Clone and relative expression of Os-IP₃R and Os-RyR to discuss the evolutionary relationship in Onchidiidae

In this study, full-length cDNA of Os-IP₃R and Os-RyR in Onchidium struma was cloned by transcriptome data mining and rapid amplification cDNA ends (RACE) methods, and we analyzed the relationship between the percentages of Os-IP₃R/Os-RyR expression and the evolution of 3 species from family Onchidiidae. The bioinformatic analysis and expression pattern of Os-IP₃R and Os-RyR in different tissues from Onchidium struma, Platevindex mortoni and Peronia verruculata detected by Real-time quantitative PCR were performed. The results show that length cDNA of Os-IP₃R consists of 4 574 base pairs (bp), and 2 808 bp open reading frame (ORF) which encodes 935 amino acids. The predicted moleculer of the deduced amino acid of IP₃R has six transmembrane domains. The length cDNA of Os-RyR consists of 1 253 base pairs (bp), and 1 131 bp open reading frame (ORF) which encodes 376 amino acids. The predicted molecular of the deduced amino acid of RyR has three transmembrane domains. The IP₃R and RyR amino acid sequences in O. struma were aligned and found to be highly conserved in the G*R*GGG*GD at region of calcium channel. Os-IP₃R and Os-RyR were detected by qRT-PCR in different tissues of three kinds of Onchidiidae, and the percentages of Os-IP₃R/Os-RyR expression from three species were consistent with their living environment (from high tide zone to shallow sea), followed by O. struma, P. mortoni and P. verruculata. The species of higher terrestrial ability with higher percentages of Os-IP₃R/Os-RyR gene expression, illustrated percentage of gene expression associated with evolutionary degree. According to the comparison of percentage in Onchidiidae, we hope to provide a valuable clue for amphibian investigators, and to give a molecular biology clue for studying sea to land transition of marine invertebrate.