Differential regulation of the two xGATA-1 genes during Xenopus development.
Xenopus laevis provides an established developmental system to study the regulation of cell lineage establishment and the generation of tissue-specific patterns of gene expression. We have isolated from Xenopus erythroid cell RNA two distinct cDNA clones encoding the xGATA-1 transcription factor. We have identified, in erythroid nuclear extracts, the sequence-specific DNA-binding protein they encode. By characterizing the expression patterns for RNA derived from two distinct homologues, we find that the two xGATA-1 genes are differentially regulated. The xGATA-1a mRNA predominates in embryos prior to terminal differentiation of erythroid cells, while the differentiated cells contain RNA derived predominantly from the xGATA-1b gene. Both proteins activate a target globin promoter in transient transfection assays. During early development, GATA-1 transcripts are localized to ventral regions of the embryo. GATA-1 should therefore provide a useful early marker for studying signalling pathways which result in the generation of ventral mesoderm. The differentially regulated genes may be distinct markers for targets of ventral mesoderm induction.
Zhang
C
C
Department of Biological Sciences, University of Pittsburgh, Pennsylvania 15260.
Evans
T
T
D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000235:genetics*; D015672:Erythroid Precursor Cells / Q000378:metabolism; D050981:Erythroid-Specific DNA-Binding Factors; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014982:Xenopus laevis
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D012333:RNA, Messenger; D014157:Transcription Factors