Predictive Adaptive Responses are changes in development made in the perinatal period in response to maternally transmitted information, and a mismatch between the diet selected during human evolution and the contemporary Western diet can produce an adult phenotype characterised by weight gain, cardiovascular disease, hypertension and diabetes. In humans, most evidence is epidemiological. Using Drosophila melanogaster, the problem can be approached from an adaptive phenotypic plasticity perspective. Health effects in humans stem from predictive adaptations made to enhance fitness and so it must first be shown that D. melanogaster make these responses. To model the human dietary transition, two equivalent fly diets were designed, one a human Palaeolithic diet and the other a contemporary Western diet. Using isofemale lines, flies were swapped between diets over three generations and fitness indicators measured in the offspring generation. Fitness indicator responses to a range of diets differing in protein: carbohydrate ratio and total macronutrient content were also investigated. There were adaptive, compensatory effects on survival rate and male thorax size from parental diet, and development time from grandparental diets, but also non-adaptive effects on development time and female thorax size from the parental diets. Higher dietary protein: carbohydrate ratios reduced development time and increased thorax size and survival rate, while increased macronutrient content increased weight, lipid content and survival. Diet had no effect on ommatidia number relative to fly size. Whether a response to diet is predictive and adaptive depends not only on diet composition, but whether offspring, parents or grandparents consumed the diet, the phenotypic character measured and the genotype of the fly. The variety of responses in relation to parental and grandparental diets show that intergenerational effects are complex, and D. melanogaster is a suitable model to help unravel the causes of human diseases.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:560811 |
| Date | January 2011 |
| Creators | Shannon, Roger |
| Contributors | Kraaijeveld, Alex ; Newland, Philip |
| Publisher | University of Southampton |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://eprints.soton.ac.uk/338975/ |
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