DNA barcoding and morphotaxonomic analyses of mosquitoes collected from Chittagong Metropolitan area

Abstract

Mosquitoes are important vectors for a wide variety of pathogens and parasites. Identification of different mosquito species are crucial for their eventual control. We have used the classical morphometry and modern molecular methods like DNA barcoding approach for reliable identification of mosquitoes that were collected from different locations of Chittagong Metropolitan area of Bangladesh. A total of 20 randomly collected specimens were included in this study. Different morphological features of head, clypeus, vertex, antenna, maxillary palp, thorax, wings, legs and abdomen of the mosquitoes were examined using three-dimensional microscopy. The morphological characteristics of the mosquitoes observed under stereo binocular microscope in the laboratory shown highly similarity with the Aedes aegypti species. Genomic DNA was extracted from all of the 20 samples using commercial kits and specific primers were used for amplification of partial cytochrome oxidase genes for molecular characterization. PCR products were then sequenced and further bioinformatics analyses was accomplished. Sequence similarity based BLASTn and phylogenetic analyses (MEGA 6) of the sequence indicated similarity with three different species namely Aedes aegypti, Culex pipiens and Aedes albopictus. Among these 5 samples, 3 samples were Aedes aegypti, 1 sample was Aedes albopictus and 1 sample was Culex pipiens. The findings were compatible with the morphological data and reliably characterized the mosquito species. The study was first DNA barcoding analyses on mosquito in the country and showed the feasibility of using molecular tools for their characterization. Further study about the origin and vector potential of these mosquitoes will enhance our capacity to improve existing vector surveillance and control program.