, and 10.0 μmol/L were cultured in this in vitro model. We demonstrated that Cd treatment can interrupt ES cell differentiation into GCs by morphology and ultrastructure observation. Four specific markers (octamer-binding transcription factor 4 (OCT4), sex-determining region Y-box 2 (SOX2), Nanog homeobox (Nanog), and Anti-müllerian hormone type II receptor (Amhr2)) were significantly changed as measured by quantitative real-time-PCR or Western blot (p < 0.05). Cd also significantly changed the DNA methylation of GC sites on the CpG island of Nanog according to the sequential mass ARRAYR methylation method (p < 0.05). The MeRIP-qPCR method was used to detect the levels of N6-methyladenosine (m6A) methylation modification of long noncoding RNA (lncRNA) 1281 and indicated that they were decreased (p < 0.05). Microarray chip analysis, miRNA screening, and bioinformatics were used to further explore the roles of marker regulation-related miRNAs, and 27 miRNAs were putatively related to Cd-interrupted differentiation in ES cells. These data indicated that Cd can interrupt ES cell differentiation into GCs and affect germ cell development, and the underlying mechanism may involve epigenetic mechanisms.

Expression of Anti-Müllerian Hormone and Its Type 2 Receptor in the Ovary of Pregnant and Cyclic Domestic Cats

To evaluate the expression of AMH and its receptor AMHRII, ovaries of 33 p cats were investigated by western blot and immunohistochemistry. After ovariohysterectomy, the cats were grouped according to pregnancy stages and ovarian/placental endocrine activity: group I (n = 3, 24−29 days), II (n = 8, 32−40 days), III (n = 4, 41−46 days), IV (n = 6, 53−61 days) and according to cycle stages: V (n = 6, interestrus) and VI (n = 6, estrus). Serum progesterone- and AMH-concentration was measured. Follicle numbers did not differ between groups. The number of corpora lutea was higher in pregnant cats than in the non-pregnant cats. Serum AMH concentration was at maximum between day 30 and 50 of gestation, and was higher than in non-pregnant cats, then decreased towards term (p < 0.05). In the ovaries, AMH immunopositivity was observed in granulosa cells of secondary and antral follicles, and in interstitial cells of corpora lutea; highest percentage of immunopositive areas was detected in group III (p < 0.05). A positive correlation between the number of corpora lutea and the positive AMH signals in ovarian tissue was determined (r2 = 0.832, p < 0.05); however, only during mid-gestation (group II). Expression of AMHRII was in close co-localization with AMH and strong in the interstitial cells surrounding follicles undergoing atresia. AMHRII expression did not differ between pregnant groups but was higher compared to estrus cats (p ˂ 0.05). We conclude that AMH and AMHRII expression in the feline ovary is comparable to other species. The high serum AMH concentration and ovarian AMHRII expression between day 30 and 50 of gestation are probably related to ovarian activity and follicular atresia.

Clinical use of Anti-Müllerian Hormone to monitor resumption of ovarian activity following removal of a 4.7 mg deslorelin implant in queens

OBJECTIVE

The use of deslorelin implants to control reproduction in cats is increasing but because of its prolonged duration, cat breeders often request implant removal before the end of the treatment. Assaying Anti Mullerian Hormone (AMH) concentrations might be useful to predict time of resumption of ovarian activity in deslorelin-treated queens following implant removal. In queens a minimum of 3 weeks during increasing photoperiod after implant removal has been described for resumption of ovarian activity but no information about AMH concentrations were observed for determining ovarian activity.

ANIMALS

Sixteen queens in which deslorelin implants were surgically removed after 3, 6 or 9 months (n = 6, 4 and 6 queens, respectively) were used in this study.

PROCEDURES

A general and reproductive health check with a GnRH stimulation test were performed before the treatment. After implant removal queens were checked every 1-2 weeks with reproductive ultrasonography, a vaginal smear and blood collection to assay AMH concentrations.

RESULTS

AMH concentrations decreased significantly at the end of the treatment to ≤ 2.5 + 0.6 ng/ml (p ≤ 0.05) and reached a nadir at 1.9 ± 0.9 (p < 0.05) one-week post-removal. Following implant removal AMH concentrations started to rise reaching a value of 3.9 ± 0.7 ng/ml on the third week and were not different from pre-treatment levels on week 6 post-removal (5.8 ng/ml + 0.9, p ≥ 0.05). AMH values did not differ depending on duration of deslorelin treatment but were lower in adult queens (p < 0.05).

CLINICAL RELEVANCE

AMH assay can be a useful tool to follow resumption of feline ovarian function following a deslorelin treatment.

Effects of stocking density on ovarian development and maturation during the rearing period in Shan-ma ducks

Stocking density critically affects the growth and subsequent performance of animals in modern poultry production. This study investigated the effects of stocking density on ovarian development, ovarian maturation, and the mRNA expression of key genes in the reproductive axis during the rearing period of Shan-ma ducks. The experiments involved 180 healthy 7-wk-old Shan-ma ducks and randomly divided into low stocking density (LSD; n = 30, density = 5 birds/m²), medium stocking density (MSD; n = 60, density = 10 birds/m²) and high stocking density groups (HSD; n = 90, density = 15 birds/m²), for rearing. After examining ovarian development and measuring hormone levels in the plasma and expression levels of key regulatory genes in the reproductive axis at 19 wk of rearing, analysis of the gonad index analysis, reflecting stocking density, uncovered statistically significant differences. The gonad index of the LSD group was significantly higher than those of the MSD and HSD groups (P < 0.01), while no significant difference was observed between the MSD and HSD groups. pre-ovulatory follicles (POFs) and small yellow follicles (SYFs) development was only apparent in the LSD group, with the large white follicles (LWFs) number of this group being significantly higher than that of the MSD group (P < 0.05). The blood levels of E2 (estradiol), P4 (progesterone), and T (testosterone) were significantly higher in the LSD group than in the MSD and HSD groups (P < 0.05 or 0.01). Also, the levels of both P4 and T were significantly higher in the MSD group than in the HSD group (P < 0.01). The gene expression levels of GnRHR, FSH, AMHR, and FSHR were significantly increased in the LSD group compared to the MSD and HSD groups (P < 0.05 or 0.01), while the expression levels of GnIHR and GDF9 were significantly decreased in the LSD and MSD groups compared to the HSD group (P < 0.05 or 0.01). Steroid biosynthesis pathway genes such as StAR, CYP11A1, 3β-HSD, CYP19A1, and BMP15 were significantly downregulated at greater stocking densities (P < 0.05 or 0.01). Likewise, the protein expression of StAR, 3β-HSD, and CYP19A1 was also significantly decreased (P < 0.05 or 0.01). These results demonstrate that both medium and high stocking densities suppressed the expression of the key reproduction-promoting factors, while the expression level of the key reproductive inhibitory factors was enhanced. Therefore, rates of ovarian development and maturation could be reduced by a high stocking density leading to a delay in reproduction performance during the rearing period of Shan-ma ducks.

