Molecular characterization and genetic divergence of seven Culex mosquito (Diptera: Culicidae) species using Mt COI gene from Odisha State, India

Abstract

Abstract Background Culex mosquitoes are involved in the transmission of arboviral diseases worldwide. Bio-ecology and identification of mosquitoes are of paramount importance to develop species-specific vector control strategies. Genetic-based species-specific approaches that reduce the burden of vector-borne diseases are made possible by molecular techniques. Results In the present study, the mitochondrial COI gene of Culex mosquitoes was used for molecular identification in addition to morpho-taxonomy. Our findings suggested the presence of important Culex mosquito vectors viz, Culex vishnui, Culex tritaeniorhynchus, Culex bitaeniorhynchus, Culex quinquefasciatus, Culex gelidus, Culex fuscocephala, and Culex fuscanus in the southern part of Odisha state, India. We examined the phylogeny and genetic diversity of the above seven different Culex populations from different geographical locations. An average intra-specific K2P distance of the COI gene was found to be 0.9%. Further, to measure the diversity of the Culex population among different geographical strains, haplotype diversity and nucleotide diversity were compared. Culex fuscanus showed high polymorphisms and mutations with high nucleotide diversity (0.013) and the Culex quinquefasciatus showed the lowest variation in P(i), 0.0013 in the intra-population polymorphism analysis of COI sequences. Similarly, the Haplotype diversity (Hd) found in Culex gelidus and Culex fuscocephala with the value of 0.972 and Culex quinquefasciatus (0.583) showed the lowest value of haplotype diversity. A haplotype network was constructed to establish the genealogical relationship between haplotypes. The phylogenetic tree was constructed that produces distinctive conspecific clusters in different Culex species. Population genetic study has illustrated the occurrence of genetic differentiation within the population. Conclusions The findings of this study contribute to greater evidence that DNA barcode sequences can be used to monitor mosquito species diversity. This study also adds valuable information about the systematics and molecular biology of seven public health important mosquito species acting as a significant vector for Japanese encephalitis in various Asian continents. This information is further used for the effective implementation of region-specific vector control strategies.