Professor Alfred Jost: the builder of modern sex differentiation

The Role of Serum Anti-Mullerian Hormone Measurement in the Diagnosis of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrinological disorder in women with significant reproductive, metabolic, and psychological health implications. The lack of a specific diagnostic test poses challenges in making the diagnosis of PCOS, resulting in underdiagnosis and undertreatment. Anti-Mullerian hormone (AMH) synthesized by the pre-antral and small antral ovarian follicles appears to play an important role in the pathophysiology of PCOS, and serum AMH levels are often elevated in women with PCOS. The aim of this review is to inform the possibility of utilizing anti-Mullerian hormone either as a diagnostic test for PCOS or as an alternative diagnostic criterion in place of polycystic ovarian morphology, hyperandrogenism, and oligo-anovulation. Increased levels of serum AMH correlate highly with PCOS, polycystic ovarian morphology, hyperandrogenism, and oligo/amenorrhea. Additionally, serum AMH has high diagnostic accuracy as an isolated marker for PCOS or as a replacement for polycystic ovarian morphology.

Functional similarity between TGF-beta type 2 and type 1 receptors in the female reproductive tract

Transforming growth factor β (TGFβ) signaling plays critical roles in reproductive development and function. TGFβ ligands signal through the TGFβ receptor type 2 (TGFBR2)/TGFBR1 complex. As TGFBR2 and TGFBR1 form a signaling complex upon ligand stimulation, they are expected to be equally important for propagating TGFβ signaling that elicits cellular responses. However, several genetic studies challenge this concept and indicate that disruption of TGFBR2 or TGFBR1 may lead to contrasting phenotypic outcomes. We have shown that conditional deletion of Tgfbr1 using anti-Mullerian hormone receptor type 2 (Amhr2)-Cre causes oviductal and myometrial defects. To determine the functional requirement of TGFBR2 in the female reproductive tract and the potential phenotypic divergence/similarity resulting from conditional ablation of either receptor, we generated mice harboring Tgfbr2 deletion using the same Cre driver that was previously employed to target Tgfbr1. Herein, we found that conditional deletion of Tgfbr2 led to a similar phenotype to that of Tgfbr1 deletion in the female reproductive tract. Furthermore, genetic removal of Tgfbr1 in the Tgfbr2-deleted uterus had minimal impact on the phenotype of Tgfbr2 conditional knockout mice. In summary, our results reveal the functional similarity between TGFBR2 and TGFBR1 in maintaining the structural integrity of the female reproductive tract.

Transforming growth factor-β superfamily and interferon-τ in ovarian function and embryo development in female cattle: review of biology and application

Survival of the embryo and establishment of a pregnancy is a critical period in the reproductive function of female cattle. This review examines how the transforming growth factor-β (TGFB) superfamily (i.e. bone morphogenetic protein (BMP) 15, growth differentiation factor (GDF) 9, anti-Müllerian hormone (AMH)) and interferon-τ (IFNT) affect ovarian function and embryo development. The oocyte in a primary follicle secretes BMP15 and GDF9, which, together, organise the surrounding granulosa and theca cells into the oocyte-cumulus-follicle complex. At the same time, the granulosa secretes AMH, which affects the oocyte. This autocrine-paracrine dialogue between the oocyte and somatic cells continues throughout follicle development and is fundamental in establishing the fertilisation potential and embryo developmental competency of oocytes. The early bovine embryo secretes IFNT, which acts at the uterine endometrium, corpus luteum and blood leucocytes. IFNT is involved in the maternal recognition of pregnancy and immunomodulation to prevent rejection of the embryo, and supports progesterone secretion. Manipulation of BMP15, GDF9, AMH and IFNT in both invivo and invitro studies has confirmed their importance in reproductive function in female cattle. This review makes the case that a deeper understanding of the biology of BMP15, GDF9, AMH and IFNT will lead to new strategies to increase embryo survival and improve fertility in cattle. The enhancement of oocyte quality, early embryo development and implantation is considered necessary for the next step change in the efficiency of natural and assisted reproduction in cattle.

