Examining the causal relationship between sex hormone-binding globulin (SHBG) and infertility: A Mendelian randomization study.

BACKGROUND: The causal relationship between sex hormone-binding globulin (SHBG) and infertility has remained unclear. Thus, we used Mendelian randomization (MR) to investigate this relationship. METHODS: Risk factors for SHBG were extracted from European individuals within the UK Biobank using single-nucleotide polymorphism (SNP) data. Summary-level data for infertility outcomes were obtained from the FinnGen dataset. The causal relationship between SHBG and infertility was examined using inverse variance weighted, weighted model, weighted median, and MR-Egger regression analyses. Additionally, Cochran's Q test and Egger intercept tests were used to confirm the heterogeneity and pleiotropy of identified instrumental variables (IVs). RESULTS: Our findings revealed a significant negative association between sex hormone-binding globulin (SHBG) levels and infertility, particularly with anovulation, a specific form of female infertility. However, SHBG did not exert a causal impact on male infertility or on female infertility of tubal origin. CONCLUSIONS: SHBG expression offers protection against the development of certain types of female infertility, suggesting it is a potential therapeutic target for infertility.

Anti-Müllerian Hormone in Pathogenesis, Diagnostic and Treatment of PCOS.

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among reproductive-aged women. It is characterized by chronic anovulation, hyperandrogenism, and the presence of polycystic ovary in ultrasound examination. PCOS is specified by an increased number of follicles at all growing stages, mainly seen in the preantral and small antral follicles and an increased serum level of Anti-Müllerian Hormone (AMH). Because of the strong correlation between circulating AMH levels and antral follicle count on ultrasound, Anti-Müllerian Hormone has been proposed as an alternative marker of ovulatory dysfunction in PCOS. However, the results from the current literature are not homogeneous, and the specific threshold of AMH in PCOS and PCOM is, therefore, very challenging. This review aims to update the current knowledge about AMH, the pathophysiology of AMH in the pathogenesis of PCOS, and the role of Anti-Müllerian Hormone in the treatment of this syndrome.

Could Cytochrome P450 2D6, 3A4 and 3A5 Polymorphisms Explain the Variability in Clinical Response to Clomiphene Citrate of Anovulatory PCOS Women?

Introduction: Cytochrome P450 2D6, 3A4 and 3A5 are involved in the metabolism of many drugs. These enzymes have a genetic polymorphism responsible for different metabolic phenotypes. They play a role in the metabolism of clomiphene citrate (CC), which is used to induce ovulation. Response to CC treatment is variable, and no predictive factors have thus far been identified. Objective: To study a possible link between the cytochrome P450 2D6, 3A4 and 3A5 polymorphisms and clinical response to CC. Study Design: Seventy-seven women with anovulatory Polycystic Ovarian Syndrome (PCOS) treated with CC were included which determined their cytochrome P450 2D6, 3A4 and 3A5 genotypes and used the results to predict ovarian response to this drug. Predicted responses based on the cytochrome genotypes were compared with the observed clinical responses using the calculation of a weighted Kappa coefficient. Main Outcome Measures: Number of dominant follicles assessed by ultrasound at the end of the follicular phase and confirmation of ovulation by blood progesterone assay in the luteal phase. Results: Concordance between the predicted and observed responses for the combination of the three cytochromes was 36.71%, with a negative Kappa coefficient (K = -0.0240), which corresponds to a major disagreement. Similarly, for predictions based on the cytochrome P450 2D6 genotype alone, only 39.24% of predictions were verified (coefficient K = -0.0609). Conclusion: The genetic polymorphism of cytochromes P450 2D6, 3A4 and 3A5 does not appear to influence clinical response to CC used to induce ovulation in anovulatory PCOS women.

CYP17 gene polymorphic sequence variation is associated with hyperandrogenism in Kashmiri women with polycystic ovarian syndrome.

