Cells of pea (Pisum sativum) that differentiate from G2 phase have extrachromosomal DNA
Velocity sedimentation in an alkaline sucrose gradient of newly replicated chromosomal DNA revealed the presence of extrachromosomal DNA that was not replicated by differentiating cells in the elongation zone. The extrachromosomal DNA had a number average molecular weight of 12 x 10/sup 6/ to 15 x 10/sup 6/ and a weight average molecular weight of 25 x 10/sup 6/, corresponding to about 26 x 10/sup 6/ and 50 x 10/sup 6/ daltons, respectively, of double-stranded DNA. The molecules were stable, lasting at least 72 h after being formed. Concurrent measurements by velocity sedimentation, autoradiography, and cytophotometry of isolated nuclei indicated that the extrachromosomal molecules were associated with root-tip-cells that stopped dividing and differentiated from G2 phase but not with those that stopped dividing and differentiated from G1 phase.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- OSTI ID:
- 6871574
- Journal Information:
- Mol. Cell. Biol.; (United States), Vol. 2:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DNA
MOLECULAR WEIGHT
DNA REPLICATION
MOLECULAR BIOLOGY
PISUM
CELL DIFFERENTIATION
AUTORADIOGRAPHY
CARBON 14 COMPOUNDS
CELL CYCLE
CHROMOSOMES
ROOTS
SEDIMENTATION
THYMIDINE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
AZINES
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEGUMINOSAE
NUCLEIC ACID REPLICATION
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PLANTS
PYRIMIDINES
RIBOSIDES
550201* - Biochemistry- Tracer Techniques