Retinoic Acid Signalling and the Control of Meiotic Entry in the Human Fetal Gonad
Figure 5
Retinoic acid promotes the expression of STRA8 but not other meiosis-associated genes in the second trimester human fetal testis.
Human fetal testis (14–15 weeks gestation) were disaggregated to a single cell suspension and cultured in serum free medium in the presence of vehicle (DMSO) or 1 µM all trans retinoic acid (1 µM RA in DMSO) for 24 hours. RA treatment induced a 2.2±0.3 fold increase in the expression of STRA8 (A) relative to vehicle treated controls (a vs b, p<0.05, n = 5), indicating that RA-regulated expression of this gene is conserved in human fetal gonads. No significant differences in the expression of meiosis markers SYCP3 (B, n.s. n = 6) or DMC1 (C, n = 6, n.s.) were detected between RA- and vehicle-treated cultures, indicating that whilst RA can stimulate STRA8 expression, it is not sufficient to cause widespread activation of the meiosis-associated gene expression programme. Values denote mean ± s.e.m..