Gene and protein expression of myosin heavy chain in Nellore cattle comparing growth or meat tenderness traits

Abstract

The objective was to investigate gene and protein expression of myosin heavy chain (MyHC) in Nellore cattle slaughtered at different weights (BW) or degrees of meat tenderness. Ninety animals with initial BW 370 ± 37 kg, 24 months of age, were slaughtered after 95 days on feed. We evaluated shear force (SF), myofibrillar fragmentation index, ribeye area, backfat thickness, marbling, color, and cooking losses. Subsequently, 24 animals were selected and divided into four contrasting groups, in which light (BW = 504.58 ± 32.36 kg) versus heavy animals (BW = 604.83 ± 42.97 kg) and animals with tender (SF = 3.88 ± 0.57 kg) versus tough meat (SF = 7.95 ± 1.04 kg) were compared. The MYH7, MYH2 and MYH1 genes were analyzed by real-time PCR. The MyHC isoforms (MyHC-I, MyHC-IIa, and MyHC-IIx) were quantified by SDS-PAGE electrophoresis. We found lower expression of MYH2 and MYH1 genes in heavy compared to light animals and a higher amount of MyHC-I isoform in the tough meat group compared to the tender meat group. Protein expression of MyHC-IIa was higher in the tender meat group. A negative correlation was found of this protein and SF (tenderness), suggesting MyHC-IIa as a biomarker of meat quality.

Keywords:

• Biochemistry
• Bos indicus
• meat science
• muscle fibers
• candidate gene

Disclosure statement

The authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or nonfinancial interest in the subject matter or materials discussed in this study.

Additional information

Funding

The authors thank the São Paulo Research Foundation FAPESP [Fundação de Amparo à Pesquisa do Estado de São Paulo, Processes 2018/00981-5 and 2015/13021-1] and the Government Funding Agency CNPq [Conselho Nacional de Desenvolvimento Científico e Tecnológico, Process 307266/2016-8]. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001.