The Effects of Hormonal Contraceptives on the Brain: A Systematic Review of Neuroimaging Studies

Background: Hormonal contraceptive drugs are being used by adult and adolescent women all over the world. Convergent evidence from animal research indicates that contraceptive substances can alter both structure and function of the brain, yet such effects are not part of the public discourse or clinical decision-making concerning these drugs. We thus conducted a systematic review of the neuroimaging literature to assess the current evidence of hormonal contraceptive influence on the human brain.

Methods: The review was registered in PROSPERO and conducted in accordance with the PRISMA criteria for systematic reviews. Structural and functional neuroimaging studies concerning the use of hormonal contraceptives, indexed in Embase, PubMed and/or PsycINFO until February 2020 were included, following a comprehensive and systematic search based on predetermined selection criteria.

Results: A total of 33 articles met the inclusion criteria. Ten of these were structural studies, while 23 were functional investigations. Only one study investigated effects on an adolescent sample. The quality of the articles varied as many had methodological challenges as well as partially unfounded theoretical claims. However, most of the included neuroimaging studies found functional and/or structural brain changes associated with the use of hormonal contraceptives.

Conclusion: The included studies identified structural and functional changes in areas involved in affective and cognitive processing, such as the amygdala, hippocampus, prefrontal cortex and cingulate gyrus. However, only one study reported primary research on a purely adolescent sample. Thus, there is a need for further investigation of the implications of these findings, especially with regard to adolescent girls.

Primary immunoprevention of adult onset cancers by vaccinating against retired tissue-specific self-proteins

Despite the enormous success of childhood prophylactic vaccination against diseases caused by pathogens, there is currently no similar preventive vaccine program against diseases confronted with age like breast cancer and ovarian cancer. With the exception of the annual influenza vaccine, current recommendations for adult vaccination are for either primary vaccines not received during childhood or for booster vaccinations to maintain the immunity against pathogens already induced during childhood. Here we describe a strategy to provide prophylactic pre-emptive immunity against the development of adult onset cancers not associated with any definitive etiopathogenic agent. We propose that safe and effective pre-emptive immunity may be induced in cancer-free subjects by vaccination against immunodominant tissue-specific self-proteins that are 'retired' from expression in normal tissues as part of the normal aging process but are expressed in tumors that emerge with age. Primary immunoprevention of adult onset cancers like breast cancer and ovarian cancer represents a great challenge and an even greater unmet need for our current healthcare.

Anti-Müllerian Hormone in Fertility Preservation: Clinical and Therapeutic Applications

Anti-Müllerian hormone (AMH) is a member of the transforming growth factor (TGF)-beta family and a key regulator of sexual differentiation and folliculogenesis. While the serum AMH level has been used in reproductive medicine as a biomarker of quantitative ovarian reserve for more than 20 years, new potential therapeutic applications of recombinant AMH are emerging, notably in the field of oncofertility. Indeed, it is well known that chemotherapy, used to treat cancer, induces ovarian follicular depletion and subsequent infertility. Animal models have been used widely to understand the effects of different cytotoxic agents on ovarian function, and several hypotheses regarding chemotherapy gonadotoxicity have been proposed, that is, it might have a direct detrimental effect on the primordial follicles constituting the ovarian reserve and/or on the pool of growing follicles secreting AMH. Recently, a new mechanism of chemotherapy-induced follicular depletion, called the “burn-out effect,” has been proposed. According to this theory, chemotherapeutic agents may lead to a massive growth of dormant follicles which are then destroyed. As AMH is one of the factors regulating the recruitment of primordial follicles from the ovarian reserve, recombinant AMH administration concomitant with chemotherapy might limit follicular depletion, therefore representing a promising option for preserving fertility in women suffering from cancer. This review reports on the potential usefulness of AMH measurement as well as AMH’s role as a therapeutic agent in the field of female fertility preservation.

