Dual tagging of GFP and Degron on endogenous COSA-1 in Caenorhabditis elegans as a crossover investigation tool

COSA-1 is essential for accurate meiosis in C. elegans . Two null mutants ( cosa-1 ( me13 ) and cosa-1 ( tm3298 ) ) have been notably studied. These null mutants exhibit severe meiotic defects, hindering the observation of the subtle or dynamic nature of COSA-1 function. To overcome these limitations, we developed a C. elegans strain with inducible COSA-1 degradation using the Auxin-Inducible Degron (AID) system. This strain exhibits normal fertility and COSA-1::GFP foci. Auxin treatment successfully depletes COSA-1, resulting in a 96% decrease in progeny viability and 12 univalent chromosomes in diakinesis oocytes. This strain serves as a valuable tool for studying the dynamics of COSA-1.