MOLECULAR CHARACTERIZATION OF CULEX MOSQUITOES FROM 10 LOCATIONS IN BAUCHI METROPOLIS

Abstract

Mosquitoes transmit numerous pathogens which are responsible for numerous diseases and a driver of numerous emerging infectious diseases around the world. Correct identification of mosquito vectors is critical to defining pathogen transmission pathways and is the first step in preventing pathogen transmission. The present study characterizes culex species using mitochondrial DNA (mtDNA) cytochrome oxidase subunit I (COI) and ribosomal RNA internal transcribed spacer 2 (ITS2) gene sequences. A total of 604 mosquitoes were collected from 10 locations in Bauchi Metropolis by human bait method from December – to April and DNA was extracted from morphologically identified Culex species, the COI and ITS2 regions of the mosquitoes were amplified and their sequences analyzed by comparison with other GenBank entries of BOLD and NCBI. These sequences together with GenBank sequences were used in phylogenetic tree construction and molecular characterization of the mosquitoes. According to morphological identification, the field-collected adult mosquitoes belong to the Culex species, Maximum likelihood trees from COI suggest that the Culex species has 99%-100% similarity to Culex quinquefaciatus, C.pipiens  Cpipien pipiens, C.molestus, and C.terzii and C piping pipiens an indication that the variability in the Culex species on this gene is slow and cannot distinguish between the various species and that of ITS 2 suggests an evolutionary relationship to C. quinquefaciatus, C.pipiens, C. pipiens molestus, C.modestus, and C. piping pipiens at maximum identity 83% shows that the species of Culex mosquitoes present in Bauchi is different from all the Culex species from those available in the NCBI and BOLD databases. Phylogeny from the sequences of all the specimens collected from locations in Bauchi with morphology characteristics of Culex form a new molecular type with close resemblance to C.quinquefaciatus, C.pipiens, and C.molestus, it also reflects the importance and feasibility of COI and ITS2 genetic markers in identifying mosquitoes and their sibling species and the significance of integrated systematic approach in mosquito taxonomy.