Nucleotide substitutions in a portion of the mitochondrial cytochrome b gene in water striders (Hemiptera: Gerridae)
2001
Muraji, M. (National Inst. of Agrobiological Sciences, Tsukuba, Ibaraki (Japan)) | Tachikawa, S.
A portion of the mitochondrial cytochrome b gene was sequenced using 22 individuals from 14 species belonging to the subfamily Gerrinae and two outgroup taxa. As reported for mitochondrial genes in many other insects, a nucleotide content bias for A and T was observed in the sequences. Among taxa belonging to Gerrinae, a relatively high frequency of T-C transitions, as well as a high level of A-T transversions was observed. Comparisons of the nucleotide sequences between pairs of 22 samples revealed that nucleotide substitutions in this DNA fragment were biased by the amino acid composition of the cytochrome b enzyme. Pairwise comparisons also suggested that strong multiple substitutions have occurred in the first and third positions of codons between distantly related taxa. On the basis of these results, the utility of the nucleotide sequences of the cytochrome b gene for estimating the phylogenetic relationship among gerrinae taxa is discussed.
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