›› 2008, Vol. 51 ›› Issue (3): 307-314.

• RESEARCH PAPERS • Previous Articles     Next Articles

Characterization and phylogenetic analysis of the mitochondrial 12S rRNA gene sequences from nine species of silk-producing insects

LIU Yan-Qun   

  • Online:2010-07-27 Published:2008-03-20


The nucleotide composition and substitution pattern of the partial mitochondrial 12S rRNA gene from nine species of silk-producing insects were investigated. The phylogenetic relationships among the nine species were then assessed by the methods of unweighted pair group method using arithmetic averages (UPGMA), neighbor-joining (NJ), minimum evolution (ME), and maximum parsimony (MP). The 12S rRNA gene sequences of 427 bp of the wild Antheraea pernyi are identical to the semi-domestic A. pernyi (Yuzao No. 1). The genera Antheraea, Samia, and Bombyx show obviously different nucleotide composition: i the AT content of Bombycidae family is higher than that of Saturniidae; ii) the nucleotide of Antheraea and Samia  (Saturniidae)  contains more Ts than As, while more As than Ts exist in Bombyx (Bombycidae). By analyzing the nucleotide substitution pattern, more transitions than transvertions were found among these species except Bombyx. All of the phylogenetic trees showed monophyly for the three genera, and the confidence limits were measured more than 96% for the clades. However, the phylogenetic tree based on UPGMA method supported the ancestral position of A. assama within Antheraea species, whereas all the trees using NJ, ME, and MP methods backed up the ancestral position of A. mylitta, suggesting that the phylogenetic relationship among Antheraea members need to be further studied with more molecular markers.

Key words: Silk-producing insects, Bombycidae, Saturniidae, 12S rRNA gene, nucleotide composition, substitution pattern, phylogenetic relationship