Specificity of cellular expression of C. variopedatus polychaete innexin in the developing embryo: evolutionary aspects of innexins' heterogeneous gene structures.
Innexins are a family of membrane proteins involved in the formation of gap junctions in invertebrates. They have been found to participate in several aspects of cell differentiation and in embryonic patterning through the formation of specific intercellular communication channels. We present here data showing that the recently identified innexin of the marine worm Chaetopterus variopedatus is expressed only in particular cells of the early stage, demonstrating cell specificity of innexin expression also in polychaete annelids. Phylogenetic analysis of all known innexins results in a phylogenetic tree clearly distinguishing insect, nematode, and other invertebrate innexins. Comparative analysis of proteins and known related genes shows that the apparent similarity of protein composition, overall structural organization, and specificity of cellular expression, typical of innexins of all studied organisms, correspond to highly heterogeneous gene structures even for genes that are in close contiguity on the same chromosome. A possible evolutionary motive producing this situation is discussed.
Department of Genetics, General and Molecular Biology, University of Naples Federico II, Via Mezzocannone 8, 80134 Naples, Italy.
Nicoletta
N
Potenza
Rosanna
R
del Gaudio
Maria Luisa
ML
Chiusano
Giuseppina Maria Rosaria
GM
Russo
Giuseppe
G
Geraci
D000595:Amino Acid Sequence; D000818:Animals; D004625:Embryo, Nonmammalian / Q000166:cytology; D018507:Gene Expression Regulation, Developmental; D019476:Insect Proteins / Q000235:genetics; D007814:Larva; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D011077:Polychaeta / Q000166:cytology / Q000196:embryology* / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D019476:Insect Proteins; D008565:Membrane Proteins