This study describes a temporal profile of gene expression from normal human fetal testes and ovaries. Gonads from 34 fetuses between 9 wk and 20 wk of gestation were obtained from the Department of Pathology and the Birth Defects Research Laboratory at the University of Washington. Relative transcript levels were determined using the Affymetrix Human Genome U133A Plus 2.0 arrays. Sex determination occurs in the human gonad at approximately 6 wk of gestation with development of the testis driven by expression of SRY. In this study, SRY transcript was present and elevated at 9 wk of gestation in the testis but was absent in the ovary. The transcript levels of other testis-specific factors SOX9 and AMH and the steroidogenic genes CYP17A1, CYP11A1, STAR, and HSD17B3 were all significantly higher in the testis. In contrast, transcripts known to be involved in meiosis, including STRA8, SPO11, SYCP3, TEX11, TEX14, and STAG3, showed highest expression in the fetal ovary beginning at Week 12. These gene expression profiles will be a resource for understanding and defining normal gonad development and provide the opportunity to dissect abnormal development.
Background Although the resident candidate interview is costly and time-consuming for both applicants and programs, it is considered critically important for resident selection. Noncognitive attributes, including communication skills and professionalism, can be assessed by the personal interview.
This study sought to determine whether the shortened follicular phase in ovulatory older women is secondary to advanced (i.e. earlier) or accelerated (i.e. more rapid) folliculogenesis. Normal ovulatory women, aged 40-45 yr (n = 15) and 20-25 yr (n = 13), underwent daily venipuncture and transvaginal ultrasonography throughout the follicular phase of a spontaneous menstrual cycle (control cycle) and after pituitary down-regulation with a GnRH agonist (study cycle). As expected, the older subjects in the control cycles demonstrated an elevated d 3 FSH and a shortened follicular phase compared with the younger subjects. After release from hypothalamic-pituitary-ovarian axis suppression, the early follicular phase FSH peak occurred earlier (6.8 vs. 9.8 d; P < 0.01) and was of a greater magnitude (12.1 vs. 6.5 mIU/ml; P < 0.01) in the older subjects. The time from release of suppression until the subsequent LH surge was also shorter (17.5 vs. 20.8 d; P < 0.01) in the older group. However, the time from FSH peak to LH surge was similar in the older and younger groups (10.7 vs. 11.0 d; P = 0.74). Compared with younger women, older subjects had normal follicular phase levels of estradiol and inhibin A and lower levels of inhibin B in both control and study cycles. We conclude that the shortened follicular phase observed in older ovulatory women is due to earlier dominant follicle selection, independent of hormonal influences from the preceding luteal phase.
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