ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The effects of the protein synthesis inhibitors trichodermin and anisomycin on the growth of the eucaryotic myxomycete Physarum polycephalum have been examined. When either of these drugs is added to log phase monoxenic cultures of myxamoebae, cell division is immediately arrested, but on continued incubation, growth resumes at a rate only slightly lower than that of drug free cultures. The length of the drug induced growth lag is roughly proportional to drug concentration. When adapted cells are transferred to fresh drug containing medium, growth is not inhibited. However, if the drug concentration is increased, transient inhibition is again exhibited. Measurement of the antibiotic concentration in used media demonstrates no significant external inactivation of either drug during adaptation. The resumption of growth cannot be attributed to the selection of stable drug-resistant mutants: single amoebal colonies arising on drug plates are found to be as drug-sensitive as control colonies when retested after subculture. In addition, when adapted cells are transferred to drug free medium, the phenotypic drug-resistance is completely lost after several generations of growth. As recovery occurs in the continuous presence of drug and is not due to the accumulation of drug-resistant mutants, this response appears to be an example of drug adaptation. Cross adaptation between anisomycin and trichodermin is also demonstrated, suggesting a common system is involved in adaptation to these structurally dissimilar, but functionally similar, drugs.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1040920312
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