Whole genome comparative analysis of CpG islands in camelid and other mammalian genomes.

Camels bear unique genotypes and phenotypes for adaptation in their environment, and as such could be very useful in the weather extremes accelerated by global climate change. Published sequences of Camelidae genomes provide an opportunity to elucidate the genomic architecture of these animals. CpG islands (CGIs) sequence patterns in complex genomes play important roles in gene regulation via epigenetic change. Comparative large-scale genome analysis of CGIs in Camelidae was carried out using five different CGI detection algorithms, evaluating numbers of CGIs, CGI density and CGI length distribution in Camelidae. All algorithms identified the alpaca genome as having the largest number of CGIs, CGI density and average length of CGIs, though, the CGI length distribution and their number could be implicitly attributed to the characteristics of an algorithm for CGI identification rather than that of the species. In addition, high algorithm-to-algorithm variability of the observed CGI properties was shown. It was well expected, since there is no clear definition of a CGI and different algorithms could identify different genome regions as CGIs. Comparison with other mammalian genomes (human, mouse, dog, horse and cow) shows that CGIs features in cow were most similar to camelid genomes. Further analysis of camelid genomes may shed more light on molecular origins and mechanisms of adaptation in these extreme heat-adapted animals. [ABSTRACT FROM AUTHOR]