@entity16448 gene variability among non- XXXX primates.

@entity1 @entity535 @entity377 @entity5357 @entity16448
Defensins are a recently described family of peptides that play an important role in innate immunity. Recent studies have shown that defensins exhibit a broad spectrum of antimicrobial activities against bacteria and fungi. Three families have been identified so far in mammals, alpha-defensins, @entity5357 , presumably derived from a common ancestral defensin. A long-term study on the evolution of these multigene families among primates has been undertaken to investigate: (1) the degree of interspecific differentiation; (2) the genetic mechanisms responsible for the variability of these molecules; and (3) the possible role of different environmental factors in their evolution. @entity377 sequences have been obtained from great and lesser apes, several African and Asian catarrhine monkeys and one New World monkey. A comparison of rates of synonymous and nonsynonymous ( @entity535 changing) @entity377 substitution indicates that the primate @entity16448 gene evolved under a pattern of random @entity377 substitution as predicted by the neutral theory of molecular evolution. These results are not consistent with the hypothesis that the primate @entity16448 gene has diversified in response to changes in the microbial species to which a given host is exposed. Analyses of interpecific variability have yielded some insights about the pattern of molecular evolution of the gene among primates. @entity1 and great apes present high levels of sequence similarity, differing in only one @entity535 residue in the mature peptide. Compared with these taxa, hylobatids and cercopithecids exhibit 3-4 @entity535 substitutions, some of which increase the net charge of the active molecule.
