Journal
JOURNAL OF EVOLUTIONARY BIOLOGY
Volume 14, Issue 1, Pages 157-170Publisher
WILEY-BLACKWELL
DOI: 10.1046/j.1420-9101.2001.00245.x
Keywords
cell geometry; competition experiments; fitness; growth rate; nutrient limitation; ploidy; temperature; yeast
Categories
Ask authors/readers for more resources
The nutrient limitation hypothesis provides a nongeneric explanation for the evolution of life cycles that retain both haploid and diploid phases: differences in nutrient requirements and uptake allow haploids to override the potential genetic advantages provided by diploidy under certain nutrient limiting conditions. The relative fitness of an isogenic series of haploid, diploid and tetraploid yeast cells (Saccharomyces cerevisiae), which were also equivalent at the mating type locus, was measured. Fitness was measured both by growth rate against a common competitor and by intrinsic growth rate in isolated cultures, under four environmental conditions: (1) rich medium (YPD) at the preferred growth temperature (30 degreesC); (2) nutrient poor medium (MM) at 30 degreesC; (3) YPD at a nonpreferred temperature (37 degreesC); and (4) MM at 37 degreesC. In contrast to the predictions of the nutrient limitation hypothesis, haploids grew significantly faster than diploids under nutrient rich conditions, but there were no apparent differences between them when fitness was determined by relative competitive ability. In addition, temperature affected the relative growth of haploids and diploids, with haploids growing proportionately faster at higher temperatures. Tetraploids performed very poorly under all conditions compared. Cell geometric parameters were not consistent predictors of fitness under the conditions measured.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available