OBJECTIVE: Polycystic ovarian syndrome is a complex reproductive as well as endocrinological disorder characterized by anovulatory dysfunction, androgen excess and polycystic ovarian morphology. Hyperandrogenism is regarded as a cardinal feature of the disease. It is believed that the excess androgens are produced due to abnormality in steroid biosynthesis pathway wherein cytochrome P450, 17α-hydroxylase (CYP17) plays an imperative role. Therefore the objective of the present study was to analyze the T/C polymorphism in 5'UTR of CYP17 gene for its association with PCOS and hyperandrogenism in Kashmiri population. METHOD: A total of 700 subjects which included 394 PCOS patients and 306 healthy controls were recruited for the study. Their anthropometric, biochemical and hormonal parameters were analyzed. DNA was extracted followed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to analyze the relationship of CYP17 gene polymorphism with PCOS and hyperandrogenism in PCOS. RESULTS AND CONCLUSION: The allelic as well as genotypic distribution did not show any significant difference between the cases and controls. However, PCOS patients with mutant genotype had significantly higher level of total testosterone and clinical features like FG score, alopecia than those of wild and heterozygous genotype, indicating association with hyperandrogenism in our Kashmiri population.

Lysyl oxidase blockade ameliorates anovulation in polycystic ovary syndrome.

STUDY QUESTION: Is overexpression of lysyl oxidase (LOX), an enzyme responsible for the cross-linking of collagens, a cause of anovulation in polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: LOX overexpression was present in PCOS ovaries, due at least in part to interleukin-1ß (IL-1ß), and inhibition of LOX activity with ß-aminopropionitrile (BAPN) ameliorated polycystic ovary morphology and anovulation. WHAT IS KNOWN ALREADY: Aberrant ovarian extracellular matrix (ECM) remodeling and inflammation may contribute to the development of PCOS. It remains unknown whether proinflammatory IL-1ß is a contributing factor for LOX overexpression in PCOS ovaries and whether inhibition of LOX can improve PCOS conditions. STUDY DESIGN, SIZE, DURATION: LOX and IL-1ß abundance in the granulosa cells and follicular fluid was compared between non-PCOS (n = 30) and PCOS (n = 39) patients. The effect and mechanism of IL-1ß on LOX expression was examined in cultured primary human granulosa cells. The improvements in PCOS conditions by LOX inhibition with BAPN was investigated in a dehydroepiandrosterone (DHEA)-induced PCOS rat model. PARTICIPANTS/MATERIALS, SETTING, METHODS: The abundance of LOX and IL-1ß was measured with quantitative real-time polymerase chain reaction (qRT-PCR), LOX activity assays and enzyme-linked immunosorbent assays (ELISA), respectively. The effect of IL-1ß on LOX expression was examined in the presence or absence of inhibitors for signaling molecules and small interfering RNA-mediated knockdown of the putative transcription factor. Chromatin immunoprecipitation assays were conducted to further identify the responsible transcription factor. The role of LOX in ovulation was investigated in a DHEA-induced PCOS rat model with administration of the LOX inhibitor BAPN. The numbers of retrieved total oocytes and MII oocytes were recorded upon ovarian stimulation. MAIN RESULTS AND THE ROLE OF CHANCE: Increased abundance of LOX (P < 0.05) and IL-1ß (P < 0.05) was observed in the granulosa cells and follicular fluid in PCOS patients. IL-1ß increased LOX expression via activation of ERK1/2 and JNK and subsequent activation of the transcription factor c-Jun. Inhibition of LOX with BAPN ameliorated irregular estrous cyclicity (P < 0.05), polycystic ovary morphology and anovulation (P < 0.05) in PCOS rats, but appeared to be ineffective in the improvement of oocyte quality. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Ovarian tissue-directed specific inhibition of LOX in combination with oocyte quality-improving drugs may be more effective in the treatment of PCOS. WIDER IMPLICATIONS OF THE FINDINGS: Inflammation of the ovary is a contributing factor for the aberrant expression of LOX in the PCOS ovary, and inhibition of LOX together with anti-inflammatory therapy may improve the core features of PCOS. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by National Key R & D Program of China (2017YFC1001403) and Doctorial Innovation Fund of Shanghai Jiao Tong University School of Medicine (BXJ201718). The authors declare no competing financial interests.

Folliculogenic factors in photoregressed ovaries: Differences in mRNA expression in early compared to late follicle development.

