Project description:Optimizing feed efficiency through the feed conversion ratio (FCR) is paramount for economic viability and sustainability. In this study, we integrated RNA-seq, ATAC-seq, and genome-wide association study (GWAS) data to investigate key functional variants associated with feed efficiency in pigs. Identification of differentially expressed genes in the duodenal and muscle tissues of low- and high-FCR pigs revealed that pathways related to digestion of dietary carbohydrate are responsible for differences in feed efficiency between individuals. Differential open chromatin regions identified by ATAC-seq were linked to genes involved in glycolytic and fatty acid processes. GWAS identified 211 significant single nucleotide polymorphisms associated with feed efficiency traits, with candidate genes PPP1R14C, TH, and CTSD. Integration of duodenal ATAC-seq data and GWAS data identified six key functional variants, particularly in the 1500985–1509676 region on chromosome 2. In those regions, CTSD was found to be highly expressed in the duodenal tissues of pigs with a high feed conversion ratio, suggesting its role as a potential target gene. Overall, the integration of multi-omics data provided insights into the genetic basis of feed efficiency, offering valuable information for breeding more efficient pig breeds.
Project description:Feed efficiency (FE) is an indicator of efficiency in converting energy, attained from macronutrient ingestion, into tissue. Adipose tissue, besides being a master regulator of systemic lipid storage, is also an active endocrine organ that communicates with skeletal muscle, liver and brain to influence appetite, lipid & glucose metabolism and energy homeostasis. Adipose tissue is hypothesised to play a vital part in regulation of FE. The objective of the present study was to sequence the subcutaneous adipose tissue transcriptome in FE-divergent pigs (n=16) and identify relevant biological processes underpinning observed differences in FE.
Project description:Residual feed intake (RFI) is a measure of feed efficiency, where low RFI denotes high feed efficiency. Caloric restriction (CR) is associated with feed efficiency in livestock species and to human health benefits such as longevity and cancer prevention. We have developed pig lines that differ in RFI and are interested to identify the genes and pathways that underlie feed efficiency. Prepubertal Yorkshire gilts with low RFI (n=10) or high RFI (n=10) were fed ad libitum or at 80% of maintenance for eight days. We measured serum metabolites and generated transcriptional profiles of liver and subcutaneous adipose tissue. 6,114 genes in fat and 305 genes in liver were differentially expressed (DE) in response to CR and 311 in fat and 147 in liver were DE due to RFI differences. Pathway analyses of CR-induced DE genes indicated a switch to a conservation mode of energy by down-regulating lipogenesis and steroidogenesis in both liver and fat. Interestingly, CR in pigs altered expression of genes in immune and cell cycle/apoptotic pathways in fat, which may explain part of the CR-driven lifespan enhancement. In-silico analysis of transcription factors revealed ESR1 as a putative regulator of the adaptive response to CR and several targets of ESR1 in our DE fat genes were annotated as cell cycle/apoptosis genes. Lipid metabolic pathway was overrepresented by down-regulated genes due to both CR and low RFI. We propose a common energy conservation mechanism, which may be controlled by PPARA, PPARG, and/or CREB in both CR and feed efficient pigs. Prepubertal Yorkshire gilts with low RFI (n=10) or high RFI (n=10) were fed ad libitum or at 80% of maintenance for eight days in 2 x 2 complete factorial arrangement.
Project description:in vivo microarray study of transcriptional changes of jejunal scratchings (mucosa) obtained from pigs divergent in feed efficiency.
Project description:in vivo microarray study of transcriptional changes of duodenum scratchings (mucosa) obtained from pigs divergent in feed efficiency.
Project description:in vivo microarray study to detect transcriptional changes in muscle tissue (M. longissimus) derived from pigs divergent in feed efficiency.
