Mechanisms that promote the correct completion of meiosis by breaking symmetry of chromosomes

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H02373
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 43010:Molecular biology-related
• Research Institution: Kyoto University
• Principal Investigator: Carlton Peter 京都大学, 生命科学研究科, 准教授 (20571813)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 減数分裂 / 線虫 / 染色体 / シナプトネマ複合体

Outline of Final Research Achievements

We achieved the aims of our project by identifying new, important mechanisms in the pathway leading from asymmetric crossover placement to the establishment of cohesion loss strictly on one of two domains on chromosomes of the nematode C. elegans. We showed that the synaptonemal complex central element protein SYP-1 and the HORMA domain protein HIM-3 both become phosphorylated specifically on the shorter of two domains created by the asymmetric placement of a single crossover, and that preventing this phosphorylation leads to failure of downstream recruitment of factors that promote chromosome segregation.
Additionally, we showed that the partitioning of phosphoproteins to the short arm depends globally on the number of crossovers in the nucleus, with partitioning failing when fewer than 4 crossovers are present. This result indicates global feedback mechanisms work to promote asymmetry of chromosome protein recruitment.

Free Research Field

分子細胞生物学

Academic Significance and Societal Importance of the Research Achievements

Since chromosome segregation in meiosis is critical for fertility and correct development, our work leads to further insight about the possible causes of failure in human meiosis, which is responsible for a significant portion of both infertility and developmental atypicalities in humans.