Open AccessFlow cytometric investigation of heterogeneous copper‐sensitivity in asynchronously grown Saccharomyces cerevisiae
Author(s) -
Howlett Niall G.,
Avery Simon V.
Publication year - 1999
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1999.tb13687.x
Subject(s) - saccharomyces cerevisiae , propidium iodide , cell cycle , flow cytometry , biophysics , sensitivity (control systems) , reactive oxygen species , biology , cell , copper , chemistry , analytical chemistry (journal) , yeast , biochemistry , microbiology and biotechnology , apoptosis , chromatography , programmed cell death , electronic engineering , engineering , organic chemistry
The variable stress‐sensitivity of individual cells within pure cultures is widely noted but generally unexplained. Here, factors determining the heterogeneous susceptibility to copper toxicity in Saccharomyces cerevisiae were examined with a rapid non‐perturbing approach based on flow cytometry. By determination of the DNA content (with propidium iodide) in cell fractions gated by forward angle light scatter (an indicator of the cell volume), it was shown that forward angle light scatter measurements gave an approximation of the cell cycle stage. Thus, our observation that cells in different forward angle light scatter fractions displayed differing Cu‐sensitivities indicated that heterogeneous Cu‐sensitivity is a function of the cell cycle stage. Furthermore, cells sorted by their Cu‐sensitivity and ‐resistance and subsequently analyzed for DNA content were found predominantly to occupy G 1 /S and G 2 /M cell cycle stages, respectively. The oxidant‐sensitive probe 2′,7′‐dichlorodihydrofluorescein diacetate was used to show that the Cu‐sensitivity of G 2 /M phase S. cerevisiae was correlated with greater levels of pre‐existing reactive oxygen species in these cells. The results indicate that differential Cu‐sensitivity in a S. cerevisiae culture is linked to the cell cycle stage and this link may be determined partly by cell cycle‐dependent fluctuations in basal reactive oxygen species generation.