Characterization of the Hydra lamin and its gene: A molecular phylogeny of metazoan lamins.

摘要: We report sequences for nuclear lamins from the teleost fish Danio and six invertebrates. These include two cnidarians (Hydra Tealia), one priapulid, echinoderms, cephalochordate Branchiostoma. Combining these results with earlier data on Drosophila, Caenorhabditis elegans, various vertebrates, following conclusions lamin evolution can be drawn. First, all invertebrate resemble in size vertebrate B-type lamin. Second, described previously amphibia, birds mammals as well first of a fish, characterized here, show cluster 7 to 12 acidic residues tail domain. Since this is absent including that Branchiostoma, it was acquired lineage. The larger A-type differentiated cells must have arisen subsequently by gene duplication insertion an extra exon. This exon A-lamins only major change domain organization metazoan evolution. Third, three introns Hydra Priapulus genes correspond position last genes. Thus entirely different C. elegans Drosophila Dmo seems reflect evolutionary drift, which probably also accounts fact has most diverse sequence. Finally we discuss possibility types, constitutively expressed developmentally regulated one, arose independently arthropod lineages.