Xenopus Pax-2 displays multiple splice forms during embryogenesis and pronephric kidney development

Mech Dev. 1997 Dec;69(1-2):83-104. doi: 10.1016/s0925-4773(97)00158-5.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing*
  • Amino Acid Sequence
  • Animals
  • Cloning, Molecular
  • DNA-Binding Proteins / drug effects
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Embryo, Nonmammalian / physiology
  • Gene Expression Regulation, Developmental*
  • Growth Substances / pharmacology
  • Kidney / embryology*
  • Molecular Sequence Data
  • Nervous System / embryology
  • Nervous System / metabolism
  • PAX2 Transcription Factor
  • Sense Organs / embryology
  • Sense Organs / metabolism
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Tissue Distribution
  • Transcription Factors / drug effects
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transcription, Genetic / drug effects
  • Xenopus laevis / embryology*


  • DNA-Binding Proteins
  • Growth Substances
  • PAX2 Transcription Factor
  • Transcription Factors

Associated data

  • GENBANK/AJ000666
  • GENBANK/AJ000667
  • GENBANK/AJ000668
  • GENBANK/AJ000669
  • GENBANK/Y10119
  • GENBANK/Y10120
  • GENBANK/Y10121
  • GENBANK/Y10122
  • GENBANK/Y10123