Polymorphism and Genomic Structure of the A+T-Rich Region of Mitochondrial DNA in the Oriental Mole Cricket, Gryllotalpa Orientalis (Orthoptera: Gryllotalpidae)

Abstract

The complete A+T-rich region of mitochondrial DNA has been cloned and sequenced from 48 individuals of Gryllotalpa orientalis (Orthoptera: Gryllotalpidae), collected from five Korean localities. Thirty-six haplotypes acquired from 48 individuals were found to range in size from 917 to 925 bp, with a sequence divergence from 0.1% to 14.3% and an A+T content from 74.5 to 76.3%. Phylogeographic analysis of the G. orientalis haplotypes showed the presence of two clearly differentiated mitochondrial clades, separated by 13.4% of a minimum uncorrected sequence divergence, which suggests the presence of an unknown, similar Gryllotalpa species or a once isolated G. orientalis population. Structural analysis in search of the conserved structural elements previously described in the caeliferan Orthoptera and Diptera revealed that the G. orientalis A+T-rich region harbored a stretch of the [TA(A)]n sequence, which has been suggested to be involved in the control of transcription or replication. In contrast to the abundance of the sequence stretches containing the stem-and-loop structure in the G. orientalis A+T-rich region, the 3' flanking sequence "G(A)nT," which is well conserved in a variety of organisms, including the caeliferan Orthoptera and Diptera, was not conserved in the A+T-rich region of G. orientalis.