Variations in the mitochondrial DNA markers in the Anopheles (Cellia) sundaicus population from the Andaman and Nicobar Islands, India

Abstract

Four sibling species in the Anopheles sundaicus complex have earlier been reported, including species D from the Andaman and Nicobar Islands of India where it constitutes 58% of all Anopheles population and is a major malaria vector. Earlier, we have reported the identical sequences for ribosomal DNA markers among the specimens of A. sundaicus from Andaman and Nicobar islands irrespective of their habitat. These ITS2 sequences were also identical to the reported sequence of variant III of Southeast Asian A. sundaicus. In the present study, we describe variations in three mitochondrial DNA markers among these specimens from Andaman and Nicobar islands. There were two different genotypes for each locus of COI and COII, and three genotypes for cytochrome-b (Cyt-b) locus resulting in three different combined genotypes (genotypes I, II and III) in the population. Specimens with combined genotype I (59%, n=100) were found only among the A. sundaicus population breeding in fresh water whereas two different multi-loci genotypes i.e. genotype II (25%, n=100) and genotype III (16%, n=100) were present in the population breeding in brackish water. Thus, the A. sundaicus population breeding in fresh water was homogenous with single multi-loci genotype and can be distinguished from the heterogenous mosquito population breeding in brackish water with these markers. These Cyt-b and COI sequences of A. sundaicus species D were also different from the reported Southeast Asian species of A. sundaicus.