Mitochondrial 16s rDNA based Analysis of some Hard Ticks Belonging to Genus Hyalomma Koch, 1844 (Acari: Ixodidae)

Abstract | A molecular analysis of mitochondrial 16s rDNA sequences of hard ticks belonging to genus Hyalomma from Haryana (India) and those available in genbank database was done so as to resolve inter-relationships between members of genus Hyalomma. For this a total of eighty one 16s rDNA sequences belonging to 16 taxa were subjected to molecular and phylogenetic analysis which was conducted in MEGA6 and Beast 1.8.0 software. Phylogenetic relationships were inferred using the bayesian, maximum likelihood (ML) and neighbor joining (NJ) methods by means of Tamura three parameter model + unequal frequency + gamma distribution (TPMuf+G). The analysis revealed 249 variable sites, 232 conserved sites, and 137 parsimony informative sites in the alignment. Results of the phylogenetic analysis provide support for monophyletic origin of genus Hyalomma. Further our results assert that H. anatolicum, H. excavatum, H. marginatum, H. lusitanicum, H. hussaini and H. brevipunctata represent closely related but rapidly diverging taxa and also substantiate H. asiaticum as a species complex. The molecular clock results exemplify divergence time of subfamily Hyalomminae from the common ancestor of subfamily Rhipicephalinae to be 61.99 mya and the origin of family Ixodidae to be 86.79 mya. A basic phylogenetic relationship tree is also provided to help future studies for phylogenetics of family Ixodidae especially for subfamily Hyalomminae.

Keywords | Hyalomma, Phylogeny, Ixodidae, 16s rDNA, Hard ticks