Understanding Maternal Effects in a Natural Population of a Long-Lived Organism

在脊椎动物的几个主要群体中，后代的性别是由胚胎发育期间经历的环境温度永久决定的。人们对这种现象（称为TSD）的许多方面的重要性知之甚少。遗传和非遗传母体效应的作用，如自然条件下的生殖生理和行为，特别需要进行严格的评估。这项拟议的研究将调查自1988年以来一直详细研究的长寿脊椎动物自然种群中TSD生物学的几个重要方面：（1）母体来源的卵黄激素的影响以及这些激素如何随母体年龄而变化，（2）TSD雌性动物筑巢行为的遗传因素，以及（3）TSD下后代性别决定的遗传因素。这些问题将通过一系列多年的实地和实验室项目来解决。一个由博士后和学生研究人员组成的团队将收集重要的新生理，行为和遗传数据。研究小组将在筑巢活动期间研究自然种群的动物。植被覆盖的巢，准确地预测后代的性别比例，和筑巢日期将被记录。然后，将获得数据的后代性别比为每个巢，孵化温度，蛋黄激素水平的鸡蛋，和后代亲子关系的焦点子集的巢。这项研究的结果将对气候变化和人类栖息地利用对TSD物种的生物学和保护的影响具有重要意义。该研究计划还将为众多学生（包括代表性不足的少数民族，残疾人和妇女）和公众提供广泛的教育机会。

In several major groups of vertebrate animals, offspring sex is determined permanently by environmental temperatures experienced during embryonic development. Little is understood about the importance of many aspects of this phenomenon (known as TSD). The roles of genetic and nongenetic maternal effects, like reproductive physiology and behavior under natural conditions, are particularly in need of critical evaluation. The proposed research will investigate several significant maternal aspects of the biology of TSD in a natural population of long-lived vertebrates that has been studied in detail since 1988: (1) the impact of maternally-derived yolk hormones and how such hormones might vary with maternal age, (2) the genetically inherited component of nesting behavior of females with TSD, and (3) the genetically inherited component of offspring sex determination under TSD.These questions will be addressed with a series of multi-year field and laboratory projects. A team of postdoctoral and student researchers will gather crucial new physiological, behavioral, and genetic data. The research team will study animals from a natural population during nesting events. Vegetation cover over nests, which accurately predicts offspring sex ratio, and nesting date will be recorded. Data will then be obtained for offspring sex ratio for each nest, and incubation temperature, yolk hormone levels in eggs, and offspring paternity for a focal subset of nests. The findings of this research will have important implications for the impacts of climate change and human habitat use on the biology and conservation of species with TSD. This research program will also provide extensive educational opportunities for numerous students (including underrepresented minorities, persons with disabilities, and women) and the public.