title: Accumulation and decay of DG42 gene products follow a gradient pattern during Xenopus embryogenesis.
abstract: The DG42 gene is expressed during a short window during embryogenesis of Xenopus laevis. The mRNA for this gene can be first detected just after midblastula, peaks at late gastrula, and decays by the end of neurulation. The sequence of the DG42 cDNA and genomic DNA predicts a 70,000-Da protein that is not related to any other known protein. Antibodies prepared against portions of the DG42 open reading frame that had been expressed in bacteria detected a 70,000-Da protein in the embryo with a temporal course of appearance and decay that follows that of the RNA by several hours. Localization of the mRNA in dissected embryos and immunohistochemical detection of the protein showed that DG42 expression moves as a wave or gradient through the embryo. The RNA is first detected in the animal region of the blastula, and by early gastrula is found everywhere except in the outer layer of the dorsal blastopore lip. By midgastrula DG42 protein is present in the inner ectodermal layer and the endoderm; it disappears from dorsal ectoderm as the neural plate is induced and later decays in a dorsoventral direction. The last remnants of DG42 protein are seen in ventral regions of the gut at the tailbud stage.
authors.affiliation: Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
authors.forename: F
authors.initials: F
authors.lastname: Rosa
authors.forename: T D
authors.initials: TD
authors.lastname: Sargent
authors.forename: M L
authors.initials: ML
authors.lastname: Rebbert
authors.forename: G S
authors.initials: GS
authors.lastname: Michaels
authors.forename: M
authors.initials: M
authors.lastname: Jamrich
authors.forename: H
authors.initials: H
authors.lastname: Grunz
authors.forename: E
authors.initials: E
authors.lastname: Jonas
authors.forename: J A
authors.initials: JA
authors.lastname: Winkles
authors.forename: I B
authors.initials: IB
authors.lastname: Dawid
mesh_terms: D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000378:metabolism; D004247:DNA / Q000235:genetics; D004475:Ectoderm / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons; D005775:Gastrula / Q000378:metabolism; D016695:Glycosyltransferases; D006651:Histocytochemistry; D007118:Immunoassay; D007438:Introns; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014018:Tissue Distribution; D014158:Transcription, Genetic; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000196:embryology*
chemical_list: D008565:Membrane Proteins; D011506:Proteins; D012333:RNA, Messenger; D029867:Xenopus Proteins; D004247:DNA; D016695:Glycosyltransferases; C056944:HAS1 protein, Xenopus