A role for Xlim-1 in pronephros development in Xenopus laevis.
Xlim-1, a LIM class homeobox gene expressed in Xenopus laevis, is one of the earliest known marker genes of pronephros development and is expressed in pronephros rudiment. In this study, we examined the role of Xlim-1 in pronephros development. Temporal expression of Xlim-1 in explants was analyzed in a series of induction assays using RT-PCR analysis. Xlim-1 was expressed 9 to 15 h after activin/retinoic acid treatment, corresponding to pronephros differentiation in explants. We further examined the role of Xlim-1 using a series of microinjection experiments. Presumptive pronephric anlagen of embryos were injected with various Xlim-1 mutants, and effects of these Xlim-1 mutants on pronephrogenesis in embryos and in explants were analyzed by RT-PCR and immunohistochemistry. Dominant-negative Xlim-1 inhibited differentiation of pronephros in activin/retinoic acid-treated animal caps. In embryos injected with a dominant-negative form of Xlim-1, development of pronephric tubules was inhibited at the late tail-bud stage. Our results suggest that Xlim-1 may not initiate differentiation of the pronephros, but that it is necessary for growth and elongation in the development of pronephric tubules.
Chan
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Department of Life Sciences, CREST, Graduate School of Arts and Sciences, Japan Science and Technology Corporation, University of Tokyo, 3-8-1 Komaba, Meguro-ku,Tokyo, 153-8902, Japan.
Takahashi
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Asashima
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D028341:Activins; D000818:Animals; D004625:Embryo, Nonmammalian / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D007265:Inhibins / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000196:embryology*; D060850:LIM-Homeodomain Proteins; D009024:Morphogenesis; D016296:Mutagenesis; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors; D014212:Tretinoin / Q000494:pharmacology; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics
D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; C543964:Lhx1 protein, Xenopus; D011994:Recombinant Proteins; D014157:Transcription Factors; D029867:Xenopus Proteins; D028341:Activins; D014212:Tretinoin; D007265:Inhibins