Journal of Vector Borne Diseases (Mar 2011)
Comparative evolutionary analyses of beta globin gene in eutherian, dinosaurian and neopterygii taxa
Abstract
Background & objectives: Comparative genomics and evolutionary analyses of conserved genes have enabled usto understand the complexity of genomes of closely related species. For example: -globin gene present inhuman hemoglobin is one such gene that has experienced many genetic changes in many related taxa andproduced more than 600 variants. One of the variant, HBS causes sickle-cell anemia in humans but offersprotection against severe malaria due to Plasmodium falciparum. In the present study, we characterized andperformed evolutionary comparative analyses of the -globin gene in different related and unrelated taxa tohave a comprehensive view of its evolution.Methods: DNA and protein sequences of -globin gene were downloaded from NCBI and characterized in detailin nine eutherian (Homo sapiens, Pan troglodytes, Macaca mulatta, Mus musculus, Rattus norvegicus, Bostaurus, Canis familiaris, Equus caballus, Oryctolagus cuniculus), a dinosaurian (Gallus gallus) and a neopterygii(Danio rerio) taxa. Three more eutherian (Papio anubis, Ovis aries and Sus scrofa) taxa were included for ananalysis at the protein level but not included at the gene level owing to lack of genomic information. Computationaland phylogenetic analyses were performed using evolutionary comparative approach.Results: Results of comparative and phylogenetic analyses revealed less conservation of genetic architecture of-globin compared to its protein architecture in all eutherian taxa. Both dinosaurian and neopterygii taxa servedas outgroups and varied at gene and protein levels.Interpretation & conclusion: Most remarkably, all primates from eutherian taxa including P. anubis showedonly nine codon position differences and an absolute similarity between H. sapiens and P. troglodytes. Absoluteconservation of coding region in Equus caballus (horse) was observed. The results were discussed with aninference on the role of evolutionary forces in maintaining such close similarities and variations across closelyrelated taxa. Further, the need to utilize more comparative approaches in understanding the disease causinggenes’ evolution in closely related taxa is hoped for.
