Biomaterial Database

Inhibitor of ribosomal RNA synthesis in Xenopus laevis embryos. VII. Inhibition of 40s pre-rRNA synthesis in Xenopus neurula cells. 1984

K Shiokawa

A fraction containing acid-soluble materials (PCA-extract) from Xenopus early blastulae preferentially inhibits the incorporation of [3H]uridine into 18S and 28S rRNA in Xenopus neurula cells. Pulse- laneling experiments revealed that whereas tubercidin, a known inhibitor of rRNA processing, produced a marked accumulation of the label in 40S pre-rRNA, Xenopus inhibitor suppressed labeling of the pre-rRNA. When tubercidin was added to cells whose activity for rRNA synthesis had been lowered by the Xenopus inhibitor, there was still an accumulation of label in the pre-rRNA. These results indicate that Xenopus inhibitor suppresses the synthesis of rRNA at transcription rather than at processing.

UI	MeSH Term	Description	Entries
D001755	Blastocyst	A post-MORULA preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper.	Embryo, Preimplantation,Blastocysts,Embryos, Preimplantation,Preimplantation Embryo,Preimplantation Embryos
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
D012335	RNA, Ribosomal	The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)	Ribosomal RNA,15S RNA,RNA, 15S
D014020	Tissue Extracts	Preparations made from animal tissues or organs (ANIMAL STRUCTURES). They usually contain many components, any one of which may be pharmacologically or physiologically active. Tissue extracts may contain specific, but uncharacterized factors or proteins with specific actions.	Extracts, Tissue
D014158	Transcription, Genetic	The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.	Genetic Transcription
D014372	Tubercidin	An antibiotic purine ribonucleoside that readily substitutes for adenosine in the biological system, but its incorporation into DNA and RNA has an inhibitory effect on the metabolism of these nucleic acids.	7-Deazaadenosine,4-Amino-7 beta-D-ribofuranosyl-7H-pyrrolo(2,3-d)pyrimidine,Deazaadenosine,7 Deazaadenosine
D014982	Xenopus laevis	The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.	Platanna,X. laevis,Platannas,X. laevi