Search Results (28)

This study reviews the main candidate genes involved in the pathophysiology of Polycystic Ovary Syndrome (PCOS). PCOS is a common endocrine–metabolic disorder in women of reproductive age, characterized by menstrual irregularity, hyperandrogenism, and polycystic ovarian morphology. It is associated with increased metabolic and cardiovascular risk and is a leading cause of infertility. Although its pathophysiology is not fully understood, alterations in the hypothalamic–pituitary–ovarian axis, insulin metabolism, and steroidogenesis have been described. Polymorphisms in genes encoding hormones, enzymes, and receptors in these pathways contribute to clinical variability and ethnic differences, offering potential for early diagnosis and personalized medicine. This review summarizes key candidate genes related to insulin metabolism (INS, INSR, IRS-1), the hypothalamic–pituitary–ovarian axis (LHβ, LHCGR, FSHR, GnRHR, AMH, AMHR2, KISS1, CAPN10), steroidogenesis (CYP11A, CYP17A1, CYP19A1, CYP21, 17β-HSD, SHBG, AR, STAR), and other clinically relevant mechanisms such as obesity, lipid metabolism (PPARG, VDR, FTO), and follicular development (ACE). Full article

Sex determination in teleost fishes exhibits remarkable evolutionary plasticity; however, the underlying mechanisms remain largely elusive for many species of high economic importance. Herein, we provide the first genome-wide investigation of the genetic basis of sex determination in the European anchovy (Engraulis encrasicolus), an ecologically and commercially vital clupeiform fish. Using low-pass whole-genome resequencing of 100 sexually mature individuals (50 females and 50 males), we conducted a genome-wide association study (GWAS) and F_ST scans to identify sex-linked loci and characterize sex-determining regions (SDRs). Our analyses revealed two major candidate SDRs located on chromosomes 14 and 18, encompassing multiple sex-associated single-nucleotide polymorphisms (SNPs) and insertions/deletions (InDels). Among these, the amhr2 (anti-Müllerian hormone type 2 receptor) gene on Chr14 displayed the strongest and most consistent association with phenotypic sex, marked by several male-specific missense SNPs and InDel variants. Comparative and transcriptomic analyses confirmed sex-biased expression of amhr2 and other SDR-linked genes, potentially indicating a male heterogametic (XY-like) genetic sex determination system. These results provide the first molecular evidence for a candidate SDR in E. encrasicolus, raise the possibility of involvement of amhr2 and additional loci in sex determination, and highlight rapid sex chromosome turnover within Clupeiformes. Our findings not only expand the understanding of teleost sex determination evolution but also establish a genomic foundation for developing molecular tools for sex identification and population management in anchovy fisheries. Full article

Sex determination and differentiation in teleosts are governed by complex genetic regulatory networks that include evolutionarily conserved mechanisms. In this study, we investigated Boleophthalmus pectinirostris, a Gobiidae species lacking heterogametic sex chromosomes, using comparative gonadal transcriptome analysis to identify sex differentially expressed genes (DEGs). RNA sequencing of ovarian and testicular tissues identified 17,214 DEGs, including 14,302 upregulated in males and 2912 upregulated in females. These DEGs were primarily associated with male (e.g., dmrt1, amh, amhr2) or female (e.g., bmp15, gdf9, rspo1) sex determination and differentiation, steroidogenesis (e.g., hsd17b1, hsd3b1, cyp17a1), and meiosis (e.g., cyp26b1, aldh1a2, piwil2). Functional enrichment analysis revealed that male upregulated DEGs were involved in spermatogenesis pathways such as calcium signaling, while female upregulated DEGs were associated with oogenesis pathways including oocyte meiosis and progesterone-mediated oocyte maturation. Conserved regulators, notably dmrt1 and amh, were predicted to act as key hubs in protein–protein interaction networks, being primarily associated with reproductive processes and sex differentiation in B. pectinirostris. The amh gene produces two alternatively spliced isoforms that differ by a partial deletion in the second exon, both expressed in ovaries and testes. Collectively, this study provides the first comprehensive molecular framework of sex determination and differentiation in Gobiidae species, offering critical insights into the regulatory mechanisms of B. pectinirostris reproductive development. Full article

