Fitness and reproductive success: Developmental plasticity as tools for adaptation

The perinatal milieu may provide a forecast about the future conditions of the external world that an individual will subsequently inhabit, which often underlies a predictive adaptive response (PAR). If this forecast does not materialize, however, the PAR may turn out to become maladaptive. A noticeable example is the increased incidence of adults with cardiometabolic diseases in affluent societies, who have been set out during the perinatal stage for a poor nutritional future. While such a mismatch (i.e. from nutritionally poor during the perinatal stage to nutritionally rich during adulthood) may have impeding health consequences later in life, the effect on fitness (the ability to reproduce and contribute to future generations) may be relatively small. The opposite case (i.e. from nutritionally rich to poor) may be more deleterious in terms of maintenance of sustainable health and fitness. In this proposal, we will directly test the PAR hypothesis in mice (C57BL6/J - Mus Musculus) by exposing breeding pairs of mice to either a diet ad libitum or calorie-restricted (80%), from which the offspring will then be exposed to either high, medium, or low nutritional conditions by manipulating litter size. Manipulation of litter size has been shown to cause differences in energy transfer from parents to offspring. We will then subject offspring after weaning to nutritionally matching or mismatching conditions and investigate various sustainable health and fitness parameters as well as their reproductive success in this generation, as well as in their descendants. Matching/mismatching effects on sustainable health, fitness, and reproduction in subsequent generations can be anticipated because parents (of which the individual variation in body structure, physiology and behavior has been caused by their perinatal condition) are the environmental interface for the next generation. Studying this under controlled laboratory conditions offers a unique insight into the origin on phenotypic variation.