Regulatory gene network from a genome-wide association study for sow lifetime productivity traits.

Among swine reproductive traits, sow lifetime productivity (SLP) is considered a profitable trait in commercial pig farming. Notably, longevity and efficiency in SLP can be adopted as the key phenotype representing SLP. In this study, we conducted a co-association network analysis using results from a genome-wide association study for SLP-related traits. A total of 656 purebred Landrace female pigs were genotyped using a 60K SNP array. Significantly associated SNPs identified from the GWAS were annotated for the specific genes. Then, we constructed an association weight matrix to build a network based on the co-associations between the genes and 10 SLP traits. The entire network consisted of 495 nodes and 37 755 significant edges. We identified three key regulatory transcription factors: STAT2 (signal transducer and activator of transcription 2), MYF6 (myogenic factor 6) and TFCP2L1 (transcription factor CP2 like 1). The network revealed that the STAT2 and MYF6 regulatory modules cooperate with each other and specifically influence the longevity and efficiency of sows, whereas the TFCP2L1 family specifically affects the improvement of litter size.

Identification of differentially expressed genes in longissimus muscle of pigs with high and low intramuscular fat content using RNA sequencing.

Intramuscular fat (IMF) content in pork is an important element of consumer preference and is positively correlated with meat quality, including tenderness and juiciness. With advances in RNA sequencing technologies, transcriptome-related differences can be associated with specific traits in animals. The objective of this study was to investigate differentially expressed genes (DEGs) closely related to IMF content in porcine longissimus muscle using RNA sequencing. A total of 107 Berkshire pigs were used for IMF content measurements, and significant differences between extremely high (H, n = 3) and low (L, n = 3) IMF content groups were found (P < 0.0001). From multi-dimensional scaling analyses, it was observed that the relationships between H and L groups were similar to each other. Here, we identified a total of 134 genes that were differentially expressed between the groups (false discovery rate <0.05; fold change ≥2). Functional analyses with DEGs revealed that lipid metabolism (SCD and FASN) was one of the significant biological processes related to IMF content determination. In addition, we found that DEGs related to muscle regeneration (MYOG and VEGFA) and extracellular matrix (COL1A1, COL1A2, COL5A1, COL14A1 and COL15A1) were changed among individuals with extreme IMF contents. These results will aid in understanding the regulation of IMF content in pigs.

A polymorphism in the porcine miR-208b is associated with microRNA biogenesis and expressions of SOX-6 and MYH7 with effects on muscle fibre characteristics and meat quality.

MicroRNAs (miRNAs) encoded by the myosin heavy chain (MHC) genes are muscle-specific miRNAs (myomiRs) and regulate the expression of MHC isoforms in skeletal muscle. These miRNAs have been implicated in muscle fibre types and their characteristics by affecting the heterogeneity of myosin. In pigs, miR-208b and miR-499 are embedded in introns of MYH7 and MYH7b respectively. Here, we identified a novel single nucleotide polymorphism (SNP) in intron 30 of MYH7 by which porcine miR-208b is encoded. Based on the association study using a total of 487 pigs including Berkshire (n = 164), Landrace (n = 121) and Yorkshire (n = 202), the miR-208b SNP (g.17104G>A) had significant effects on the proportions of types I and IIb fibre numbers (P < 0.010) among muscle fibre characteristics and on drip loss (P = 0.012) in meat quality traits. Moreover, the SNP affected the processing of primary miR-208b into precursor miR-208b with a marginal trend towards significance (P = 0.053), thereby leading to significant changes in the levels of mature miR-208b (P = 0.009). These SNP-dependent changes in mature miR-208b levels were negatively correlated with the expression levels of its target gene, SOX-6 (P = 0.038), and positively associated with the expression levels of its host gene, MYH7 (P = 0.046). Taken together, our data suggest that the porcine miR-208b SNP differentially represses the expression of SOX-6 by regulating miRNA biogenesis, thereby affecting the expression of MYH7 and the traits of muscle fibre characteristics and meat quality.