A SNP in a Steroidogenic Enzyme Is Associated with Phenotypic Sex in Seriola Fishes

Vertebrate sex development consists largely of two processes: "sex determination," the initial bifurcation of sexual identity, and "sex differentiation," which subsequently facilitates maleness or femaleness according to the sex determination signal. Steroid hormones promote multiple types of sexual dimorphism in eutherian mammals and avians [1-3], in which they are indispensable for proper sex differentiation. By contrast, in many poikilothermic vertebrates, steroid hormones have been proposed to be key players in sex determination as well as sex differentiation [4-8]. This hypothesis was introduced more than 50 years ago but has never been rigorously tested due to difficulties in discriminating the roles of steroids in sex determination and differentiation. We found that a missense SNP in the gene encoding the steroidogenic enzyme 17β-hydroxysteroid dehydrogenase 1 (Hsd17b1) was perfectly associated with ZZ/ZW sex determination in Seriola fishes. Biochemical analyses revealed that a glutamate residue present specifically in Z-type HSD17B1 attenuated interconversion between 17-keto and 17β-hydroxy steroids relative to the allelic product from the W chromosome, which harbors glycine at that position, by disrupting the hydrogen bond network between the steroid and the enzyme's catalytic residues. Hsd17b1 mRNA is constitutively expressed in undifferentiated and differentiating gonads of both genotypic sexes, whereas W-type mRNA is expressed only in genotypic females. Meanwhile, Cyp19a1 is predominantly expressed in differentiating ovary. We conclude that the combination of Hsd17b1 alleles determines sex by modulating endogenous estrogen levels in Seriola species. These findings strongly support the long-standing hypothesis on steroids in sex determination.

Comparing the role of anti-Müllerian hormone as a marker of FSH action in male and female fertility

INTRODUCTION

Originally limited to the assessment of disorders of sex development, anti-Müllerian hormone (AMH) measurement has more recently been extended to several conditions affecting the reproductive axis in males and females. Follicle-stimulating hormone (FSH) regulation of gonadal function has been extensively studied, but its role on AMH production has been explored only recently.

AREAS COVERED

We addressed the relationship between FSH action on the gonads and the usefulness of AMH as a marker in conditions affecting the reproductive axis.

EXPERT OPINION

Sertoli cells are the most active cell population in the prepubertal testis. Serum AMH is an excellent marker of FSH action on Sertoli cell proliferation and function in patients with hypogonadotropic hypogonadism. Low serum AMH is expected to predict low sperm production and prompts initial FSH treatment followed by human chorionic gonadotropin (hCG) or luteinizing hormone (LH) addition. Gonadotropin treatment may be more effective if installed to mimic the postnatal activation stage of the hypothalamic-pituitary-testicular axis. In females, AMH secretion by small antral follicles is stimulated by FSH. Elevated AMH indicates increased follicle numbers and should be considered as a potential contraindication of gonadotropin treatment in infertile patients due to an increased risk of developing ovarian hyperstimulation syndrome.

Müllerian inhibiting substance/anti-Müllerian hormone type II receptor protein and mRNA expression in the healthy and cancerous endometria

Müllerian inhibiting substance/anti-Müllerian hormone (MIS/AMH) is a regulator of the female reproductive system, an indicator of ovarian reserve and a growth inhibitor of Müllerian duct-derived tumors in vivo and in vitro. The objective of the present study was to analyze MIS/AMH type II receptor (MIS/AMHRII) protein and mRNA expression in healthy human endometria compared with patients with endometrial hyperplasia and endometrial cancer, providing a foundation for MIS/AMH as a biological modifier for treatment of endometrial hyperplasia and endometrial cancer. The present study included healthy endometrial tissues (n=20), simple endometrial hyperplasia tissues without atypia (n=17), complex endometrial hyperplasia tissues without atypia (n=24) and endometrial cancer tissues (n=8). The location and variation of MIS/AMHRII protein expression was observed by immunohistochemistry. The expression was graded by two pathologists and was categorized as follows: Negative, weakly positive, moderately positive or strongly positive. Reverse transcription-quantitative polymerase chain reaction was used to quantify MIS/AMHRII mRNA expression. The expression of MIS/AMHRII protein was observed in the cytoplasm of healthy human endometria, endometrial hyperplasia and endometrial cancer cells. The frequency of MIS/AMHRII protein expression was 20.22±10.35% in the proliferative phase of the healthy endometrium and 24.09±11.73% in the secretory phase of the healthy endometrium. However, no differences were observed in the menstrual cycle phases. The frequency was 54.50±16.59% in endometrial hyperplasia without atypia, 55.10±15.87% in endometrial hyperplasia with atypia and 73.88±15.70% in endometrial cancer, indicating that expression was enhanced as the disease progressed from healthy to malignant status. In endometrial hyperplasia, MIS/AMHRII protein expression was significantly associated with histological complexity compared with atypia status. The present study demonstrated that MIS/AMHRII is present in healthy endometria, endometrial hyperplasia and endometrial cancer. The low expression frequency of MIS/AMHRII was not significantly different among normal endometrial tissues, however, the protein expression was elevated in endometrial hyperplasia and endometrial cancer. These findings indicated that the study of bioactive MIS/AMH, as a possible treatment for tumors expressing the MIS/AMH receptor, is essential.

