Biomaterial Database

Synthesis of heterogeneous nuclear RNA in full-grown oocytes of Xenopus laevis (Daudin). 1977

D M Anderson, and L D Smith

At various times following injection of either 3H-GTP or 32PO4 into full-grown (stage 6) Xenopus laevis oocytes, RNA has been extracted and fractionated on polyacrylamide gels. Based on size, base composition and incorporation data, we have defined the kinetics of synthesis and accumulation of ribosomal RNA (40S, 28S, 18S), heterogeneous RNA of high molecular weight (greater than 40S) and heterogeneous RNA migrating with molecular weights of from 4S to 40S. Nuclear isolations have been performed to determine the cellular distribution of these classes of RNA as a function of time. Evidence is presented which shows that stage 6 oocytes synthesize RNA which by virtue of its size, base composition, rapid turnover and nuclear location is equivalent to the heterogeneous nuclear RNA observed in somatic cells. In addition, the data suggest synthesis of a class of nuclear RNA with a half-life of several hours. A small fraction (5%) of the nuclear RNA is stable, enters the cytoplasm and may represent RNA added to the stockpile of maternal transcripts known to be present in stage 6 oocytes.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009865	Oocytes	Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).	Ovocytes,Oocyte,Ovocyte
D010063	Ovum	A mature haploid female germ cell extruded from the OVARY at OVULATION.	Egg,Egg, Unfertilized,Ova,Eggs, Unfertilized,Unfertilized Egg,Unfertilized Eggs
D003596	Cytosine	A pyrimidine base that is a fundamental unit of nucleic acids.
D005260	Female		Females
D006147	Guanine
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012313	RNA	A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	RNA, Non-Polyadenylated,Ribonucleic Acid,Gene Products, RNA,Non-Polyadenylated RNA,Acid, Ribonucleic,Non Polyadenylated RNA,RNA Gene Products,RNA, Non Polyadenylated