title: Characterization of RNA polymerase II-dependent transcription in Xenopus extracts.
abstract: We examine the RNA polymerase II-dependent transcription directed by several promoters in extracts prepared from distinct developmental stages of Xenopus laevis. RNA polymerase II accurately initiates transcription from the cytomegalovirus, herpes simplex virus thymidine kinase, and Xenopus heat-shock protein (hsp) 70 promoters. The efficiency of transcription of these different promoters is dependent on whether extracts from oocytes, eggs, or somatic cells are used and on the temperature of incubation. In contrast to the viral promoters, the hsp 70 promoter is more active at heat shock temperatures in oocyte and egg extracts (31 degrees-34 degrees C) than at physiological temperatures for Xenopus (20 degrees-25 degrees C). These in vitro transcription extracts should be useful in examining the molecular mechanisms responsible for differential gene expression during Xenopus development.
authors.affiliation: Laboratory of Molecular Embryology, National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: T
authors.initials: T
authors.lastname: Toyoda
authors.forename: A P
authors.initials: AP
authors.lastname: Wolffe
mesh_terms: D000818:Animals; D001483:Base Sequence; D002457:Cell Extracts / Q000737:chemistry; D002474:Cell-Free System; D004330:Drosophila / Q000378:metabolism; D006360:Heat-Shock Proteins; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D010063:Ovum / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000032:analysis*; D014158:Transcription, Genetic; D014982:Xenopus laevis / Q000196:embryology*
chemical_list: D002457:Cell Extracts; D006360:Heat-Shock Proteins; D012319:RNA Polymerase II