Abstract

Meiotic defects derived from incorrect DNA repair during gametogenesis can lead to mutations, aneuploidies and infertility. The coordinated resolution of meiotic recombination intermediates is required for crossover formation, ultimately necessary for the accurate completion of both rounds of chromosome segregation. Numerous master kinases orchestrate the correct assembly and activity of the repair machinery. Although much less is known, the reversal of phosphorylation events in meiosis must also be key to coordinate the timing and functionality of repair enzymes. Cdc14 is a crucial phosphatase required for the dephosphorylation of multiple CDK1 targets in many eukaryotes. Mutations that inactivate this phosphatase lead to meiotic failure, but until now it was unknown if Cdc14 plays a direct role in meiotic recombination. Here, we show that the elimination of Cdc14 leads to severe defects in the processing and resolution of recombination intermediates, causing a drastic depletion in crossovers when other repair pathways are compromised. We also show that Cdc14 is required for the correct activity and localization of the Holliday Junction resolvase Yen1/GEN1. We reveal that Cdc14 regulates Yen1 activity from meiosis I onwards, and this function is essential for crossover resolution in the absence of other repair pathways. We also demonstrate that Cdc14 and Yen1 are required to safeguard sister chromatid segregation during the second meiotic division, a late action that is independent of the earlier role in crossover formation. Thus, this work uncovers previously undescribed functions of the evolutionary conserved Cdc14 phosphatase in the regulation of meiotic recombination.

Highlights

  • Meiotic recombination is initiated by the conserved Spo11 transesterase, which introduces numerous DNA Double-Strand Breaks (DSBs) into the genome [1]

  • We reveal that Cdc14 is involved in ensuring correct meiotic recombination by gradually implementing Yen1 activity following Cdc5 activation

  • We propose that Yen1, controlled by Cdc14, implements its resolvase function when other enzymatic activities begin to decline outside of their optimum operative time-window by the end of prophase I, and that Yen1 covers a wider gap extending its action until the end of the second meiotic division

Read more

Summary

Introduction

Meiotic recombination is initiated by the conserved Spo transesterase, which introduces numerous DNA Double-Strand Breaks (DSBs) into the genome [1]. The association of single-strand DNA binding proteins, including RPA, Rad and the meiosis specific recombinase, Dmc, with the resected DSB ends promotes strand invasion into the intact homologous non-sister chromatid template, which culminates in the formation of a displacement loop (D-loop). The stabilization of the D-loop followed by second-end capture gives rise to even more stable structures, such as double Holliday Junction (dHJ) intermediates. DHJs are most frequently resolved into crossovers (COs) through the combined action of Mlh1-Mlh (MutLγ) and Exo1 [3,4,5]. A second class of COs arises from the resolution of recombination intermediates via the Structure-Selective

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call