Genetic Similarity within Isolates of Population of the Cattle Tick, Rhipicephalus microplus Based on Mitochondrial Cytochrome Oxidase Subunit-I Gene Sequencess

摘要

Molecular phylogenetic analysis was carried out using mitochondrial nucleotide sequences(COI) to provide evidence in genetic relatedness among various isolates of cattle tickRhipicephalus microplus collected from different locations in Chennai, Tamil Nadu, India. The mitochondrialCOI gene region of ticks was amplified and sequenced. A multiple sequence alignment using editedsequences of various isolates of ticks was carried out and a phylogenetic tree was constructed.The results on multiple sequence alignment and phylogram revealed that COI gene sequence of the eightisolates of ticks collected had more than 99.90 % similarity. It confirmed that COI gene was most conserved inthe mitochondrial DNA of the collected cattle tick, R. microplus. Subsequently, the sequences were used topredict the secondary structure models of COI which also revealed similar such close relationships.These results in the present study reflect a single monophyletic group with no functional diversity at themitochondrial COI gene region either in the sequence or structures was observed at various isolates of cattletick R. microplus. The indication of absence of genetic variation within isolates of ticks was revealed in thepresent.