Responsiveness of the chicken germinal disc region to testosterone and corticosterone
Wrobel, Elizabeth Rose
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Female birds skew offspring sex ratios based on environmental and social stimuli, but the mechanism mediating these skews remains unknown. Testosterone and corticosterone may influence meiosis, as they skew sex ratios when elevated before. It’s unknown if the germinal disc (GD) contains hormone receptors. Ovarian follicles were collected at 5h pre-ovulation (just before meiosis) and 20h pre-ovulation (sex chromosomes are arrested), and we measured androgen receptor (AR) and mineralocorticoid receptor (MR) protein levels. ARs and MRs were in GD and non-GD regions. AR levels were higher in GD regions than non-GD regions, but MR levels didn’t differ. We tested if subcutaneous injections of these hormones at 5h pre-ovulation changed gene expression in hens. We collected GD regions 1.5h post-injection and identified several genes differentially expressed between the corticosterone and control group. This work revealed that follicles contain receptors for these hormones, and that they may influence gene expression to mediate offspring sex.