Meeting Abstract

86.3  Thursday, Jan. 7  Transgenerational adaptation to obesogenic environments in a rodent COVENY, A.H.**; VICKERS, M.H.; CUPIDO, C.L.; GLUCKMAN, P.D.; RAUBENHEIMER, D.; Liggins Institute, Univ. of Auckland, New Zealand; Massey Univ., Auckland, New Zealand a.coveny@auckland.ac.nz

Numerous studies have examined the ways that animals respond adaptively to their nutritional environments either within a generation through phenotypic plasticity, or across multiple generations through genetic evolution. In contrast, there is little information on whether and how animals adapt at intermediate time-scales, across a single or a few generations. We report experiments in which female rats were transitioned at puberty from a grain-based diet to one of three dietary regimes involving synthetic foods differing in their nutrient (protein, carbohydrate and fat) content and ration (ad libitum vs. 70% of ad lib.). Intake, body composition and reproductive output were monitored over five generations. The first generation exposed throughout development to the synthetic diets (henceforth F0) showed increased caloric intake and adult adiposity compared with non-transitioned rats raised on the grain-based diet. However, the F1 (offspring of F0) rats showed reduced intake and adiposity compared with F0, but to a greater extent when carbohydrate was the main energy source compared with fat. Adiposity was further reduced on the high-carbohydrate diet when rats were restricted to 70% of ad lib. intake, with only minor effects on reproductive outcome. Despite the reduction in intake and adiposity, the rats in all treatments either maintained or increased their lean growth across generations by increasing the efficiency with which ingested protein was converted to growth. Reproductive output in all groups was initially poor with reduced survival of F1 neonates, but improved in subsequent generations. Our data provide enticing evidence for transgenerational adaptation to perturbations in the nutritional environment.