A brief history of sex determination

A fundamental biological question that has puzzled, but also fascinated mankind since antiquity is the one pertaining to the differences between sexes. Ancient cultures and mythologies poetically intended to explain the origin of the two sexes; philosophy offered insightful albeit occasionally paradoxical perceptions about men and women; and society as a whole put forward numerous intuitive observations about the traits that distinguish the two sexes. However, it was only through meticulous scientific research that began in the 16th century, and gradual technical improvements that followed over the next centuries, that the study of sex determination bore fruit. Here, we present a brief history of sex determination studies from ancient times until today, by selectively interviewing some of the milestones in the field. We complete our review by outlining some yet unanswered questions and proposing future experimental directions.

Disorders of sex development

Normal sex development depends on the precise spatio-temporal sequence and coordination of mutually antagonistic activating and repressing factors. These factors regulate the commitment of the unipotential gonad into the binary pathways governing normal sex development. Typically, the presence of the SRY gene on the Y chromosome triggers the cascade of molecular events that lead to male sex development. Disorders of sex development comprise a heterogeneous group of congenital conditions associated with atypical development of internal and external genitalia. These disorders are generally attributed to deviations from the typical progression of sex development. Disorders of sex development can be classified into several categories including chromosomal, gonadal, and anatomic abnormalities. Genetic tools such as microarray analyses and next-generation sequencing techniques have identified novel genetic variants among patients with disorders of sexual development. Most importantly, patient management needs to be individualized, especially for decisions related to sex of rearing, surgical interventions, hormone treatment, and potential for fertility preservation.

Disorders of Sex Development with Testicular Differentiation in SRY-Negative 46,XX Individuals: Clinical and Genetic Aspects

Virilisation of the XX foetus is the result of androgen excess, resulting most frequently from congenital adrenal hyperplasia in individuals with typical ovarian differentiation. In rare cases, 46,XX gonads may differentiate into testes, a condition known as 46,XX testicular disorders of sex development (DSD), or give rise to the coexistence of ovarian and testicular tissue, a condition known as 46,XX ovotesticular DSD. Testicular tissue differentiation may be due to the translocation of SRY to the X chromosome or an autosome. In the absence of SRY, overexpression of other pro-testis genes, e.g. SOX family genes, or failure of pro-ovarian/anti-testis genes, such as WNT4 and RSPO1, may underlie the development of testicular tissue. Recent experimental and clinical evidence giving insight into SRY-negative 46,XX testicular or ovotesticular DSD is discussed.

Studies of gonadal sex differentiation

Gonadal differentiation has a determinative influence on sex development in human embryos. Disorders of sexual development (DSD) have been associated with persistent embryonal differentiation stages. Between 1998 and 2015, 139 female patients with various (DSD) underwent operations at the Scientific Center of Obstetrics, Gynaecology and Perynatology in Moscow, Russia. Clinical investigations included karyotyping, ultrasound imaging, hormonal measurement and investigations of gonadal morphology. The male characteristics in the embryo are imposed by testicular hormones. When these are absent or inactive, the fetus may be arrested at between developmental stages, or stay on indifferent stage and become phenotypically female. A systematic analysis of gonadal morphology in DSD patients and a literature review revealed some controversies and led us to formulate a new hypothesis about sex differentiation. Proliferation of the mesonephric system (tubules and corpuscles) in the gonads stimulates the masculinization of gonads to testis. Sustentacular Sertoli cells of the testes are derived from mesonephric excretory tubules, while interstitial Leydig cells are derived from the original mesenchyme of the mesonephros. According of the new hypothesis, the original mesonephric cells (tubules and corpuscles) potentially persist in the ovarian parenchyma. In female gonads, some mesonephric excretory tubules regress and lose the tubular structure, but form ovarian theca interna and externa, becoming analogous to the sustentacular Sertoli cells in the testis. The ovarian interstitial Leydig cells are derived from intertubal mesenchyme of the mesonephros, similar to what occurs in male gonads (testis). Surprisingly, the leading determinative factor in sexual differentiation of the gonads is the mesonephros, represented by the embryonic urinary system.

