Amy Osborne, Sarah Morgan, Praneeta Ramsey and Peter Dearden
University of Otago, Dunedin
Developmental pathways are established in early life and differences in these pathways can influence response to environmental exposure during adulthood. For example, a fetus exposed to signals of nutritional deficiency will set its metabolic trajectory to expect such an environment; the fetus has predicted its future environment in response to maternal cues, known as a predictive adaptive response (PAR). If this prediction is incorrect (and the offspring is biologically mismatched to its environment), the individual’s response to later environmental exposures can be affected, either positively or negatively. This has been demonstrated in many species, and advantages gained from the predictive adaptive response are able to persist across generations; if the environment remains constant, the predictive trait may become fixed (genetic assimilation).
Here we use the fruitfly Drosophila melanogaster to investigate PARs and the specific mechanisms that lead to transgenerational inheritance of the resulting traits. We are manipulating the diet of D. melanogaster by altering the carbohydrate and protein ratios of their food whilst maintaining constant caloric content. We are using quantitative PCR to investigate differential gene expression resulting from this manipulation in the F1 and F2 generations, on both matched and mismatched diets, to enable assessment of the nature of the PAR and consequences for correct and incorrect prediction. This work also extends to the F3 generation and beyond. Our research will provide us with a phenotype through which to investigate the exact genetic nature of the PAR mechanism via whole transcriptome sequencing.
Results from these experiments will be integral in understanding how transduction of environmental cues from mother to offspring can elicit a genetic response and how this can be maintained through the germ line to the F2 generation, F3 and beyond. Crucially, these data will provide an insight into how development can influence future health outcomes, aiding the understanding of the developmental origins of health and disease.