The early stages of ovarian folliculogenesis generally progress independent of gonadotropins, whereas later stages require signaling initiated by FSH. In Siberian hamsters, cycles of folliculogenesis are mediated by changes in photoperiod which depress the hypothalamic pituitary gonadal axis. Reduced gonadotropins lead to decreases in mature follicle development and ovulation; however, early stages of folliculogenesis have not been explored in regressed ovaries. We hypothesized that intraovarian factors that contribute predominantly to later stages of folliculogenesis would react to changes in photoperiod, whereas factors contributing to earlier stages would not change. To probe if the early stages of folliculogenesis continue in the photoinhibited ovary while late stages decline, we measured the mRNA abundance of factors that interact with FSH signaling (Fshr, Igf1, Cox2) and factors that can function independently of FSH (c-Kit, Kitl, Foxo3, Figla, Nobox, Sohlh1, Lhx8). While plasma FSH, antral follicles, and corpora lutea numbers declined with exposure to inhibitory photoperiod, the numbers of primordial, primary, and secondary follicles did not change. Expression of factors that interact with FSH signaling changed with changes in photoperiod; however, expression of factors that do not interact with FSH were not significantly altered. These results suggest that the photoinhibited ovary is not completely quiescent, as factors important for follicle selection and early follicle growth are still expressed in regressed ovaries. Instead, the lack of gonadotropin support that characterizes the non-breeding season appears to inhibit only final stages of folliculogenesis in Siberian hamsters.

Identification of differentially expressed genes in pathways of cerebral neurotransmission of anovulatory mice.

Polycystic ovary syndrome is the classic example of loss of functional cyclicity and anomalous feedback. In this case, the excessive extra-glandular production and conversion of androgens to estrogens are the pathophysiological basis of the chronic anovulation. The literature describes an experimental model of the polymicrocystic ovary in obese diabetic mice with insulin resistance. The fact that these animals exhibit obesity, insulin resistance, and infertility demonstrates their skill as an experimental model for polycystic ovary. A recent study using long protocol for up to 40 weeks showed that anovulatory and obese mice transplanted with adipose tissue from animals with normal weight have multiple changes in their phenotype. These changes include reduction of body weight, prevention of obesity, insulin level normalization, and insulin tolerance tests, preventing the elevation of steroids and especially the reversal of fertility restoration with anovulation. Considering that there are close relationships between the ovulation process and the central nervous system, we propose to evaluate the gene expression levels of 84 different genes involved in neurotransmission and insulin pathways in addition to examining the neurolipidosis differential murine brain before and after reversal of anovulation. The present study showed changes in gene expression of molecular markers in brain tissue of animals for brain neurotransmission pathways as well as pathways for insulin. GABAergic genes, muscarinic, serotonin receptors, receptor tyrosine kinase, and genes of interleukin 6 showed overexpression profile. There was also a change in the lipid content in anovulatory brain, obesity, and insulin resistant mice (Ob-/Ob-) compared with controls. The re-introduction of leptin in these animals appears to reverse, at least in part, this profile.

The incidence of metabolic syndrome in adolescents with different phenotypes of PCOS.

OBJECTIVES: To evaluate the incidence of metabolic syndrome in Turkish adolescents with different phenotypes of polycystic ovary syndrome (PCOS). MATERIAL AND METHODS: This cross-sectional study was performed on the Youth Center clinic of a tertiary referral hospital in Turkey. Adolescents with PCOS (n = 144) were classified into four phenotype groups according to the presence of oligo/anovulation (O), hyperandrogenism (H), and polycystic ovarian morphology (P) as follows: Phenotype A (O + H + P), Phenotype B (H + O), Phenotype C (H + P), Phenotype D (O + P). The adolescents gave early follicular phase blood samples for endocrine and metabolic tests. The incidence and the presence of parameters of metabolic syndrome were assessed among the four groups. RESULTS: In total, 54.9% of the adolescents with PCOS were overweight and 25.7% had metabolic syndrome. The incidence of metabolic syndrome in Phenotypes A-D were as follows: 39.5%, 20.5%, 26.5%, and 15.2%, respectively. Although body mass index was higher in the Phenotype A group, insulin resistance was similar in all of the phenotype groups. The most common dyslipidemia was low HDL-C levels and this was present in more than half of the adolescents with PCOS. Both body mass index and total testosterone levels were significantly higher in adolescents with metabolic syndrome in comparison to those without metabolic syndrome. CONCLUSIONS: Although low HDL-C levels and insulin resistance are common PCOS findings in adolescents, the metabolic profile seems to be worse in Phenotype A than the other phenotypes. Therefore, screening programs should evaluate patients based on the known risk factors and phenotypes for adolescents with PCOS.

