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Mechanism and regulation of meiotic recombination

减数分裂重组的机制和调控

基本信息

批准号：
9071085
负责人：
Scott Keeney
金额：
$ 28.88万
依托单位：
SLOAN-KETTERING INST CAN RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-05-01 至 2021-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9071085
关键词：
Address Area Back Biological Assay Biology Cells Chromosome Segregation Chromosomes Complex DNA Damage Defect Developmental Disabilities Disease Ensure Evolution Excision Exonuclease Feedback Feeds Genetic Recombination Genome Germ Lines Germ-Line Mutation Heritability Human Lesion Maps Meiosis Meiotic Recombination Methods Molecular Mus Mutate Nucleotides Outcome Pathway interactions Process Property Pseudoautosomal Region Regulation Repetitive Sequence Reproductive Biology Reproductive Health Resolution Risk Saccharomyces cerevisiae Saccharomycetales Sex Chromosomes Shapes Source Spermatocytes Spo11 protein Spontaneous abortion Sterile coverings Sterility Time Work X Chromosome Y Chromosome ataxia telangiectasia mutated protein egg genome integrity genome-wide homologous recombination killings male novel public health relevance repaired response sperm cell whole genome

项目摘要

DESCRIPTION (provided by applicant): Homologous recombination during meiosis is essential for genome integrity in the germ line, but is also a powerful determinant of genome diversity, evolution, and (when mistakes occur) instability. Meiotic recombination is initiated by double-strand breaks (DSBs) made by the Spo11 protein. DSBs are important for successful meiosis, but are also dangerous lesions that can mutate or kill, so cells ensure that DSBs are made only at the right times, places, and amounts. DSB processing and recombination are also controlled to maximize repair efficiency and minimize risks of deleterious outcomes. A fundamental problem in reproductive biology and genome integrity is to understand the molecular mechanisms of DSB formation and of the processes that regulate DSBs and recombination. Mouse and the budding yeast S. cerevisiae will be used to explore these critical aspects of chromosome biology. Specific areas of inquiry include the following: * Recent work uncovered a complex network of circuits that control the number, timing, and distribution of DSBs. One important circuit involves DSB-dependent activation of the DNA damage-response kinase ATM, which feeds back to inhibit additional break formation. A second, distinct feedback circuit suppresses DSB formation in places where homologous chromosomes have successfully engaged one another. The outlines of this network are understood in only broad strokes; an important challenge now is to define detailed mechanisms and interactions between different regulatory circuits. The nonrandom distribution of DSBs has important consequences for heritability and genome evolution, but factors shaping the DSB landscape remain poorly understood. This lack of essential information will be ad- dressed using powerful methods that were recently developed to map DSB distributions genome-wide at nucleotide resolution. DSB ends must be processed by exonucleases to allow recombination, but little is known about the mechanism. A novel whole-genome assay for DSB resection has been devised that will permit unprecedented exploration of this important, but understudied, aspect of recombination. Recombination between dispersed copies of repetitive sequences is a potent source of germ line mutations. Important challenges now are to understand the mechanisms of this non-allelic homologous recombination and to understand the pathways cells exploit to minimize this risk. Sex chromosome segregation is particularly fraught in mammalian male meiosis because the X and Y chromosomes share only a small region of homology (the pseudoautosomal region, or PAR) within which re- combination must occur. Defects in PAR recombination cause sterility or sex chromosome missegregation. Key questions will be addressed concerning the properties of the PAR and of spermatocytes that ensure the fidelity of sex chromosome segregation.