Sister chromatid segregation in meiosis II : Deprotection through phosphorylation

Abstract

Meiotic divisions (meiosis I and II ) are specialized cell divisions to generate haploid gametes. The first meiotic division with the separation of chromosomes is named reductional division. The second division, which takes place immediately after meiosis I without intervening S-phase, is equational, with the separation of sister chromatids, similar to mitosis. This meiotic segregation pattern requires the two-step removal of the cohesin complex holding sister chromatids together: cohesin is removed from chromosome arms that have been subjected to homologous recombination in meiosis I and from the centromere region in meiosis II . Cohesin in the centromere region is protected from removal in meiosis I, but this protection has to be removed-deprotected-for sister chromatid segregation in meiosis II . Whereas the mechanisms of cohesin protection are quite well understood, the mechanisms of deprotection have been largely unknown until recently. In this review I summarize our current knowledge on cohesin deprotection. © 2013 Landes Bioscience.