Multifaceted origins of sex differences in the brain

Studies of sex differences in the brain range from reductionistic cell and molecular analyses in animal models to functional imaging in awake human subjects, with many other levels in between. Interpretations and conclusions about the importance of particular differences often vary with differing levels of analyses and can lead to discord and dissent. In the past two decades, the range of neurobiological, psychological and psychiatric endpoints found to differ between males and females has expanded beyond reproduction into every aspect of the healthy and diseased brain, and thereby demands our attention. A greater understanding of all aspects of neural functioning will only be achieved by incorporating sex as a biological variable. The goal of this review is to highlight the current state of the art of the discipline of sex differences research with an emphasis on the brain and to contextualize the articles appearing in the accompanying special issue.

The role of Amh signaling in teleost fish--Multiple functions not restricted to the gonads

This review summarizes the important role of Anti-Müllerian hormone (Amh) during gonad development in fishes. This Tgfβ-domain bearing hormone was named after one of its known functions, the induction of the regression of Müllerian ducts in male mammalian embryos. Later in development it is involved in male and female gonad differentiation and extragonadal expression has been reported in mammals as well. Teleosts lack Müllerian ducts, but they have amh orthologous genes. amh expression is reported from 21 fish species and possible regulatory interactions with further factors like sex steroids and gonadotropic hormones are discussed. The gonadotropin Fsh inhibits amh expression in all fish species studied. Sex steroids show no consistent influence on amh expression. Amh is produced in male Sertoli cells and female granulosa cells and inhibits germ cell proliferation and differentiation as well as steroidogenesis in both sexes. Therefore, Amh might be a central player in gonad development and a target of gonadotropic Fsh. Furthermore, there is evidence that an Amh-type II receptor is involved in germ cell regulation. Amh and its corresponding type II receptor are also present in brain and pituitary, at least in some teleosts, indicating additional roles of Amh effects in the brain-pituitary-gonadal axis. Unraveling Amh signaling is important in stem cell research and for reproduction as well as for aquaculture and in environmental science.

An update on Mullerian-inhibiting substance: its potential application against ovarian cancer

Each year, ∼25 000 women are newly diagnosed with ovarian cancer in the USA. The vast majority (>90%) of cases are of epithelial origin. This highly lethal cancer carries a mortality rate of >50% and a high risk of recurrence after conventional, first-line chemotherapy. Müllerian-inhibiting substance (MIS) is a gonadal hormone that causes regression of the Müllerian ducts. A series of studies have demonstrated that MIS also has multiple extra-Müllerian functions including inhibition of epithelial ovarian cancer cells in vitro and in vivo. Accumulating evidence has shown that many human cancers are organized hierarchically and contain a small population of cancer stem cells (CSCs) that are inherently resistant to common chemotherapy and radiation therapy. The effect of MIS on ovarian CSC seems to be particularly useful in rescuing ovarian cancer patients with resistance to conventional treatment. Based on recent studies evaluating MIS, this review updates our current understanding of the molecular genetic aspects of MIS, its pathophysiology, as well as its potential to treat chemoresistant epithelial ovarian cancer.

Anti-Mullerian hormone and risk of invasive serous ovarian cancer

PURPOSE

Epithelial ovarian cancers either arise directly from Mullerian-type epithelium or acquire Mullerian characteristics in the course of neoplastic transformation. The anti-Mullerian hormone (AMH) causes regression of Mullerian structures during fetal development in males and has been shown to inhibit the growth of epithelial ovarian cancer. Therefore, we hypothesized that pre-diagnostic serum concentrations of AMH are inversely associated with risk of invasive serous ovarian cancer.

