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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Quality and Safety Assessment Research Unit » Research » Publications at this Location » Publication #405590
Research Project: Assessment of Quality Attributes of Poultry Products, Grain, Seed, Nuts, and Feed

Location: Quality and Safety Assessment Research Unit

Title: Potential role of ribonucleotide reductase enzyme in mitochondria function and woody breast condition in broiler chickens

Author
item SHAKERI, MAJID - Oak Ridge Institute For Science And Education (ORISE)
item Kong, Byungwhi
item Zhuang, Hong
item Bowker, Brian

Submitted to: Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/18/2023
Publication Date: 6/20/2023
Citation: Shakeri, M., Kong, B.C., Zhuang, H., Bowker, B.C. 2023. Potential role of ribonucleotide reductase enzyme in mitochondria function and woody breast condition in broiler chickens. Animals. https://doi.org/10.3390/ani13122038.
DOI: https://doi.org/10.3390/ani13122038

Interpretive Summary: The woody breast (WB) myopathy in broiler chickens results in inferior quality breast meat. The underlying biological mechanisms that cause WB development are not well understood. This study demonstrated that WB and normal breast muscles exhibited differences in the expression of ribonucleotide reductase (enzyme necessary for DNA synthesis and repair) and genes related to mitochondria function, suggesting a possible pathway for WB to impair energy production in the affected muscle.

Technical Abstract: The cellular events leading to the development of the woody breast (WB) myopathy in broiler breast muscle are unclear. Affected WB muscle exhibits muscle fiber degeneration/regeneration, connective tissue accumulation, and adverse morphological changes in mitochondria. Ribonucleotide reductase (RNR) is an enzyme for synthesis of dNTP, which is important for mitochondrial DNA (mtDNA). RNR consists of two subunits: RRM1/RRM2. Reduction in RRM2 is associated with reduction in mtDNA and mitochondrial 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, NDUBF7 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 suggest increased fatty acid oxidation. Citric synthase activity and NAD/NADH ratio (P=0.02) both reduced for WB, while it increased CHRND expression (P=0.001), a possible indicator of high reactive oxygen species levels. In conclusion, reduction of RRM2 impaired mitochondria function and potentially ATP synthesis in WB by increasing fibrosis and the down-regulation of several genes related to mitochondria function.