Effects of calpain genotypes on meat tenderness and carcass traits of Angus bulls

TMT-based quantitative proteomics reveals protein biomarkers from cultured Pacific abalone (Haliotis discus hannai) in different regions

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TMT-based proteomics was used to study and compare the muscle protein profiles of Pacific abalones between northern and southern China.

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729 differential abundance proteins were identified in different regions.

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Fatty acid synthase and other 3 proteins were identified as candidate biomarkers for identification of northern and southern abalone.

Due to latitude, the growth cycle of abalone in southern China is significantly lower than that in the northern regions. Therefore, it often occurs merchants use southern abalone to disguise as northern abalone. This study aims to explore the differences in the muscle proteome of Pacific abalone (Haliotis discus hannai) in different regions. A total of 1,569 proteins were detected and 729 proteins were identified as differential abundance proteins (DAPs) in Haliotis discus hannai cultured in Northern (Liaoning Province) and Southern (Fujian Province) China. Bioinformatics analysis revealed and Western blot verified that fatty acid synthase, troponin I, calpain small subunit 1, and myosin light chain 6 are candidate biomarkers for abalone cultured in different regions. This study provides a deeper understanding of how to distinguish which region abalone is harvested from to improve abalone quality controls, and prevent food fraud.

Feeding strategies alter gene expression of the calpain system and meat quality in the longissimus muscle of Braford steers

Objective

The aim of the present study was to determine the effect of supplementing pasture-finished steers with corn silage on the expression level of the calpain system proteins and beef tenderization.

Methods

Thirty Braford steers grazing on summer pasture were used for the study. For 120 days fifteen animals were supplemented with corn silage at 1% of body weight per head per day (Suppl) whereas the remaining 15 steers only received pasture (Contr). Carcass and meat traits were evaluated and compared between groups. Gene expression and activities of proteases (calpain 1 and calpain 2) and inhibitor (calpastatin) were measured using real-time polymerase chain reaction and casein zymography.

Results

Carcass and meat traits were significantly different between feeding systems. Supplemented steers showed higher hot carcass weight (p<0.01), fat content (p = 0.02), and Warner-Bratzler shear force (p = 0.03). Furthermore, the control group showed higher protease:inhibitor ratios, at mRNA (p = 0.01) and protein levels (p<0.10). Warner-Bratzler shear force and mRNA calpains:calpastatin ratio were associated in both feeding systems (p<0.01).

Conclusion

Based on the results obtained in the study, beef tenderness differences among finishing strategies could be modulated through differential expression of the calpain system proteins.

Association of μ-Calpain and Calpastatin Polymorphisms with Meat Tenderness in a Brahman-Angus Population

Autogenous proteolytic enzymes of the calpain family are implicated in myofibrillar protein degradation. As a result, the μ-calpain gene and its specific inhibitor, calpastatin, have been repeatedly investigated for their association with meat quality traits in cattle; however, no functional mutation has been identified for these two genes. The objectives of this study were: (1) to assess breed composition effect on tenderness; (2) to perform a linkage disequilibrium (LD) analysis in μ-calpain and calpastatin genes as well as an association analyses with tenderness; and (3) to analyze putative functional SNPs inside the significant LD block for an effect on tenderness. Tenderness measurements and genotypes for 16 SNPs in μ-calpain gene and 28 SNPs in calpastatin gene from 673 steers were analyzed. A bioinformatic analysis identified “putative functional SNPs” inside the associated LD block – polymorphisms able to produce a physical and/or chemical change in the DNA, mRNA, or translated protein in silico. Breed composition had a significant (P < 0.0001) effect on tenderness where animals with more than 80% Angus composition had the most tender meat. One 11-kb LD-block and three LD-blocks of 37, 17, and 14 kb in length were identified in the μ-calpain and calpastatin genes, respectively. Out of these, the LD-block 3 in calpastatin, tagged by SNPs located at 7-98566391 and 7-98581038, had a significant effect on tenderness with the TG-CG diplotype being approximately 1 kg more tender than the toughest diplotype, TG-CG. A total of 768 SNPs in the LD-block 3 of calpastatin were included in the bioinformatic analysis, and 28 markers were selected as putative functional SNPs inside the LD-block 3 of calpastatin; however, none of them were polymorphic in this population. Out of 15 initial polymorphisms segregating inside the LD-block 3 of calpastatin in this population, markers ARSUSMARC116, Cast5, rs730723459, and rs210861835 were found to be significantly associated with tenderness.

Análisis computacional del efecto de polimorfismos de genes del sistema μ-Calpaína/Calpastatina sobre la calidad de la carne bovina

<p>Los genes del sistema de enzimas μ-Calpaína/Calpastatina han sido ampliamente evaluados en estudios de asociación respecto de parámetros de calidad cárnica como la terneza; previamente se han identificado varios polimorfismos asociados con la variación fenotípica en poblaciones no relacionadas de bovinos. Usando herramientas computacionales se logró postular la asociación de cuatro polimorfismos encontrados en μ-Calpaína y 11 en Calpastatina que producen una alteración de los parámetros físico-químicos, tanto del ARNm (estabilidad y polimorfismo conformacional), como de la proteína (punto isoeléctrico, potencial electroestático y superficie molecular). Es importante poder establecer el soporte biológico de polimorfismos genéticos asociados con parámetros fenotípicos que mejoren la productividad animal, lo que hace que la aproximación in silico se convierta en una herramienta útil para tal fin.</p>