Age-Dependent Alterations in Meiotic Recombination Cause Chromosome Segregation Errors in Spermatocytes.

ABSTRACT: Faithful chromosome segregation in meiosis requires crossover (CO) recombination, which is regulated to ensure at least one CO per homolog pair. We investigate the failure to ensure COs in juvenile male mice. By monitoring recombination genome-wide using cytological assays and at hotspots using molecular assays, we show that juvenile mouse spermatocytes have fewer COs relative to adults. Analysis of recombination in the absence of MLH3 provides evidence for greater utilization in juveniles of pathways involving structure-selective nucleases and alternative complexes, which can act upon precursors to generate noncrossovers (NCOs) at the expense of COs. We propose that some designated CO sites fail to mature efficiently in juveniles owing to inappropriate activity of these alternative repair

SUBMITTER: Zelazowski MJ 

PROVIDER: S-EPMC5679441 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature