title: Tackling proteome changes in the longissimus thoracis bovine muscle in response to pre-slaughter stress.
abstract: Pre-slaughter stress has adverse effects on meat quality that can lead to the occurrence of Dark Firm Dry (DFD) meat in cattle. This study explores the previously uncharacterized proteome changes linked to pre-slaughter stress in the longissimus thoracis (LT) bovine muscle. Differential proteome profiles of DFD and normal (non-DFD) LT meat samples from male calves of the Rubia Gallega breed were assessed by 2-DE coupled to MS analysis (LC-MS/MS and MALDI TOF/TOF MS). A total of seven structural-contractile proteins (three different myosin light chain isoforms, two fast skeletal myosin light chain 2 isoforms, troponin C type 2 and cofilin-2) and three metabolism enzymes (triosephosphate isomerase, ATP synthase and beta-galactoside alpha-2,6-sialyltransferase) were found to have statistically significant differential abundance in sample groups. In addition, 2-DE in combination with the phosphoprotein-specific fluorescent dye Pro-Q DPS revealed that highly phosphorylated fast skeletal myosin regulatory light chain 2 isoforms underwent the most intense relative change in muscle conversion to DFD meat. Therefore, they appear to be the most sensitive biomarkers of stress just prior to slaughter in Rubia Gallega. Overall, these findings will facilitate a more integrative understanding of the biochemical processes associated with stress in cattle muscle and their effects in meat quality.
  
  
  CONCLUSIONS
  Pre-slaughter stress is a crucial factor in meat production. Animals destined for slaughter are stressed by a variety of endogenous and exogenous factors that negatively affect the complex post-mortem biochemical events underlying the conversion of muscle into meat. The study of the muscle proteome has a great relevance for understanding the molecular mechanisms associated with stress. However, there is no information available on the molecular changes linked to pre-slaughter stress in cattle on the proteome scale. Our study led to the identification of a number of candidate proteins associated with the response to pre-slaughter stress in the LT bovine muscle of the Rubia Gallega breed. The functions of those significantly changed proteins have a clear biological relationship with stress response. These findings contribute to a deeper insight into the molecular pathways that respond to stress in cattle.
authors: Meat Technology Center of Galicia, r/ Galicia 4, Parque Tecnolóxico de Galicia, San Cibrao das Viñas, Ourense-32900, Galicia-Spain.
authors: Daniel
authors: D
authors: Franco
authors: Department of Genetics, University of Santiago de Compostela, Santiago de Compostela-15782, Spain.
authors: Ariadna
authors: A
authors: Mato
authors: Department of Biochemistry and Molecular Biology, University of Santiago de Compostela, Santiago de Compostela-15782, Spain.
authors: Francisco J
authors: FJ
authors: Salgado
authors: Department of Genetics, University of Santiago de Compostela, Santiago de Compostela-15782, Spain.
authors: María
authors: M
authors: López-Pedrouso
authors: Spanish National Research Council (CSIC), Marine Research Institute (IIM), Eduardo Cabello 6, Vigo-36208, Pontevedra, Spain.
authors: Mónica
authors: M
authors: Carrera
authors: Proteomics Laboratory, CHUS, Santiago de Compostela-15782, Spain.
authors: Susana
authors: S
authors: Bravo
authors: Department of Genetics, University of Santiago de Compostela, Santiago de Compostela-15782, Spain.
authors: María
authors: M
authors: Parrado
authors: Spanish National Research Council (CSIC), Marine Research Institute (IIM), Eduardo Cabello 6, Vigo-36208, Pontevedra, Spain.
authors: José M
authors: JM
authors: Gallardo
authors: Department of Genetics, University of Santiago de Compostela, Santiago de Compostela-15782, Spain. Electronic address: c.zapata@usc.es.
authors: Carlos
authors: C
authors: Zapata
mesh_terms: D000818:Animals; D002417:Cattle; D008297:Male; D009124:Muscle Proteins / Q000096:biosynthesis*; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D020543:Proteome / Q000096:biosynthesis*; D013315:Stress, Psychological / Q000378:metabolism* / Q000473:pathology
chemical_list: D009124:Muscle Proteins; D020543:Proteome
keywords: Bos taurus; DFD meat; Longissimus thoracis; Pre-slaughter stress biomarkers; Proteome; Relative change measure