Superproduction of heavy minicircular mitochondrial DNA in aging wheat coleoptiles.
On incubation of 7-day-old wheat seedlings in the presence of [3H]thymidine, the radioactivity incorporated into coleoptile DNA is found to be localized mainly (greater than 95%) in the fraction of heavy mitochondrial DNA (H-mt DNA; rho = 1.716 gm/cm3). Upon long (48-72 h) incubation of cut-off seedlings in water, the amount of this DNA shows a dramatic increase and corresponds to about 10% of the total coleoptile DNA. H-mtDNA is represented by open circular molecules with a contour length varying from 0.12 to 0.6 microns. The functional role of this DNA is still unknown.
Kirnos
M D
MD
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, USSR.
Alexandrushkina
N I
NI
Zagorskaya GYa
Kireev
I I
II
Vanyushin
B F
BF
D004270:DNA, Circular / Q000378:metabolism*; D004272:DNA, Mitochondrial / Q000378:metabolism*; D004587:Electrophoresis, Agar Gel; D008854:Microscopy, Electron; D008970:Molecular Weight; D014908:Triticum / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure
D004270:DNA, Circular; D004272:DNA, Mitochondrial