Analysis of genetic diversity in CYTB and control region sequences of Melanochelys trijuga (Schweigger, 1812) from Karnataka

Melanochelys trijuga indigenously called Indian black turtle is an endemic freshwater turtle species of Asia. Current study is the first report on mitochondrial marker of M. trijuga from this region. The study highlights intraspecies nucleotide diversity in CYTB and control region (CR) sequences. The CYTB gene analyzed revealed 4.47% variability with no indels and CR region consist 13.5% variability with 22 indels. In CYTB pyrimidine transitions (Ts) (T↔C) exceeded purine Ts (A↔G). This resulted in synonymous substitutions of amino acids in the protein without altering its structure and function. The partial fragment of CR contained CSB 1, 2, 3 that are required for its regulatory function and consist more of Ts than transversions. The nucleotide diversity (π) for CR was greater than that of CYTB which indicates CR is highly susceptible for mutation. The number of haplotypes and haplotype diversity were poorly resolved and probable reasons have been discussed.