Bradshaw, Sasha;
(2025)
Fitness, Trade-offs and Life History: Phenotypic Effects of X-linked Meiotic Drive in the Malaysian Stalk-eyed Fly Teleopsis dalmanni.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
This thesis investigates the phenotypic effects of X-linked meiotic drive (SR) in the Malaysian stalk-eyed fly, Teleopsis dalmanni. This selfish genetic element destroys Ybearing sperm in affected males, leading to broods that are up to 100% female-biased. Genomic inversions on the X chromosome maintain linkage between the genes contributing to meiotic drive, as well as permitting higher rates for the accumulation of deleterious mutations. It is predicted that these manifest as ‘costs’ in SR drive carriers, as documented in other meiotic drive systems. Some have already been characterised in this species (e.g., reduced fecundity and reduced egg-to-adult viability) and are indicative of reduced fitness. The first chapter explores the extent to which drive males suffer by investigating reproductive and morphological traits, in particular, testes and accessory glands development, alongside trade-offs with eyespan. The next chapter investigates the underlying mechanisms at the physiological level. Metabolism is an important life history trait and is relatively understudied in the context of meiotic drive, though some notable discoveries in the t haplotype system in mice have paved the way for this research. This chapter considers how mitochondrial function, respiration and diet consumption are affected by pleiotropic mutational load in the genome of SR carriers. The following chapter analyses field data from wild populations of stalk-eyed flies in Ulu Gombak, Peninsular Malaysia, to assess whether meiotic drive influences the dynamics of sexual selection, demography and morphological characteristics in natural populations. The thesis concludes with a review of the literature on the sister species Teleopsis whitei, which also exhibits meiotic drive and observable sex ratio bias in the progeny. A methodological approach is described to isolate individuals with meiotic drive, with the aim of establishing a breeding line of SR carriers in the laboratory for future experimentation.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Fitness, Trade-offs and Life History: Phenotypic Effects of X-linked Meiotic Drive in the Malaysian Stalk-eyed Fly Teleopsis dalmanni |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2025. 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 > 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 UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences > Genetics, Evolution and Environment UCL |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10211449 |
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