Environmental Sex Determination and Endocrine Disruption

目前有两种明显的环境影响正在影响所有的生命形式：气候变化和人为的化学污染。红耳滑龟胚胎已被证明是一个特殊的模型系统来评估这些环境因素的作用以及它们如何相互作用。这个物种的性别决定取决于温度；也就是说，温度（和激素）在发育的一个狭窄窗口期起作用，决定了个体的性别。这项研究将揭示温度信号是如何被转导成导致卵巢或睾丸的分子开关的。它还将评估胚胎对人为环境化合物的易感性，这些化合物统称为内分泌干扰化学物质（EDCs），它们可以破坏正常的类固醇微环境，导致发育和生殖异常。本研究整合了这两个领域的研究，重点关注物理和化学环境如何改变性腺决定和性别分化的分子和细胞发育途径。先前nsf支持的研究证实，两个不同的基因“磁带”参与了这两个过程。这些磁带是一组功能相关的基因，它们以特定的方式相互作用，导致细胞或组织水平的结果。在这种情况下，第一个盒子是由性腺决定基因的保守核心组成的，这些基因调节所有脊椎动物的性腺分化。第二个盒子由编码产生（类固醇生成酶）和感知（激素受体）类固醇激素的分子的基因组成。了解这些磁带是如何相互作用的，它们在时间和空间上是如何相互作用的，以及每个磁带中的基因在正常条件下以及暴露于EDCs后是如何相互作用的，是这个项目的长期目标。该研究项目将为培养研究生和本科生提供跨学科的研究机会。区域指导活动将侧重于来自代表性不足群体的本科生。产生的序列数据将存入GenBank。

Two clear and present environmental impacts are affecting all life forms: climate change and anthropogenic chemical contamination. The red-eared slider turtle embryo has proven to be an exceptional model system to evaluate the role of each of these environmental factors and how they may interact. This species has temperature-dependent sex determination; that is, temperature (and hormones) acting during a narrow window of development, determine the sex of the individual. This research will reveal how the temperature signal is transduced into a molecular switch that results in an ovary or a testis. It will also evaluate the susceptibility of the embryo to anthropogenic environmental compounds, collectively known as endocrine disrupting chemicals (EDCs), which can cause disruptions in the normal steroid microenvironment causing developmental and reproductive abnormalities. This research integrates both areas of research and focuses on how the physical and chemical environments modify the molecular and cellular developmental pathways underlying gonad determination and sexual differentiation. Prior NSF-supported research established that two different "cassettes" of genes are involved in both processes. These cassettes are groups of functionally related genes that interact in a particular manner to cause an outcome at the cellular or tissue level. In this instance the first cassette is composed of a conserved core of gonad-determining genes that regulate gonadal differentiation in all vertebrates. The second cassette consists of the genes that code for the molecules that produce (steroidogenic enzymes) and sense (hormone receptors) steroid hormones. Understanding how these cassettes are engaged, how they interact with one another both temporally and spatially, and how the genes within each cassette interact under normal conditions as well as after exposure to EDCs are the long-term goals of this project. The research program will provide interdisciplinary research opportunities for training graduate and undergraduate students. Regional mentoring activities will focus on undergraduate students from underrepresented groups. Sequence data generated will be deposited in GenBank.