Vol. 3, Issue 1 (2018)
COI vs 16s rRNA sequences: Molecular characterization of Culex (Diptera: Culicidae) vector species from India
Author(s): Gatreddi Srinu
Abstract: Culex is the main source of vector for several diseases in India. In the present study, a comprehensive genetic diversity study of Cytochrome Oxidase I (COI) and 16s rRNA in 2 species of Culex mosquitoes (Culex tritaeniorhynchus and Culex quinquefasciatus) from India was carried out using 257 partial sequences. Genetic divergence analysis based on COI and 16s rRNA sequences revealed a clear gap between intraspecific and interspecific distances of 2 species from India. However, 16sRNA based phylogeny of Culex species failed to adequately differentiate species in a whole country context whereas COI sequences were succeed. Average genetic divergence values of COI gene for within species for Culex quinquefasciatus and Culex tritaeniorhynchus were 0.020% and 0.010% respectively whereas for 16s rRNA gene average genetic divergence within species for Culex quinquefasciatus and Culex tritaeniorhynchus were 0.001% and 0.005% respectively. Maximum value of A/T content observed in COI sequence (72.0%) followed by 16s rRNA sequences (41.7%) followed by COI partial sequences (34.7%). The GC2 content is dominated followed by GC3 and GC1 in COI sequences indicates the synonymous mutations occur mostly at the GC2 followed by GC3 and GC1. It can be concluded as validation with COI mitochondrial gene was successful and helps in successful estimation of genetic structure of Culex species in India.