METHODS

A case-control study (107 cases, 208 controls) was nested within the population-based Finnish Maternity Cohort (1986-2007). The sample donated during the first trimester of the last pregnancy preceding cancer diagnosis of the case subjects was selected for the study. For each case, two controls, matched on age and date at sampling, as well as parity at sampling and at cancer diagnosis were selected. AMH was measured by a second-generation AMH ELISA. Conditional logistic regression was used to compute odds ratios (OR) and 95 % confidence intervals (CI) for invasive serous ovarian cancer associated with AMH concentrations.

RESULTS

Overall AMH concentrations were not associated with risk of invasive serous ovarian cancer (OR 0.93; 95 % CI 0.49-1.77 for top vs. bottom tertile, P trend=0.83). In women older than the median age at sampling (32.7 years), a doubling of AMH was associated with decreased risk (OR 0.69; 95 % CI 0.49-0.96), whereas an increased risk (OR 1.64; 95 % CI 1.06-2.54) was observed in younger women, P homogeneity = 0.002.

CONCLUSIONS

In this first prospective investigation, risk of invasive serous ovarian cancer was not associated with pre-diagnostic AMH concentrations overall; however, the association may depend on age at AMH measurement.

Lhx1 is required in Müllerian duct epithelium for uterine development

The female reproductive tract organs of mammals, including the oviducts, uterus, cervix and upper vagina, are derived from the Müllerian ducts, a pair of epithelial tubes that form within the mesonephroi. The Müllerian ducts form in a rostral to caudal manner, guided by and dependent on the Wolffian ducts that have already formed. Experimental embryological studies indicate that caudal elongation of the Müllerian duct towards the urogenital sinus occurs in part by proliferation at the ductal tip. The molecular mechanisms that regulate the elongation of the Müllerian duct are currently unclear. Lhx1 encodes a LIM-homeodomain transcription factor that is essential for male and female reproductive tract development. Lhx1 is expressed in both the Wolffian and Müllerian ducts. Wolffian duct-specific knockout of Lhx1 results in degeneration of the Wolffian duct and consequently the non-cell-autonomous loss of the Müllerian duct. To determine the role of Lhx1 specifically in the Müllerian duct epithelium, we performed a Müllerian duct-specific knockout study using Wnt7a-Cre mice. Loss of Lhx1 in the Müllerian duct epithelium led to a block in Müllerian duct elongation and uterine hypoplasia characterized by loss of the entire endometrium (luminal and glandular epithelium and stroma) and inner circular but not the outer longitudinal muscle layer. Time-lapse imaging and molecular analyses indicate that Lhx1 acts cell autonomously to maintain ductal progenitor cells for Müllerian duct elongation. These studies identify LHX1 as the first transcription factor that is essential in the Müllerian duct epithelial progenitor cells for female reproductive tract development. Furthermore, these genetic studies demonstrate the requirement of epithelial-mesenchymal interactions for uterine tissue compartment differentiation.

Müllerian inhibiting substance in the caudate amphibian Pleurodeles waltl

Müllerian inhibiting substance (MIS, also known as anti-Müllerian hormone), is a key factor of male sex differentiation in vertebrates. In amniotes, it is responsible for Müllerian duct regression in male embryos. In fish, despite the absence of Müllerian ducts, MIS is produced and controls germ cell proliferation during gonad differentiation. Here we show for the first time the presence of MIS in an amphibian species, Pleurodeles waltl. This is very astonishing because in caudate amphibians, Müllerian ducts do not regress in males. Phylogenetic analysis of MIS P. waltl ortholog revealed that the deduced protein segregates with MIS from other vertebrates and is clearly separated from other TGF-β family members. In larvae, MIS mRNA was expressed at higher levels in the developing testes than in the ovaries. In the testis, MIS mRNA expression was located within the lobules that contain Sertoli cells. Besides, expression of MIS was modified in the case of sex reversal: it increased after masculinizing heat treatment and decreased after estradiol feminizing exposure. In addition to the data obtained recently in the fish medaka, our results suggest that the role of MIS on Müllerian ducts occurred secondarily during the course of evolution.

Serum anti-müllerian hormone, follicle stimulating hormone and antral follicle count measurement cannot predict pregnancy rates in IVF/ICSI cycles

PURPOSE

To investigate whether serum anti-müllerian hormone (AMH), follicle stimulating hormone (FSH), or antral follicle count (AFC) are predictive for clinical pregnancy in in vitro fertilization (IVF) patients.

