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

在几个主要的脊椎动物群体中，后代的性别永久地由胚胎发育过程中经历的环境温度决定。对于这种现象(称为TSD)的许多方面的重要性，人们知之甚少。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，尤其需要进行批判性评估。这项拟议的研究将调查自1988年以来一直被详细研究的长寿脊椎动物自然种群中TSD生物学的几个重要的母体方面：(1)母源卵黄激素的影响以及这些激素如何随着母亲的年龄变化而变化；(2)患有TSD的雌性TSD的筑巢行为的遗传成分；以及(3)TSD下后代性别决定的遗传成分。这些问题将通过一系列多年的野外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的生理、行为和基因数据。研究小组将在筑巢活动期间研究自然种群中的动物。巢上的植被覆盖，准确地预测后代的性别比例，以及筑巢日期将被记录下来。然后将获得每个巢的后代性别比例、孵化温度、鸡蛋中的卵黄激素水平以及部分巢的后代父子关系的数据。这项研究的结果将对气候变化和人类栖息地利用对生物和TSD物种保护的影响产生重要影响。该研究项目还将为众多学生(包括少数族裔、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.