Format

Send to

Choose Destination
J Cell Sci. 1989 Aug;93 ( Pt 4):605-13.

Changes in the nuclear distribution of DNA polymerase alpha and PCNA/cyclin during the progress of the cell cycle, in a cell-free extract of Xenopus eggs.

Author information

1
Department of Genetics and Developmental Biology, School of Biological Sciences, University of Sussex, Brighton, UK.

Abstract

The nuclear distribution of DNA polymerase alpha and PCNA/cyclin in embryonic nuclei has been investigated, in a cell-free extract of Xenopus eggs that recapitulates a basic cell-cycle in vitro, by indirect immunofluorescence microscopy. Both antigens co-distribute with the chromatin in S-phase nuclei; however, as DNA replication is completed and nuclei progress into a G2 state anti-PCNA fluorescence disappears and anti-DNA polymerase alpha fluorescence becomes resolved into bright spots. These spots are initially associated with the chromatin strands and can be seen to share both anti-PCNA and anti-DNA polymerase alpha fluorescence, but as anti-PCNA fluorescence fades the spots become dissociated from the chromatin and are redistributed throughout the nucleus until they are dispersed during nuclear envelope breakdown. The loss of anti-PCNA fluorescence and displacement of anti-DNA polymerase alpha fluorescence from the chromatin can be prevented by inhibiting DNA synthesis with aphidicolin. Under these conditions both antigens remain associated with the chromatin even after nuclear envelope breakdown and lamin dispersal. The association of these antigens with mitotic figures appears to be functional, as both biotin-11-dUTP and [32P]dCTP can be incorporated efficiently into DNA during the mitotic period.

PMID:
2575094
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center