Metabolic efficiency and the regulation of metabolism under different circumstances are important for the development of obesity and play important roles not only in humans but also in the livestock industry. NMR-based metabonomics is well suited to providing system-wide information on these conditions. Here, we used NMR-based metabonomics to investigate plasma in two ovine models, the Callipyge mutation (metabolic efficiency), and periconceptional overnutrion (obesity development).
1) The Callipyge mutation causes postnatal muscle hypertrophy. The phenotype is only expressed by paternal heterozygotes (polar overdominance), i.e. the NmatCpat genotype. NMR-based metabonomics was used to assess metabolic responses in plasma from NmatCpat and NmatNpat sheep at two postnatal developmental time points, 8 and 12 weeks, when the muscling phenotype and changes in expression of genes flanking the Callipyge mutation were apparent. Postnatal lamb age affects the plasma metabolic profile, and the impact of the Callipyge mutation on plasma metabolites could be discerned at the later age. The latter metabolite changes were consistent with increased emphasis on glycolytic metabolism in affected skeletal muscles from NmatCpat lambs.
2) Increasing evidence indicates that factors such as maternal obesity or overnutrition during pregnancy can influence long-term energy balance in offspring. Maternal obesity has been associated with offspring weight at birth as well as childhood and adolescence obesity. The mechanisms underlying these observations are unclear. To investigate these effects we have used an ovine model of periconception overnutrition and employed NMR-based metabonomics profiling of plasma. One dimensional 1H NMR spectra of plasma samples from the lambs and from donor ewes during the period of periconceptual overnutrition were analysed by multivariate statistics. This analysis indicated the metabolic pathways involved in responses of donor ewes and lambs to periconceptional overnutrition.