Phylogenetic analysis of some Puntius species based on 18S rDNA

Abstract

The molecular characterization and phylogenetic analysis have been carried out in four Puntius species using 18S rDNA sequences. The size of the consensus sequences of 18S rDNA ranged between 1807-1817 bp (i.e. 1810 bp in P. chola, 1809 bp in P. conchonius, 1817 bp in P. sophore and 1807 bp in P. ticto). The GC and AT content (%) was 56.96 and 43.04 in P. chola, 55.67 and 44.33 in P. conchonius, 56.69 and 43.31 in P. sophore and 55.06 and 44.94 in P. ticto. The dataset after multiple sequence alignment of these Puntius species contained 1906 nucleotide positions, out of which 1430 were conserved, 467 variable, 205 singleton, and 256 parsimony informative. The inter-specific genetic variation was low. P. chola revealed lowest genetic distance with P. sophore and same was true between P. conchonius and P. ticto. The evolutionary history was inferred by three methods, namely Maximum Parsimony, Neighbour-Joining and the Maximum Likelihood. The three different phylogenetic approaches resulted mostly in similar tree topologies and the clades were well supported with bootstrap values. P. chola and P. sophore clustered together as sister group and same was true with P. conchonius and P. ticto, which showed their close relationship. The phylogenetic reconstruction of present study was also in agreement with earlier studies based on morphometric, cytogenetic studies, mitochondrial cytochrome b gene and restriction fragment polymorphism analysis.