RNA polymerase activity in PtK1 micronuclei containing individual chromosomes: an in vitro and in situ study

Journal Article · Sun Mar 01 00:00:00 EST 1987 · Exp. Cell Res.; (United States)

DOI:https://doi.org/10.1016/0014-4827(87)90241-2· OSTI ID:6526161

Labidi, B; Gregoire, M; Frackowiak, S; Hernandez-Verdun, D; Bouteille, M

Micronuclei have been induced by colchicine in rat kangaroo (Potorous tridactylis) PtK1 cells. The synthesis of RNA was investigated both in isolated micronuclei by quantifying RNA polymerase activities at different ionic strengths with or without inhibitors, and in micronucleated cells by radioautography after (/sup 3/H)uridine pulse labeling. In vitro transcription shows that isolated micronuclei are able to take up (/sup 3/H)UTP. The rate curves of incorporation are close to those of isolated diploid nuclei, though the level of incorporation was relatively lower (65-70%) than control nuclei. This indicates that micronuclei react to the ionic environment and to inhibitors in the same manner as described for many species of isolated diploid nuclei. The labelling distributions plotted from radioautographs show that micronuclei were able to efficiently incorporate the hot precursor. Furthermore, for short pulses there is no homogeneity in the labelling density among the different micronuclei and there is no correlation between the labelling intensity and the size of micronuclei. After 60-min pulse time, there is an enhanced uptake of (/sup 3/H)uridine and all the micronuclei exhibit considerable labelling, although less than control cells. Thus, the micronuclei exhibit some characteristic RNA transcriptional activity in situ as well as after isolation. This material should be a particular interesting model with which to study the physiological activity and the role of each individual interphasic chromosome.

• Research Organization: Institut Biomedical des Cordeliers, Paris, France
• OSTI ID: 6526161
• Journal Information: Exp. Cell Res.; (United States), Vol. 169:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
AUTORADIOGRAPHY
CELL NUCLEI
ENZYME ACTIVITY
RNA POLYMERASES
BIOCHEMISTRY
COLCHICINE
IN VITRO
IN VIVO
TRITIUM COMPOUNDS
URIDINE
ALKALOIDS
ANTIMITOTIC DRUGS
ANTIPYRETICS
AZINES
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
CHEMISTRY
DRUGS
ENZYMES
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
LABELLED COMPOUNDS
NUCLEOSIDES
NUCLEOTIDES
NUCLEOTIDYLTRANSFERASES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
POLYMERASES
PYRIMIDINES
RIBOSIDES
TRANSFERASES
URACILS
550201* - Biochemistry- Tracer Techniques