Evolutionary fate of duplicate genes encoding aspartic proteinases. Nothepsin case study

Evolutionary analysis of the transferrin gene in Antarctic Notothenioidei: A history of adaptive evolution and functional divergence

“…Noteworthy, in the pairwise comparisons between sequences, larger values have been obtained for the terminal lineages leading to the four Notothenioids, suggesting that the evolution of these sequences may have occurred under stronger positive selection. This observation is in keeping with the evolutionary history and the cold-adapted features of many proteins and enzymes present in this fish group (Bargelloni et al, 1998;Ota et al, 2003;Carginale et al, 2004;Borrelli et al, 2006). On the contrary, among the Eutherian mammals, the estimated dN/dS ratios were smaller than 1.…”

Iron metabolism genes in Antarctic notothenioids: A review

“…Analyses aimed at establishing adaptive evolution instances in transferrin gene in relation to functional diversification of the Antarctic notothenioids demonstrate evidence of positive selection for the branch leading to the notothenioid fish (Trinchella et al, 2008). This observation is in keeping with the evolutionary history and the cold-adapted features of many proteins and enzymes present in this fish group (Bargelloni et al, 1998;Ota et al, 2003;Carginale et al, 2004;Borrelli et al, 2006). By applying the relative rate ratio test and the neutral substitution test to detect instances of adaptive evolution (Creevey and McInerney, 2002), we found that tranferrins from Antarctic notothenioids evolved under positive non-directional selection (Trinchella et al, 2008), a condition describing a selective regime where the environment is altering and where sequence change is required just to maintain an acceptable level of fitness.…”

Beta-Secretase: Structure, Function, and Evolution

“…The origin of metazoan genome complexity is thought to be correlated to gene duplication events [189]. There is evidence to indicate that gene duplication is followed by a period of positive selection [189].…”

“…There is evidence to indicate that gene duplication is followed by a period of positive selection [189]. According to the data shown, the evolution of aspartyl proteases includes numerous gene duplication events, leading to the segregation of various groups of paralogs.…”

“…Increasing evidence indicates that the persistence of duplicated genes can be found by subfunctionalization, a mechanism by which each duplicate retains some ancestral function [191]. One way this can occur is by the division of gene expression after gene duplication in the tissue-specific expression of the daughter genes produced [189]. Comparisons of genes encoding aspartyl proteases from organisms including yeast, fungi, nematodes, protozoa, plants and vertebrates shows that though intron position varies throughout the protein family, the genes encoding the enzymes share structural similarity [192].…”