Pseudo-exponential growth in length of the fission yeast, Schizosaccharomyces pombe.
The growth patterns of individual cells of the fission yeast (Schizosaccharomyces pombe wild-type cells, strain 972 h-; cells exposed to hydroxyurea; and cdc mutants, 11-123, 2-33) were investigated by time-lapse photomicrography. Wild-type cells showed one, two, or three linear-growth segments followed by a constant-length stage. Cells with two segments were most frequent. Hydroxyurea cells that divided as oversized cells (about three times the birth length) had three linear-growth segments in a cycle. Mutant cdc11-123 cells did not divide but had a constant-length stage separating the cycles; both the first and second cycles consisted of two linear-growth segments, and cells were oversized at the second constant-length stage (about 3.5 times the birth length). Elongating cdc2-33 cells that did not divide and were oversized (about five times the birth length) while under observation, showed four linear-growth segments. Cells of all strains showed 30 to 40% increase in growth rate at the rate-change point and maintained approximate exponential (pseudo-exponential) growth. We conclude that the normal growth pattern of individual fission-yeast cells is the pseudo-exponential pattern.
Miyata
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Division of Biological Sciences, National Research Council of Canada, Ottawa, Ont.
Miyata
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Johnson
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D006918:Hydroxyurea / Q000494:pharmacology; D007700:Kinetics; D009154:Mutation; D004718:Saccharomycetales / Q000254:growth & development*; D012568:Schizosaccharomyces / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*
D006918:Hydroxyurea