ISSN:
1432-0983
Keywords:
Schizosaccharomyces pombe
;
pH sensitivity
;
lacZ
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We report on a series of experiments inSchizosaccharomyces pombe to detect the blue-colour colony phenotype associated with expression of theEscherichia coli lacZ gene. Increasing the pH in solid minimal medium to optimize blue colony colour revealed a pH-sensitive phenotype in auxotrophic strains requiring uracil and leucine as external supplements. This phenotype was observed among commonS. pombe stock strains, 5-fluoroorotic acid (5-FOA)-selected strains, and random genetic segregants. Growth of prototrophicS. pombe strains 972 and 975 or the adenine auxotrophic strain NCYC 1860 were unaffected by an increase in external pH. Analysis of genetic segregants from three independent crosses indicated that a single auxotrophic marker (ura4 - orleu1-32) was sufficient for yeast cell-growth inhibition when the medium pH was increased above 6.6. In contrast, growth of aSaccharomyces cerevisiae strain isogenic to AH22, requiring uracil, leucine and histidine, was unaffected by changes in the pH of the medium. These observations suggest that uptake of uracil and leucine intoS. pombe cells is compromised by alterations in external pH. Our results have implications for detection of thelacZ gene-encoded bluecolour colony phenotype inS. pombe, which is optimized by growth in the presence of 5-bromo-4-chloro-3-indolyl-β-D-galactoside (Xgal) at pH 7.0. We discuss the conditions under which this blue-colour phenotype can be routinely observed inS. pombe.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02221514
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