Muscle structure and gene expression in pectoralis major muscle in response to deep pectoral myopathy induction in fast- and slow-growing commercial broilers

Abstract

1. The objective of this study was to determine muscle structure and gene expression in pectoralis major (p. major) muscle of broilers in response to deep pectoral myopathy (DPM) induction. 2. A total of 160 chickens from slow- and fast-growing broilers were raised under same conditions. Half of the broilers from each strain were encouraged to wing flap when they reached 2800 g body weight. Pectoralis minor (p. minor) muscle of the broilers was inspected for the occurrence of DPM and p. major samples were collected from broilers with or without DPM. The muscle fibre area and number, capillary number and the signalling pathways of vascular development (vascular endothelial growth factor A, VEGFA) and muscle contraction regulation (actin alpha 1, ACTA1; myosin light chain kinase 2, MYLK2 and ATPase Ca transporting gene 1, ATP2A1) were studied in p. major muscle. 3. DPM induction increased fibre area of p. major muscle with a greater rate in the slow-growing strain compared with fast-growing line. Although the capillary number was higher in slow-growing compared with fast-growing broilers, in the case of DPM induction, the number of capillaries was similar between strains. 4. Expression of VEGFA, MYLK2 and ATP2A1 was greater in slow- than in fast-growing broilers. DPM induction increased expression of ACTA1, VEGFA and ATP2A1 in p. major muscle of broilers from both strains; however, MYLK2 expression was downregulated. 5. Changes in capillary density and expression of VEGFA found in the p. major muscle of broilers with DPM suggest increased blood flow to increase oxygen availability. The upregulation of ATP2A1 by DPM induction could be attributable to alterations in calcium ion transportation from the cytoplasm into the sarcoplasmic reticulum. 6. The results are evidence of changes in muscle structure and gene expression pathways in p. major muscle of broilers with DPM.

Comprehensive Proteomic Characterization of the Pectoralis Major at Three Chronological Ages in Beijing-You Chicken

“…Moreover, pathway analysis showed that these proteins were involved in the calcium signaling pathway, the oxytocin signaling pathway, cardiac muscle contraction, and adrenergic signaling in cardiomyocytes. These results were consistent with the results of previous studies, supporting the views that proteins involved in calcium channel moderation and muscle contraction were associated with water-holding capacity (WHC) (Paião et al, 2013;Yalcin et al, 2019). Notably, heat shock protein 70 (HSP70) was more abundant at 120 d than at 90 d ( Supplementary Table S2).…”

Differential Expression of Myogenic and Calcium Signaling-Related Genes in Broilers Affected With White Striping

“…Furthermore, the reduced MYLK2 mRNA levels in WS-affected chickens could lead to a decrease of the light chain phosphorylation, changing the myosin formation and muscle contraction. A similar pattern of MYLK2 expression was observed in a study evaluating broilers affected with deep pectoral myopathies (Yalcin et al, 2018), showing a similar expression profile of this gene across different myopathies.…”

Effects of nicotinamide and sodium butyrate on meat quality and muscle ubiquitination degradation genes in broilers reared at a high stocking density

“…VEGF expression was higher in the HD group than in the LD group, as well as with the treatments HN, LB, and HB. Deep chest muscle disease is typically associated with increased VEGFA expression ( Yalcin et al., 2018 ). Thus, HD rearing may increase the risk of muscle disorders; however, dietary supplementation with NAM and BA may help prevent the occurrence of muscle disorder by inhibiting VEGFA expression.…”