Details of Award
NERC Reference : NE/B500190/1
Genome-wide approaches to fitness and speciation in yeast.
Fellowship Award
- Fellow:
- Professor D Delneri, The University of Manchester, Life Sciences
- Grant held at:
- The University of Manchester, Life Sciences
- Science Area:
- Terrestrial
- Overall Classification:
- Terrestrial
- ENRIs:
- Biodiversity
- Science Topics:
- Environmental Microbiology
- Environmental Genomics
- Population Genetics/Evolution
- Systematics & Taxonomy
- Abstract:
- Thanks to its versatile nature, Saccharomyces cerevisiae is an excellent experimental model for biological and medical studies, including environmental and functional genomics analyses. S. cerevisiae has also become a model organism for pioneering studies on speciation and genome evolution. The availability of vast amounts of sequence information from the genomes of closely related yeast species provide a unique opportunity for an in-depth analysis of genetic redundancy, conservation of synteny and gene order in the hemiascomycete yeasts. Moreover, new theories of the polyploid origin of the yeast genome have been proposed. The genus Saccharomyces includes seven Saccharomyces 'sensu stricto' species, that exhibits inter-mating ability (they are all able to mate with one another, but the resulting hybrids are sterile). However, several chromosomal translocations have been found in the genomes of these species. According to the chromosomal speciation theory, some kinds of karyotypic rearrangement may play an active role in the speciation process, acting as post-zygotic barriers. Surprisingly, most of the translocations occurred between closely related species (with more distant ones having collinear genomes), suggesting that chromosomal rearrangements are not a prerequisite for speciation in yeast, but may intensify the reproductive isolation between species without playing a causal role in their generation. Recent studies showed that imposed genomic collinearity between two Saccharomyces 'sensu stricto' species, initially differing by one or two translocations, allowed the generation of hybrids able to produce a large proportion of spores that are viable, although extensively aneuploid. Genomic rearrangements in yeast populations have also often been observed as a response to selective environmental pressures and similar karyotypic changes were found to recur in different strains. I propose to establish whether gross karyotypic rearrangements (mainly translocations) have adaptive value in asexually propagated yeast populations. I intend to engineer genotypes differing only by specific chromosomal rearrangements to analyse relationships between genotype, phenotype and fitness. Competition experiments will be performed, in six different chemostat cultures (glucose-limited aerobic and anaerobic, ethanol-limited, ammonium-limited, phosphate-limited and sulphate-limited). It would be interesting to define whether some translocations are more advantageous (or disadvantageous) than others under different environmental stresses, and to observe whether there is anything particularly favourable about the karyotypes found in the existing Saccharomyces 'sensu stricto' species. If natural selection is recapitulated, there should be a domination of genotypes matching those of the present-day species, in one or more of the physiological contexts. The relative fitness of the selected rearranged strains will then be assessed in different limited resources, and transcriptome experiments will be carried out under the same environmental conditions. This should bring insights into which molecular events are involved in adaptation and suggest candidate genes that are of particular evolutionary significance. The generation of a large pool of different karyotypes will also offer the opportunity to investigate the structural role of chromosomal inversions in both the genome shuffling and process of yeast speciation. Previous studies on the relationship between genome collinearity and hybrid fertility generated viable spores, that were extensively aneuploid. However, it is still unclear whether this aneuploidy occurred during the formation of the zygote or during the meiotic process (chromosome loss events may have happened before, during, or after meiosis). Therefore, I plan to perform a detailed molecular genetic analysis on the aneuploid spores from the hybrid zygotes derived from crosses between species with imposed genome ...
- NERC Reference:
- NE/B500190/1
- Grant Stage:
- Completed
- Scheme:
- Advanced Fellow
- Grant Status:
- Closed
- Programme:
- Advanced Fellow
This fellowship award has a total value of £289,887
FDAB - Financial Details (Award breakdown by headings)
| Total - Staff | Total - Other Costs |
|---|---|
| £234,886 | £55,000 |
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