Correlation of DNA synthesis and DNA polymerase activity in the developing chick heart

Journal Article · Tue Jan 01 04:00:00 EST 1974 · Dev. Biol.; (United States)

DOI:https://doi.org/10.1016/0012-1606(74)90174-2· OSTI ID:5192971

Doyle, C M; Zak, R; Fischman, D A

Net DNA synthesis continues throughout the embryonic development of chick ventricular tissue but the rate of DNA accumulation declines during the perinatal period. This slowing of DNA accumulation is paralleled by a decreased capacity of chick ventricular slices and of perfused whole hearts to incorporate /sup 3/H-thymidine into DNA. Synthesis of DNA by slices and whole hearts is completely inhibited by cytosine arabinoside (ara-C). At least two classes of DNA polymerase which are dependent upon exogenous DNA have been measured in the 100,000 g supernatant fraction of chick ventricular homogenates. The predominant polymerase, active with a denatured DNA primer, exhibits a decline in activity which is correlated with the fall-off in DNA synthesis in ventricular tissue. The activity of a second DNA polymerase, active with a native DNA primer, remains constant throughout the developmental stages examined. The decrease in polymerase activity with a denatured DNA primer cannot be ascribed to soluble inhibitors of the polymerase or to detectable DNase activity in older myocardial tissue. Several characteristics of the crude enzyme have been examined, including primer and substrate dependence, glycerol and magnesium ion optima, and enzyme inhibition with N-ethylmaleimide (NEM) and 1-..beta..-D-arabinofuranosylcytosine triphosphate (ara-CTP). Polymerase activity with denatured and native DNA primers is differentially susceptible to these reagents.

• Research Organization: Univ. of Chicago
• OSTI ID: 5192971
• Journal Information: Dev. Biol.; (United States), Journal Name: Dev. Biol.; (United States) Vol. 37; ISSN DEBIA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
BIRDS
BODY
CARDIOVASCULAR SYSTEM
CHICKENS
DNA
EMBRYOS
ENZYMES
FOWL
HEART
KINETICS
LABELLED COMPOUNDS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
POLYMERASES
PROTEIN DENATURATION
RADIOACTIVE MATERIALS
REACTION KINETICS
SYNTHESIS
TRITIUM COMPOUNDS
VERTEBRATES