TY - JOUR
T1 - A cycloheximide-resistant mutant of Tetrahymena pyriformis
AU - Roberts, Ch T.
AU - Orias, E.
N1 - Funding Information:
Support for this research by USPHS grant GM 19290-01to E. 0. is gratefully acknowledged.
PY - 1973/10
Y1 - 1973/10
N2 - A mutant of Tetrahymena pyriformis, syngen 1, resistant to cycloheximide was obtained after mutagenesis (with N-methyl-N′-nitro-N-nitrosoguanidine) followed by a cross (to obtain macro-nuclear expression of the mutant phenotype). A genetic analysis has shown that cycloheximide resistance in the mutant strain is due to a dominant nuclear allele, designated chx-1. Heterozygotes ( chx-1 chx+) are initially resistant but segregate stable, sensitive cell lines during vegetative growth, demonstrating that allelic exclusion occurs with this determinant, as with many others in syngen 1. This feature, coupled with the selective advantage conferred by the chx-1 allele in the presence of cycloheximide, makes this mutation a useful genetic tool. A strain homozygous for the chx-1 allele exhibits an exponential growth rate identical to that of the wild type in proteose peptone-yeast extract medium in the absence of cycloheximide. In 10 μg/ml of the drug, the resistant cells grow at a somewhat lower rate, after an initial lag and adaptation to the presence of the drug. This concentration causes complete inhibition of growth and eventual lysis of wild-type cells. The cellular basis for cycloheximide resistance and adaptation in the mutant is presently under investigation.
AB - A mutant of Tetrahymena pyriformis, syngen 1, resistant to cycloheximide was obtained after mutagenesis (with N-methyl-N′-nitro-N-nitrosoguanidine) followed by a cross (to obtain macro-nuclear expression of the mutant phenotype). A genetic analysis has shown that cycloheximide resistance in the mutant strain is due to a dominant nuclear allele, designated chx-1. Heterozygotes ( chx-1 chx+) are initially resistant but segregate stable, sensitive cell lines during vegetative growth, demonstrating that allelic exclusion occurs with this determinant, as with many others in syngen 1. This feature, coupled with the selective advantage conferred by the chx-1 allele in the presence of cycloheximide, makes this mutation a useful genetic tool. A strain homozygous for the chx-1 allele exhibits an exponential growth rate identical to that of the wild type in proteose peptone-yeast extract medium in the absence of cycloheximide. In 10 μg/ml of the drug, the resistant cells grow at a somewhat lower rate, after an initial lag and adaptation to the presence of the drug. This concentration causes complete inhibition of growth and eventual lysis of wild-type cells. The cellular basis for cycloheximide resistance and adaptation in the mutant is presently under investigation.
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U2 - 10.1016/0014-4827(73)90520-X
DO - 10.1016/0014-4827(73)90520-X
M3 - Article
C2 - 4202358
AN - SCOPUS:0015808914
SN - 0014-4827
VL - 81
SP - 312
EP - 316
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 2
ER -