A novel mitochondrial gene rearrangement delineate Magallana gryphoides species from other Magallana crassostreine oysters

Abstract

Background The Magallana genus represents commercially most important oysters globally. Due to phenotypic plasticity, members of Magallana genus are often confused morphologically and limit their taxonomical as well as conservation efforts. On this background, the complete mitochondrial genome of Magallana gryphoides was sequenced. Methods and results The complete mitochondrial genome (mitogenome) of Magallana gryphoides was sequenced for the first time employing the next-generation sequencing. Results suggest that the mitogenome of M. gryphoides is of 18313 bp in length (accession number OR177662). The mitogenome contain 13 protein-coding genes including ATP8 and 26 tRNAs with 3 new suppressor tRNAs as well as 2 rRNAs. Further, presence of two copies of rrnS and rrnL lack 3’ half are unique, unusual and absent in other Crassostreinae oysters. The positions of COX1, trnG, trnV, and ND2 genes in the mitogenome of M. gryphoides are significantly altered. The phylogenetic analysis indicates a close relationship of M. gryphoides with the native Indian oyster Magallana bilineata and other Asian oyster Magallana iredalei. Conclusion Taken together, these data provide a new insight into phylogenetic relationship of oysters and may help to place the correct taxonomical status of M. gryphoides, M. bilineata and M. iredalei that that are often confused in the Ostreidae taxonomy due to phenotypic plasticity.