Comparative Genomic Analysis and Evolutionary Study of CD4 Antigen

CD4 antigen is important to act as the primary receptor for the HIV. In order to understand the human CD4 gene and to determine its evolutionary aspects, we characterized this gene in detail in six different organisms. A comparative study was made of nucleotide length variations, intron and exon sizes and number variations, differential compositions of coding to non-coding bases, etc., to look for similarities/dissimilarities in the CD4 gene across all six taxa. Phylogenetic analysis showed the pattern found in other genes, as Homo sapiens and Pan troglodytes were placed in a single clade, and Rattus norvegicus and Mus musculus in another. We further focused on the two primates and aligned the amino acid sequences; there were small differences between humans and chimpanzees; both w ere more different from the other organisms.