关键词: 真螨总目, 无气门亚目, 甜果螨, 线粒体基因组, 二级结构, 系统发育

Abstract: 【Aim】 To sequence and analyze the complete mitochondrial genome of Carpoglyphus lactis, and to explore the phylogenetic position of C. lactis in Acariformes based on the mitochondrial genome sequence, so as to provide a scientific basis for the classification of Acariformes and the study of mitochondrial genome of Carpoglyphidae. 【Methods】 Genomic DNA of C. lactis was initially extracted from adult mites of C. lactis bred in the laboratory using conventional phenol-chloroform and commercial DNA extraction kit. Partial sequences of mitochondrial genes including cox1, cob, rrnS and nad4-nad5 were amplified by PCR using universal primers for arthropods or mites. Species-specific primers were designed for long-PCR amplification and primer-walking sequencing, and the complete mitochondrial genome of C. lactis was sequenced. Bioinformatic software SeqMan, SEQUIN 9.0 and tRNAscan were used to analyze the genetic structure of complete mitochondrial genome. Finally, the phylogenetic relationship was constructed by using maximum likelihood method (ML) based on the nucleotide sequences of concatenated proteincoding genes (PCGs) of 17 species of Acariformes. 【Results】 The complete mitochondrial genome of C. lactis (GenBank accession no.: MN073839) is 14 060 bp in length. It is a classical closed circular double-stranded DNA molecule, and comprises 37 coding genes, including 13 proteincoding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes, and one large non-coding region (LNR). The results of phylogenetic analysis showed that C. lactis belongs to Acaroidea and clustered into one branch with Aleuroglyphus ovatus. Acaroidae and Histiostomatoidae clustered into a group, forming a sister group to Psoroptidia. 【Conclusion】 We successfully sequenced and analyzed the complete mitochondrial genome of C. lactis. The relationship between C. lactis and A. ovatus is close.

Key words: Acariformes, Astigmata; Carpoglyphus lactis, mitogenome, secondary structure, phylogeny