Comparative Analysis Of Internal Repeating Segments In Proteins Of Source Functional Gene With Derivate Retropseudogene

The two features of the mammals are (1) abundant internal repeating segments(IRS) in proteins (2) large numbers of retropseudogenes in genome. Comparative analysis of internal repeating segments in proteins of source functional gene with their derivate retropseudogene can facilitate the study of the evolution and mutation of IRS. We analysed the IRS of presumed proteins of retropseudogenes in human and mouse. And we found that, when comparing with the retropseudogenes, the IRS of the source functional gene which generated those retropseudogenes increases by ~ 30% . This result show that the IRS were strongly preserved in proteins during evolution. What's more, the random mutation simulations show that, the mutation of retropseudogenes should not be regard as random or completely release from selective pressure: they discarded IRS is less than the situation of random mutation; further more, the pro portion of simple sequence repeat (SSR) within IRS is easily drop in situation of random mutation, but the proportion of SSR of the retropseudogenes is equivalent to the source functional gene. Moreover, a comparison is made between the proteome and the retropseudogenes-generating functional gene in the pattern of all tetra-peptides in the way of 4pep-matrix-plotting. The finding is that that the former has the phenomena of SSR enrichment, but not for the latter.