Abstract
Liver is a metabolically complex organ that influences nutrient partitioning and potentially modulates the efficiency of converting energy acquired from macronutrients ingestion into a muscle and/or adipose tissue (referred to as feed efficiency, FE). The objective of this study was to sequence the hepatic tissue transcriptome of closely related but differently feed efficient pigs (n = 16) and identify relevant biological processes that underpin the differences in liver phenotype between FE groups. Liver weight did not significantly differ between the FE groups, however, blood parameters showed that total protein, glucose, cholesterol and percentage of lymphocytes were significantly greater in high-FE pigs. Ontology analysis revealed carbohydrate, lipid and protein metabolism to be significantly enriched with differentially expressed genes. In particular, high-FE pigs exhibited gene expression patterns suggesting improved absorption of carbohydrates and cholesterol as well as enhanced reverse cholesterol transport. Furthermore, the inferred decrease in bile acid synthesis in high-FE pigs may contribute to the observed greater levels of serum glucose, which can be then delivered to cells and utilized for growth and maintenance. Gene ontology analysis also suggested that livers of more efficient pigs may be characterized by higher protein turnover and increased epithelial cell differentiation, whereby an enhanced quantity of invariant natural killer T-cells and viability of natural killer cells could induce a quicker and more effective hepatic response to inflammatory stimuli. Our findings suggest that this prompt hepatic response to inflammation in high-FE group may contribute to the more efficient utilization of nutrients for growth in these animals.
Highlights
Liver is a central organ for systemic metabolism (Rui, 2014; Shimizu et al, 2015) and plays an important role in modulating the efficiency of converting energy acquired from macronutrients into muscle and/or adipose tissue affecting feed efficiency (FE)
Biochemical analysis of serum revealed that total protein, glucose and cholesterol were significantly (P < 0.05) higher in high-FE pigs compared to low-FE pigs
In this study we investigated the hepatic transcriptome of pigs divergent in FE and identified a number of biological functions and pathways affiliated with lipid, protein and carbohydrate metabolism as well as hepatic growth and immune response
Summary
Liver is a central organ for systemic metabolism (Rui, 2014; Shimizu et al, 2015) and plays an important role in modulating the efficiency of converting energy acquired from macronutrients into muscle and/or adipose tissue affecting feed efficiency (FE). Liver can convert energy from a dietary source to triacylglycerol and export it by very low density lipoproteins (VLDL) either to muscle for use there or to adipose tissue for storage (Gruffat et al, 1996). Low density lipoproteins (LDL) deliver cholesterol to peripheral organs, whilst high density lipoproteins (HDL) transport excess cholesterol from these tissues back to the liver (Feingold and Grunfeld, 2000), which is utilized, e.g., for synthesis of bile acids that enable intestinal absorption of dietary fats (Boyer, 2013). Fueling immune response is an energetically expensive process resulting in less nutrients available for growth (Patience et al, 2015). It has been postulated that high-FE animals have a more efficient immune response to fight off inflammation and more energy available for growth and muscle deposition (Paradis et al, 2015)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
