Higgins, Andrew James;
(2021)
Experimental evolution of environment dependent gene regulation.
Masters thesis (M.Phil), UCL (University College London).
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Abstract
The effects of environment on evolution can be explored by experimentally controlling the environment experienced by a population. Data can be collected continuously on evolutionary change and related to the experimental environment. Further, the controlled conditions allow theoretical predictions to be tested. This thesis reports on the development of two experimental evolution systems that can be used to investigate the effects of environmental change on the evolution of gene regulation. In both systems the fission yeast Schizosaccharomyces pombe grows under defined selection pressures in two alternating environments. Conditions in both environments are under tight control, with one selecting positively for expression of a target gene, and the other selecting negatively against expression. Alternating growth between the two environments creates a selection pressure for environment dependent regulation of the gene. This is an example of phenotypic plasticity – an environment dependent phenotypic change. Thus, the two systems can be used to investigate phenotypic plasticity and gene regulation, including testing of related theories. The first system targets the expression of the ura4 gene. This gene is necessary for the production of uracil, so an environment lacking uracil selects strongly for expression. The alternate environment contains the compound 5-fluoroorotic acid (FOA) which is metabolised by URA4 into a toxin, thus strongly selecting against expression. The second system targets the expression of an introduced green fluorescent protein (GFP) gene using fluorescence activated cell sorting (FACS). The sorting can alternately select for high and low expressing cells from a population. Environmental conditions between the sorts can be altered to provide a cue for the selection the population will face next, thus allowing evolution of environment dependent expression. Experimental work in developing and testing these systems is presented.
| Type: | Thesis (Masters) |
|---|---|
| Qualification: | M.Phil |
| Title: | Experimental evolution of environment dependent gene regulation. |
| Event: | UCL |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2021. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10122915 |
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