ELF, P.K.*; RHEN, T.; FIVIZZANI, A.J.; CREWS, D.; University of Minnesota Crookston; University of North Dakota, Grand Forks; University of North Dakota, Grand Forks; University of Texas Austin: Relationships between female circulating plasma hormones and hormones deposited in eggs of the leopard gecko, Eublepharis macularius.
Hormones deposited in the yolks of eggs during vitellogenesis are thought to derive from maternal circulation, but few studies have measured female circulating plasma levels in conjunction with yolk hormones to document this relationship. Rhen et al., described the dynamics of progesterone, estradiol, testosterone and dihydrotestosterone during the reproductive cycle in a population of leopard geckos, Eublepharis macularius, a TSD reptile. They reported a relationship between the incubation temperature that the female had experienced during her development and the levels of circulating hormone present during her reproductive effort. They also reported individual female differences in circulating hormone levels that were independent of embryonic incubation temperature. Eggs produced by this population of females during the documented reproductive cycle were collected upon laying and frozen for yolk hormone analysis. Eggs were later dissected, any embryos present were collected for staging, and extraembryonic material was collected for extraction and quantification of hormones. The extract was column separated and androstenedione, dihydrotestosterone, estradiol and testosterone were all measured using I125-labeled radioimmunoassays. Here we report correlations between circulating female hormones and hormones found in the extraembryonic material of eggs from the leopard gecko. pelf@mail.crk.umn.edu
