scholarly journals Evaluation of Myosin Heavy Chain Isoforms in Biopsied Longissimus Thoracis Muscle for Estimation of Meat Quality Traits in Live Pigs

Animals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 9
Author(s):  
Min Young Park ◽  
Youn-Chul Ryu ◽  
Chung-Nam Kim ◽  
Kyung-Bo Ko ◽  
Jun-Mo Kim

Estimating meat quality prior to slaughter will be beneficial for the rapid identification of specific traits or poor quality pork compared to a conventional assessment at postmortem. In this study, we identified and quantified myosin heavy chain (MHC) isoforms from a biopsied longissimus thoracis muscle of pigs, and determined their correlation with postmortem muscle fiber characteristics and meat quality. MHC slow and fast isoforms proportions from biopsied samples correlated with postmortem percentage of type I and type IIB muscle fibers, respectively (p < 0.05). The percentage of the biopsied MHC slow isoform showed a positive correlation with pH at 45 min postmortem, and negative correlations with filter-paper fluid uptake and drip loss in pork (p < 0.05). Furthermore, clustering the pigs into three groups based on the biopsied MHC isoform proportions was not only significantly associated with muscle fiber number and proportions of muscle fiber area, but also correlated with pH at 45 min postmortem and the National Pork Producers Council color score (p < 0.05). Collectively, our findings indicate that the biopsied MHC isoforms serve as parameter for estimating meat quality, with the association between the higher proportion of MHC slow isoforms and pH at 45 min postmortem in particular being indicative of better pork quality.

1996 ◽  
Vol 81 (6) ◽  
pp. 2540-2546 ◽  
Author(s):  
Robert J. Talmadge ◽  
Roland R. Roy ◽  
V. Reggie Edgerton

Talmadge, Robert J., Roland R. Roy, and V. Reggie Edgerton.Distribution of myosin heavy chain isoforms in non-weight-bearing rat soleus muscle fibers. J. Appl. Physiol. 81(6): 2540–2546, 1996.—The effects of 14 days of spaceflight (SF) or hindlimb suspension (HS) (Cosmos 2044) on myosin heavy chain (MHC) isoform content of the rat soleus muscle and single muscle fibers were determined. On the basis of electrophoretic analyses, there was a de novo synthesis of type IIx MHC but no change in either type I or IIa MHC isoform proportions after either SF or HS compared with controls. The percentage of fibers containing only type I MHC decreased by 26 and 23%, and the percentage of fibers with multiple MHCs increased from 6% in controls to 32% in HS and 34% in SF rats. Type IIx MHC was always found in combination with another MHC or combination of MHCs; i.e., no fibers contained type IIx MHC exclusively. These data suggest that the expression of the normal complement of MHC isoforms in the adult rat soleus muscle is dependent, in part, on normal weight bearing and that the absence of weight bearing induces a shift toward type IIx MHC protein expression in the preexisting type I and IIa fibers of the soleus.


Author(s):  
Emre Sirin

This study was conducted to determine muscle fiber characteristics and their effect on some meat quality parameters in Longissimus dorsi (LD) and Semitendinosus (ST) muscles from kids of some Turkish native goat breeds. Male kids of Hair (n=6), Angora (n=6), Kilis (n=6) and Honamli (n=6) (pure breeds) were used as experimental animals. All kids were slaughtered at 3 months of weaning age and muscles samples were collected for determination of type I, IIA and IIB muscle fibers and some meat quality parameters. It was found that type IIA fiber number of Hair and Honamli kids were higher than those of other breeds in LD muscle. Similarly, Hair kids had higher number of (P less than 0.05) type IIA in ST muscle compared to other breeds. Generally, there were negative correlations between tenderness, pH and number of muscle fiber types in LD and ST muscles of all breeds (P less than0.05). Also, there were positive correlations between intra muscular fat and number of muscle fiber types in LD muscles of all breeds (P less than 0.05). Conclusively, kids of Turkish native goat breeds had different muscle fiber characteristics which can affect meat quality.


2020 ◽  
Vol 20 (1) ◽  
pp. 231-243
Author(s):  
Dorota Wojtysiak

AbstractThis study evaluated myosin heavy chain composition and the effect of aging time (45 min, 24 h, 96 h and 168 h) on meat quality parameters and dystrophin and integrin degradation pattern in longissimus thoracis and psoas major muscles of 24 Polish Landrace fatteners slaughtered at 100 kg body weight. It was found that m. longissimus thoracis had a greater percentage of MyHC-IIB (P≤0.05) and a significantly lower percentage of type I and IIA/IIX (P≤0.05) compared with the m. psoas major. Moreover, psoas major muscle had significantly higher (P≤0.05) pH45, pH24 and lower drip loss values for 45 min to 24 h, 45 min to 96 h and 45 min to 168 h than m. longissimus thoracis. Muscle type also had a significant effect on the rate of dystrophin and integrin degradation postmortem, which were significantly (P≤0.05) more rapidly degraded in the m. longissimus thoracis compared to the m. psoas major. It is concluded from the obtained results that the muscles with a greater percentage of MyHC-IIB show lower pH values, which translates into more rapid rate of integrin and dystrophin degradation. Ultimately, this may contribute to higher drip loss values during refrigerated storage.


2002 ◽  
Vol 111 (11) ◽  
pp. 962-967 ◽  
Author(s):  
Tatsutoshi Suzuki ◽  
Diane M. Bless ◽  
Nadine P. Connor ◽  
Charles N. Ford ◽  
Kyungah Lee ◽  
...  

Deficits in voice and swallowing are found in the elderly, but the underlying neuromuscular mechanisms are unclear. A potential mechanism may be denervation-induced muscle fiber transformation to a slower-contracting type of muscle fiber. This study examined young, old, and denervated rat laryngeal muscles (lateral thyroarytenoid, lateral cricoarytenoid, and posterior cricoarytenoid) to examine differences in myosin heavy chain (MHC) composition. Results of sodium dodecyl sulfate–polyacrylamide gel electrophoresis analyses indicated that all muscles were composed predominately of type IIB MHC. With aging and denervation, type IIB was reduced and type IIX, a slower-contracting isoform, was increased in the lateral thyroarytenoid and lateral cricoarytenoid muscles. In the posterior cricoarytenoid muscle, the MHC composition was relatively unchanged. These findings suggest that aging may affect laryngeal adductory function by altering muscle fiber type composition to a slower-contracting isoform, in a manner similar to that observed with denervation.


Sign in / Sign up

Export Citation Format

Share Document