title: A fork head/HNF-3 homolog expressed in the pharynx and intestine of the Caenorhabditis elegans embryo.
abstract: We have cloned a member of the fork head/HNF-3 family of transcription factors from the nematode Caenorhabditis elegans. Within the predicted DNA binding domain, this gene, called Ce-fkh-1, is 75-78% identical to the Drosophila fork head and rat liver HNF-3 alpha, beta, and gamma genes. Ce-fkh-1 mRNA is highly enriched in embryos. The Ce-fkh-1 gene produces three major transcripts: the longest mRNA retains its original 5'-end but two shorter mRNAs are trans-spliced at the beginning of exons 2 and 3, respectively. In situ hybridization and transgenic Ce-fkh-1::lacZ reporter constructs indicate that the Ce-fkh-1 gene is expressed in both pharynx and intestine of the embryo, beginning at the midproliferation stage. A second phase of Ce-fkh-1 expression occurs in cells of the larval somatic gonad. The pharynx-gut expression of Ce-fkh-1 in the C. elegans embryo is compared with expression of fork head throughout the gut of Drosophila embryos and with expression of HNF-3 (alpha beta gamma) in the endoderm of mammalian embryos. Such conserved patterns of gene expression point to universal features of gastrulation and of digestive tract formation.
authors.affiliation: Department of Medical Biochemistry, University of Calgary, Alberta, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Azzaria
authors.forename: B
authors.initials: B
authors.lastname: Goszczynski
authors.forename: M A
authors.initials: MA
authors.lastname: Chung
authors.forename: J M
authors.initials: JM
authors.lastname: Kalb
authors.forename: J D
authors.initials: JD
authors.lastname: McGhee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics; D051858:Forkhead Transcription Factors; D018507:Gene Expression Regulation, Developmental; D051541:Hepatocyte Nuclear Factor 3-alpha; D051542:Hepatocyte Nuclear Factor 3-beta; D051543:Hepatocyte Nuclear Factor 3-gamma; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000096:biosynthesis / Q000378:metabolism*; D014157:Transcription Factors
chemical_list: D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D051858:Forkhead Transcription Factors; D051541:Hepatocyte Nuclear Factor 3-alpha; D009687:Nuclear Proteins; C113277:Pha-4 protein, C elegans; D015534:Trans-Activators; D014157:Transcription Factors; D051543:Hepatocyte Nuclear Factor 3-gamma; D051542:Hepatocyte Nuclear Factor 3-beta