Whittier J M, Corrie F, Limpus C
Department of Anatomical Sciences, University of Queensland, St. Lucia, Australia.
Gen Comp Endocrinol. 1997 Apr;106(1):39-47. doi: 10.1006/gcen.1996.6848.
Plasma levels of four hormones-progesterone (P), testosterone (T), estradiol 17-beta (E2), and corticosterone (B)-were measured in samples taken from nesting female loggerhead turtles (Caretta caretta) by using specific radioimmunoassays. Samples were taken in an early, middle, or late period during the summer nesting season from females at first, second, third, or > fourth nesting episodes, defined as successive within-season nesting events, at Mon Repos Beach, Queensland, Australia. Data on individual patterns of nesting, collected over the past 20 years by the Queensland Turtle Research Project, and the seasonal nesting data, were analyzed with respect to influences on hormonal profiles. Circulating levels of E2 were mostly undetectable, suggesting either that this estrogen is not produced at this time of nesting, or that, perhaps, another estrogen may be present that is not detected by the specific radioimmunoassay. P, T, and B profiles in the nesting females were associated with the individual turtles' progression through successive nesting episodes, with a marked decline in all three hormones by the last (> 4) nesting episode of the season. Nesting episode accounted for significant changes that were related to season, in that nesting episode and season were significantly correlated. These patterns were observed in the population, when singly sampled at each time period or nesting episode, and in individual females sampled repeatedly over time. Moreover, T and B were highly and significantly correlated in females at all nesting episodes and time periods, and in the singly and repeatedly sampled females. The magnitude of change in T and B over time was also highly and significantly correlated in repeatedly sampled females. Together these results suggest the hypothesis that T and B interact over the period of successive nesting and may be involved in reproductive functions such as the mobilization of reserves for egg production in C. caretta.
通过使用特定的放射免疫测定法，对从正在筑巢的雌性蠵龟（蠵龟属）采集的样本中的四种激素——孕酮（P）、睾酮（T）、雌二醇17-β（E2）和皮质酮（B）的血浆水平进行了测量。样本采集于澳大利亚昆士兰州蒙雷波斯海滩夏季筑巢季节的早期、中期或晚期，采集对象为处于首次、第二次、第三次或大于第四次筑巢期的雌性蠵龟，这些筑巢期定义为同一季节内连续的筑巢事件。昆士兰海龟研究项目在过去20年收集的关于个体筑巢模式的数据以及季节性筑巢数据，针对其对激素水平的影响进行了分析。E2的循环水平大多无法检测到，这表明要么这种雌激素在筑巢这个时期不产生，要么可能存在另一种未被特定放射免疫测定法检测到的雌激素。筑巢雌性蠵龟体内的P、T和B水平与个体海龟在连续筑巢期的进展情况相关，在该季节最后一次（大于4次）筑巢期时，这三种激素水平均显著下降。筑巢期导致了与季节相关的显著变化，因为筑巢期和季节显著相关。这些模式在每次时间段或筑巢期单独采样的群体中以及随时间重复采样的个体雌性中均被观察到。此外，在所有筑巢期和时间段的雌性中，以及在单独采样和重复采样的雌性中，T和B高度显著相关。在重复采样的雌性中，T和B随时间变化的幅度也高度显著相关。这些结果共同表明了一个假设，即T和B在连续筑巢期间相互作用，并且可能参与了诸如蠵龟产卵储备动员等生殖功能。
