Phylogenetic relationships among Anopheles (Diptera: Culicidae) based on mitochondrial cytochrome oxidase II gene

Mitochondrial COII gene sequences have been predominantly used to estimate phylogenetic relationships at various taxonomic levels across insects. The complete CDS of the mt DNA cytochrome oxidase II gene of Anopheles stephensi was sequenced and submitted in GenBank nucleotide database. The COII sequence was found to have a higher A+T content (74.5%). The nucleotide sequences codes for 228 amino acid peptide. Of the 685 nucleotides encoding for the gene, 205 nucleotide sites (29.9%) are variable that accounts for 26 synonymous substitutions out of which most of them were found at third codon postions. This sequence was compared at nucleotide as well as amino acids level with COII gene sequences of 17 other Anopheles species belonging to different taxonomical series. Phylogenetic analysis using the full COII coding sequence was used to examine the evolution of COII genes among group of Anopheles. All the COII gene sequences conformed to four major clades with high bootstrap values with Anopheles messeae as an exceptional outgroup. The evolutionary pattern so revealed has been analysed and will be discussed