Xenopus Pax-2 displays multiple splice forms during embryogenesis and pronephric kidney development.
Kidney organogenesis is initiated with the formation of the pronephric kidney and requires Pax-2 gene function. We report here the cloning and characterization of Pax-2 cDNAs from the frog Xenopus laevis, a model system suitable for the study of early kidney organogenesis. We show that expression of Xenopus Pax-2 (XPax-2) genes was confined to the nervous system, sensory organs, the visceral arches, and the developing excretory system. DNA sequencing of XPax-2 cDNAs isolated from head and pronephric kidney libraries revealed seven novel alternatively spliced Pax-2 isoforms. They all retain DNA-binding domains, but can differ significantly in their C termini with some isoforms containing a novel Pax-2 exon. We investigated the spectrum of XPax-2 splice events in pronephric kidneys, animal cap cultures and in whole embryos. Splicing of XPax-2 transcripts was found to be extensive and temporally regulated during Xenopus embryogenesis. Since all investigated tissues expressed essentially the full spectrum of XPax-2 splice variants, we conclude that splicing of XPax-2 transcripts does not occur in a tissue-specific manner.
Heller
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Institute of Cell Biology, Swiss Federal Institute of Technology, Zürich.
Brändli
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AW
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D006133:Growth Substances / Q000494:pharmacology; D007668:Kidney / Q000196:embryology*; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology / Q000378:metabolism; D051762:PAX2 Transcription Factor; D012679:Sense Organs / Q000196:embryology / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014157:Transcription Factors / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D014982:Xenopus laevis / Q000196:embryology*
D004268:DNA-Binding Proteins; D006133:Growth Substances; D051762:PAX2 Transcription Factor; D014157:Transcription Factors