title: Evolutionary genomics of the recently duplicated amphioxus Hairy genes.
abstract: Amphioxus Hairy genes have gone through a number of lineage-specific duplications, resulting in eight members, some of which are differentially expressed in the embryo. In order to gain insights into the evolution and function of this gene family we have compared their genomic structure and searched for conserved non-coding sequence elements. We have found that introns have been lost independently from these genes at least twice and after the duplication events. By carrying out phylogenetic footprinting between paralogues expressed in the embryo, we have found a differential distribution of conserved elements that could explain the limited overlap in expression patterns of Hairy genes in the amphioxus embryo. Furthermore, clustering of RBP-Jk binding sites in these conserved elements suggests that amphioxus Hairy genes are downstream targets of the Notch signaling pathway, as occurs in vertebrates. All of this evidence suggests that amphioxus Hairy genes have gone through a process of subfunctionalization shortly after their duplication, representing an extreme and rapid case of the duplication-degeneration-complementation model.
authors.affiliation: Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, 08028 Barcelona, Spain.
authors.forename: Senda
authors.initials: S
authors.lastname: Jiménez-Delgado
authors.forename: Miguel
authors.initials: M
authors.lastname: Crespo
authors.forename: Jon
authors.initials: J
authors.lastname: Permanyer
authors.forename: Jordi
authors.initials: J
authors.lastname: Garcia-Fernàndez
authors.forename: Miguel
authors.initials: M
authors.lastname: Manzanares
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics*; D043344:Chordata / Q000145:classification* / Q000235:genetics*; D019143:Evolution, Molecular; D020131:Genes, Duplicate / Q000235:genetics*; D023281:Genomics / Q000379:methods*; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D051792:Basic Helix-Loop-Helix Proteins