Comparisons of Distribution of CpG Islands Through the Sex-Chromosomes Between Rat (Rattus norvegicus) and Swine (Sus scrofa)

CpG islands typically occur at or near the transcription start site of genes, particularly housekeeping genes, invertebrates. Normally a C (cytosine) base followed immediately by a G (guanine) base (a CpG) is rare in vertebrate DNA because the cytosines in such an arrangement tend to be methylated. Described DNA methylation mediated gene silencing occurs by direct inhibition of transcription factor binding to their relative sites and by recruitment of methyl binding domain proteins. The present study aims at predicting the CpG islands using Perl and R environment codes. The results indicated that the average length of the CpG islands in the X-chromosomes is comparable, however, the number of CpG islands is three times in swine (13539), as compared to that of rats (4465). The average CpG percent and the Average Guanine+Cytosine percent are also similar in the X-Chromosomes of both species. Similar results were evident for Y-Chromosome. The results obtained need validation through wet-lab experimentation.