Affiliation:
1. U.S. National Poultry Research Center, USDA-ARS, Athens, GA 30605, USA
Abstract
The cellular events leading to the development of the woody breast myopathy in broiler breast muscle are unclear. Affected woody breast muscle exhibits muscle fiber degeneration/regeneration, connective tissue accumulation, and adverse morphological changes in mitochondria. Ribonucleotide reductase (RNR) is an enzyme for the synthesis of dNTP, which is important for mitochondria DNA content (mtDNA). RNR consists of two subunits: RRM1/RRM2. A decrease in RRM2 is associated with a decrease in mtDNA and mitochondria proteins, leading to impaired ATP production. The objective of this study was to investigate potential RNR differences between woody breast (WB) and normal (N) breast muscle by examining RRM2 expression and associated pathways. Gene expression and enzyme activities were examined by qPCR and commercial kits. Results showed that RRM2 expression reduced for WB (p = 0.01) and genes related to mitochondria, including ATP6 (p = 0.03), COX1 (p = 0.001), CYTB (p = 0.07), ND2 (p = 0.001) and ND4L (p = 0.03). Furthermore, NDUFB7 and COX 14, which are related to mitochondria and ATP synthesis, tended to be reduced in WB. Compared to N, GLUT1 reduced for WB (p = 0.05), which is responsible for glucose transport in cells. Consequently, PDK4 (p = 0.0001) and PPARG (p = 0.008) increased in WB, suggesting increased fatty acid oxidation. Citric synthase activity and the NAD/NADH ratio (p = 0.02) both reduced for WB, while WB increased CHRND expression (p = 0.001), which is a possible indicator of high reactive oxygen species levels. In conclusion, a reduction in RRM2 impaired mitochondria function, potentially ATP synthesis in WB, by increasing fibrosis and the down-regulation of several genes related to mitochondria function.
Subject
General Veterinary,Animal Science and Zoology
Reference30 articles.
1. Comparison of quality traits among breast meat affected by current muscle abnormalities;Baldi;Food Res. Int.,2019
2. Barbut, S. (2020, January 19–22). Understanding the woody breast syndrome and other myopathies in modern broiler chickens. Proceedings of the Australian Poultry Science Symposium, Sydney, Australia.
3. Characteristics of broiler chicken breast myopathies (spaghetti meat, woody breast, white striping) in Ontario, Canada;Che;Poult. Sci.,2022
4. Broiler genetics influences proteome profiles of normal and woody breast muscle;Zhang;Poult. Sci.,2021
5. Hisasaga, C. (2021). Assessing the Accuracy of a Woody Breast Identification Technique and Evaluating the Association between Mitochondria Values to Woody Breast Severity. [Ph.D. Thesis, California State University].