Journal of Vector Borne Diseases (Sep 2009)
Evolutionary insights into duffy gene in mammalian taxa with comparative genetic analysis
Abstract
Background & objectives: Evolutionary analyses of genes conserved across taxa are keys tounderstand the complexity of gene and genome variation. Since malaria is a highly infectioushuman disease and its susceptibility in human is genetically controlled, characterization andevolutionary analyses of such genes are of prime importance to understand genetic mechanisms ofdisease susceptibility. In the present study we have characterized and performed comparativegenomic analyses of the human Duffy gene responsible for malaria pathogenesis in nine differentmammalian taxa.Methods: DNA sequences of human duffy gene were downloaded from public domain and havebeen characterized in detail and compared with eight other different mammalian taxa (Pantroglodytes, Macaca mulatta, Pongo pygmaeus, Rattus norvegicus, Mus musculus, Monodelphisdomestica, Bos taurus and Canis familiaris). Comparative and evolutionary analyses were performedusing statistical software and tools.Results: We observed that the genetic architecture of this gene was entirely different across all thenine taxa and a close similarity between Homo sapiens and Pan troglodytes (chimpanzee) wasevident for several aspects of this gene. Comparisons on several aspects, such as ratio of codingand non-coding regions, total gene length number and size of introns and difference of number ofnucleotides in human and chimpanzees have revealed interesting features. Phylogenetic inferencesbased on the Duffy gene among nine different taxa were found to be different than other genespreviously studied.Interpretation & conclusion: Most remarkably, human and chimpanzee were only 0.75% differentin this gene. The results were discussed on the similarities between human and chimpanzee andgain of introns in human-chimpanzee clade with an inference on the role of evolutionary forces(mainly natural selection) in maintaining such variations across closely-related mammalian taxa.