Improving reproductive efficiency in beef cattle remains a key objective for sustainable genetic progress, particularly in extensively managed autochthonous breeds such as the Spanish Retinta. In this study, we applied a weighted single-step genome-wide association approach (wssGWAS) to identify genomic regions associated with four fertility-related traits: age at first calving (AFC), interval between first and second calving (IC12), average calving interval (ACI), and reproductive efficiency (RE). A total of 215,125 calving records from 44,032 cows and the genomic information of 1030 animals (Axiom™ Bovine Genotyping v3 Array 65k) were analyzed. Heritability was estimated using a single-step genomic best linear unbiased prediction (ssGBLUP) that incorporated both pedigree and genomic data, and estimates ranged from 0.15 (0.008) for AFC to 0.27 (0.012) for ACI. The wssGWAS identified 96 1 Mb-windows explaining over 1% of additive genetic variance (40 of them are common for more than one trait and 46 windows are unique), notably on chromosomes 2 and 5. Candidate genes related to folliculogenesis, steroidogenesis, immune modulation, and cell cycle control were identified, including ACVR1B, AMHR2, CYP27B1, CDK2, and IFNG. Additionally, a significant proportion of lncRNAs were detected, suggesting regulatory roles in reproductive processes through the modulation of gene expression at different levels. These findings enhance our understanding of the genetic architecture underlying female fertility in beef cattle and provide valuable markers for incorporation into genomic selection programs aimed at improving reproductive performance and long-term sustainability in the Retinta breed. Full article

The Anti-Müllerian hormone (AMH) is widely recognized for promoting Müllerian duct regression in higher vertebrates and regulating key reproductive functions like steroidogenesis, folliculogenesis, and Leydig cell development. In teleost fish, which lack Müllerian ducts, Amh primarily influences male reproductive functions, including sex determination, testis differentiation, and germ cell proliferation. In adult fish, Amh supports gonad development and spermatogenesis, but its role in teleost gonadal physiology remains largely underexplored. This study reveals a novel steroidogenic function in the European sea bass (Dicentrarchus labrax) using in vitro testis culture, in vivo plasmid injection, and cell-based transactivation assays. The Amh-induced significant increase in androgen levels was also confirmed in Japanese medaka (Oryzias latipes) treated with recombinant sea bass Amh. Beyond activating the canonical Smad pathway, Amh also triggered the cAMP/PKA signalling pathway via its cognate type II receptor, Amhr2. Inhibitors of these pathways independently and synergistically counteracted Amh-induced CRE-Luc activity, indicating pathway crosstalk. Moreover, inhibition of the cAMP pathway suppressed Amh-induced androgen production in testis cultures, emphasizing the crucial role of protein kinase A in mediating Amh steroidogenic action. These findings uncover a novel steroidogenic function of Amh in teleosts and highlight its broader role in male reproductive physiology. Full article

The anti-Müllerian hormone (amh) and its receptor, amhr2, along with the downstream bone morphogenetic protein receptors (bmprs), have been recognized as the central regulators in teleost sex determination (SD) and differentiation. However, their evolution and function in reproduction among diverse teleost lineages may represent species-specific patterns and still need more explanation. In this study, systematic investigations of amh signaling genes, including amh, amhy (Y-linked paralog of amh), amhr2, bmpr1, and bmpr2, were conducted among teleost species. The results revealed generally conserved gene copy number, phylogeny, structure, and synteny, among teleost amh signaling genes. Notably, significantly accelerated evolutionary rates (dN/dS) were found in teleost amhy compared to amh, and amh exhibited faster molecular evolution in amhy-SD teleosts than in non-amhy-SD teleosts, suggesting their enhanced evolutionary plasticity in teleosts. Expression profiling identified testis-biased expression of the most amh signaling genes in fish species with different SD genes and mechanisms, including Lateolabrax maculatus and Dicentrarchus labrax from Order Perciformes, Cynoglossus semilaevis and Paralichthys olivaceus from Order Pleuronectiformes, and Salmo salar and Oncorhynchus mykiss from Order Salmoniformes, with ovary-biased expression also found in Salmoniformes. A weighted gene co-expression network analysis further uncovered strong species-specific functional interactions between amh signaling components and genes of germ-cell development, the meiotic process, etc. Collectively, the integrated evidence from this study supports the hypothesis that amh signaling provides the key molecules governing sex differentiation in a species-specific manner in diverse teleost lineages, independent of its SD role, and interacts with functions of both testis and ovary development. Full article

