Stress is more than just busy days at work and not enough time. Animals and plants can also suffer from stress. Among the things that stresses them are unsuitable environmental conditions – such as extreme temperatures, but stress can also occur on the genetic level, for example in the form of inbreeding. This typically happens in small populations where there is a great risk of mating between closely related individuals.

The various stress factors can affect each other and make matters even worse. In the worst case, stress can threaten species survival.

More precisely how various stress factors affect animals and how these factors interact is what project scientist and Steno research fellow Torsten Nygård Kristensen from the Faculty of Agricultural Sciences, University of Aarhus, have started investigating.

Stress that diminishes fitness (the ability to survive and reproduce) reduces a population’s chances of survival over a period of time.

While environment and genetic stress can each have an unfortunate effect on fitness by themselves, the two types of stress also interact.

- Most of the knowledge that we have about how plants and animals react when they are subject to stress is based on laboratory studies. Performing experiments in the laboratory is advantageous because there we can test specific hypotheses in a controlled manner. However, nature is much more complex than the laboratory and results obtained in the laboratory can therefore be misleading compared to natural conditions, says Torsten Nygård Kristensen.

He will investigate which mechanisms are important for adaptation to environmental stress as well as inbreeding in nature. For that he will be using different species of fruit flies (Drosophila). The different fruit fly species that will be investigated all have their genome mapped, but they have completely different stress tolerances.

The scientists will take a closer look at which genes are affected by and are important for adaptation to stress, how quickly the species can adapt to changes in environmental conditions through evolutionary adaptation, and the importance of population size for these processes.

The results will contribute new knowledge about connections between variations in the genetic make-up, how the genes are expressed, and how fit the animals are. They will also clarify how environmental and genetic stress affects the insects’ physiology and will contribute facts that can be used for conservation and breeding of plants and animals.

The four-year project is financed by the Danish Natural Science Research Council (FNU) and will be carried out in collaboration with the Department of Biological Sciences at the Faculty of Science, University of Aarhus.

For more information please contact: Project scientist Torsten Nygård Kristensen, Department of Genetics and Biotechnology, Faculty of Agricultural Sciences, University of Aarhus, telephone: +45 8999 1076, e-mail: Torsten.Nygaard@agrsci.dk