Premium
LIFE‐HISTORY EVOLUTION AND DENSITY‐DEPENDENT GROWTH IN EXPERIMENTAL POPULATIONS OF YEAST
Author(s) -
Jasmin JeanNicolas,
Zeyl Clifford
Publication year - 2012
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.2012.01711.x
Subject(s) - biology , galactose , clone (java method) , yeast , saccharomyces cerevisiae , growth rate , population , yield (engineering) , genetic correlation , doubling time , genetics , genetic variation , biochemistry , gene , cell culture , demography , geometry , mathematics , materials science , sociology , metallurgy
We studied the evolution of the correlation between growth rate r and yield K in experimental lineages of the yeast Saccharomyces cerevisiae . First, we isolated a single clone every approximately 250 generations from each of eight populations selected in a glucose‐limited medium for 5000 generations at approximately 6.6 population doublings per day (20 clones per line × 8 lines) and measured its growth rate and yield in a new, galactose‐limited medium (with ∼1.3 doubling per day). For most lines, r on galactose increased throughout the 5000 generations of selection on glucose whereas K on galactose declined. Next, we selected these 160 glucose‐adapted clones in the galactose environment for approximately 120 generations and measured changes in r and K in galactose. In general, growth rate increased and yield declined, and clones that initially grew slowly on galactose improved more than did faster clones. We found a negative correlation between r and K among clones both within each line and across all clones. We provide evidence that this relationship is not heritable and is a negative environmental correlation rather than a genetic trade‐off.