Proteomic profiling of bovine M. longissimus lumborum from Crossbred Aberdeen Angus and Belgian Blue sired steers varying in genetic merit for carcass weight1

Abstract

Bovine skeletal muscle is a tissue of signifi cant value to the beef industry and global economy. Proteomic analyses offer the opportunity to detect molecular mechanisms regulating muscle growth and intramuscular fat accumulation. The current study aimed to investigate differences in protein abundance in skeletal muscle tissue of cattle from two breeds of contrasting maturity (early vs. late maturing), adiposity, and muscle growth potential, namely, Belgian Blue (BB) × Holstein Friesian and Aberdeen Angus (AA) × Holstein Friesian. Twenty AA (n = 10) and BB (n = 10) sired steers, the progeny of sires of either high or low genetic merit, expressed as expected progeny difference for carcass weight (EPD cwt ), and bred through AI, were evaluated as 4 genetic groups, BB-High, BB-Low, AA-High, and AA-Low (n = 5 per treatment). Chemical composition analysis of M. longissimus lumborum showed greater protein and moisture and decreased lipid concentrations for BB-sired compared with AA-sired steers. To investigate the effects of both sire breed and EPD cwt on M. longissimus lumborum, proteomic analysis was performed using 2-dimensional difference gel electrophoresis followed by mass spectrometry. Proteins were identifi ed from their peptide sequences, using the National Center for Biotechnology Information (NCBI) and Swiss-prot databases. Metabolic enzymes involved in glycolysis (glycogen phosphorylase, phosphoglycerate mutase) and the citric acid cycle (aconitase 2, oxoglutarate dehydrogenase) were increased in AA-vs. BB-sired steers. Expression of proteins involved in cell structure, such as myosin light chain isoforms and troponins I and T, were also altered due to sire breed. Furthermore, heat shock protein β-1 and peroxiredoxin 6, involved in cell defense, had increased abundance in muscle of AA-sired relative to BB-sired steers. Protein abundance of glucose-6-phosphate isomerase, enolase-3, and pyruvate kinase was greater in AA-sired animals of High compared with Low EPD cwt . Changes in the expression of these proteins were supported by gene expression analysis using quantitative real-time PCR. This information will aid in our understanding of genetic infl uences controlling muscle growth and fat accumulation and could contribute to future breeding programs to increase lean tissue gain of beef cattle.

Intermuscular and intramuscular adipose tissues: Bad vs. good adipose tissues

“…Increased expression of IGF-1 and IGFBP3 with increased muscle growth of cattle 149,150 Cholesterol and bile acid homeostasis…”

“…111,166,167 Insulin growth factor-1 (IGF-1) and IGFBP3 have been associated with increased muscle growth of cattle resulting in elevation in metabolic enzymes with greater IM, suggesting an increased nutrient utilization through amino acid metabolism. 149 …”

Differences in Beef Quality between Angus (Bos taurus taurus) and Nellore (Bos taurus indicus) Cattle through a Proteomic and Phosphoproteomic Approach

“…Proteomic studies comparing fresh muscle or beef from cattle breeds with different beef quality merits were able to identify differentially abundant proteins related to beef sensory attributes [15, 16, 17]. However, proteomics and phosphoproteomics studies comparing muscle or beef of zebu and taurine have not been conducted.…”

Comparative Skeletal Muscle Proteomics Using Two-Dimensional Gel Electrophoresis

“…An interesting negative regulator of muscle growth is myostatin, a secreted differentiation factor that belongs to the TGF-β superfamily [163]. Semitendious muscles from Belgium Blue bulls that lack myostatin were shown to be characterized by a higher proportion of fast-twitch glycolytic fibers with alterations in contractile protein isoform expression patterns and an increase in myosin binding protein MBP-H [164,165]. …”

“…Gel-based meat proteomics has been used to establish reference maps of bovine muscle [113,119], rabbit muscle [122] and pig muscle [114], as well as for studying tissue growth [164,165,241,242] and p ost mortem changes in bovine, porcine and chicken muscles [243,244,245,246,247,248]. The findings from meat proteomics are important for maximizing muscle growth, meat production, slaughter methods, muscle-to-meat processing and meat storage [249,250,251].…”