Transcriptomic analysis of sheep hypothalamus on sex-dependent differences in body weight of progeny born to dams supplemented with omega-3 fatty acids or methionine during late-gestation

Feeding dams during gestation affects the development of the offspring for their entire life. The objective of the current experiment was to evaluate the changes of the transcriptome in the hypothalamus of the offspring lambs born from dams supplemented with: i) a control diet (without lipids or methionine supplementation), ii) an omega 3 fatty acid supplementation, or iii) a methionine supplementation. The supplementation took place in the last third of gestation and the hypothalamus of male and female offspring was collected after being on a fattening diet for 54 days. Hypothalamus samples were used to extract RNA and analyzed using RNA sequencing. There was an interaction due to sex and methionine supplementation. The pathways that were modified were chromatin structure, developmental processes, and organ morphology. The modification observed on these pathways could explain the sex-by-treatment interaction differences previously observed in growth. There was no sex by omega-3 fatty acid interaction on the hypothalamus transcriptome. Therefore, the sexual dimorphism observed by methionine supplementation may be regulated by the hypothalamus. Overall design: Ewes received i) a basal diet without omega-3 fatty acids or methionine supplementation as control (NFNM), ii) omega-3 fatty acids supplementation (PUFANM), or iii) methionine supplementation (NFM). Data were compared as NFNM vs. PUFANM, and NFNM vs. NFM. A treatment by sex interaction was also evaluated.