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RADIOAUTOGRAPHIC STUDIES IN SYNCHRONIZED CULTURES OF OEDOGONIUM CARDIACUM
Author(s) -
Banerjee S. N.,
Horsley R. J.
Publication year - 1968
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1968.tb07406.x
Subject(s) - biology , dna synthesis , zoospore , dna , nucleus , biochemistry , bacteria , cell cycle , thymidine , cell division , botany , cell , microbiology and biotechnology , spore , genetics
Synthesis of deoxyribonucleic acid (DNA) in synchronized cultures of Oedogonium cardiacum has been studied by radioautography. The germinated zoospores are pulse‐labelled for 15 min with thymidine‐2‐C 14 . Use of penicillin in the medium reduces the background in the radioautographs by suppressing the growth of bacteria on Oedogonium cells. Incorporation of labelled precursor is greatly enhanced by growing the cells in a conditioned inorganic medium. The length of the DNA synthesis period (S), as estimated from the curve of percentage of labelled cells versus age during the first cell cycle is about 5‐7 hr. The rate of labelling in the nucleus is non‐uniform showing a dip during the mid S period. Concomitant with the doubling of DNA in the nucleus a fourfold increase in the nuclear volume is observed.