Background/Objectives: Endometriosis has a marked impact on fertility, although the mechanisms behind this relationship remain poorly understood, particularly in cases without significant anatomical distortions or in the context of ovarian endometriomas. This study aimed to investigate the effect of peritoneal endometriosis on ovarian function by assessing ovarian reserve and apoptosis. Methods: Peritoneal endometriosis was surgically induced in Sprague Dawley rats through the autotransplantation of uterine fragments onto the bowel mesothelium. One month post-surgery, ovarian structures were counted, follicle and corpora lutea apoptosis was evaluated by TUNEL, and apoptotic-related protein expression in ovaries was assessed by Western blot. Additionally, a co-culture system using 12Z endometriotic and KGN granulosa cell lines was utilized to evaluate gene expression by RT-qPCR. Results: Rats with peritoneal endometriosis exhibited a significant reduction in ovarian structures characterized by a low number of total follicles, particularly primordial, primary, preantral, and late-antral follicles. Consistently, AMH protein expression was decreased in ovaries in the presence of endometriosis. In addition, this disease led to a significant increase in late-antral follicles that were TUNEL-positive and in the number of apoptotic cells in corpora lutea, indicating higher apoptosis in endometriosis ovaries. Concomitantly, the altered expression of apoptosis-related proteins was observed, with increased procaspase 3 and decreased BCL-2 expression. In addition, KGN granulosa cells co-cultured with 12Z endometriotic cells displayed reduced KITLG mRNA expression and increased AMHR2 mRNA expression. Conclusions: Peritoneal endometriosis significantly impairs ovarian health by disrupting folliculogenesis, reducing ovarian reserve, and increasing apoptosis, potentially accelerating ovarian aging and contributing to infertility. These results underscore the need for further research to identify the molecular pathways involved and to develop targeted therapeutic strategies. Full article

Background: Endometrial proliferative lesions (EPLs) encompass endometrial hyperplasia (EH) and endometrial carcinoma (EC). Atypical endometrial hyperplasia (AEH) is associated with an elevated risk of progression to EC. Patients with polycystic ovarian syndrome (PCOS) exhibit higher serum levels of anti-Müllerian hormone (AMH) and a correspondingly increased incidence of EPLs. AMH has the capacity to inhibit the cell proliferation of EPLs derived from Müllerian duct tissue through the AMH-AMH receptor (AMHR) signaling pathway. Methods: Pairs of samples matched by preference scores were randomly selected. Immunohistochemistry was employed to assess the expression levels of AMHR type II (AMHR2) in endometrial tissue. A comparative analysis was performed between tissues from individuals with PCOS and those without, as well as between a normal endometrium and endometrial tissue from individuals with EPLs. This study aimed to elucidate differences in AMHR2 expression among these tissue types. By focusing on AMHR2 expression, the impact of the PCOS-related background on the endometrial AMH-AMHR cascade signaling pathway was initially investigated. Results: The AMHR2 protein was expressed in the endometrium of both the PCOS group and the non-PCOS group during the reproductive age (20–39 years). The expression of the AMHR2 protein in the AEH endometrium of PCOS patients did not differ significantly from that in the normal endometrium of PCOS patients; however, it was significantly higher than in the AEH endometrium of non-PCOS patients (p = 0.011). Conversely, the expression of the AMHR2 protein in the AEH endometrium of non-PCOS patients was significantly lower than that in the normal endometrium of non-PCOS patients (p = 0.021). Notably, there was no significant difference in AMHR2 protein expression in a normal endometrium between PCOS and non-PCOS patients. Conclusions: The involvement of the endometrial AMH-AMHR cascade signaling pathway and its biological effects in the pathogenesis of AEH are evident. The pathophysiological conditions associated with PCOS, such as elevated serum AMH levels and other pathological states, may directly or indirectly influence the AMH-AMHR cascade signaling pathway in the endometrium. This influence could contribute to the progression of AEH. Full article

