THE HNF-3 GENE FAMILY OF TRANSCRIPTION FACTORS IN MICE - GENE STRUCTURE, CDNA SEQUENCE, AND MESSENGER-RNA DISTRIBUTION

The rat HNF-3 (hepatocyte nuclear factor 3) gene family encodes three transcription factors known to be important in the regulation of gene expression in liver and lung. We have cloned and characterized the mou se genes and cDNAs for HNF-3 alpha, beta, and gamma and analyzed their expression patterns in various adult tissues and mouse embryonic stag es. The HNF-3 proteins are highly conserved between mouse and rat, wit h the exception of the amino terminus of HNF-3 gamma, which in mouse i s more similar to those of HNF-3 alpha and beta than to the amino term ini of the rat HNF-3 gamma protein. The mouse HNF-3 genes are small an d contain only two or three (HNF-3 beta) exons with conserved intron-e xon boundaries. The proximal promoter of the mouse HNF-3 beta gene is remarkably similar to that of the previously cloned rat HNF-3 beta gen e, but is different from the promoters of the HNF-3 alpha: and gamma g enes. The mRNA distribution of the mouse HNF-3 genes was analyzed by q uantitative RNase protection with gene-specific probes. While HNF-3 al pha and beta are restricted mainly to endoderm-derived tissues (lung, liver, stomach, and small intestine), HNF-3 gamma is more extensively expressed, being present additionally in ovary, testis, heart, and adi pose tissue, but missing from lung. Transcripts for HNF-3 beta and alp ha are detected most abundantly in midgestation embryos (Day 9.5), whi le HNF-3 gamma expression peaks around Day 15.5 of gestation. (C) 1994 Academic Press,Inc.