Galactokinase-deficient mutants of Tetrahymena thermophila: Selection and characterization

Charles Roberts, Daniel E. Morse

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

We have isolated a series of mutants of Tetrahymena thermophila which are resistant to inhibition of growth by the galactose analog, 2-deoxygalactose. These mutants were obtained after mutagenesis with nitrosoguanidine and the induction of cytogamy to permit the recovery of recessive mutations induced in the germline micronucleus. Resistance to 2-deoxygalactose is correlated with a decreased rate of growth in galactose minimal medium and greatly reduced levels of galactokinase. The resistant phenotype of the mutants is apparently due to the galactokinase deficiency, which prevents the accumulation of toxic phosphorylated metabolites of 2-deoxygalactose. Genetic analyses reveal that the 2-deoxygalactose resistance alleles segregate as single Mendelian loci. The galactokinase-deficient strains described here represent the first mutants in this organism for which the biochemical basis of the mutant phenotype is known. These mutants, as well as others isolated similarly, should be of value in the elucidation of the mechanisms governing galactokinase gene regulation and in improving techniques of selection for other recessive mutations in Tetrahymena.

Original languageEnglish (US)
Pages (from-to)129-134
Number of pages6
JournalMGG Molecular & General Genetics
Volume180
Issue number1
DOIs
StatePublished - Nov 1980
Externally publishedYes

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Galactokinase
Tetrahymena thermophila
Fucose
Galactose
Germline Micronucleus
Galactosemias
Nitrosoguanidines
Phenotype
Tetrahymena
Mutation
Poisons
Growth
Mutagenesis
Alleles
Genes

ASJC Scopus subject areas

  • Genetics

Cite this

Galactokinase-deficient mutants of Tetrahymena thermophila : Selection and characterization. / Roberts, Charles; Morse, Daniel E.

In: MGG Molecular & General Genetics, Vol. 180, No. 1, 11.1980, p. 129-134.

Research output: Contribution to journalArticle

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