Effects of phospholipid hydroperoxide glutathione peroxidase mRNA expression on meat quality of M. longissimus dorsi in pigs

Abstract

Antioxidant enzymes protect muscle tissues against oxidation from reactive oxygen species and increase the stability of the muscle. Phospholipid hydroperoxide glutathione peroxidase (GPx4) is an important antioxidant enzyme in muscle tissue. So the aim of this study was to identify the effects of mRNA expression level of GPx4 gene on meat quality properties in Longissimus dorsi of three pig breeds. Total 36 pigs (12 pigs for each breed) were used to measure the meat quality properties and to analyze the expression levels of GPx4 gene by quantitative real-time PCR. The results showed that meat quality, GPx4 activity, and GPx4 mRNA levels were affected by pig breeds. There were the lowest expressible moisture, drip loss, and cooking loss in Laiwu Pig among the three breeds, and also there were the highest GPx4 activity and the expression levels of GPx4 gene in Laiwu Pig compared with the other two pig breeds. Analysis of meat samples divergent for water-holding capacity identified highly negative associations between expressions levels of GPx4 gene and expressible moisture, drip loss and cooking loss. These results suggest that the higher mRNA expression level of GPx4 gene up-regulate the water-holding capacity and the activity of GPx4, and the expression of GPx4 gene plays an important role in physiological changes related to the meat quality properties and the mechanisms of the antioxidant ion of meat.