[Multiple nuclear pseudogenes of mitochondrial cytochrome oxidase I gene in Scylla paramamosain (Decapoda : Portunidae)].

Abstract

Nuclear mitochondrial pseudogenes (Numts), widely existing in nuclear genomes of many organisms, are those nuclear DNA sequences which have high similarity with mtDNAs. In this study, we identified 14 different multiple nuclear pseudogenes of mitochondrial cytochrome oxidase I gene from an individual Scylla paramamosain (Decapoda: Portunidae). Of these sequences, ninety-six variable sites were detected, accounting for 15.7%. Nucleotide diversity (Pi) index and Haplo-type diversity (Hd) index were 0.05682 and 0.8800, respectively. Among the 14 pseudogenes, the copies of sequence one were the most, occupying 30.8% of total copies, and sequence two run the second one (occupying 19.2%). These sequences were divided into two groups compared with their homologues. In Group 1, there were no insertion or deletion sites, while 8 deletion and 5 insertion sites were detected in Group 2, resulting in frame-shift mutations. It was proved that these two groups of pseudogenes were evolved from at least two independent mtDNA integrations into S. paramamosain nuclear genomes through Chi-square and homogeneity tests.