title: Adaptive evolution and functional divergence of pepsin gene family.
abstract: In vertebrates, a large proportion of genes is organized in gene families. Paralogous gene groups generated by gene duplication are related by homology, high degree of sequence identity and similar structural architecture of their products. Aspartic proteinases form a widely distributed protein superfamily including cathepsins, pepsins, renin and napsin. In the present study, the nucleotide sequences coding for various pepsins in 30 vertebrate species have been used to derive a gene phylogeny. Gene duplication and losses have been inferred from a reconciled tree, reconstructed by combining information from gene tree and species tree. Our findings based on the results of the relative rate ratio test and maximum likelihood analysis suggest that each round of gene duplication is characterized by adaptive evolution, although instances of evolution under positive selection have been found also long after divergence of gene families. The results of functional divergence analysis provided statistical evidence for shifted evolutionary rate after gene duplication.
authors.affiliation: CNR Institute of Protein Biochemistry, Via Marconi 10, 80125 Naples, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Carginale
authors.forename: Francesca
authors.initials: F
authors.lastname: Trinchella
authors.forename: Clemente
authors.initials: C
authors.lastname: Capasso
authors.forename: Rosaria
authors.initials: R
authors.lastname: Scudiero
authors.forename: Marilisa
authors.initials: M
authors.lastname: Riggio
authors.forename: Elio
authors.initials: E
authors.lastname: Parisi
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000818:Animals; D019143:Evolution, Molecular; D005785:Gene Conversion; D017353:Gene Deletion; D020440:Gene Duplication; D014644:Genetic Variation; D006801:Humans; D008957:Models, Genetic; D010434:Pepsin A / Q000235:genetics* / Q000502:physiology; D010802:Phylogeny
chemical_list: D010434:Pepsin A