Elevated circulating micro-ribonucleic acid (miRNA)-200b and miRNA-429 levels in anovulatory women.

OBJECTIVE: To study the role of micro-RNA (miRNA)-200b and miRNA-429 in human ovulation and to measure their expression levels in ovulatory and anovulatory patients. DESIGN: Micro-RNA-200b and miRNA-429 expression analysis in human serum and granulosa cells at different phases of the ovulation cycle in normal cycling women and women undergoing assisted reproductive technology cycles. SETTING: University-affiliated hospital and academic research laboratory. PATIENT(S): Forty women (7 normally ovulating, 15 normally ovulating with pure male infertility factor, and 18 with polycystic ovary syndrome) were included in this study. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The expression profile of circulating miRNAs and granulosa cells was assessed by means of real-time quantitative reverse transcription-polymerase chain reaction analysis. RESULT(S): We identified miRNA-200b and miRNA-429 in the sera of all women tested. These miRNA expression levels were elevated during the early follicular phase of the cycle compared with serum levels during the early luteal phase. Anovulatory women, diagnosed with polycystic ovary syndrome, expressed significantly higher levels of miRNA-200b and miRNA-429 compared with spontaneously ovulating women. Ovulation induction with exogenous gonadotropins during an IVF cycle reduced these levels to the levels measured in normal ovulating women. CONCLUSION(S): Our findings suggest an involvement of miRNA-200b and miRNA-429 in the pituitary regulation of human ovulation. Although it is unclear whether this altered miRNA expression profile is a cause or a result of anovulation, the levels of these molecules in the serum of anovulatory women may serve as serum biomarkers for the ovulation process.

Crowding and Follicular Fate: Spatial Determinants of Follicular Reserve and Activation of Follicular Growth in the Mammalian Ovary.

Initiation of growth of resting ovarian follicles is a key phenomenon for providing an adequate number of mature oocytes in each ovulation, while preventing premature exhaustion of primordial follicle reserve during the reproductive lifespan. Resting follicle dynamics strongly suggest that primordial follicles are under constant inhibitory influences, by mechanisms and factors whose nature remains ill defined. In this work, we aimed to assess the influence of spatial determinants, with special attention to clustering patterns and crowding, on the fate of early follicles in the adult mouse and human ovary. To this end, detailed histological and morphometric analyses, targeting resting and early growing follicles, were conducted in ovaries from mice, either wild type (WT) or genetically modified to lack kisspeptin receptor expression (Kiss1r KO), and healthy adult women. Kiss1r KO mice were studied as model of persistent hypogonadotropism and anovulation. Different qualitative and quantitative indices of the patterns of spatial distribution of resting and early growing follicles in the mouse and human ovary, including the Morisita's index of clustering, were obtained. Our results show that resting primordial follicles display a clear-cut clustered pattern of spatial distribution in adult mouse and human ovaries, and that resting follicle aggrupation is inversely correlated with the proportion of follicles initiating growth and entering into the growing pool. As a whole, our data suggest that resting follicle crowding, defined by changes in density and clustered pattern of distribution, is a major determinant of follicular activation and the fate of ovarian reserve. Uneven follicle crowding would constitute the structural counterpart of the major humoral regulators of early follicular growth, with potential implications in ovarian ageing and pathophysiology.

Infertility in Female Mice with a Gain-of-Function Mutation in the Luteinizing Hormone Receptor Is Due to Irregular Estrous Cyclicity, Anovulation, Hormonal Alterations, and Polycystic Ovaries.