Genetics of anti-Müllerian hormone and its signaling pathway

Anti-Müllerian hormone (AMH) is a member of the TGF-β family produced essentially by the supporting somatic cells of the testis. Initially known for its inhibiting role upon the development of female internal organs, AMH has been shown to exert many other effects namely upon germ cells. Circulating AMH reflects the ovarian reserve of young developing follicles and is used to evaluate the fertility potential in assisted reproduction. The signaling pathway of AMH is both similar and different from that of other members of the TGF-β family. Like these, it signals through two distinct serine/threonine receptors, type 1 and type 2, that phosphorylate cytoplasmic effectors, the Smads. It also shares type 1 receptors and Smads with other members of the family. However, AMH is the only family member with its own, dedicated, ligand-specific type 2 receptor, AMHR2. The monogamic relationship between AMH and AMHR2 is supported by molecular studies of the Persistent Müllerian Duct Syndrome, characterized by the presence of Müllerian derivatives in otherwise normally virilized males: mutations of AMH or AMHR2 are clinically indistinguishable.

Anti-Müllerian Hormone Signal Transduction involved in Müllerian Duct Regression

Over seventy years ago it was proposed that the fetal testis produces a hormone distinct from testosterone that is required for complete male sexual development. At the time the hormone had not yet been identified but was invoked by Alfred Jost to explain why the Müllerian duct, which develops into the female reproductive tract, regresses in the male fetus. That hormone, anti-Müllerian hormone (AMH), and its specific receptor, AMHR2, have now been extensively characterized and belong to the transforming growth factor-β families of protein ligands and receptors involved in growth and differentiation. Much is now known about the downstream events set in motion after AMH engages AMHR2 at the surface of specific Müllerian duct cells and initiates a cascade of molecular interactions that ultimately terminate in the nucleus as activated transcription factors. The signals generated by the AMH signaling pathway are then integrated with signals coming from other pathways and culminate in a complex gene regulatory program that redirects cellular functions and fates and leads to Müllerian duct regression.

Synergistic Regulatory Effect of Inhibin and Anti-Müllerian Hormone on Fertility of Mice

Inhibin (INH) and anti-Müllerian hormone (AMH) are essential in ovarian folliculogenesis and play an inhibitory role in mammalian fertility. However, the interactive effect of INH and AMH on the animal reproduction remains unknown. This study aimed to determine the possible interaction and synergy between INH and AMH in steroidogenesis by primary granulosa cells, and investigate their synergistic effect on fertility in mice. In in vitro granulosa cell culture system, we found that the treatment of either INHA or AMH had no significant effect on basal estradiol and progesterone production, whereas both significantly attenuated FSH-induced steroid hormone secretion. Importantly, combined treatment with INHA and AMH showed additive inhibitory effect on FSH-induced estradiol and progesterone production, accompanying a significant downregulation in the expression of FSH-stimulated CYP19A1, HSD3B, CYP11A1, StAR transcripts. The interrelationship of INH and AMH combinations was further investigated through active immune neutralization strategy. Female mice were immunized against INH and AMH eukaryotic expression plasmids, and the litter size was recorded after successfully mating. We observed that both INH and AMH plasmids were able to induce either anti-AMH or anti-INH antibodies in the immunized mice. In comparison with the control group, co-immunization with INH and AMH plasmids induced higher levels of estradiol, resulting in more litter size. Moreover, there was no significant difference on the offspring's weight between each group. Collectively, the results of the present study suggest that INH and AMH have synergistic effect in regulating steroidogenesis and the litter size in mice.

Anti-Müllerian Hormone in Female Reproduction

Anti-Müllerian hormone (AMH), also called Müllerian inhibiting substance, was shown to be synthesized by the ovary in the 1980s. This article reviews the main findings of the past 20 years on the regulation of the expression of AMH and its specific receptor AMHR2 by granulosa cells, the mechanism of action of AMH, the different roles it plays in the reproductive organs, its clinical utility, and its involvement in the principal pathological conditions affecting women. The findings in respect of regulation tell us that AMH and AMHR2 expression is mainly regulated by bone morphogenetic proteins, gonadotropins, and estrogens. It has now been established that AMH regulates the different steps of folliculogenesis and that it has neuroendocrine effects. On the other hand, the importance of serum AMH as a reliable marker of ovarian reserve and as a useful tool in the prediction of the polycystic ovary syndrome (PCOS) and primary ovarian failure has also been acknowledged. Last but not least, a large body of evidence points to the involvement of AMH in the pathogenesis of PCOS.

