Sex-Specific Regulation of Meiotic Recombination Hotspots

描述（申请人提供）：减数分裂重组事件沿染色体分布不均匀，受遗传背景和性别调节。本项目的目的是确定减数分裂重组性别特异性的调节因素，包括其沿染色体的区域分布和性别特异性重组热点的活性。我们将寻找两种小鼠品系之间存在差异并影响热点Esrrg-1和Tmem182性别特异性的显性和隐性反式作用基因。热点Esrrg-1在女性中具有相同的活性，但在男性B6xCAST中的活性是WSBxCAST的两倍。热点Tmem182依赖于PWD遗传背景，在女性B6xPWD中比WSBxPWD活跃两倍，而在男性中则相反。我们将使用遗传杂交来分别评估显性问题和剂量效应，为此，我们将开发两个具有B6遗传背景的新小鼠品系，将为本研究创建的重组定位基因Prdm9的敲入等位基因与Chr1上的CAST或PWD序列结合起来，从而创建新的遗传资源。我们将使用一种新开发的大规模平行测序方法来测试单个动物精子和卵子中的热点活动。我们还将通过比较具有相同遗传背景但端粒长度不同的两个遗传杂交，详细描述mTert（-/-）端粒缩短蛋白对全基因组、区域和局部重组率的性别特异性影响。

DESCRIPTION (provided by applicant): Meiotic recombination events are distributed unevenly along the chromosomes and are regulated by genetic background and sex. The goal of this project is to determine the factors regulating sex specificity of meiotic recombination, boh its regional distribution along the chromosomes and the activity of sex-specific recombination hotspots. We will search for both dominant and recessive trans-acting genes that differ between two mouse strains and affect sex specificity of hotspots Esrrg-1 and Tmem182. Hotspot Esrrg-1 has the same activity in females, but is two-fold more active in male B6xCAST than in WSBxCAST. Hotspot Tmem182 is dependent on PWD genetic background and is two-fold more active in female B6xPWD compared to WSBxPWD, but the reverse is true in males. We will use genetic crosses that will allow us to assess dominance issues and dosage effects separately, for which we will create new genetic resources by developing two new mouse strains on a B6 genetic background combining knockin alleles of the recombination positioning gene Prdm9 created for this study with CAST or PWD sequences on Chr1. We will test for hotspot activity in sperm and eggs of individual animals using a newly developed massive parallel sequencing assay. We will also characterize in detail the sex-specific effect of mTert(-/-) telomere shortenin on genome-wide, regional and local recombination rates by comparing two genetic crosses on the same genetic background but differing in their telomeric lengths.