The luteinizing hormone receptor, LHCGR, is essential for fertility in males and females, and genetic mutations in the receptor have been identified that result in developmental and reproductive defects. We have previously generated and characterized a mouse model (KiLHR(D582G)) for familial male-limited precocious puberty caused by an activating mutation in the receptor. We demonstrated that the phenotype of the KiLHR(D582G) male mice is an accurate phenocopy of male patients with activating LHCGR mutations. In this study, we observed that unlike women with activating LHCGR mutations who are normal, female KiLHR(D582G) mice are infertile. Mice exhibit irregular estrous cyclicity, anovulation, and precocious puberty. A temporal study from 2-24 wk of age indicated elevated levels of progesterone, androstenedione, testosterone, and estradiol and upregulation of several steroidogenic enzyme genes. Ovaries of KiLHR(D582G) mice exhibited significant pathology with the development of large hemorrhagic cysts as early as 3 wk of age, extensive stromal cell hyperplasia and hypertrophy with luteinization, numerous atretic follicles, and granulosa cell tumors. Ovulation could not be rescued by the addition of exogenous gonadotropins. The body weights of the KiLHR(D582G) mice were higher than wild-type counterparts, but there was no increase in the body fat composition or metabolic abnormalities such as impaired glucose tolerance and insulin resistance. These studies demonstrate that activating LHCGR mutations do not produce the same phenotype in female mice as in humans and clearly illustrate species differences in the expression and regulation of LHCGR in the ovary, but not in the testis.

Genetic analysis and cAMP measurement: comparison between lean and obese anovulating mice.

PURPOSE: To evaluate genes differentially expressed in ovaries from lean (wild type) and obese (ob/ob) female mice and cyclic AMP production in both groups. METHODS: The expression on messenger RNA levels of 84 genes concerning obesity was analyzed through the PCR array, and cyclic AMP was quantified by the enzyme immunoassay method. RESULTS: The most downregulated genes in the Obesity Group included adenylate cyclase-activating polypeptide type 1, somatostatin, apolipoprotein A4, pancreatic colipase, and interleukin-1 beta. The mean decrease in expression levels of these genes was around 96, 40, 9, 4.2 and 3.6-fold, respectively. On the other hand, the most upregulated genes in the Obesity Group were receptor (calcitonin) activity-modifying protein 3, peroxisome proliferator activated receptor alpha, calcitonin receptor, and corticotropin-releasing hormone receptor 1. The increase means in the expression levels of such genes were 2.3, 2.7, 4.8 and 6.3-fold, respectively. The ovarian cyclic AMP production was significantly higher in ob/ob female mice (2,229 ± 52 fMol) compared to the Control Group (1,814 ± 45 fMol). CONCLUSIONS: Obese and anovulatory female mice have reduced reproductive hormone levels and altered ovogenesis. Several genes have their expression levels altered when leptin is absent, especially adenylate cyclase-activating polypeptide type 1.

Genetic analysis and cAMP measurement: comparison between lean and obese anovulating mice / Análise genética e dosagem de AMP cíclico: comparação entre camundongos fêmeas anovuladoras magras e obesas

PURPOSE: To evaluate genes differentially expressed in ovaries from lean (wild type) and obese (ob/ob) female mice and cyclic AMP production in both groups. METHODS: The expression on messenger RNA levels of 84 genes concerning obesity was analyzed through the PCR array, and cyclic AMP was quantified by the enzyme immunoassay method. RESULTS: The most downregulated genes in the Obesity Group included adenylate cyclase-activating polypeptide type 1, somatostatin, apolipoprotein A4, pancreatic colipase, and interleukin-1 beta. The mean decrease in expression levels of these genes was around 96, 40, 9, 4.2 and 3.6-fold, respectively. On the other hand, the most upregulated genes in the Obesity Group were receptor (calcitonin) activity-modifying protein 3, peroxisome proliferator activated receptor alpha, calcitonin receptor, and corticotropin-releasing hormone receptor 1. The increase means in the expression levels of such genes were 2.3, 2.7, 4.8 and 6.3-fold, respectively. The ovarian cyclic AMP production was significantly higher in ob/ob female mice (2,229±52 fMol) compared to the Control Group (1,814±45 fMol). CONCLUSIONS: Obese and anovulatory female mice have reduced reproductive hormone levels and altered ovogenesis. Several genes have their expression levels altered when leptin is absent, especially adenylate cyclase-activating polypeptide type 1. .