Follicle Rescue From Prepubertal Ovaries After Recent Treatment With Cyclophosphamide-An Experimental Culture System Using Mice to Achieve Mature Oocytes for Fertility Preservation

Ovarian tissue cryopreservation is the only feasible method for fertility preservation in prepubertal girls that will undergo gonadotoxic chemotherapy. To date, the only clinical use of cryopreserved tissue is by a later tissue retransplantation to the patient. Clinical challenges in fertility preservation of very young patients with cancer include time constraints that do not allow to retrieve the tissue for cryopreservation before starting chemotherapy and the preclusion of future ovarian tissue transplantation due to the risk of reintroduction of malignant cells in patients with systemic diseases. To overcome these two challenges, we investigated using an experimental model the feasibility of retrieving secondary follicles from ovaries of prepubertal mice after cyclophosphamide (CPA) treatment in increasing doses of 50, 75, and 100 mg/kg. The follicles were thereafter cultured and matured in vitro. The main outcomes included the efficiency of the method in terms of obtained matured oocytes and the safety of these potentially fertility preservative procedures in terms of analyses of oocyte competence regarding normality of the spindle and chromosome configurations. Our findings demonstrated that it was feasible to isolate and culture secondary follicles and to obtain mature oocytes from prepubertal mice ovaries recently treated with CPA. The efficiency of this method was highly demonstrated in the 100 mg/kg CPA group, with near 90% follicle survival rate after 12 days' culture, similarly to control. Around 80% of the follicles met the criteria to put into maturation, and more than 40% of them achieved metaphase II, with normal spindle and chromosome configurations observed. Suboptimal results were obtained in the 50 and 75 mg/kg CPA groups. These paradoxical findings towards CPA dose might probably reflect a more difficult selection of damaged growing follicles from ovaries recently treated with lower doses of CPA and a hampered ability to identify and discard those with reduced viability for the culture.

Functional Activity of Recombinant Forms of Amh and Synergistic Action with Fsh in European Sea Bass Ovary

Although anti-Müllerian hormone (AMH) has classically been correlated with the regression of Müllerian ducts in male mammals, involvement of this growth factor in other reproductive processes only recently come to light. Teleost is the only gnathostomes that lack Müllerian ducts despite having amh orthologous genes. In adult teleost gonads, Amh exerts a role in the early stages of germ cell development in both males and females. Mechanisms involving the interaction of Amh with gonadotropin- and growth factor-induced functions have been proposed, but our overall knowledge regarding Amh function in fish gonads remains modest. In this study, we report on Amh actions in the European sea bass ovary. Amh and type 2 Amh receptor (Amhr2) are present in granulosa and theca cells of both early and late-vitellogenic follicles and cannot be detected in previtellogenic ovaries. Using the Pichia pastoris system a recombinant sea bass Amh has been produced that is endogenously processed to generate a 12–15 kDa bioactive mature protein. Contrary to previous evidence in lower vertebrates, in explants of previtellogenic sea bass ovaries, mature Amh has a synergistic effect on steroidogenesis induced by the follicle-stimulating hormone (Fsh), increasing E2 and cyp19a1a levels.

Anti-Müllerian hormone as a qualitative marker - or just quantity?

PURPOSE OF REVIEW

In this review, we will summarize research looking into anti-Müllerian hormone (AMH) as a measure of oocyte quality.

RECENT FINDINGS

AMH is a key factor involved in embryogenesis but also in the development of early follicles. Owing to its relatively small inter and intracycle variability, it has become a widely used method of ovarian reserve testing. In the realm of assisted reproductive technology, it has demonstrated a reliable ability to gauge the number of oocytes obtained during an in-vitro fertilization cycle. For these purposes, AMH is a readily measured quantitative tool. However, its qualitative role is as yet undefined.

SUMMARY

Although levels of this hormone have been associated with fertilization, blastulation, implantation, and clinical pregnancy rates, there is no clear link with live-birth rates. Furthermore, AMH levels do not appear to correspond with risk of fetal trisomy. AMH does show significant predictive value for the risk of premature ovarian insufficiency and time to onset of menopause.

Characterization of Anti-Müllerian Hormone (AMH) Gene in Buffaloes and Goats

The Anti-Müllerian Hormone (AMH) is a member of the transforming growth factor beta (TGF-β) superfamily, playing a significant role in cell proliferation, differentiation and apoptosis. In females, AMH is secreted throughout their reproductive life span from ovaries, whereas in males it is secreted by gonadal cells at a very early stage of testicular development. AMH is a promising marker of ovarian reserve in women and can be used to measure the female reproductive lifespan. In the present study, we cloned and sequenced the GC rich AMH gene from Indian riverine buffalo (Bubalus bubalis) and goat (Capra hircus). Obtained sequences were compared to the AMH sequences of other mammals, and corresponding amino acid sequences revealed that the caprine and bovine AMH sequences are more closely related to each other than to those of other mammals. Furthermore, we analyzed the chromosomal localization of AMH genes in mammalian species to understand potential syntenic relationship. The AMH gene is localized between the sequences for the SF3A and JSRP1 genes and maintains this precise location in relation to other nearby genes. The dN/dS ratio of AMH gene did not indicate any pressure for either positive or negative selection; thus, the physiological function of the AMH gene in the reproduction of these two ruminant species remains very vital. Similar to other mammals, the AMH gene may be an important indicator for regulating female reproductive biology function in bovine, cetacean, caprine, and camelidae.

Effect of anti-müllerian hormone on the development and selection of ovarian follicle in hens

To elucidate the role of anti-müllerian hormone (AMH) in regulating the development of ovarian follicles in laying hens, the expressions of follicle-stimulating hormone receptor (FSHR), AMH receptor type 2 (AMHR2), steroidogenic-related genes steroidogenic acute regulatory protein (STAR), cytochrome P450 side-chain cleavage (CYP11A1), and 3β-hydroxysteroid dehydrogenase (HSD3B1) genes were measured from different sized follicles and granulosa cells. The results showed that the expressions of FSHR and AMHR2 genes were higher in small follicles and decreased after follicular selection. Oppositely, the expressions of STAR, CYP11A1, and HSD3B1 were significantly increased after follicular selection. It indicated that AMHR2 might mediate AMH suppression in the stimulating effects of follicle-stimulating hormone (FSH) on steroidogenic-related genes expression. To make sure the effects of AMH in this process, a total of 40 hens were treated (negative control, sham operation, 150 ng AMH/d or 300 ng AMH/d) for 25 d. We analyzed ovarian morphology, progesterone concentration in blood plasma, and the expressions of steroidogenic genes in ovaries and follicles. The AMH300 group had significantly lower weight of ovary and hierarchical follicles. Egg weight and ovary weight in AMH150 group were higher than those of sham operation and AMH300 groups, so did hierarchical follicles weight. The steroidogenic genes expressions showed an increase in ovarian tissue and the largest follicle of AMH150 and AMH300 groups. However, progesterone level in the blood was reduced by AMH injection with different concentrations. To further verify the above results, granulosa cells from 6 to 8 mm follicles were cultured with AMH (0, 5, 10, 20, 40, or 80 ng/mL). The results revealed that excessive AMH (80 ng/mL) exerted an inhibitory effect on progesterone synthesis and the expressions of STAR, CYP11A1, and HSD3B1. However, these genes expressions showed a significant increase in 20 ng/mL AMH-treated group. In summary, AMH inhibited the development of prehierarchical follicles in laying hens. The effects of AMH treatment with different concentrations on follicle development showed the follicle was selected by changing FSH responsiveness of prehierarchical follicles.

