Functional Analysis of Genes Involved in Glycerolipids Biosynthesis (GPAT1 and GPAT2) in Pigs

SIMPLE SUMMARY: Pork consumption is the highest among all meats in Poland and in the world. Current breeding programs were designed to obtain high meat content and low levels of fat in pork carcasses. This resulted in a decrease in the quality of meat. Numerous researchers indicated that intramuscular fat content (IMF) is the determining factor for meat quality and consumer’s acceptance of meat. The genes GPAT1 and GPAT2, being the objective of this study are involved in triacylglycerol (TAG) synthesis. TAGs are the main constituents of animal fat as well as of IMF. The aim of this study was to assess the expression level of the GPAT1 and GPAT2 genes in musculus longissimus lumborum, subcutaneous fat and liver of pigs. Moreover, association analysis between the genes’ expression, production traits, quality and sensory parameters of pork was carried out. The results obtained showed significant differences in the mRNA expression of analyzed genes between tissues and breeds of pigs. Furthermore, association analysis showed significant associations between expression level of the genes and some of the production traits, sensory and quality parameters of pork. The results of this study indicated the possibility of modification of desired traits through transcriptional control of gene expression. ABSTRACT: Glycerol-3-phosphate acyltransferase (GPAT) enzymes catalyze the first step in triacylglycerol (TAG) synthesis. Genes that belong to the GPAT family are potential genetic markers for intramuscular fat content (IMF) content and thus meat quality. The objective of this study was to analyze the expression of GPAT1 and GPAT2 genes in musculus longissimus lumborum, liver and subcutaneous fat of various breeds of pigs. Furthermore, correlations between the genes’ expression abundance and utility traits, meat quality and meat texture parameters of pork were determined. The results obtained showed significant differences in the mRNA level of GPAT1 between analyzed tissues and breeds. The highest expression of GPAT1 gene was observed in liver tissue (p ≤ 0.01). Furthermore, significantly higher GPAT1 transcript level in the m. longissimus lumborum was observed for duroc in comparison to other analyzed breeds (p ≤ 0.05). Expression of the GPAT2 gene was shown only in the liver tissues, however statistically significant differences between the analyzed breeds were not observed. Correlation analysis confirmed the highest association between GPAT2 gene expression level in liver and cohesiveness and resilience traits of m. longissimus lumborum (p ≤ 0.01).