Selenium Deficiency Mainly Influences the Gene Expressions of Antioxidative Selenoproteins in Chicken Muscles

Dietary selenium (Se) deficiency induces muscular dystrophy in chicken, but the molecular mechanism remains unclear. The aim of the present study was to investigate the effect of dietary Se deficiency on the expressions of 25 selenoproteins. One-day-old broiler chickens were fed either an Se deficiency diet (0.033 mg Se/kg; produced in the Se-deficient area of Heilongjiang, China) or a diet supplemented with Se (as sodium selenite) at 0.2 mg/kg for 55 days. Then, the mRNA levels of 25 selenoproteins in chicken muscles were examined, and the principal component was further analyzed. The results showed that antioxidative selenoproteins especially Gpxs and Sepw1 were highly and extensively expressed than other types of selenoproteins in chicken muscles. In 25 selenoproteins, Gpxs, Txnrd2, Txnrd 3, Dio1, Dio 3, Selk, Sels, Sepw1, Selh, Sep15, Selu, Selpb, Sepp1, Selo, Sepx1, and SPS2 were downregulated (P < 0.05), and other selenoproteins were not influenced (P > 0.05). Se deficiency decreased the expressions of 19 selenoproteins (P < 0.05), 11 of which were antioxidative selenoproteins. And, principal component analysis (PCA) further indicated that antioxidative selenoproteins, especially Gpx3, Gpx4, and Sepw1, may play crucial roles in chicken muscles. However, compared with these antioxidative selenoproteins, some other lower expressed selenoproteins (Dio1, Selu, Selpb, Sepp1) were excessively decreased (more than 60 %, P < 0.05) by Se deficiency. Thus, it may save the limited Se levels and be beneficial to remain the level of some crucial selenoproteins. These results suggested that Se deficiency mainly influenced the expressions of antioxidative selenoproteins in chicken muscles. And, antioxidative selenoproteins especially Gpxs and Sepw1 may play a crucial role in chicken muscles. Thus, it helps us focus on some specific selenoproteins when studying the role of Se in chicken muscles.