OBJETIVO: Avaliar os genes diferencialmente expressos em ovários de camundongos fêmeas magras (tipo selvagem) e obesas (ob/ob) e a produção de AMP cíclico em ambos os grupos. MÉTODOS: A expressão nos níveis de RNA mensageiro de 84 genes relacionados à obesidade foi analisada por PCR Array, e o AMP cíclico foi quantificado por método imunoenzimático. RESULTADOS: Os genes que mais sofreram diminuição da expressão no Grupo Obesidade incluíram o tipo 1 de polipeptídeo ativador da adenilato ciclase, o da somatostatina, da apolipoproteína A4, da colipase pancreática e da beta interleucina 1. A média de redução na expressão desses genes foi de aproximadamente 96, 40, 9, 4,2 e 3,6 vezes, respectivamente. Por outro lado, os genes que mais tiveram aumento na expressão no Grupo Obesidade foram o gene da proteína modificadora da atividade do receptor de calcitonina 3, do proliferador de peroxissomos ativados por proteína alfa, do receptor de calcitonina e do receptor para hormônio liberador de corticotropinas 1. As médias de acréscimo nos níveis de expressão de tais genes foram de 2,3, 2,7, 4,8 e 6,3 vezes, respectivamente. A produção de AMP cíclico ovariana foi significantemente aumentada em camundongos fêmeas ob/ob (2.229±52 fMol) quando comparada ao Grupo Controle (1.814±45 fMol). CONCLUSÕES: Camundongos fêmeas obesas e anovuladoras possuem níveis de hormônio reprodutivo reduzidos e ovulogênese alterada. Vários genes mostram níveis de expressão alterados quando a leptina está ausente, principalmente o tipo 1 de polipeptídeo ativador da adenilato ciclase. .

Follicle-stimulating hormone receptor polymorphism affects the outcome of ovulation induction in normogonadotropic (World Health Organization class 2) anovulatory subfertility.

OBJECTIVE: To assess whether an FSH receptor polymorphism (Asn680Ser, rs6166) can affect the outcome of ovulation induction in normogonadotropic (World Health Organization class 2 [WHO2]) anovulatory subfertile women. DESIGN: Prospective, longitudinal, cohort study. SETTING: University-based fertility unit. PATIENT(S): A total of 240 consecutive women diagnosed with WHO2 anovulatory subfertility who underwent ovulation induction therapy. Results were replicated in a retrospective cohort of 185 patients with polycystic ovary syndrome (PCOS) (Rotterdam criteria). INTERVENTION(S): Ovulation induction using clomiphene citrate (CC) as first-line and exogenous gonadotropins (exFSH) as second-line therapy. MAIN OUTCOME MEASURE(S): Clomiphene-resistant anovulation (CRA), clomiphene failure (CCF), and ongoing pregnancy rate. RESULT(S): Genotyped patients (n = 159) were similar to nongenotyped women (n = 81) regarding clinical characteristics and outcomes of ovulation induction. The 680(Ser) allele was associated with CRA. A pooled analysis of both cohorts showed an 89% higher chance of CRA after CC treatment (odds ratio 1.9 [95% confidence interval 1.1-3.3]) in homozygous carriers of the FSH receptor variant (680(Ser/Ser)). A lower chance of ongoing pregnancy (hazard ratio 0.51 [95% confidence interval 0.27-0.98]) was observed among these patients during CC treatment in the prospective cohort. CONCLUSION(S): An FSH receptor polymorphism is associated with CRA during treatment with clomiphene citrate. These data may be used to design a treatment algorithm that is more efficacious and better tailored to the individual patient.

Transcriptome profiling identifies differentially expressed genes in Huoyan goose ovaries between the laying period and ceased period.

