Sperm competition promotes a shortening of sperm protein CATSPER1 in murid rodents

VICENS, ALBERTO; TOURMENTE, MAXIMILIANO; ROLDAN, EDUARDO R. S.

Holderness

Conferencia; Gordon Research Conference: Fertilization & Activation of Development; 2013

Gordon Research Conferences Comitee

Sperm competition is an important force driving the evolution of traits which make sperm more competitive and it has been proposed to promote positive selection in genes related to such reproductive traits. High divergence of many reproductive genes has been observed at nucleotide level, but insertions and deletions (indels) also occur in protein-coding sequences. We analyzed the structural evolution of CATSPER1 protein, a voltage-gated calcium channel essential for sperm motility and fertilization. Our results show evidence of a shortening of CATSPER1 protein driven by sperm competition. This shortening is associated with increases in sperm velocity, suggesting that structural variation in CATSPER1 ultimately results in an improvement of sperm swimming, an essential trait in the success of fertilization. Future studies determining the function of the N-intracellular domain of CATSPER1 will help to clarify the adaptive significance of the structural changes in this sperm channel.