Regulates Motility of Fresh and Cryopreserved Sperm in Pacific Abalone, .

As structural components of sperm, tektins are thought to play a fundamental role in sperm flagellar motility. In this study, Tektin-4 () gene was successfully cloned and characterized from the testis tissue in Pacific abalone, . The full-length cDNA of was 1,983 bp, with a coding region of 1,350 bp encoding 51.83 kDa putative protein of 449 deduced amino acids. contains a tektin domain including a nonapeptide signature motif (RPGVDLCRD). Fluorescence hybridization revealed that localized in the spermatids of Pacific abalone testis. qRT-PCR analysis showed that was predominantly expressed in testis tissues. mRNA expression was upregulated during the fully mature testicular developmental stage in both seasonal development and EAT exposed abalone. Furthermore, mRNA expression of was significantly higher in sperm with higher motility than in sperm with lower motility during peak breeding season, induced spawning activity stages, and after cryopreservation in different cryoprotectants. Taken together, these results indicate that the expression of in Pacific abalone sperm might have a positive correlation with sperm motility.