Identification and characterization of LMO4, an LMO gene with a novel pattern of expression during embryogenesis.
LMO4 is a novel member of the LIM-only (LMO) subfamily of LIM domain-containing transcription factors. LMO1, LMO2, and LMO4 have distinct expression patterns in adult tissue, and we demonstrate that nuclear retention of LMO proteins is enhanced by the nuclear LIM interactor (NLI). In situ hybridization to early mouse embryos of 8-14.5 days revealed a complex pattern of LMO4 expression spatially overlapping with NLI and LHX genes. LMO4 expression in somite is repressed in mice mutant for the segment polarity gene Mesp2 and expanded in Splotch mutants. During jaw and limb outgrowth, LMO4 and LMO2 expression define mesenchyme that is uncommitted to regional fates. Although both LMO2 and LMO4 are activated in thymic blast cells, only LMO4 is expressed in mature T cells. Mesenchymal and thymic blast cell expression patterns of LMO4 and LMO2 are consistent with the suggestion that LMO genes inhibit differentiation.
Kenny
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DA
Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0650, USA.
Jurata
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LW
Saga
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Y
Gill
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GN
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D005314:Embryonic and Fetal Development; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D018398:Homeodomain Proteins / Q000737:chemistry*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D060588:LIM Domain Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013234:Stem Cells / Q000502:physiology; D014157:Transcription Factors / Q000737:chemistry*
D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C486312:LDB1 protein, human; D060588:LIM Domain Proteins; C102084:Ldb1 protein, mouse; C491976:Lmo4 protein, mouse; D009687:Nuclear Proteins; D012333:RNA, Messenger; D014157:Transcription Factors