Format

Send to

Choose Destination
Fly (Austin). 2011 Apr-Jun;5(2):134-40. Epub 2011 Apr 1.

Meiotic checkpoints and the interchromosomal effect on crossing over in Drosophila females.

Author information

1
Waksman Institute and Department of Genetics, Rutgers the State University of New Jersey, Piscataway, NJ, USA.

Abstract

During prophase of meiosis I, genetic recombination is initiated with a Spo11-dependent DNA double-strand break (DSB). Repair of these DSBs can generate crossovers, which become chiasmata and are important for the process of chromosome segregation. To ensure at least one chiasma per homologous pair of chromosomes, the number and distribution of crossovers is regulated. One system contributing to the distribution of crossovers is the pachytene checkpoint, which requires the conserved gene pch2 that encodes an AAA+ATPase family member. Pch2-dependent pachytene checkpoint function causes delays in pachytene progression when there are defects in processes required for crossover formation, such as mutations in DSB-repair genes and when there are defects in the structure of the meiotic chromosome axis. Thus, the pachytene checkpoint appears to monitor events leading up to the generation of crossovers. Interestingly, heterozygous chromosome rearrangements cause Pch2-dependent pachytene delays and as little as two breaks in the continuity of the paired chromosome axes are sufficient to evoke checkpoint activity. These chromosome rearrangements also cause an interchromosomal effect on recombination whereby crossing over is suppressed between the affected chromosomes but is increased between the normal chromosome pairs. We have shown that this phenomenon is also due to pachytene checkpoint activity.

PMID:
21339705
PMCID:
PMC3127062
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for PubMed Central
Loading ...
Support Center