AMH has no role in predicting oocyte quality in women with advanced age undergoing IVF/ICSI cycles

It has been widely acknowledged that anti-Müllerian hormone (AMH) is a golden marker of ovarian reserve. Declined ovarian reserve (DOR), based on experience from reproductive-aged women, refers to both the quantitative and qualitative reduction in oocytes. This view is challenged by a recent study clearly showing that the quality of oocytes is similar in young women undergoing IVF cycles irrespective of the level of AMH. However, it remains elusive whether AMH indicates oocyte quality in women with advanced age (WAA). The aim of this study was to investigate this issue. In the present study, we retrospectively analysed the data generated from a total of 492 IVF/ICSI cycles (from January 2017 to July 2020), and these IVF/ICSI cycles contributed 292 embryo transfer (ET) cycles (from June 2017 to September 2019, data of day 3 ET were included for analysis) in our reproductive centre. Based on the level of AMH, all patients (= > 37 years old) were divided into 2 groups: the AMH high (H) group and the AMH low (L) group. The parameters of in vitro embryo development and clinical outcomes were compared between the two groups. The results showed that women in the L group experienced severe DOR, as demonstrated by a higher rate of primary diagnosis of DOR, lower antral follicle count (AFC), higher level of basal follicle stimulating hormone (FSH) and cancelation cycles, lower level of E2 production on the day of surge, and fewer oocytes and MII oocytes retrieved. Compared with women in the H group, women in the L group showed slightly reduced top embryo formation rate but a similar normal fertilization rate and blastocyst formation rate. More importantly, we found that the rates of implantation, spontaneous miscarriage and livebirth were similar between the two groups, while the pregnancy rate was significantly reduced in the L group compared with the H group. Further analysis indicated that the higher pregnancy rate of women in the H group may be due to more top embryos transferred per cycle. Due to an extremely low implantation potential for transfer of non-top embryos from WAA (= > 37 years old) in our reproductive centre, we assumed that all the embryos that implanted may result from the transfer of top embryos. Based on this observation, we found that the ratio of embryos that successfully implanted or eventually led to a livebirth to top embryos transferred was similar between the H and the L groups. Furthermore, women with clinical pregnancy or livebirth in the H or L group did not show a higher level of serum AMH but were younger than women with non-pregnancy or non-livebirth. Taken together, this study showed that AMH had a limited role in predicting in vitro embryo developmental potential and had no role in predicting the in vivo embryo developmental potential, suggesting that in WAA, AMH should not be used as a marker of oocyte quality. This study supports the view that the accumulation of top embryos via multiple oocyte retrieval times is a good strategy for the treatment of WAA.

Stage-dependent actions of antimüllerian hormone in regulating granulosa cell proliferation and follicular function in the primate ovary

OBJECTIVE

To study the direct action and physiological role of antimüllerian hormone (AMH) in regulating ovarian follicular development and function in vivo in primates.

DESIGN

Animals were assigned to six treatment sequences in a crossover design study. Intraovarian infusion was performed during the follicular phase of the menstrual cycle with agents including: control vehicle; recombinant human AMH (rhAMH); and neutralizing anti-human AMH antibody (AMHAb). Before ovariectomy after the final treatment, the animals received intravenous injections of bromodeoxyuridine (BrdU).

SETTING

National primate research center.

ANIMALS

Adult female rhesus macaques (Macaca mulatta).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Cycle length, follicle cohorts, and serum steroid levels were assessed. Ovarian histology, as well as granulosa cell (GC) proliferation and oocyte viability, were evaluated.

RESULTS

In vehicle-infused ovaries, a dominant follicle was observed at midcycle E2 peak. However, rhAMH-treated ovaries exhibited an increased number of small antral follicles, whereas AMHAb-treated ovaries developed multiple large antral follicles. Serum E2 levels in the follicular phase decreased after rhAMH infusion and increased after AMHAb infusion. The rhAMH infusion increased serum T levels. Whereas early-growing follicles of rhAMH-treated ovaries contained BrdU-positive GCs, antral follicles containing BrdU-positive GCs were identified in AMHAb-treated ovaries. Autophagy was observed in oocytes of early-growing and antral follicles exposed to AMHAb and rhAMH, respectively.

CONCLUSIONS

AMH enhanced early-stage follicle growth, but prevented antral follicle development and function via its stage-dependent regulation of GC proliferation and oocyte viability. This study provides information relevant to the pathophysiology of ovarian dysfunction and the treatment of infertility.

What is the impact of PPAR-γ agonist-rosiglitazone on ovarian reserve after hysterectomy? An experimental study

Background/aim

To evaluate the effects of hysterectomy on rat ovaries and the possible protective role of peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist-rosiglitazone against ovarian reserve decrement.

Materials and methods

Forty-five adult Wistar albino rats were randomly divided into three groups. Hysterectomy was performed (n = 15) in group 1 [H]; 1 mg/kg/day PPAR-γ agonist/rosiglitazone was used for 50 days after hysterectomy (n = 15) in group 2 [H + R]; a sham operation was performed (n = 15) in group 3 [control, C]. Blood samples were collected for anti-Müllerian hormone (AMH) evaluation in all groups and simultaneous ovarian Doppler examination was performed in [H] and [H + R] groups before and after (50 days) hysterectomy. All animals were sacrificed to obtain ovaries for histological examination.

