Sperm specific expression of temperature-sensitive ion channel TRPM8 correlates with vertebrate evolution

Transient Receptor Potential subfamily Melastatin member 8 (TRPM8) is involved in detection of cold temperature and different noxious compounds, execute thermo- as well as chemo-sensitive responses at cellular levels. Here we explored the molecular evolution of TRPM8 by analyzing sequences from different species. We elucidate that different regions of TRPM8 had different levels of selection pressure and the 4-5th transmembrane regions remain highly conserved. Synteny analysis suggests that since vertebrate origin, TRPM8 gene is linked with SPP2, a bone morphogen. We found 16656 TRPM8 variants in 1092 human genomes with top variations are SNPs, insertions and deletions. 692 missense mutations are also mapped to human TRPM8 protein. TRPM8 expresses endogenously in sperm cells of different vertebrates ranging from fish to human. We conclude that TRPM8 has emerged during vertebrate evolution (ca 450 MYA) and sperm-specific expression has guided its molecular evolution. These understandings may have medical importance as well.