# Nuances in the control of separase activity between mitosis and meiosis

## TL;DR

This paper explores how separase activity is controlled in mammalian oocytes during meiosis, revealing differences from somatic cells.

## Contribution

The study identifies that cyclin B/CDK1 and securin, not SGO2, control separase activity in meiosis.

## Key findings

- Separase activity in meiosis is regulated by cyclin B/CDK1 and securin.
- The Mad2/SGO2 complex does not control separase in mammalian oocytes as previously thought in somatic cells.

## Abstract

Mammalian oocytes are prone to chromosome segregation errors, which frequently lead into aneuploidy and pregnancy loss. A new study in PLOS Biology addresses the role of the Mad2/SGO2 complex in the control of separase activity in these cells during meiosis.

Separase plays an important role in cleaving cohesin complexes that hold chromosomes together during cell division. This Primer explores a new study in PLOS Biology showing that control of separase activity is accomplished by cyclin B/CDK1 and securin, and does not involve SGO2 as reported in somatic cells.