Introduction: Persistent Müllerian duct syndrome (PMDS) is a rare disorder of sex development (DSD) caused by mutations in the genes coding anti-Müllerian hormone (AMH) or the AMH receptor, characterized by the persistence of Müllerian derivatives, the uterus and/or fallopian tubes, in otherwise normally virilized boys. Testicular regression syndrome is common in PMDS, yet the association with supernumerary testis has been reported in only two patients where genetic testing was not performed. Method: Thus, we report an individual with this particular association caused by a previously unreported homozygous variant in the AMHR2 gene to enable future genotype–phenotype correlations in this rare disorder. In addition, a search of PMDS associated with congenital anomalies reported in the literature was performed to provide a comprehensive overview of this pathology. Results: We present the case of a 13-year-old boy with a history of bilateral cryptorchidism. Two attempts of right orchidopexy were performed at the age of 4 and 5 years. At that time, exploratory laparoscopy identified an intra-abdominal left testicle. In addition, a fibrous structure extending from the left intra-abdominal testicle to the deep inguinal ring (Müllerian duct remnants) and a medially located abdominal mass, bilaterally fixated to the parietal peritoneum (uterine remnant), were detected. The left testicular biopsy revealed immature prepubertal testicular tissue. The uterine remnant was dissected and removed and the left orchidopexy was performed. The karyotype was 46, XY without other numerical or structural chromosomal abnormalities. Reinterventions on the left testicle were performed at the age of 9 and 12 years when a testicular remnant was identified in the left inguinal canal and removed. Three months after left orchidectomy, ultrasound followed by abdominopelvic MRI identified a structure resembling a testis in the left inguinal area. Another surgical exploration was performed, and a mass located outside (lateral) the inguinal canal was found. A biopsy from the suspected mass was performed. The histopathologic examination showed characteristics of immature prepubertal testis. The patient was later referred to our clinic with the suspicion of DSD. Serum AMH and inhibin B were normal. Therefore, the diagnosis of PMDS was suspected. Genetic testing was performed using next-generation sequencing in a gene panel that included AMH and AMHR2 genes. A homozygous variant classified as likely pathogenic in the AMHR2 gene was identified but remains unreported in the literature (NC_000012.11:g.53823315T>C in exon 8 of the AMHR2 gene). Conclusions: A high degree of suspicion and awareness is needed to diagnose this condition in order to avoid iterative surgery. The coexistence of two extremely rare conditions (PMDS and supernumerary testes) has been reported previously in only two patients, yet the association could have a common pathophysiologic background. Our case, reporting a novel AMHR2 variant, highlights the importance of genetic testing in these individuals in order to elucidate a possible genotype–phenotype correlation. Full article

Insulin receptor signaling promotes cell differentiation, proliferation, and growth which are essential for oocyte maturation, embryo implantation, endometrial decidualization, and placentation. The dysregulation of insulin signaling in women with metabolic syndromes including diabetes exhibits poor pregnancy outcomes that are poorly understood. We utilized the Cre/LoxP system to target the tissue-specific conditional ablation of insulin receptor (Insr) and insulin-like growth factor-1 receptor (Igf1r) using an anti-Mullerian hormone receptor 2 (Amhr2) Cre-driver which is active in ovarian granulosa and uterine stromal cells. Our long-term goal is to examine insulin-dependent molecular mechanisms that underlie diabetic pregnancy complications, and our conditional knockout models allow for such investigation without confounding effects of ligand identity, source and cross-reactivity, or global metabolic status within dams. Puberty occurred with normal timing in all conditional knockout models. Estrous cycles progressed normally in Insr^d/d females but were briefly stalled in diestrus in Igf1r^d/d and double receptor (DKO) mice. The expression of vital ovulatory genes (Lhcgr, Pgr, Ptgs2) was not significantly different in 12 h post-hCG superovulated ovaries in knockout mice. Antral follicles exhibited an elevated apoptosis of granulosa cells in Igf1r^d/d and DKO mice. However, the distribution of ovarian follicle subtypes and subsequent ovulations was normal in all insulin receptor mutants compared to littermate controls. While ovulation was normal, all knockout lines were subfertile suggesting that the loss of insulin receptor signaling in the uterine stroma elicits implantation and decidualization defects responsible for subfertility in Amhr2-Cre-derived insulin receptor mutants. Full article

