title: Phylogenetic analysis of three complete gap junction gene families reveals lineage-specific duplications and highly supported gene classes.
abstract: Gap junctions, composed of connexin proteins in chordates, are the most ubiquitous form of intercellular communication. Complete connexin gene families have been identified from human (20) and mouse (19), revealing significant diversity in gap junction channels. We searched current databases and identified 37 putative zebrafish connexin genes, almost twice the number found in mammals. Phylogenetic comparison of entire connexin gene families from human, mouse, and zebrafish revealed 23 zebrafish relatives of 16 mammalian connexins, and 14 connexins apparently unique to zebrafish. We found evidence for duplication events in all genomes, as well as evidence for recent tandem duplication events in the zebrafish, indicating that the complexity of the connexin family is growing. The identification of a third complete connexin gene family provides novel insight into the evolution of connexins, and sheds light into the phenotypic evolution of intercellular communication via gap junctions.
authors.affiliation: Department of Biological Sciences, Lehigh University, 111 Research Drive, Iacocca B-217, Bethlehem, PA 18015, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Eastman
authors.forename: Tim H-P
authors.initials: TH
authors.lastname: Chen
authors.forename: Matthias M
authors.initials: MM
authors.lastname: Falk
authors.forename: Tamra C
authors.initials: TC
authors.lastname: Mendelson
authors.forename: M Kathryn
authors.initials: MK
authors.lastname: Iovine
mesh_terms: D000818:Animals; D017630:Connexins / Q000235:genetics; D017629:Gap Junctions / Q000235:genetics*; D020440:Gene Duplication; D006801:Humans; D005810:Multigene Family; D010802:Phylogeny
chemical_list: D017630:Connexins