title: Evolution of hematopoiesis: Three members of the PU.1 transcription factor family in a cartilaginous fish, Raja eglanteria.
abstract: T lymphocytes and B lymphocytes are present in jawed vertebrates, including cartilaginous fishes, but not in jawless vertebrates or invertebrates. The origins of these lineages may be understood in terms of evolutionary changes in the structure and regulation of transcription factors that control lymphocyte development, such as PU.1. The identification and characterization of three members of the PU.1 family of transcription factors in a cartilaginous fish, Raja eglanteria, are described here. Two of these genes are orthologs of mammalian PU.1 and Spi-C, respectively, whereas the third gene, Spi-D, is a different family member. In addition, a PU.1-like gene has been identified in a jawless vertebrate, Petromyzon marinus (sea lamprey). Both DNA-binding and transactivation domains are highly conserved between mammalian and skate PU.1, in marked contrast to lamprey Spi, in which similarity is evident only in the DNA-binding domain. Phylogenetic analysis of sequence data suggests that the appearance of Spi-C may predate the divergence of the jawed and jawless vertebrates and that Spi-D arose before the divergence of the cartilaginous fish from the lineage leading to the mammals. The tissue-specific expression patterns of skate PU.1 and Spi-C suggest that these genes share regulatory as well as structural properties with their mammalian orthologs.
authors.affiliation: Stowers Institute for Medical Research, Kansas City, MO 64110, USA.
authors.forename: M K
authors.initials: MK
authors.lastname: Anderson
authors.forename: X
authors.initials: X
authors.lastname: Sun
authors.forename: A L
authors.initials: AL
authors.lastname: Miracle
authors.forename: G W
authors.initials: GW
authors.lastname: Litman
authors.forename: E V
authors.initials: EV
authors.lastname: Rothenberg
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D005075:Biological Evolution; D002645:Chickens / Q000235:genetics; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D019143:Evolution, Molecular; D005399:Fishes / Q000145:classification / Q000235:genetics / Q000276:immunology; D005796:Genes; D006410:Hematopoiesis / Q000235:genetics; D006801:Humans; D007448:Invertebrates / Q000235:genetics / Q000276:immunology; D007798:Lampreys / Q000235:genetics / Q000276:immunology; D016131:Lymphocyte Subsets / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family; D009928:Organ Specificity; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics* / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012860:Skates, Fish / Q000235:genetics* / Q000276:immunology; D013045:Species Specificity; D013154:Spleen / Q000737:chemistry; D015534:Trans-Activators / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics*; D014714:Vertebrates / Q000145:classification / Q000235:genetics / Q000276:immunology; D029867:Xenopus Proteins; D000099232:Proto-Oncogene Protein Spi-1
chemical_list: D004247:DNA; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D020033:Protein Isoforms; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D029867:Xenopus Proteins; D000099232:Proto-Oncogene Protein Spi-1; C486039:SPIC protein, human; C423919:Spi-D protein, Xenopus; C423918:Spic protein, mouse; C076877:SPIB protein, human