The transforming growth factor β (TGFβ) superfamily, consisting of protein ligands, receptors, and intracellular SMAD transducers, regulates fundamental biological processes and cancer development. Our previous study has shown that sustained activation of TGFβ receptor 1 (TGFBR1) driven by anti-Mullerian hormone receptor type 2 (Amhr2)-Cre in the mouse testis induces the formation of testicular granulosa cell tumors (TGCTs). As Amhr2-Cre is expressed in both Sertoli cells and Leydig cells, it remains unclear whether the activation of TGFBR1 in Sertoli cells alone is sufficient to induce TGCT formation. Therefore, the objective of this study was to determine whether Sertoli cell-activation of TGFBR1 drives oncogenesis in the testis. Our hypothesis was that overactivation of TGFBR1 in Sertoli cells would promote their transdifferentiation into granulosa-like cells and the formation of TGCTs. To test this hypothesis, we generated mice harboring constitutive activation of TGFBR1 in Sertoli cells using anti-Mullerian hormone (Amh)-Cre. Disorganized seminiferous tubules and tumor nodules were found in TGFBR1^CA; Amh-Cre mice. A histological analysis showed that Sertoli cell-specific activation of TGFBR1 led to the development of neoplasms resembling granulosa cell tumors, which derailed spermatogenesis. Moreover, TGCTs expressed granulosa cell markers including FOXL2, FOXO1, and INHA. Using a dual fluorescence reporter line, the membrane-targeted tdTomato (mT)/membrane-targeted EGFP (mG) mouse, we provided evidence that Sertoli cells transdifferentiated toward a granulosa cell fate during tumorigenesis. Thus, our findings indicate that Sertoli cell-specific activation of TGFBR1 leads to the formation of TGCTs, supporting a key contribution of Sertoli cell reprogramming to the development of this testicular malignancy in our model. Full article

Gonadotropin-releasing hormone (GnRH) neurons are key neuroendocrine cells in the brain as they control reproduction by regulating hypothalamic-pituitary-gonadal axis function. In this context, anti-Müllerian hormone (AMH), growth hormone (GH), and insulin-like growth factor 1 (IGF1) were shown to improve GnRH neuron migration and function in vitro. Whether AMH, GH, and IGF1 signaling pathways participate in the development and function of GnRH neurons in vivo is, however, currently still unknown. To assess the role of AMH, GH, and IGF1 systems in the development of GnRH neuron, we evaluated the expression of AMH receptors (AMHR2), GH (GHR), and IGF1 (IGF1R) on sections of ex vivo mice at different development stages. The expression of AMHR2, GHR, and IGF1R was assessed by immunofluorescence using established protocols and commercial antibodies. The head sections of mice were analyzed at E12.5, E14.5, and E18.5. In particular, at E12.5, we focused on the neurogenic epithelium of the vomeronasal organ (VNO), where GnRH neurons, migratory mass cells, and the pioneering vomeronasal axon give rise. At E14.5, we focused on the VNO and nasal forebrain junction (NFJ), the two regions where GnRH neurons originate and migrate to the hypothalamus, respectively. At E18.5, the median eminence, which is the hypothalamic area where GnRH is released, was analyzed. At E12.5, double staining for the neuronal marker ß-tubulin III and AMHR2, GHR, or IGF1R revealed a signal in the neurogenic niches of the olfactory and VNO during early embryo development. Furthermore, IGF1R and GHR were expressed by VNO-emerging GnRH neurons. At E14.5, a similar expression pattern was found for the neuronal marker ß-tubulin III, while the expression of IGF1R and GHR began to decline, as also observed at E18.5. Of note, hypothalamic GnRH neurons labeled for PLXND1 tested positive for AMHR2 expression. Ex vivo experiments on mouse sections revealed differential protein expression patterns for AMHR2, GHR, and IGF1R at any time point in development between neurogenic areas and hypothalamic compartments. These findings suggest a differential functional role of related systems in the development of GnRH neurons. Full article