Results

AMH levels were found to be significantly decreased at postoperative day 50 in all groups (P < 0.05). Histopathologic analysis showed that primary, preantral, and antral follicle counts were significantly higher in the [H] group as compared to the [C] and [H + R] groups (P < 0.05). There was no significant difference between the [C] and [H + R] groups in terms of follicle numbers (P > 0.05). In the ovarian Doppler blood flow analysis, all parameters were significantly decreased in group [H] (P < 0.05), but not in the [H + R] group (P > 0.05) on postoperative day 50.

Conclusion

Hysterectomy affects the histopathological structure of rat ovaries and PPAR-γ agonist-rosiglitazone improves the ovarian Doppler blood flow parameters.

Dissecting Cell Lineage Specification and Sex Fate Determination in Gonadal Somatic Cells Using Single-Cell Transcriptomics

Sex determination is a unique process that allows the study of multipotent progenitors and their acquisition of sex-specific fates during differentiation of the gonad into a testis or an ovary. Using time series single-cell RNA sequencing (scRNA-seq) on ovarian Nr5a1-GFP⁺ somatic cells during sex determination, we identified a single population of early progenitors giving rise to both pre-granulosa cells and potential steroidogenic precursor cells. By comparing time series single-cell RNA sequencing of XX and XY somatic cells, we provide evidence that gonadal supporting cells are specified from these early progenitors by a non-sex-specific transcriptomic program before pre-granulosa and Sertoli cells acquire their sex-specific identity. In XX and XY steroidogenic precursors, similar transcriptomic profiles underlie the acquisition of cell fate but with XX cells exhibiting a relative delay. Our data provide an important resource, at single-cell resolution, for further interrogation of the molecular and cellular basis of mammalian sex determination.

Multigenerational and transgenerational effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure on ovarian reserve and follicular development through AMH/AMHR2 pathway in adult female rats

2,3,7,8-Tetrachlorobenzo-p-dioxin (TCDD), one of the key endocrine disruptors, has been shown to cause reproductive and developmental disorders. Our previous studies have primarily focused on TCDD induced impairment of ovarian follicular development in female F1 rats. It is unknown whether TCDD exposure will interfere with follicular development by altering mRNA expression of anti-Müllerian hormone (AMH) and AMH receptor type II (AMHR2) in the ovary. In the present study, pregnant Sprague Dawley rats were treated with TCDD (100 or 500 ng/kg body weight) dissolved in a corn oil vehicle by gavage from gavage from gestational days (GD) 8-14, while the control group received solely corn oil. The F1 rats were mated with unexposed males for the F2 generation, while another portion of the female offspring (F2) were mated for the F3 generation. Serum AMH levels and ovarian AMH/AMHR2 mRNA expression in the adult female offspring (F1, F2 and F3 generations) were measured. Follicle count and granulosa cell apoptosis were evaluated in the F2 and F3 generations. The results showed that in the F2 generation, TCDD exposure affected the number of primordial follicles, secondary follicles, and corpora lutea. It also increased serum AMH concentration and the apoptosis rate of granulosa cells. These results might be associated with the upregulation of AMH/AMHR2 mRNA expression in the ovary. In conclusion, TCDD exposure reduced the ovarian reserve in rats and inhibited follicular development in adult female offspring, an effect that persisted for multiple generations. The altered AMH and AMHR2 mRNA expression may contribute to the observed adverse effects.

Do Resveratrol and Dehydroepiandrosterone Increase Diminished Ovarian Reserve?

Objective

In this study, the aim is to observe changes induced by dehydroepiandrosterone (DHEA) and resveratrol (RES) in diminished ovarian follicles that was induced by 4-vinylcyclohexenediepoxide (VCD).

Materials and Methods

Twenty four Wistar albino female rats were divided into 3 groups: control, DHEA and RES. Unilateral oophorectomy was performed in control group to remove the right ovary of 4 rats and the left ovary of 4 rats. After administration of 160 mg/kg VCD, remaining ovaries were removed. Following the same VCD treatment, in DHEA and RES groups, 60 mg/kg DHEA and 20 mg/kg RES were given for 45 days respectively and residual ovaries were removed. Hematoxylin-eosin and TUNEL staining were performed. Follicle stimulating hormone (FSH), estradiol (E2) and anti-mullerian hormone (AMH) values were measured.

Results

In control group, VCD-induced apoptosis in follicles increased the TUNEL-positive cell counts (p<0.001) with decreased number of follicles. On the other hand, DHEA significantly increased all three follicle types in the ovaries and decreased apoptosis (p<0.001). The decreased follicle number in all three follicle types after VCD treatment were found to be significantly increased after RES treatment (p<0.001). Apoptosis in the follicles was significantly decreased by RES administration (p<0.001). FSH values were found to be increased with VCD and to reach control values with DHEA and RES. E2 values significantly decreased with VCD, but significantly increased with RES and DHEA.

Conclusion

Both DHEA and RES may improve VCD-induced diminished ovarian reserve. DHEA and RES increased the number of primary, primordial and growing follicles, with no significant difference between them.

Dynamin 2-dependent endocytosis is essential for mouse oocyte development and fertility

During folliculogenesis, oocytes are dependent on metabolic and molecular support from surrounding somatic cells. Here, we examined the role of the dynamin (DNM) family of mechanoenzymes in mediating endocytotic uptake into growing follicular oocytes. We found DNM1 and DNM2 to be highly expressed in growing follicular oocytes as well as in mature germinal vesicle (GV) and metaphase II (MII) stage oocytes. Moreover, oocyte-specific conditional knockout (cKO) of DNM2 (DNM2Δ) led to complete sterility, with follicles arresting at the preantral stage of development. In addition, DNM2Δ ovaries were characterized by disrupted follicular growth as well as oocyte and follicle apoptosis. Further, the loss of DNM activity, either through DNM2 cKO or through pharmacological inhibition (Dyngo 6a) led to the impairment of endocytotic pathways in preantral oocytes as well as in mature GV and MII oocytes, respectively. Loss of DNM activity resulted in the redistribution of endosomes and the misslocalization of clathrin and actin, suggesting dysfunctional endocytosis. Notably, there was no observable effect on the fertility of DNM1Δ females. Our study has provided new insight into the complex and dynamic nature of oocyte growth during folliculogenesis, suggesting a role for DNM2 in mediating the endocytotic events that are essential for oocyte development.

