GSE107064
Liver transcriptomic and plasma metabolic profile of fattening lambs is modified by feed restriction during the suckling period.
Purpose: The present study was designed to identify both differentially expressed (DE) genes in the liver tissues of fattening Merino lambs and differences in metabolites accumulated in plasma, thus trying to identify modified metabolic pathways as a consequence of milk restriction during the suckling period. Methods: Twenty-four male Merino lambs were assigned to 2 different groups (n=12 per dietary treatment). The first group (ad libitum, ADL) was kept permanently with the dams whereas the other group (restricted, RES) was milk restricted. When they reached 15 kg of live body weight, all the lambs were offered the same complete pelleted diet at the same level to ensure no differences in dry matter intake. All the lambs were slaughtered with 27 kg.  For transcriptomic analysis, 4 liver samples representative from each group (8 samples in total) were selected for RNA sequencing methodology (RNA-seq). Results: 38 DE annotated genes were identified by RNA-seq, with 23 DE genes being down-regulated and 15 up-regulated in the liver of RES relative to the ADL group (P < 0.10). In general, those genes and pathways involved in protein synthesis or protease inhibitors were down-regulated in the RES group, whereas those related to proteolytic degradation were up-regultated, thus suggesting a higher catabolism of proteins in these lambs. Contrarily, RES lambs showed over-expression of xenobiotic metabolism pathways, whereas those genes related to ß-oxidation of fatty acids were down expressed. Conclusions: According to the data obtained, early feed restriction during the suckling period of Merino lambs promoted long-term effects on hepatic transcriptomic profile and plasma metabolic profile wich might have modified fatty acids metabolism, catabolism of proteins and detoxification of xenobiotics, thus reducing feed efficiency of fattening period. Overall design: A transcriptomic analysis was carried out using next-generation sequencing (RNA-seq) from liver samples: 4 animals from ADL group and 4 animals from RES group, 8 samples in total.