Adult-specific collagen COL-19 is dispensable for contact-mediated mate recognition in Caenorhabditis elegans.

Mate recognition in C. elegans involves the integration of multiple sensory cues to facilitate the identification of suitable mates for reproductive behaviors. The cuticle, serving as the protective outer layer enveloping the entire body, has been implicated in eliciting contact responses essential for contact-mediated mate recognition in males. However, the specific constituents of cuticular cues have yet to be identified. In this study, we investigate the potential modulatory role of adult-specific collagen COL-19 in contact-mediated mate recognition. Our study shows that the expression of COL-19 ::GFP is adult-specific and not sexually dimorphic. Knockdown of col-19 via RNAi does not affect mate attractiveness of hermaphrodites in male retention assay, as corroborated by generating two independent col-19 putative null mutants via CRISPR/Cas9. These findings suggest that col-19 does not contribute to contact-mediated mate recognition, thereby advancing our mechanistic understanding of the intricate social interactions between sexes in C. elegans .