F28D1.2 influences meiosis to maintain germline chromosomal integrity in Caenorhabditis elegans (#188)
Faithful chromosome inheritance during meiosis is critical for the prevention of several congenital diseases and infertility. Meiosis can be summarised as DNA replication accompanied by two rounds of chromosome segregation (meiosis I and II), where homologous chromosomes synapse in meiosis I for successful meiotic recombination. This process involves a complex of proteins called the sister chromatid cohesion complex, which later separate in meiosis II resulting in the production of haploid cells. We have identified an uncharacterised protein, F28D1.2, in Caenorhabditis elegans as a novel gene that is required for germline chromosome integrity. Deletion of F28D1.2 results in statistically significant embryonic lethality and a reduction in overall brood size. In addition to this, F28D1.2 deletion mutants display abnormal chromosome morphology and a mild him phenotype (High Incidence of Males), suggesting chromosome segregation defects. Interestingly, this phenotype does not appear to be exacerbated by exposure to DNA damage repair agents such as hydroxyurea or camptothecin or an increase in germ cell apoptosis, suggesting that this phenotype is independent of errors associated with DNA damage repair mechanisms. Moreover, we show that F28D1.2 deletion mutants display a reduction in germ cells that transition from mitosis to meiosis. This observation is also accompanied by a depletion of the core meiotic cohesion complex protein, REC-8, in F28D1.2 deletion mutant germlines. Overall, this data suggests that F28D1.2 is required for promoting meiosis in C. elegans to maintain germline integrity.