Amh regulate female folliculogenesis and fertility in a dose-dependent manner through Amhr2 in Nile tilapia

In the present study, Amh was found to be abundantly expressed in the granulosa cells of the primary growth follicles, and Amhr2 in the granulosa cells, oogonia and phase I oocytes in tilapia by immunohistochemistry. In addition, Amh and Amhr2 were also found to be expressed in the brain and pituitary. Heterozygous mutation of either amh or amhr2 resulted in increased primary growth follicles and decreased fertility, and homozygous mutation resulted in hypertrophic ovaries with significantly increased primary follicles and failed transition from primary to vitellogenic follicles. Expression of gnrh3 in the brain, fsh and lh in the pituitary and serum E2 concentration were significantly decreased in both mutants. Significantly increased apoptosis of follicle cells was observed in both mutants. However, administration of E2 failed to rescue the folliculogenesis defects of the mutants. Our results suggested that Amh acts in a dose-dependent manner by binding Amhr2 in tilapia.

Ethnicity/Race and Age-Specific Variations of Serum AMH in Women-A Review

PURPOSE OF REVIEW

In this review, we summarize ethnic/race- and age-related variation in AMH and discuss the underpinnings behind these differences.

RECENT FINDINGS

Anti-mullerian hormone (AMH) has become a widely used method of ovarian reserve testing over the last 15 years. Numerous studies have shown substantial ethnic/race and age-related differences. When compared to age-matched Caucasian women, AMH levels tend to be lower in black and Hispanic women. Chinese women tend to have significantly greater AMH levels prior to age 25 than Caucasian women. When considering subpopulations within ethnicities, at least one study noted lower AMH levels among Maya women compared to other Hispanic women. Age exhibits a positive trend with AMH up until at least 25 years of age with a consistent decline after 34 years of age extending to menopause.

SUMMARY

AMH levels are highly variable among ethnicities and race with higher age-matched levels typically seen in Caucasian women. Age does not exhibit a consistent linear relationship with AMH, but a consistent decline is seen starting in the third decade of life and proceeding to menopause.

Regulation of AMH, AMHR-II, and BMPs (2,6) Genes of Bovine Granulosa Cells Treated with Exogenous FSH and Their Association with Protein Hormones

Anti-Mullerian hormone (AMH) is an important reproductive marker of ovarian reserve produced by granulosa cells (GCs) of pre-antral and early-antral ovarian follicles in several species, including cattle. This hormone plays a vital role during the recruitment of primordial follicles and follicle stimulating hormone (FSH)-dependent follicular growth. However, the regulatory mechanism of AMH expression in follicles is still unclear. In this study, we compared the expression of AMH, AMHR-II, BMP2, BMP6, FSHR, and LHCGR genes during follicular development. In-vitro expression study was performed with and without FSH for AMH, AMHR-II, BMP2, and BMP6 genes in bovine GCs which were isolated from 3–8 mm follicles. Association among the mRNA expression and hormone level was estimated. GCs were collected from small (3–8 mm), medium (9–12 mm) and large size (13 to 24 mm) follicles before, during onset, and after deviation, respectively. Further, mRNA expression, hormones (AMH, FSH, and LH), apoptosis of GCs, and cell viability were detected by qRT-PCR, ELISA, flow cytometry, and spectrophotometry. AMH, AMHR-II, BMP2, and FSHR genes were highly expressed in small and medium follicles as compared to large ones. In addition, the highest level of AMH protein (84.14 ± 5.41 ng/mL) was found in medium-size follicles. Lower doses of FSH increased the viability of bovine GCs while higher doses repressed them. In-vitro cultured GCs treated with FSH significantly increased the AMH, AMHR-II, and BMP2 expression levels at lower doses, while expression levels decreased at higher doses. We found an optimum level of FSH (25 ng/mL) which can significantly enhance AMH and BMP2 abundance (p < 0.05). In summary, AMH, AMHR-II, and BMP2 genes showed a higher expression in follicles developed in the presence of FSH. However, lower doses of FSH demonstrated a stimulatory effect on AMH and BMP2 expression, while expression started to decline at the maximum dose. In this study, we have provided a better understanding of the mechanisms regulating AMH, AMHR II, and BMP2 signaling in GCs during folliculogenesis, which would improve the outcomes of conventional assisted reproductive technologies (ARTs), such as superovulation and oestrus synchronization in bovines.

Overview of Anti-Müllerian hormone (AMH) and association with fertility in female cattle

Anti-Müllerian hormone (AMH) is produced by granulosa cells of early-antral follicles found on the ovary. After production, it enters circulation and can be detected from a blood sample with an ELISA. Multiple works have found that circulating AMH is a reliable marker of the antral follicle population (AFP) of an animal as well as directly correlated to an animal's response to a superovulation protocol. Research has also found high repeatability within an animal's oestrous cycle. Further use of AMH may be valuable as a reproductive management tool, based on previous research linking productive life with circulating AMH in heifers and success to various breeding protocols by AMH concentration. The aim of this review was to summarize previous works describing basic function of AMH as well as explore recent research examining AMH as a reproductive tool and measurement of fertility in dairy animals.

The role of anti-Müllerian hormone (AMH) in ovarian disease and infertility

PURPOSE

In this review, the current knowledge on anti-Müllerian hormone (AMH) is presented, concerning its value in disease and IVF treatment as well as in terms of its prospective clinical use.

