Abstract:

【Aim】 To sequence and analyze the complete mitochondrial genome (mtgenome) of Anopheles lindesayi, and to construct and discuss the molecular phylogenetic relationships of the genus Anopheles based on the known mtgenomes. 【Methods】 The complete mtgenome of An. lindesayi was sequenced and annotated, and its general features and base composition were analyzed. The phylogenetic relationships between An. lindesayi and other 32 species in the genus Anopheles were reconstructed using maximum likelihood (ML) and Bayesian inference (BI) methods based on the concatenated nucleotide sequences and amino acid sequences of 13 protein-coding genes (PCGs), and the systematics of the genus Anopheles was discussed based on the phylogenetic analysis. 【Results】 The complete mtgenome sequence of An. lindesayi is 15 366 bp in length, which contains 13 PCGs, 22 tRNA genes, two rRNA genes, and one control region. The mtgenome has a clear bias in nucleotide composition with a positive AT-skew and a negative GC-skew. The initiation codons of PCGs comply with the ATN rule except that COX1 uses TCG and ND5 uses GTG as the start codon, and the termination codon is TAA or incomplete T. The tRNAs have the typical clover-leaf structure, but  tRNA^Ser(AGN) has a large loop instead of the conserved stem-and-loop structure. The control region has the highest AT content 94.54%). The sliding window analysis suggested that the PCGs are the most suitable markers to elucidate the phylogenetic relationships at the subgenus and genus levels. The phylogenetic analysis strongly supported each of the subgenera Cellia, Anopheles, Nyssorhynchus and Kerteszia to be a monophyletic group. An. lindesayi and An. atroparvus+An. quadrimaculatus A, the latter two traditionally classified as Anopheles Series, are separated by An. sinensis in Myzorhynchus Series on all the four phylogenetic trees, raising a new debate on the taxonomy of the two Series. 【Conclusion】This study obtained the complete mtgenome sequence of An. lindesayi and explored the mtgenome characteristics and phylogeny of the genus Anopheles, establishing the information frame for further studying the mtgenomes and phylogeny of the family Culicidae.

Key words:  Culicidae, Anopheles, Anopheles lindesayi, mitochondrial genome, nucleotide composition, phylogeny