TOP-2 is differentially required for the proper maintenance of the cohesin subunit REC-8 on meiotic chromosomes in Caenorhabditis elegans spermatogenesis and oogenesis
Date
2022-08-11
Journal Title
Journal ISSN
Volume Title
Publisher
Genetics
Abstract
During meiotic prophase I, accurate segregation of homologous chromosomes requires the establishment of chromosomes with a meiosis-specific architecture. The sister chromatid cohesin complex and the enzyme Topoisomerase II (TOP-2) are important components of meiotic chromosome architecture, but the relationship of these proteins in the context of meiotic chromosome segregation is poorly defined. Here, we analyzed the role of TOP-2 in the timely release of the sister chromatid cohesin subunit REC-8 during spermatogenesis and oogenesis of Caenorhabditis elegans. We show that there is a different requirement for TOP-2 in meiosis of spermatogenesis and oogenesis. The loss-of-function mutation top-2(it7) results in premature REC-8 removal in spermatogenesis, but not oogenesis. This correlates with a failure to maintain the HORMA-domain proteins HTP-1 and HTP-2 (HTP-1/2) on chromosome axes at diakinesis and mislocalization of the downstream components that control REC-8 release including Aurora B kinase. In oogenesis, top-2(it7) causes a delay in the localization of Aurora B to oocyte chromosomes but can be rescued through premature activation of the maturation promoting factor via knockdown of the inhibitor kinase WEE-1.3. The delay in Aurora B localization is associated with an increase in the length of diakinesis bivalents and wee-1.3 RNAi mediated rescue of Aurora B localization in top-2(it7) is associated with a decrease in diakinesis bivalent length. Our results imply that the sex-specific effects of TOP-2 on REC-8 release are due to differences in the temporal regulation of meiosis and chromosome structure in late prophase I in spermatogenesis and oogenesis.
Description
This is a pre-copyedited, author-produced version of an article accepted for publication in Genetics following peer review. The version of record Christine Rourke, Aimee Jaramillo-Lambert, TOP-2 is differentially required for the proper maintenance of the cohesin subunit REC-8 on meiotic chromosomes in Caenorhabditis elegans spermatogenesis and oogenesis, Genetics, 2022;, iyac120, https://doi.org/10.1093/genetics/iyac120 is available online at: https://doi.org/10.1093/genetics/iyac120. This article will be embargoed until 08/11/2023.
Keywords
topoisomerase II, TOP-2, REC-8, chromosome segregation, Caenorhabditis elegans, meiosis
Citation
Christine Rourke, Aimee Jaramillo-Lambert, TOP-2 is differentially required for the proper maintenance of the cohesin subunit REC-8 on meiotic chromosomes in Caenorhabditis elegans spermatogenesis and oogenesis, Genetics, 2022;, iyac120, https://doi.org/10.1093/genetics/iyac120