METHODS

AMH is becoming the most appropriate biomarker for the ovarian reserve measured predominantly for assisted reproductive treatment (ART) patients in comparison to the currently used antral follicle count (AFC). However, this is not the only way AMH measurements can be used in the clinics. Because of this, we reviewed the current literature for the use of AMH in current or prospective clinical practice.

RESULTS

We found that AMH has a high predictive value in assessing the ovarian reserve, which can lead to a better efficiency of in vitro fertilization (IVF) procedures. It has a high potential to be developed as a staple diagnostic marker of ovarian disease, especially for ovarian cancers and even as a possible treatment tool for certain cancers. It could potentially be used to prevent oocyte loss due to chemo- or radiotherapy.

CONCLUSION

AMH is an important hormone especially in women reproductive organs and is currently seen as the best biomarker for a multitude of uses in reproductive medicine. Currently, the biggest issue lies in the lack of international standardization of AMH. However, it is encouraging to see that there is interest in AMH in the form of research on its action and use in reproductive medicine.

Investigation of soluble anti-Müllerian hormone receptor type 2 as a biomarker for diagnosis of female fertility disorders

RESEARCH QUESTION

The ectodomain of the anti-Müllerian hormone (AMH) type 2 receptor is shed by proteases under certain conditions, which makes it measurable in the blood. The aim of this study was to identify correlations of soluble anti-Müllerian hormone receptor type 2 (sAMHR2) with other sex hormone concentrations and to assess whether sAMHR2 may serve as a new biomarker in fertility disorders.

DESIGN

In a retrospective cross-sectional study of women (n = 186) with different gynaecological-endocrinological disorders, mixed-effect models were used to analyse the correlation with established diagnostic hormone tests. Receiver operating characteristic curve analysis was performed to assess the diagnostic performance.

RESULTS

There was a strong correlation of sAMHR2 with LH (r = 0.898) and FSH (r = 0.846) and a moderate correlation of AMH with testosterone (r = 0.666) and androstenedione (r = 0.696) (all P < 0.001). In diagnoses of polycystic ovary syndrome (PCOS), AMH showed the best performance (area under the curve [AUC] 0.981, cut-off 4 ng/ml) with 96% sensitivity and 94% specificity. sAMHR2 concentrations and sAMHR2/AMH ratios were elevated in women with ovarian insufficiency, compared with all other study groups, including post-menopausal women on hormone replacement therapy. Highest sensitivity and specificity (100% and 98.2%, respectively) were achieved with sAMHR2/AMH ratio for the diagnosis of post-menopausal status (cut-off 68.85). The sAMHR2/AMH ratio (AUC 0.997) had a better performance than sAMHR2 (AUC 0.947), FSH (AUC 0.989) and LH (AUC 0.967).

CONCLUSIONS

The sAMHR2/AMH ratio may serve as a useful biomarker for infertility diagnostics to identify post-menopausal women.

Anti-Müllerian hormone inhibits luteinizing hormone-induced androstenedione synthesis in porcine theca cells

AMH (Anti-Müllerian Hormone) is involved in the regulation of follicle growth initiation and inhibits FSH-induced aromatase expression and estrogen production in granulosa cells. However, the function of AMH in steroidogenesis by theca cells remains unclear. The aim of this study is to investigate the role of AMH as a regulator of the basal and stimulated steroid production by pig granulosa cells (pGCs) and theca cells (pTCs). PGCs and pTCs were incubated with hormones AMH, LH (luteinizing hormone), FSH (follicle stimulating hormone), individually or in combination. The expression of CYP19A1, HSD3B1, CYP11A1, LHCGR, and CYP17A1 mRNA were evaluated by quantitative reverse transcriptase PCR. In pGCs, 10 ng/mL AMH significantly decreased the FSH-stimulated effect on FSHR and CYP19A1 expression and estradiol production. In pTCs, LH treatment significantly increased the expression of HSD3B1, CYP11A1, LHCGR, and androstenedione or progesterone production (P < 0.05). Additionally, 10 ng/mL AMH also significantly decreased the LH-stimulated effects on the expression of HSD3B1, CYP11A1, CYP17A1, LHCGR and androstenedione production. Transfection with siAMHR2-I abolished the suppressive effects of AMH on LH-induced HSD3B1 expression and androstenedione production. Taken together, these results demonstrate that AMH is involved in FSH induced estradiol production in pGCs and LH induced androstenedione production in pTCs by regulating the steroidogenesis pathway.

Impact of hypogonadotropic hypogonadism on ovarian reserve and response

OBJECTIVE

To evaluate the hormonal profile, antral follicle count (AFC) and ovarian response of patients with hypogonadotropic hypogonadism (HH).

DESIGN

Observational retrospective cohort including infertile women with HH undergoing assisted reproductive treatment (ART).

SETTING

University-affiliated infertility center.

PATIENT(S)

Thirty-three women with HH who underwent ART between January 2007 and September 2018. The control group comprised 66 age-matched counterparts with tubal or male factor infertility. The patients with an abnormal karyotype, and those presenting primary or secondary amenorrhea due to other causes, were cautiously excluded.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcome was serum levels of anti-Müllerian hormone (AMH) and AFC. We also investigated whether HH impacts ovarian response and reproductive outcomes.

RESULT(S)

Although AFC was similar between groups, HH patients showed significantly higher AMH levels (4.6 ± 2.7 ng/mL vs. 3.0 ± 1.9, p = 0.010) and lower basal FSH and LH. While the HH group needed longer stimulation [13 days (11-26) vs. 10 (7-14), p < 0.001] and higher gonadotropin doses [2700 IU (825-6300) vs. 2100 (425-5000), p = 0.038 ], no significant differences were detected in either the number or maturity of retrieved oocytes, or in the fertilization rate, number of embryos transferred, implantation rate, clinical pregnancy rate and live birth rate per cycle.

CONCLUSION(S)

HH patients present higher AMH levels, but similar AFC. Despite requiring longer stimulation and higher gonadotropin doses, ovarian response and reproductive outcomes seem unaffected.

