Biomaterial Database

Estrogen withdrawal in chick oviduct. Characterization of RNA synthesized in isolated nuclei using a mercurated precursor. 1978

S Mizuno, and N A Tallman, and R F Cox

1. As a prerequisite for analyzing the effect of estrogen on transcription in chick oviduct, we describe suitable methods for the synthesis (under conditions restricting reinitiation), and isolation of RNA transcripts from oviduct nuclei in vitro, utilizing mercurated UTP (Hg-UTP) as an RNA precursor and chromatography on sulphydryl-Sepharose (SH-Sepharose) to recover mercurated RNA (Hg-RNA). The techniques described include treatment of Hg-RNA with p-hydroxymercuribenzoate, to improve the efficiency of binding to SH-Sepharose, and elution of Hg-RNA from SH-Sepharose after treatment with 60% formamide at 90 degrees C, to eliminate contamination by aggregated nucleic acid. 2. RNA synthesized by endogenous form B RNA polymerase (using either UTP or Hg-UTP as precursor) was recovered in nuclear lysates in the form of 30--85-S heterogeneous RNA . protein complexes, and after removal of protein, was 10--12 S in size. 3. The nature of RNA transcripts synthesized in vitro was examined by hybridization. More than 90% of the RNA was complementary to "unique" DNA sequences, and 50--60% of the hybridized RNA could be competed with homologous, steady-state nuclear RNA, indicating a significant degree with homologous, steady-state nuclear RNA, indicating a significant degree of homology between in vitro transcripts and in vivo RNA. The level of homology was similar whether RNA synthesis was performed in low salt, or in high salt in the presence of heparin. Possible reasons for only partial competition in these experiments are discussed. 4. Withdrawal of estrogen from chicks leads to a 50% reduction in endogenous RNA polymerase activities in nuclei within 48 h. Similar levels of competition with Hg-RNA transcripts for "unique" DNA were obtained using oviduct nuclear RNAs isolated before or after estrogen withdrawal, and even with liver nuclear RNA. Thus, in oviduct, those sequences present in primary transcripts, and analyzed under our experimental conditions, are present in different hormonal states and also in other chick tissues.

UI	MeSH Term	Description	Entries
D008628	Mercury	A silver metallic element that exists as a liquid at room temperature. It has the atomic symbol Hg (from hydrargyrum, liquid silver), atomic number 80, and atomic weight 200.59. Mercury is used in many industrial applications and its salts have been employed therapeutically as purgatives, antisyphilitics, disinfectants, and astringents. It can be absorbed through the skin and mucous membranes which leads to MERCURY POISONING. Because of its toxicity, the clinical use of mercury and mercurials is diminishing.
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D010057	Oviducts	Ducts that serve exclusively for the passage of eggs from the ovaries to the exterior of the body. In non-mammals, they are termed oviducts. In mammals, they are highly specialized and known as FALLOPIAN TUBES.	Oviduct
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D002645	Chickens	Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.	Gallus gallus,Gallus domesticus,Gallus gallus domesticus,Chicken
D005260	Female		Females
D006160	Guanosine Triphosphate	Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.	GTP,Triphosphate, Guanosine
D006589	Hexestrol	A synthetic estrogen that has been used as a hormonal antineoplastic agent.	Dihydrodiethylstilbestrol,Hexestrol, (R,R)-(+-)-Isomer,Hexestrol, (R,S)-Isomer,Hexestrol, (R-(R,R))-Isomer,Hexestrol, (S-(R,R))-Isomer
D006902	Hydroxymercuribenzoates	Hydroxylated benzoic acid derivatives that contain mercury. Some of these are used as sulfhydryl reagents in biochemical studies.