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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-3-18
pubmed:abstractText
The jawless Agnatha (lampreys and hagfishes) represent the phylogenetically oldest order of vertebrates that are believed to lack the adaptive immune system of jawed vertebrates. In order to search for molecular markers specific for cellular components of the adaptive immune system in lampreys, we used the polymerase chain reaction (PCR) to identify genes for transcription factors of the Ikaros family in genomic DNA and cDNA libraries from two species of lampreys, Petromyzon marinus and Lampetra fluviatilis. The mammalian Ikaros-like family of transcription factors consists of five members, Ikaros, Helios, Aiolos, Eos and Pegasus, of which the first three appear to be essential for lymphocyte development. Two different Ikaros-like genes, named IKLF1 and IKLF2, were identified in lamprey. They both have the conserved exon-intron structure of seven exons and show alternative splicing like their counterparts in jawed vertebrates. The genes code for predicted proteins of 589 and 513 amino acid residues, respectively. The proteins contain six highly conserved zinc finger motifs that are 83-91% identical to the mammalian members of the Ikaros-like family. The remaining parts of the sequences are, however, mostly unalignable. Phylogenetic analysis based on the alignable segments of the sequences does not identify the orthologous gene in jawed vertebrates but rather shows equidistance of the lamprey Ikaros-like factors to each other and to Ikaros, Helios, Aiolos and Eos. Expression studies by reverse transcription (RT)-PCR and in situ hybridization (ISH), however, provide evidence for moderate expression in presumed lymphoid tissues like the gut epithelium and for high levels of expression in the gonads, especially in the ovary.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0300-9475
pubmed:author
pubmed:issnType
Print
pubmed:volume
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
162-70
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed-meshheading:11896932-Amino Acid Sequence, pubmed-meshheading:11896932-Animals, pubmed-meshheading:11896932-Base Sequence, pubmed-meshheading:11896932-Conserved Sequence, pubmed-meshheading:11896932-DNA, Complementary, pubmed-meshheading:11896932-DNA-Binding Proteins, pubmed-meshheading:11896932-Exons, pubmed-meshheading:11896932-Female, pubmed-meshheading:11896932-Gene Expression, pubmed-meshheading:11896932-Ikaros Transcription Factor, pubmed-meshheading:11896932-Introns, pubmed-meshheading:11896932-Lampreys, pubmed-meshheading:11896932-Male, pubmed-meshheading:11896932-Molecular Sequence Data, pubmed-meshheading:11896932-Ovary, pubmed-meshheading:11896932-Phylogeny, pubmed-meshheading:11896932-Sequence Homology, Amino Acid, pubmed-meshheading:11896932-Tissue Distribution, pubmed-meshheading:11896932-Transcription Factors, pubmed-meshheading:11896932-Zinc Fingers
pubmed:year
2002
pubmed:articleTitle
Identification of two Ikaros-like transcription factors in lamprey.
pubmed:affiliation
Max-Planck-Institut für Biologie, Abt. Immungenetik, Corrensstr. 42, 72076 Tübingen, Germany. werner.mayer@tuebingen.mpg.de
pubmed:publicationType
Journal Article