A common single nucleotide polymorphism in exon 10 of the human follicle stimulating hormone receptor is a major determinant of length and hormonal dynamics of the menstrual cycle

CONTEXT: FSH is essential for follicular maturation. Data from ovarian hyperstimulation cycles suggest that FSH action is attenuated by a frequent single nucleotide polymorphism of the FSH receptor gene exchanging Asn for Ser at codon 680. OBJECTIVE: We hypothesized that the FSH receptor genotype influences menstrual cycle dynamics. DESIGN: Menstrual cycle was monitored from the midluteal phase through ovulation until the consecutive menstruation. SETTING: The study was conducted at the University research center. SUBJECTS: Women homozygous for the Asn680 (n = 12) and Ser680 (n = 9) variants with normal menstrual cycles volunteered for the study. INTERVENTIONS: There were no interventions. MAIN OUTCOME MEASUREMENTS: Follicular growth, serum LH, FSH, estradiol, progesterone, inhibin A, inhibin B and antimullerian hormone were measured. RESULTS: During the luteo-follicular transition, serum levels of estradiol, progesterone, and inhibin A were significantly lower, and FSH started to rise earlier in the Ser680/Ser680 group. FSH levels were steadily and significantly higher, and the mean area under the FSH curve was 31% greater in this group (P < 0.002). No differences were observed in estradiol, inhibin B, and growth velocities of dominant follicles. The time from luteolysis to ovulation was significantly longer in women with the Ser680/Ser680 (13.6 +/- 1.01 d) compared with Asn680/Asn680 (11.3 +/- 0.61 d, P < 0.05) genotype with a significant difference in total menstrual cycle length (29.3 vs. 27.0 d, respectively; P < 0.05). CONCLUSIONS: The FSH receptor Ser680/Ser680 genotype is associated with higher ovarian threshold to FSH, decreased negative feedback of luteal secretion to the pituitary during the intercycle transition, and longer menstrual cycles.     

Both protamine-1 to protamine-2 mRNA ratio and Bcl2 mRNA content in testicular spermatids and ejaculated spermatozoa discriminate between fertile and infertile men

BACKGROUND: Human sperm contain similar amounts of protamine-1 (P1) and protamine-2 (P2). Although aberrant protamine ratios have been observed in infertile men, functional evidence is provided by protamine knockout mice exhibiting male infertility. As sperm DNA integrity is known to be linked with DNA fragmentation and apoptosis, we investigated whether the protamine ratio or Bcl2 content represent a reliable biomarker to discriminate fertile and infertile men. METHODS: Real-time quantitative RT-PCR was used for P1, P2 and the apoptotic marker Bcl2 in testicular biopsies (TB; 74 infertile men versus 17 controls) and ejaculates (E; 95 infertile men versus 10 controls). RESULTS: The P1-P2 mRNA ratio differed significantly between groups, namely 1:4 versus 1:3.2 in TB (P = 0.0038) and 1:1.7 versus 1:1 in E (P = 0.0002), for infertile men and controls, respectively. Bcl2 mRNA content was correlated with protamine mRNA ratio (P = 0.0250 for TB; P = 0.0003 for E). Infertile men exhibit a more than 10-fold (P = 0.0155 for TB; P = 7.0 x 10(-6) for E) higher Bcl2 mRNA content versus controls. No correlation was found between absolute sperm density and the protamine mRNA ratio or Bcl2 mRNA content. No significant correlation was demonstrated with fertilization rate after ICSI and either protamine ratio or Bcl2 content. CONCLUSIONS: We found significantly aberrant protamine ratios and a higher Bcl2 content in TB and E of infertile men compared to controls, suggesting that these molecules may be useful biomarkers for predicting male infertility.