Sequence Analysis and Phylogenetic Tree Construction of Cytb Gene in Cyrenobatissa Subsulcata

The phylogenetic status of Cyrenobatissa subsulcata was preliminarily explored in this study to provide preliminary data for the molecular genetics research of Cyrenobatissa subsulcata. The PCR method was used to amplify the mitochondrial cytochrome b (Cytb) gene fragment sequence of Cyrenobatissa subsulcata. The sequence length was 624 bp. The Blast comparison analysis was performed on the NCBI by using the NT database to construct a phylogenetic tree and discuss the taxonomic status of Cyrenobatissa subsulcata. The results showed that there was no Cytb gene information of Cyrenobatissa subsulcata in the database. The sequence amplified in this study had 88% similarity with the Cytb gene fragments of other species of the Corbicula, and had 77.02%-78.53% similarity with other clam shellfish, indicating that the fragments amplified by PCR were from the Cytb gene fragment of Cyrenobatissa subsulcata. Based on Kimura's 2-parameter model, the genetic distance between the three individuals of Cyrenobatissa subsulcata was only 0-0.0016, which was far less than that between the species in Corbicula (0.002-0.114) and with Corbicula was 0.127-0.144, and the genetic distance between the three individuals of Corbicula and the species of Veneridae was 0.282-0.335. The phylogenetic tree showed that the samples of Cyrenobatissa subsulcata were clustered into one branch independently and clustered with Corbicula into a large branch with a support degree of 99, which indicated that Cyrena was closely related to Corbicula, while had a long genetic distance from Veneridae.