• Molecules and Cells
• /
• v.37 no.3
• /
• pp.241-247
• /
• 2014

Sudden cardiac death (SCD), which is primarily caused by lethal heart disorders resulting in structural and arrhythmogenic abnormalities, is one of the prevalent modes of death in most developed countries. Myocardial ischemia, mainly due to coronary artery disease, is the most common type of heart disease leading to SCD. However, postmortem diagnosis of SCD is frequently complicated by obscure histological evidence. Here, we show that certain mRNA species, namely those encoding hemoglobin A1/2 and B (Hba1/2 and Hbb, respectively) as well as pyruvate dehydrogenase kinase 4 (Pdk4), exhibit distinct postmortem expression patterns in the left ventricular free wall of SCD subjects when compared with their expression patterns in the corresponding tissues from control subjects with non-cardiac causes of death. Hba1/2 and Hbb mRNA expression levels were higher in ischemic SCD cases with acute myocardial infarction or ischemic heart disease without recent infarction, and even in cardiac death subjects without apparent pathological signs of heart injuries, than control subjects. By contrast, Pdk4 mRNA was expressed at lower levels in SCD subjects. In conclusion, we found that altered myocardial Hba1/2, Hbb, and Pdk4 mRNA expression patterns can be employed as molecular signatures of fatal cardiac dysfunction to forensically implicate SCD as the primary cause of death.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.11
• /
• pp.1649-1656
• /
• 2015

Gene expression profiling has offered new insights into postmortem molecular changes associated with meat quality. To acquire reliable transcript quantification, high quality RNA is required. The objective of this study was to analyze integrity of RNA isolated from chicken skeletal muscle (pectoralis major) and its capability of serving as the template in quantitative real-time polymerase chain reaction (qPCR) as a function of postmortem intervals representing the end-points of evisceration, carcass chilling and aging stages in chicken abattoirs. Chicken breast muscle was dissected from the carcasses (n = 6) immediately after evisceration, and one-third of each sample was instantly snap-frozen and labeled as 20 min postmortem. The remaining muscle was stored on ice until the next rounds of sample collection (1.5 h and 6 h postmortem). The delayed postmortem duration did not significantly affect $A_{260}/A_{280}$ and $A_{260}/A_{230}$ ($p{\geq}0.05$), suggesting no altered purity of total RNA. Apart from a slight decrease in the 28s:18s ribosomal RNA ratio in 1.5 h samples (p<0.05), the value was not statistically different between 20 min and 6 h samples ($p{\geq}0.05$), indicating intact total RNA up to 6 h. Abundance of reference genes encoding beta-actin (ACTB), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), hypoxanthine-guanine phosphoribosyltransferase (HPRT), peptidylprolylisomerase A (PPIA) and TATA box-binding protein (TBP) as well as meat-quality associated genes (insulin-like growth factor 1 (IGF1), pyruvate dehydrogenase kinase isozyme 4 (PDK4), and peroxisome proliferator-activated receptor delta (PPARD) were investigated using qPCR. Transcript abundances of ACTB, GAPDH, HPRT, and PPIA were significantly different among all postmortem time points (p<0.05). Transcript levels of PDK4 and PPARD were significantly reduced in the 6 h samples (p<0.05). The findings suggest an adverse effect of a prolonged postmortem duration on reliability of transcript quantification in chicken skeletal muscle. For the best RNA quality, chicken skeletal muscle should be immediately collected after evisceration or within 20 min postmortem, and rapidly preserved by deep freezing.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.2
• /
• pp.246-253
• /
• 2017

Objective: Present study explores the effect of hot summer period on the glycolytic rate of early post-mortem meat quality of Ghungroo and Large White Yorkshire (LWY) pig and comparative adaptability to high temperature between above breeds by shifting the expression of stress related genes like mono-carboxylate transporters (MCTs) and heat shock proteins (HSPs). Methods: Healthy pigs of two different breeds, viz., LYW and Ghungroo (20 from each) were maintained during hot summer period (May to June) with a mean temperature of about $38^{\circ}C$. The pigs were slaughtered and meat samples from the longissimus dorsi (LD) muscles were analyzed for pH, glycogen and lactate content and mRNA expression. Following 24 h of chilling, LD muscle was also taken from the carcasses to evaluate protein solubility and different meat quality measurements. Results: LWY exhibited significantly (p<0.01) higher plasma cortisol and lactate dehydrogenase concentration than Ghungroo indicating their higher sensitivity to high temperature. LD muscle from LWY pigs revealed lower initial and ultimate pH values and higher drip loss compared to Ghungroo, indicating a faster rate of pH fall. LD muscle of Ghungroo had significantly lower lactate content at 45 min postmortem indicating normal postmortem glycolysis and much slower glycolytic rate at early postmortem. LD muscle of LWY showed rapid postmortem glycolysis, higher drip loss and higher degrees of protein denaturation. Ghungroo exhibited slightly better water holding capacity, lower cooking loss and higher protein solubility. All HSPs (HSP27, HSP70, and HSP90) and MCTs (MCT1, MCT2, and MCT4) in the LD muscle of pigs inclined to increase more in Ghungroo than LWY when exposed to high temperature. Conclusion: Effect of high temperature on the variation of HSPs and MCTs may play a crucial role in thermal tolerance and adaptation to different climatic conditions, pH regulation, muscle acidification, drip loss, protein denaturation and also in postmortem meat quality development.

