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Biomedical subjects

J C Game

Publications and source records attributed to J C Game.

25 records · Page 2Linked to original sources

Yeast cell-cycle mutant cdc21 is a temperature-sensitive thymidylate auxotroph.

Genetic tests with the yeast cell-cycle mutant cdc21 isolated by Hartwell indicate that the CDC21 gene in yeast is the same as the TMP1 gene, whose mutant alleles confer an auxotrophic requirement for thymidine-5'-monophosphate (dTMP). Yeast strains carrying cdc21 can grow at 37 degrees in the presence of dTMP provided that they are premeable to this compound. The gene is shown to be linked to ade2 on Chr. XV, and a case of intragenic complementation between cdc21 and another tmp1 allele is reported.

Cell Division↗

Yeast mutants sensitive to trimethoprim.

Wild-type strains of Saccharomyces cerevisiae are resistant to growth inhibition by the folate antagonist trimethoprim. A mutant strain sensitive to trimethoprim was isolated. It was found to be sensitive to both ultraviolet light and X-irradiation. Genetic tests revealed that it was allelic with a known radiation-sensitive strain of Saccharomyces cerevisiae, rad 6-I. Strains harbouring a variety of mutant alleles conferring radiation-sensitivity were tested for sensitivity to trimethoprim. It was found that rad 6-I and each of the four known alleles of rad 18 conferred sensitivity to the drug, but all other rad mutants tested were trimethoprim-resistant. All trimethoprim-sensitive strains, including double mutants of rad 6 rad 18, gave rise to trimethoprim-resistant outgrowths at a rather high frequency (similar to 10-minus 5). Several resistant outgrowths were analysed. A wide variation in phenotype with respect of UV-sensitivty was found. Genetical analysis revealed that resistance to trimethoprim resulted from forward mutations at separate loci rather than back mutations of rad 6 or rad 18 alleles.

Alleles↗