权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Epigenomic Analysis of Temperature-dependent Sex Determination

温度依赖性性别决定的表观基因组分析

基本信息

批准号：
1558034
负责人：
Turk Rhen
金额：
$ 81.98万
依托单位：
University of North Dakota Main Campus
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2016
资助国家：
美国
起止时间：
2016-02-15 至 2020-01-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1558034&HistoricalAwards=false
关键词：
Epigenomic Analysis Temperature dependent Sex

项目摘要

Temperature-dependent gender determination was first reported nearly 50 years ago in an African lizard. It has since been shown that temperature determines gender in some fish and amphibians, many lizards, numerous turtles, and all crocodilians. Yet, the mechanism that converts temperature into a biological signal for male versus female development is not known. The Rhen lab has identified novel temperature sensitive genes that respond quickly to temperature change in snapping turtle embryos. These particular genes are known to turn on or turn off gene expression during embryonic development in other species by modifying chromosomal structure. Such factors are also known as epigenetic regulators and may play a role in gender determination. The proposed studies will test the hypothesis that epigenetic mechanisms regulate expression of genes required for testis or ovary development. Ultimately, this research will advance our understanding of temperature-dependent gender determination and provide insight into the role epigenetic mechanisms play in testis and ovary development in all vertebrates. Educational activities will enhance learning through semester long projects in the classroom, improve undergraduate research experiences through extended internships of 2-3 years, and increase the participation of women and underrepresented minorities in biology. Outreach activities will train Rhen lab members to communicate science more effectively to the public, disseminate findings to a wider audience through production of a mini-documentary about temperature-dependent gender determination, and target a demographic that is neglected in STEM outreach through an informal class for older Americans.The Rhen lab has developed the common snapping turtle as a model to study unique and conserved mechanisms of gender determination in vertebrates. The overarching hypothesis is that temperature-dependent changes in histone methylation play a key role in regulating transcriptional programs for testis versus ovary development. Experiments test the specific hypothesis that Polycomb Repressive Complex 2 and lysine-specific demethylase 6B regulate methylation of histone H3 on lysine 27 (H3K27) in gonads from embryos incubated under male and female thermal regimes. Polycomb Repressive Complex 2 methylates histone H3 at lysine 27. Trimethylated histone H3 (H3K27me3) is a stable epigenetic mark that represses transcription. Conversely, lysine-specific demethylase 6B allows gene expression by demethylating H3K27me3 to H3K27me2 and H3K27me1. In Aim 1, chromatin immunoprecipitation (ChIP) and quantitative PCR will be used to analyze temperature effects on H3K27 methylation at conserved gender-determining loci. In Aim 2, ChIP-Sequencing will be used to analyze temperature effects on genome-wide patterns of H3K27 methylation in embryonic gonads. In Aim 3, experiments will test whether Polycomb Repressive Complex 2 and lysine-specific demethylase 6B are causally involved in gender determination by perturbing gene expression and/or using pharmacological inhibitors of these proteins. This research will clarify the molecular mechanisms underlying temperature-dependent expression of gender-determining genes. Findings will be presented in public databases, in peer-reviewed publications, and at national/international meetings.

近50年前，在一种非洲蜥蜴身上首次报道了依赖温度的性别决定。自那以后，研究表明，温度决定了一些鱼类和两栖动物、许多蜥蜴、许多海龟和所有鳄鱼的性别。然而，温度转化为男性与女性发育的生物信号的机制尚不清楚。莱恩实验室已经确定了新的温度敏感基因，这些基因可以在捕捉海龟胚胎的过程中对温度变化做出快速反应。众所周知，这些特定的基因通过改变染色体结构，在其他物种的胚胎发育过程中开启或关闭基因表达。这些因素也被称为表观遗传调节因素，可能在性别决定中发挥作用。拟议的研究将检验表观遗传机制调节睾丸或卵巢发育所需基因表达的假设。最终，这项研究将促进我们对依赖温度的性别决定的理解，并为所有脊椎动物的表观遗传机制在睾丸和卵巢发育中所起的作用提供洞察力。教育活动将通过课堂上长达一学期的项目来加强学习，通过延长2-3年的实习来改善本科生的研究经验，并增加妇女和代表性不足的少数群体对生物学的参与。外展活动将训练Rhen实验室的成员更有效地向公众传播科学，通过制作一部关于依赖温度的性别决定的迷你纪录片向更广泛的受众传播研究结果，并通过针对美国老年人的非正式课程针对STEM外展中被忽视的人群。Rhen实验室开发了常见的乌龟作为研究脊椎动物独特和保守的性别决定机制的模型。最重要的假设是，组蛋白甲基化的温度依赖性变化在调节睾丸与卵巢发育的转录程序中发挥关键作用。实验验证了多梳抑制复合体2和赖氨酸特异性去甲基酶6B调节组蛋白H3在雄性和雌性受热条件下孵育的胚胎的性腺中赖氨酸27(H3K27)的甲基化的特定假设。多梳抑制复合体2使组蛋白H3在赖氨酸27位甲基化。三甲基化组蛋白H3(H3K27me3)是一种稳定的抑制转录的表观遗传标记。相反，赖氨酸特异的去甲基酶6B通过将H3K27me3去甲基化为H3K27me2和H3K27me1来实现基因表达。在目标1中，将使用染色质免疫沉淀(ChIP)和定量PCR来分析温度对H3K27在保守的性别决定基因座上甲基化的影响。在目标2中，将使用芯片测序来分析温度对胚胎性腺中H3K27甲基化全基因组模式的影响。在目标3中，实验将测试多梳抑制复合体2和赖氨酸特异性去甲基酶6B是否通过干扰基因表达和/或使用这些蛋白质的药理抑制剂来因果地参与性别决定。这项研究将阐明性别决定基因表达依赖于温度的分子机制。调查结果将在公共数据库、同行评议出版物和国家/国际会议上公布。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Evolutionary Turnover in Wnt Gene Expression but Conservation of Wnt Signaling during Ovary Determination in a TSD Reptile

DOI：
10.1159/000516973
发表时间：
2021-07
期刊：
Sexual Development
影响因子：
2.3
作者：
T. Rhen;Zachary Even;Alaina Brenner;Alexandra Lodewyk;Debojyoti Das;Sunil Kumar Singh;R. Simmons
通讯作者：
T. Rhen;Zachary Even;Alaina Brenner;Alexandra Lodewyk;Debojyoti Das;Sunil Kumar Singh;R. Simmons

Embryonic Temperature Programs Phenotype in Reptiles

胚胎温度决定爬行动物的表型