HABITAT ZONES AND VARIATIONS AT MITOCHONDRIAL GENOME LEVEL IN FRESH WATER DOLPHIN

Abstract

Fresh water dolphins are present in geographically different areas of the world. Although they are the descendents of the single ancestor yet they have some genetic variabilities. The present study was conducted to discuss the characteristics and to analyze genomic differences among different fresh water dolphins. Literature survey was done to find out major habitat zone of fresh water dolphins. The mitochondrial DNA sequence of dolphins was taken from GenBank. Mitochondrial nucleotide sequence alignment of dolphins was performed using bio-informatics tool Clustal W. Phylogenetic tree was constructed and percentage similarity was calculated among different species of fresh water dolphins. On the basis of habitat, fresh water dolphins are divided into five major zones. Indus Dolphin mitochondrial genome indicated 99% homology with Ganges dolphin and 83% homology with Baiji Dolphin, 81% homology with the Franciscana Dolphin and 82% homology with the Boto Dolphin. The Baiji Dolphin has 85 % homology with the Boto Dolphin and 73% homology with Ganges Dolphin and the Franciscana Dolphin while the Boto Dolphin has 83 % homology with the Franciscana Dolphin. The Ganges Dolphin has 66 % homology with the Franciscana Dolphin. According to phylogenetic tree four species of fresh water dolphin were closely related while one was different. There are genetic variations at mitochondrial genome level between Indus dolphin and other fresh water dolphins.