A 28-year-old man with congenital hypogonadotropic hypogonadism (CHH) was found to be heterozygous for the GNRH1 p.R31C mutation, reported in the literature as pathogenic and dominant. The same mutation was found in his son at birth, but the testing of the infant at 64 days confirmed the hormonal changes associated with minipuberty. This led to further genetic sequencing of the patient and his son, which found a second variant, AMHR2 p.G445_L453del, in the heterozygous form, reported as pathogenic in the patient but not in his son. This suggests a digenic cause of the patient’s CHH. Together, these mutations are postulated to contribute to CHH by the lack of anti-Müllerian hormone (AMH) signalling, leading to the impaired migration of gonadotrophin releasing hormone (GnRH) neurons, the lack of the AMH effect on GnRH secretion, and altered GnRH decapeptide with reduced binding to GnRH receptors. This led us to the conclusion that the observed GNRH1 mutation in the heterozygous state is not certain to be dominant or, at least, exhibits incomplete penetrance and variable expressivity. This report also emphasises the opportunity afforded by the time window of minipuberty in assessing the inherited genetic disorders of hypothalamic function. Full article

The anti-Müllerian hormone (Amh) is a protein belonging to the TGF-β superfamily, the function of which has been considered important for male sex differentiation in vertebrates. The Japanese flounder (Paralichthys olivaceus) is a teleost fish that has an XX/XY sex determination system and temperature-dependent sex determination. In this species, amh expression is up-regulated in genetic males and in temperature-induced masculinization during the sex differentiation period. However, to the best of our knowledge, no reports on the Amh receptor (Amhr2) in flounder have been published, and the details of Amh signaling remain unclear. In this study, we produced amhr2-deficient mutants using the CRISPR/Cas9 system and analyzed the gonadal phenotypes and sex-related genes. The results revealed that the gonads of genetically male amhr2 mutants featured typical ovaries, and the sex differentiation-related genes showed a female expression pattern. Thus, the loss of Amhr2 function causes male-to-female sex reversal in Japanese flounder. Moreover, the treatment of genetically male amhr2 mutants with an aromatase inhibitor fadrozole, which inhibits estrogen synthesis, resulted in testicular formation. These results strongly suggest that Amh/Amhr2 signaling causes masculinization by inhibiting estrogen synthesis during gonadal sex differentiation in the flounder. Full article

On-orbit object detection has received extensive attention in the field of artificial intelligence (AI) in space research. Deep-learning-based object-detection algorithms are often computationally intensive and rely on high-performance devices to run. However, those devices usually lack space-qualified versions, and they can hardly meet the reliability requirement if directly deployed on a satellite platform, due to software errors induced by the space environment. In this paper, we evaluated the impact of space-environment-induced software errors on object-detection algorithms through large-scale fault injection tests. Aside from silent data corruption (SDC), we propose an extended criterial SDC-0.1 to better quantify the effect of the transient faults on the object-detection algorithms. Considering that a bit-flip error could cause severe detection result corruption in many cases, we propose a novel automated model hardening with reinforcement learning (AMHR) framework to solve this problem. AMHR searches for error-sensitive kernels in a convolutional neural network (CNN) through trial and error with a deep deterministic policy gradient (DDPG) agent and has fine-grained modular-level redundancy to increase the fault tolerance of the CNN-based object detectors. Compared to other selective hardening methods, AMHR achieved the lowest SDC-0.1 rates for various detectors and could tremendously improve the mean average precision (mAP) of the SSD detector by 28.8 in the presence of multiple errors. Full article