- THIS ARTICLE
- Full Text
- Full Text (PDF)
-
All Versions of this Article:
genetics.104.027102v1
169/4/1825 most recent - Alert me when this article is cited
- Alert me if a correction is posted
- SERVICES
- Similar articles in this journal
- Similar articles in PubMed
- Alert me to new issues of the journal
- Download to citation manager
- Reprints & Permissions
- CITING ARTICLES
- Citing Articles via HighWire
- Citing Articles via Google Scholar
- GOOGLE SCHOLAR
- Articles by Zeyl, C.
- Search for Related Content
- PUBMED
- PubMed Citation
- Articles by Zeyl, C.
Originally published as Genetics Published Articles Ahead of Print on March 2, 2005.
Genetics, Vol. 169, 1825-1831, April 2005, Copyright © 2005
doi:10.1534/genetics.104.027102
The Number of Mutations Selected During Adaptation in a Laboratory Population of Saccharomyces cerevisiae
Clifford Zeyl1
Department of Biology, Wake Forest University, Winston-Salem, North Carolina 27109
1 Address for correspondence: Department of Biology, Wake Forest University, P.O. Box 7325, Winston-Salem, NC 27109.
E-mail: zeylcw{at}wfu.edu
There is currently limited empirical and theoretical support for the prevailing view that adaptation typically results from the fixation of many mutations, each with small phenotypic effects. Recent theoretical work suggests that, on the contrary, most of the phenotypic change during an episode of adaptation can result from the selection of a few mutations with relatively large effects. I studied the genetics of adaptation by populations of budding yeast to a culture regime of daily hundredfold dilution and transfer in a glucose-limited minimal liquid medium. A single haploid genotype isolated after 2000 generations showed a 76% fitness increase over its ancestor. This evolved haploid was crossed with its ancestor, and tetrad dissections were used to isolate a complete series of six meiotic tetrads. The Castle-Wright estimator of the number of loci at which adaptive mutations had been selected, modified to account for linkage and variation among mutations in the size of their effect, is 4.4. The estimate for a second haploid genotype, isolated from a separate population and with a fitness gain of 60%, was 2.7 loci. Backcrosses to the ancestor with the first evolved genotype support the inference that adaptation resulted primarily from two to five mutations. These backcrosses also indicated that deleterious mutations had hitchhiked with adaptive mutations in this evolved genotype.
This article has been cited by other articles:
 |
|
 |
|
  L. Perfeito, L. Fernandes, C. Mota, and I. Gordo Adaptive Mutations in Bacteria: High Rate and Small Effects Science, August 10, 2007; 317(5839): 813 - 815. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. A. Hill and S. P. Otto The Role of Pleiotropy in the Maintenance of Sex in Yeast Genetics, March 1, 2007; 175(3): 1419 - 1427. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Sliwa and R. Korona Loss of dispensable genes is not adaptive in yeast PNAS, December 6, 2005; 102(49): 17670 - 17674. [Abstract] [Full Text] [PDF]
|
|