Effects on transcriptional regulation and lipid droplet characteristics in the liver of female juvenile pigs after early postnatal feed restriction and refeeding are dependent on birth weight

Low (U) and normal (N) birth weight female porcine offspring were used to study molecular and physiological changes in the liver before and after postnatal feed restriction (R, 50% of controls) and after subsequent refeeding period in comparison to non-restricted control animals (K). Overall, the following questions were addressed at the transcriptional, epigenomic and metabolic level: 1) Are there differences in the hepatic transcriptional profile between U and normal birth weight 2) Are these effects reflected on the metabolic level? 3) Could the possible birth weight-dependent effects be modified through feed restriction intervention? 4) Are these effects persistent and, moreover, can improvements with regard to lipid homeostasis be observed? Microarrays were used to study the effects of birth weight and/or feed restriction on the transcriptional level. For whole genome expression analysis, RNA was isolated from liver samples of three randomly chosen animals per group (NK, NR, UK, UR) and time point. Liver tissue was harvested at the age of 75 days (before feed restriction, T1), at the age of 98 days (after 3 wk feed restriction, T2) and at the age of 131 days (after 5 wk refeeding period, T3), resulting in a total of 10 experimental groups.