Details of Award
NERC Reference : NE/R010579/1
Sexual selection, condition dependence and meiotic drive
Grant Award
- Principal Investigator:
- Professor A Pomiankowski, University College London, Genetics Evolution and Environment
- Co-Investigator:
- Professor TA Burke, University of Sheffield, School of Biosciences
- Co-Investigator:
- Professor K Fowler, University College London, Genetics Evolution and Environment
- Grant held at:
- University College London, Genetics Evolution and Environment
- Science Area:
- Terrestrial
- Overall Classification:
- Panel C
- ENRIs:
- Biodiversity
- Science Topics:
- Animal reproduction
- Behavioural Ecology
- Evolution & populations
- Population Genetics/Evolution
- Environmental Genomics
- Abstract:
- In many species, females show strong sexual preferences to mate with particular males - those with elaborate and exaggerated sexual ornaments. These traits are thought to be honest signals of male genetic quality. But what is the nature of the "good genes" benefits that females derive from mate preference? We will address this fundamental question using the stalk-eyed fly, an iconic example of extreme sexually-selected morphological evolution. Male flies have greatly exaggerated eyespan and females prefer to mate with males with the most extreme eyespan. Of great interest, stalk-eyed flies harbour a selfish genetic element on the X chromosome that causes sex-ratio distortion through meiotic drive. In normal male meiosis, the X and Y chromosomes segregate equally into sperm. But the meiotic drive element produces a toxin that attacks the Y chromosome, causing Y-bearing sperm to die. So all sperm contain the drive X chromosome, and only female offspring are produced. Meiotic drive persists in populations of stalk-eyed flies because of the two-fold advantage the element gains in meiosis (it is passed on to all offspring, whereas other genes are only passed to half the offspring). But its spread is limited because it has overt deleterious effects on the fitness of the organism. Most obviously, it is bad because it kills half of a male's sperm. But it is also bad because the genes causing meiotic drive exist in an "inversion" - a part of the X chromosome that has been flipped around and is orientated in the opposite direction. Inversions cannot undergo normal processes like genetic recombination, and tend to accumulate deleterious mutations. We hypothesise that females gain benefits from avoiding mating with meiotic drive males, as they have low genetic quality. We will test the prediction that females discriminate against drive males. Preliminary work supports this, as drive males have small eyespan. We will investigate this further by exposing males to a range of environmental stresses that are typical of those experienced in the wild, to test whether the sexual ornament is an "honest" signal of genetic quality, in turn explaining why females use it to select a mate. We will characterise in depth how meiotic drive disrupts fertility (by measuring reproductive organ size, sperm allocation and sperm competition) and survival components of fitness, again under variable environmental stress. An interesting prediction is that the rest of the genome has evolved counter-adaptations to drive that will ameliorate loss of performance. We will investigate evidence for this at both the organismal and genomic levels. Evolutionary responses will be tracked at the sequence level by creating high-quality reference genomes of drive and non-drive chromosomes and investigating genomic signatures of changes that are deleterious or beneficial to fitness. Intensive laboratory experiments will be backed up by extensive field investigations of female mating behaviour and male trait distribution of drive-carrying flies in the wild, and how the frequency of drive varies with environmental stress under field conditions. All these strands contribute to our overarching goal: to show how sexual selection, on males and females, interacts with a chromosomal region with clear deleterious effects on organismal fitness.
- NERC Reference:
- NE/R010579/1
- Grant Stage:
- Completed
- Scheme:
- Standard Grant FEC
- Grant Status:
- Closed
- Programme:
- Standard Grant
This grant award has a total value of £633,554
FDAB - Financial Details (Award breakdown by headings)
| DI - Other Costs | Indirect - Indirect Costs | DA - Investigators | DI - Staff | DA - Estate Costs | DA - Other Directly Allocated | DI - T&S |
|---|---|---|---|---|---|---|
| £59,695 | £161,280 | £39,951 | £263,254 | £67,169 | £22,190 | £20,018 |
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