title: Members of the Ikaros gene family are present in early representative vertebrates.
abstract: Members of the Ikaros multigene family of zinc finger proteins are expressed in a tissue-specific manner and most are critical determinants in the development of both the B and T lymphocytes as well as NK and dendritic APC lineages. A PCR amplification strategy that is based on regions of shared sequence identity in Ikaros multigene family members found in mammals and several other vertebrates has led to the recovery of cDNAs that represent the orthologues of Ikaros, Aiolos, Helios, and Eos in Raja eglanteria (clearnose skate), a cartilaginous fish that is representative of an early divergence event in the phylogenetic diversification of the vertebrates. The tissue-specific patterns of expression for at least two of the four Ikaros family members in skate resemble the patterns observed in mammals, i.e., in hematopoietic tissues. Prominent expression of Ikaros in skate also is found in the lymphoid Leydig organ and epigonal tissues, which are unique to cartilaginous fish. An Ikaros-related gene has been identified in Petromyzon marinus (sea lamprey), a jawless vertebrate species, in which neither Ig nor TCRs have been identified. In addition to establishing a high degree of evolutionary conservation of the Ikaros multigene family from cartilaginous fish through mammals, these studies define a possible link between factors that regulate the differentiation of immune-type cells in the jawed vertebrates and related factors of unknown function in jawless vertebrates.
authors.affiliation: Department of Pediatrics and Institute for Biomolecular Sciences, University of South Florida College of Medicine, Children's Research Institute, St. Petersburg, FL 33701, USA.
authors.forename: R N
authors.initials: RN
authors.lastname: Haire
authors.forename: A L
authors.initials: AL
authors.lastname: Miracle
authors.forename: J P
authors.initials: JP
authors.lastname: Rast
authors.forename: G W
authors.initials: GW
authors.lastname: Litman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D004268:DNA-Binding Proteins; D005784:Gene Amplification; D015870:Gene Expression / Q000276:immunology; D006801:Humans; D051740:Ikaros Transcription Factor; D007798:Lampreys / Q000235:genetics* / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000276:immunology*; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D012860:Skates, Fish / Q000235:genetics* / Q000276:immunology; D014157:Transcription Factors / Q000235:genetics*; D014337:Trout; D015027:Zebrafish; D029961:Zebrafish Proteins; D016335:Zinc Fingers / Q000235:genetics / Q000276:immunology
chemical_list: D004268:DNA-Binding Proteins; C497239:IKZF1 protein, human; D014157:Transcription Factors; D029961:Zebrafish Proteins; C497238:Zfpn1a1 protein, mouse; C497240:ikzf1 protein, zebrafish; D051740:Ikaros Transcription Factor