Amey A P, Whittier J M
Department of Anatomical Sciences, The University of Queensland, Australia.
Gen Comp Endocrinol. 2000 Mar;117(3):335-42. doi: 10.1006/gcen.2000.7426.
Pogona barbata is an Australian lizard that produces several large clutches of eggs between August and December (spring to early summer). Mating takes place around ovulation. The seasonal pattern of reproductive hormones in males and females of P. barbata was determined by radioimmunoassay of plasma progesterone (P), estradiol-17beta (E-17beta), corticosterone (B), and total androgen (TA). In females, P began to rise in August and was elevated from September to December. Corticosterone and TA were detectable but low and did not vary with time of year or reproductive condition. Estradiol-17beta was only detectable in a few females and exhibited no elevation with vitellogenic activity. These results suggest that B and TA are not involved in female reproduction. Estrogens may be either so low they could not be detected or they were present in a form other than estradiol-17beta. The high sensitivity of the estradiol-17beta radioimmunoassay suggests the latter. In males, TA peaked at the beginning of spring. They then declined to a minimum during November and December. However, concentrations recovered in the postbreeding activity period, January to April (summer and autumn). These patterns are consistent with the observation of maximum spermatogenic activity in spring, followed by the cessation of spermatogenesis directly after the breeding period and testicular recrudescence in February (late summer).
髯狮蜥是一种澳大利亚蜥蜴，在8月至12月（春季至初夏）期间会产下几窝大型卵。交配发生在排卵前后。通过放射免疫分析法测定血浆孕酮（P）、雌二醇-17β（E-17β）、皮质酮（B）和总雄激素（TA），确定了髯狮蜥雄性和雌性生殖激素的季节性模式。在雌性中，P在8月开始上升，并从9月至12月保持在较高水平。皮质酮和TA可检测到但水平较低，且不随年份时间或生殖状况而变化。雌二醇-17β仅在少数雌性中可检测到，且未随卵黄生成活性而升高。这些结果表明，B和TA不参与雌性繁殖。雌激素可能要么低到无法检测到，要么以雌二醇-17β以外的形式存在。雌二醇-17β放射免疫分析的高灵敏度表明是后者。在雄性中，TA在春季开始时达到峰值。然后在11月和12月降至最低水平。然而，在繁殖后活动期（1月至4月，夏季和秋季）浓度恢复。这些模式与春季精子发生活性最高的观察结果一致，随后在繁殖期后直接停止精子发生，并在2月（夏末）睾丸再生。