METHODS

Serum AMH, inhibin B, FSH, luteinizing hormone (LH), estradiol (E2), prolactin, and thyroid stimulating hormone (TSH) levels and AFC of 189 women under 40 years of age were investigated. Pregnant and non-pregnant women were compared.

RESULTS

Forty-seven (24.8 %) clinical pregnancies were observed in 189 women. There was no significant difference in terms of mean age, duration of infertility, body mass index, AMH, LH, FSH, E2, TSH, Inhibin B, AFC and total oocyte number between women who did and who did not become pregnant. Additionally, there was no significant difference in clinical pregnancy rates between the quartiles of AMH, FSH and AFC. (P values were 0.668, 0.071, and 0.252, respectively.)

CONCLUSION

Serum AMH and FSH, and AFC cannot predict clinical pregnancy in IVF patients under 40; the pregnancy rate tends to increase as AMH increases, although this remains non-significant.

Proteolytically activated, recombinant anti-mullerian hormone inhibits androgen secretion, proliferation, and differentiation of spermatogonia in adult zebrafish testis organ cultures

Anti-Müllerian hormone (Amh) is in mammals known as a TGFβ type of glycoprotein processed to yield a bioactive C-terminal homodimer that directs regression of Müllerian ducts in the male fetus and regulates steroidogenesis and early stages of folliculogenesis. Here, we report on the zebrafish Amh homologue. Zebrafish, as all teleost fish, do not have Müllerian ducts. Antibodies raised against the N- and C-terminal part of Amh were used to study the processing of endogenous and recombinant Amh. The N-terminally directed antibody detected a 27-kDa protein, whereas the C-terminally directed one recognized a 32-kDa protein in testes extracts, both apparently not glycosylated. The C-terminal fragment was present as a monomeric protein, because reducing conditions did not change its apparent molecular mass. Recombinant zebrafish Amh was cleaved with plasmin to N- and C-terminal fragments that after deglycosylation were similar in size to endogenous Amh fragments. Mass spectrometry and N-terminal sequencing revealed a 21-residue N-terminal leader sequence and a plasmin cleavage site after Lys or Arg within Lys-Arg-His at position 263-265, which produce theoretical fragments in accordance with the experimental results. Experiments using adult zebrafish testes tissue cultures showed that plasmin-cleaved, but not uncleaved, Amh inhibited gonadotropin-stimulated androgen production. However, androgens did not modulate amh expression that was, on the other hand, down-regulated by Fsh. Moreover, plasmin-cleaved Amh inhibited androgen-stimulated proliferation as well as differentiation of type A spermatogonia. In conclusion, zebrafish Amh is processed to become bioactive and has independent functions in inhibiting both steroidogenesis and spermatogenesis.

Dicer is required for female reproductive tract development and fertility in the mouse

Dicer encodes a riboendonuclease required for microRNA biosynthesis. Dicer was inactivated in Müllerian duct mesenchyme-derived tissues of the reproductive tract of the mouse, using an Amhr2-Cre allele. Although Amhr2-Cre; Dicer conditional mutant males appeared normal and were fertile, mutant females were infertile. In adult mutant females, there was a reduction in the size of the oviducts and uterine horns. The oviducts were less coiled compared to controls and cysts formed at the isthmus near the uterotubal junction. Unfertilized, degenerate oocytes were commonly found within these cysts, indicating a defect in embryo transit. Beads transferred into the mutant oviduct failed to migrate into the uterus. In addition, blastocysts transferred directly into the mutant uterus did not result in pregnancy. Histological analysis demonstrated that the mutant uterus contained less glandular tissue and often the few glands that remained were found within the myometrium, an abnormal condition known as adenomyosis. In adult mutants, there was ectopic expression of Wnt4 and Wnt5a in the luminal epithelium (LE) and glandular epithelium (GE) of the uterus, and Wnt11 was ectopically expressed in GE. These results demonstrate that Dicer is necessary for postnatal differentiation of Müllerian duct mesenchyme-derived tissues of the female reproductive tract, suggesting that microRNAs are important regulators of female reproductive tract development and fertility.