The Huoyan goose is famous for its high egg-laying performance and is listed as a nationally protected domestic animal by the Chinese government. To elucidate the key regulatory genes involved in Huoyan goose egg laying, RNA from ovarian tissue during the ceased and laying periods was sequenced using the Illumina HiSeq 2000 sequencing platform. More than 12 million reads were produced in ceased and laying libraries that included 11,896,423 and 12,534,799 clean reads, respectively. More than 20% of the reads were matched to the reference genome, and 23% of the reads were matched to reference genes. Genes with a false discovery rate (FDR) ≤0.001 and log2ratio ≧1 or ≤-1 were characterized as differentially expressed, and 344 up-regulated and 344 down-regulated genes were classified into functional categories. Twelve genes that are mainly involved in pathways for reproduction regulation, such as steroid hormone biosynthesis, GnRH signaling pathways, oocyte meiosis, progesterone-mediated oocyte maturation, steroid biosynthesis, calcium signaling pathways, and G-protein coupled receptor signaling pathway were selected for validation by a quantitative real-time polymerase chain reaction (qRT-PCR) analysis, the qRT-PCR results are consistent with the general expression patterns of those genes from the Illumina sequencing. These data provide comprehensive gene expression information at the transcriptional level that might increase our understanding of the Huoyan goose's reproductive biology.

Follicle-stimulating hormone receptor gene polymorphism in chronic anovulatory women, with or without polycystic ovary syndrome: a cross-sectional study.

BACKGROUND: Polymorphisms at codons 307 and 680 are the most commonly encountered allelic variants of the follicle-stimulating hormone receptor (FSHR) gene. Studies in Caucasians suggest that certain FSHR variants are more common in women with polycystic ovary syndrome (PCOS) than normal women. The objective of this study was to determine the distribution of FSHR gene polymorphisms at codons 307 and 680 in Thai women with chronic anovulation, without (121 women) and with PCOS (133 women), using 132 known fertile women as controls. METHODS: DNA samples from peripheral blood lymphocytes were extracted and analyzed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The prevalence of Threonine307Threonine (TT), Threonine307Alanine (TA), and Alanine307Alanine (AA) genotypes at codon 307 was 53.0% (95% CI = 44.2-61.7%), 42.4% (95% CI = 34-51.3%), and 4.5% (95% CI = 1.9-10.1%) in controls; 52.6% (95% CI = 43.8-61.3%), 39.8% (95% CI = 31.6-48.7%), and 7.5% (95% CI = 3.9-13.7%) in PCOS women; and 50.4% (95% CI = 42.8-61.2%), 45.4% (95% CI = 34.9-53.1%), and 4.5% (95% CI = 1.5-9.6%) in anovulatory women without PCOS, respectively. The prevalence of Asparagine680Asparagine (NN), Asparagine680Serine (NS), and Serine680Serine (SS) genotypes at codon 680 was 54.5% (95% CI = 45.7-63.2%), 40.9% (95% CI = 32.5-49.8%), and 4.5% (95% CI = 1.9-10.1%) in controls; 51.9% (95% CI = 43.1-60.6%), 44.4% (95% CI = 35.8-53.2%), and 3.8% (95% CI = 1.4-9.0%) in PCOS women; and 47.9% (95% CI = 40.4-58.8%), 47.1% (95% CI = 36.5-54.7%), and 5.0% (95% CI = 2-10.9%) in anovulatory women without PCOS, respectively. The prevalence of FSHR gene polymorphisms at both codons were not statistically different among the three groups. CONCLUSIONS: In Thai women, there was no association between the FSHR gene polymorphism at codons 307 and 680 and chronic anovulation.

Aromatase gene polymorphism does not influence clinical phenotype and response to oral contraceptive pills in polycystic ovary syndrome women.