Promoter Identification and Transcriptional Regulation of the Goose AMH Gene

Simple Summary

Anti-Müllerian hormone (AMH) plays a vital role in the development of follicles. We found that the cloning nucleotide sequence of AMH was high homology in geese with other species. Several regulatory elements were identified and transcriptional factors were predicted in the AMH promoter sequence. Through a double-luciferase reporter assay, potential regulatory relationship spanning from −637 to −87 bp were identified. In addition, the mRNA expression of AMH gradually decreased during the development of follicles in geese. In the Chinese hamster ovary (CHO) cell line, the luciferase activity significantly increased by co-expression of AMH and GATA-4. However, when the binding sites of GATA-4 to the promoter of AMH were mutated, the luciferase activity significantly decreased. These results indicated that the transcription of AMH was activated by GATA-4 to inhibit the development of follicles in geese.

Abstract

Anti-Müllerian hormone (AMH) is recognized as a reliable marker of ovarian reserve. However, the regulatory mechanism of goose AMH gene remains poorly understood. In the present study, both the full-length coding sequence (CDS) and promoter sequence of goose AMH have been cloned. Its CDS consisted of 2013 nucleotides encoding 670 amino acids and the amino acid sequence contained two structural domain: AMH-N and transforming growth factor beta (TGF-β) domain. The obtained promoter sequence spanned from the −2386 bp to its transcription start site (ATG). Core promoter regions and regulatory elements were identified as well as transcription factors were predicted in its promoter sequence. The luciferase activity was the highest spanning from the −331 to −1 bp by constructing deletion promoter reporter vectors. In CHO cells, the luciferase activity significantly increased by co-expression of AMH and GATA binding protein 4 (GATA-4), while that significantly decreased by mutating the binding sites of GATA-4 located in the −778 and −1477 bp. Results from quantitative real-time polymerase chain reaction (qPCR) indicated that levels of AMH mRNA in geese granulosa layers decreased gradually with the increasing follicular diameter. Taken together, it could be concluded that the transcriptional activity of AMH was activated by GATA-4 to inhibit the development of small follicles in goose.

Anti-Müllerian hormone type II receptor in avian follicle development

Anti-Müllerian hormone (AMH) helps maintain the ovarian reserve by regulating primordial follicle activation and follicular selection in mammals, although its role within the avian ovary is unknown. In mammals, AMH is primarily produced in granulosa cells of preantral and early antral follicles. Similarly, in the hen, the granulosa cells of smaller follicles are the predominant source of AMH. The importance of AMH in mammalian ovarian dynamics suggests the protein and its specific Type II receptor, AMHRII, may have conserved functions in the hen. AMHRII mRNA expression is highest (P < 0.01) in small follicles of the hen and decreases as follicle size increases. Similarly, expression of AMHRII and AMH is highest in granulosa cells from small follicles as compared to larger follicles. Dissection of 3-5 mm follicles into ooplasm and granulosa components shows that AMHRII mRNA levels are greater in ooplasm than granulosa cells. Furthermore, immunohistochemistry also revealed AMHRII staining in the oocyte and granulosa cells. AMH expression in mammals is elevated during periods of reproductive dormancy, possibly protecting the ovarian reserve. AMHRII and AMH mRNA were significantly higher (P < 0.05) in nonlaying ovaries of broiler hens. In molting layer hens, AMHRII mRNA was significantly greater (P < 0.05) compared to nonmolting hen ovaries. These results suggest that AMH may have a direct effect on the oocyte and, thereby, contribute to bidirectional communication between oocyte and granulosa cells. Enhanced expression of AMHRII and AMH during reproductive quiescence supports a potential role of AMH in protecting the ovarian reserve in hens.

Reproductive functions of Kisspeptin/KISS1R Systems in the Periphery

Kisspeptin and its G protein-coupled receptor KISS1R play key roles in mammalian reproduction due to their involvement in the onset of puberty and control of the hypothalamic-pituitary-gonadal axis. However, recent studies have indicated a potential role of extra-hypothalamic kisspeptin in reproductive function. Here, we summarize recent advances in our understanding of the physiological significance of kisspeptin/KISS1R in the peripheral reproductive system (including the ovary, testis, uterus, and placenta) and the potential role of kisspeptin/KISS1R in reproductive diseases. A comprehensive understanding of the expression, function, and potential molecular mechanisms of kisspeptin/KISS1R in the peripheral reproductive system will contribute to the diagnosis, treatment and prevention of reproductive diseases.

Neoadjuvant Treatment With Müllerian-Inhibiting Substance Synchronizes Follicles and Enhances Superovulation Yield

Müllerian-inhibiting substance (MIS), also known as anti-Müllerian hormone, is thought to be a negative regulator of primordial follicle activation. We have previously reported that treatment with exogenous MIS can induce complete ovarian suppression within 5 weeks of treatment in mice. To investigate the kinetics of the return of folliculogenesis following the reversal of suppression, we treated animals with recombinant human MIS (rhMIS) protein for 40 days in adult female Nu/Nu mice and monitored the recovery of each follicle type over time. Following cessation of MIS therapy, secondary, and antral follicles returned within 30 days, along with the normalization of reproductive hormones, including LH, FSH, MIS, and Inhibin B. Furthermore, 30 days following MIS pretreatment, the number of antral follicles were significantly higher than controls, and superovulation with timed pregnant mare serum gonadotropin and human chorionic gonadotropin stimulation at this time point resulted in an approximately threefold increased yield of eggs. Use of the combined rhMIS-gonadotropin superovulation regimen in a diminished ovarian reserve (DOR) mouse model, created by 4-vinylcyclohexene dioxide treatment, also resulted in a twofold improvement in the yield of eggs. In conclusion, treatment with rhMIS can induce a reversible ovarian suppression, following which a rapid and synchronized large initial wave of growing follicles can be harnessed to enhance the response to superovulation. Therapies modulating MIS signaling may therefore augment the response to current ovarian stimulation protocols and could be particularly useful to women with DOR or poor responders to controlled ovarian hyperstimulation during in vitro fertilization.