{Reference Type}: Journal Article
{Title}: The chromatin-associated 53BP1 ortholog, HSR-9, regulates recombinational repair and X chromosome segregation in the Caenorhabditis elegans germ line.
{Author}: Li Q;Hariri S;Calidas A;Kaur A;Huey E;Engebrecht J;
{Journal}: Genetics
{Volume}: 227
{Issue}: 4
{Year}: 2024 Aug 7
{Factor}: 4.402
{DOI}: 10.1093/genetics/iyae102
{Abstract}: 53BP1 plays a crucial role in regulating DNA damage repair pathway choice and checkpoint signaling in somatic cells; however, its role in meiosis has remained enigmatic. In this study, we demonstrate that the Caenorhabditis elegans ortholog of 53BP1, HSR-9, associates with chromatin in both proliferating and meiotic germ cells. Notably, HSR-9 is enriched on the X chromosome pair in pachytene oogenic germ cells. HSR-9 is also present at kinetochores during both mitotic and meiotic divisions but does not appear to be essential for monitoring microtubule-kinetochore attachments or tension. Using cytological markers of different steps in recombinational repair, we found that HSR-9 influences the processing of a subset of meiotic double-stranded breaks into COSA-1-marked crossovers. Additionally, HSR-9 plays a role in meiotic X chromosome segregation under conditions where X chromosomes fail to pair, synapse, and recombine. Together, these results highlight that chromatin-associated HSR-9 has both conserved and unique functions in the regulation of meiotic chromosome behavior.