AIMS: To assess whether a single nucleotide polymorphism (SNP50) of the aromatase gene (CYP19) is associated with polycystic ovary syndrome (PCOS) phenotypes and to investigate the influence of this polymorphism on the response of PCOS to treatment with oral contraceptive pills (OCP). METHODS: 162 hirsute women were stratified into a classic PCOS group (hyperandrogenism, ovulatory dysfunction, c-PCOS) and an ovulatory PCOS group (hyperandrogenism, ovulatory cycles, polycystic ovaries, ov-PCOS). 51 women completed a 6-month OCP trial (20 µg ethinyl estradiol + 75 µg gestodene, 21/28 days per cycle, plus 100 mg spironolactone in 32 women with moderate to severe hirsutism). We considered the presence of the polymorphic allele A (AG+AA) in comparison to the absence of the polymorphism (GG) to express results and to perform the comparisons regarding clinical variables. RESULTS: Mean age was 23.3 ± 6.9 years. Hirsutism score was similar in c-PCOS and ov-PCOS (15 (11-20) vs. 13 (11-20)). The differences in hormone and metabolic variables between phenotypes were independent of the presence of allele A. In the OCP trial subsample, no differences were observed between genotypes after 6 months' treatment. CONCLUSION: The differences between c-PCOS and ov-PCOS cannot be explained by the genetic variation at SNP50 in the CYP19 gene.

Mice harboring Gnrhr E90K, a mutation that causes protein misfolding and hypogonadotropic hypogonadism in humans, exhibit testis size reduction and ovulation failure.

GnRH, produced in the hypothalamus, acts on pituitary gonadotropes to stimulate release of the gonadotropins LH and FSH. Reduced responsiveness of gonadotropes to GnRH is a primary cause of hypogonadotropic hypogonadism (HH), a disease characterized by gonadal dysfunction and low blood levels of gonadotropins. Loss-of-function mutations in the gene encoding the receptor for GnRH (GNRHR) are a common cause of HH. Sequencing of the GNRHR gene in patients with HH revealed mainly point mutations producing single amino acid substitutions that cause misfolding and misrouting of this G protein-coupled receptor. To generate a mouse model that mimics the human disease, we introduced a single amino acid substitution (E90K) into the mouse Gnrhr gene, which is identical to a known human recessive mutation. In humans, E90K causes severe HH by preventing formation of the E90-K121 salt bridge, which is essential for correct folding. In cell cultures, E90K causes misfolding that leads to almost complete retention by the protein quality control system and subsequent degradation. Here we report that the primary phenotype of mice homozygous for E90K is female infertility due to ovulation failure. Mutant males are fertile despite reduced gonadotropin levels and smaller testes. These results suggest decreased GnRH receptor signaling in the mutant animal, compared with wild type. Our findings suggest that a threshold level of GnRH receptor activity is required for ovulation.

Acute dietary restriction in heifers alters expression of genes regulating exposure and response to gonadotrophins and IGF in dominant follicles.

Dietary restriction in growing cattle and severe negative energy balance in lactating cows have been associated with altered gonadotropin secretion, reduced follicle diameter, reduced circulating oestradiol concentrations and anovulation. Therefore, we hypothesised that acute dietary restriction would influence the fate and function of the dominant follicle by altering the expression for genes regulating gonadotrophin and IGF response in ovarian follicles. Newly selected dominant follicles were collected 7-8 days after prostaglandin F(2α) (PGF) administration from heifers (n=25) that were individually fed a diet supplying 1.2 maintenance (M; control, n=8) or 0.4 M (restricted, n=17) for a total duration of 18-19 days. Heifers within 0.4 M were ovulatory (n=11) or anovulatory (n=6) depending on whether the dominant follicle present at PGF ovulated or became atretic following luteolysis. Control animals were all ovulatory. Acute dietary restriction decreased IGF-I (P<0.001) and insulin (P<0.05) in circulation; oestradiol (P<0.01) and IGF-I (P<0.01) in follicular fluid; and mRNA for FSHR (P<0.01) in granulosa cells but increased mRNA for IGFBP2 (P<0.05) in theca cells of the newly selected dominant follicle. However, this only led to anovulation when dietary restriction also decreased mRNA for CYP19A1 (P<0.05), IGF2 (P<0.01) and IGF1R (P<0.05) in granulosa cells and LHCGR (P<0.05) in theca cells of follicles collected from heifers fed 0.4 M. These results suggest that the catabolic environment induced by dietary restriction may ultimately cause anovulation by reducing oestradiol synthesis, FSH-responsiveness and IGF signaling in granulosa, and LH-responsiveness in theca cells of dominant follicles.