• Food Science of Animal Resources
• /
• v.38 no.4
• /
• pp.703-710
• /
• 2018

Bromodomain-containing protein 2 (BRD2) is a nuclear serine/threonine kinase involved in transcriptional regulation. We investigated the expression and association of the BRD2 gene as a candidate gene for meat quality traits in Berkshire pigs. BRD2 mRNA was expressed at relatively high levels in muscle tissue. Statistical analysis revealed that the c.1709G>C polymorphism of the BRD2 gene was significantly associated with carcass weight, meat color ($a^*$, redness), protein content, cooking loss, water-holding capacity, carcass temperatures 4, 12 and 24 h postmortem, and the 24 h postmortem pH in 384 Berkshire pigs. Therefore, this polymorphism in the porcine BRD2 gene may be used as a candidate genetic marker to improve meat quality traits in pigs.

• Animal Bioscience
• /
• v.34 no.4
• /
• pp.743-750
• /
• 2021

Objective: The objectives of this study were to explore the expression patterns of myosin heavy chain (MyHC) genes of different skeletal muscles from Chinese cattle, and to investigate the relationship between myofiber characteristics and meat quality of M. longissimus lumborum (LL), M. psoas major (PM), and M. semimembranosus (SM) from Chinese Luxi and Qinchuan cattle. Methods: Three major muscles including LL, PM, and SM from Chinese Luxi cattle and Chinese Qinchuan cattle were used in this study. The myofiber characteristics were measured by histochemical analysis. The MyHC isoforms expression was evaluated by real-time quantitative polymerase chain reaction. Quality traits including pH value, meat color, cooking loss, Warner-Bratzler shear force (WBSF) and sarcomere length were determined at day 5 postmortem. Results: PM muscle had higher pH value, a* value, sarcomere length and lower WBSF value compared to LL and SM muscles (p<0.05). Numbers of type I myofiber and the relative expression of MyHC I mRNA in PM muscle were higher than those of LL and SM muscles (p<0.05). Myofiber diameter of PM muscle was lower than that of LL and SM muscles, regardless of myofiber types (p<0.05). Conclusion: According to the stepwise linear regression analyses, tenderness was influenced by myofiber characteristics in all three examined muscles. Tenderness of beef muscles from Qinchuan and Luxi cattle could be improved by increasing numbers of type I myofiber.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.3
• /
• pp.394-400
• /
• 2013

A total of 192 broiler chicks were used to evaluate the influence of dietary ${\alpha}$-lipoic acid (ALA) on growth performance, carcass characteristics and meat quality of broiler chickens with the purpose of developing a strategy to prevent the occurrence of pale, soft, and exudative (PSE) meat and to improve the meat quality of broilers. At 22 d of age, birds were allocated to 4 ALA treatments (0, 400, 800, and 1200 ppm). The results showed that dietary ALA significantly decreased average feed intake (AFI), average daily gain (ADG), final live body weight (BW) and carcass weight (p<0.05), while no difference in feed conversion ratio (FCR) was detected among chickens fed with and without ALA. Abdominal fat weight significantly decreased (p<0.05) for broilers fed 800 and 1200 ppm ALA. However when calculated as the percentage of carcass weight there was no significant difference between control and ALA treatments. Meat quality measurements showed that dietary ALA regulated postmortem glycolysis and improved meat quality as evidenced by increased muscle pH and decreased drip loss of meat (p<0.05). Although ALA did not change the tenderness of meat as indicated by meat shear force, dietary ALA decreased collagen content and mRNA expression of COL3A1 gene (p<0.05). In conclusion, the results indicate that dietary ALA may contribute to the improvement of meat quality in broilers.