Roles of Cohesin and Condensin in Chromosome Dynamics During Mammalian Meiosis

Meiosis is a key step for sexual reproduction in which chromosome number is halvedby two successive meiotic divisions after a single round of DNA replication. In thefirst meiotic division (meiosis I), homologous chromosomes pair, synapse, andrecombine with their partners in prophase I. As a result, homologous chromosomes arephysically connected until metaphase I and then segregated from each other at theonset of anaphase I. In the subsequent second meiotic division (meiosis II), sisterchromatids are segregated. Chromosomal abnormality arising during meiosis is one ofthe major causes of birth defects and congenital disorders in mammals including humanand domestic animals. Hence understanding of the mechanism underlying these uniquechromosome behavior in meiosis is of great importance. This review focuses on theroles of cohesin and condensin, and their regulation in chromosome dynamics duringmammalian meiosis.