关键词: 大蚕蛾科, 柞蚕属, 琥珀蚕, 线粒体基因组, 系统发育

Abstract: 【Aim】 Analyzing the mitochondrial genomes of insects can well indicate the genetic relationship among insect species. This study aims to explore the mitochondrial genome of Antheraea assama and to understand the intergeneric and interspecific molecular and evolutionary relationships of Saturniidae based on the mitochondrial genome sequences. 【Methods】 The complete mitochondrial genome sequence of Antheraea assama, a rare silk-spinning insect, was determined by using PCR and primer walking, and its general features and base composition were analyzed. The phylogenetic tree of mitochondrial proteincoding genes of fourteen species of Saturniidae and the outgroup was constructed by using the neighbor-joining method (NJ), and the phylogenetic relationships of A. assama within Saturniidae were analyzed. 【Results】 The mitochondrial genome of A. assama (GenBank accession no.: KU301792) is 15 312 bp in length, and contains 13 proteincoding genes (PCGs), 22 tRNA genes, 2 ribosomal RNA genes and a 332 bp A+T-rich region. The sequenced genome displays the genomic components and gene order of the typical lepidopteran mitochondrial genome. The sequence analysis revealed that the mitochondrial genome of A.assama is biased toward a high A+T content (80.18%). All protein-coding genes start with a typical ATN initiation codon, except that COX1 starts with the CGA codon. Majority of the 13 PCGs have a complete termination codon (TAA or TAG), except that COX1, COX2 and ND5 genes terminates with the incomplete stop codon T. The secondary structure of 22 tRNA genes by predicting showed the classic clover-leaf structure, except that the dihydrouridine (DHU) arm of tRNA^Ser(AGN) forms a simple loop. The NJ tree based on the mtDNA protein-coding gene sequences showed that A. assama formed the clade of Antheraea (Lepidoptera: Saturniidae) with Antheraea pernyi, Antheraea yamamai and Antheraea frithi. In nine species of Saturniidae studied, A. assama has the closest relationship with A. yamamai of Antheraea, and has a farther relationship with Attacus atlas of Attacus. 【Conclusion】 The gene arrangement pattern of the mitochondrial genome of A. assama is identical to those of other lepidopteran insects that have been assayed. The phylogenetic relationships of Saturniidae constructed based on the mitochondrial genomes are consistent with those in traditional morphological taxonomy, i.e., A. assama belongs to.

Key words: Saturniidae, Antheraea, Antheraea assama, mitochondrial genome, phylogeny