Estimation of pork quality traits using exsanguination blood and postmortem muscle metabolites.

The current study was designed to estimate the pork quality traits using metabolites from exsanguination blood and postmortem muscle simultaneously under the Korean standard pre- and post-slaughter conditions. A total of 111 Yorkshire (pure breed and castrated male) pigs were evaluated under the Korean standard conditions. Measurements were taken of the levels of blood glucose and lactate at exsanguination, and muscle glycogen and lactate content at 45 min and 24 h postmortem. Certain pork quality traits were also evaluated. Correlation analysis and multiple regression analysis including stepwise regression were performed. Exsanguination blood glucose and lactate levels were positively correlated with each other, negatively related to postmortem muscle glycogen content and positively associated with postmortem muscle lactate content. A rapid and extended postmortem glycolysis was associated with high levels of blood glucose and lactate, with high muscle lactate content, and with low muscle glycogen content during postmortem. In addition, these were also correlated with paler meat color and reduced water holding capacity. The results of multiple regression analyses also showed that metabolites in exsanguination blood and postmortem muscle explained variations in pork quality traits. Especially, levels of blood glucose and lactate and content of muscle glycogen at early postmortem were significantly associated with an elevated early glycolytic rate. Furthermore, muscle lactate content at 24 h postmortem alone accounted for a considerable portion of the variation in pork quality traits. Based on these results, the current study confirmed that the main factor influencing pork quality traits is the ultimate lactate content in muscle via postmortem glycolysis, and that levels of blood glucose and lactate at exsanguination and contents of muscle glycogen and lactate at postmortem can explain a large portion of the variation in pork quality even under the standard slaughter conditions.

Effects of hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1 polymorphisms on fat androstenone level and gene expression in Duroc pigs.

A high level of androstenone in porcine adipose tissue is a major factor contributing to boar taint. Porcine hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1 (3ß-HSD, also known as HSD3B1) plays a key role in the hepatic metabolism that catalyzes androstenone to ß-androstenol. Therefore, 3ß-HSD is a candidate gene for boar taint. This study aimed to investigate functional 3ß-HSD polymorphisms in Duroc pigs. We found eight single nucleotide polymorphisms (SNPs) in the full-length porcine 3ß-HSD. Four of the SNPs had restriction enzyme sites, and we genotyped them in 147 uncastrated male Duroc pigs using a polymerase chain reaction-restriction fragment length polymorphism method. Pigs with the GG genotype at the g.165262G>A locus (SNP5) had significantly lower androstenone levels than did those with other genotypes (P = 0.030). SNP5 also was associated with differences in 3ß-HSD mRNA levels: pigs with the GG genotype had higher levels than those with other genotypes (P = 0.019). The SNP5 polymorphism could affect the hepatic catabolism of androstenone and consequently impact androstenone accumulation in the adipose tissue. Therefore, SNP5 in the 3ß-HSD of Duroc pigs could be a useful selective marker for decreasing boar taint.

Polymorphisms of the 5' regulatory region of the porcine PPARGC1A gene and the effects on muscle fiber characteristics and meat quality.

The purpose of this study was to determine the structure of the porcine PPARGC1A 5' upstream region, and to find suitable molecular markers for improved meat quality and good lean meat production. Ten DNA polymorphisms, including 7 SNPs, 2 microsatellites, and 1 insertion or deletion were newly found in the 5' upstream region of PPARGC1A. Three SNPs that had restriction enzyme site were evaluated for associations with muscle fiber characteristics and production traits. Two hundred fifty-two pigs (Yorkshire and Landrace) were used in this analysis. The c.-2894G>A genotypes was significantly associated with muscle fiber characteristics, including the number of fiber type I and IIb composition (P < 0.05), mean cross-sectional area of fibers (P < 0.01), and fiber number per unit area (P < 0.05). The animals with the GG genotype had a higher percentage of type I fibers and a lower percentage of type IIb fibers with better meat quality [higher pH value (P < 0.05) and lower drip loss (P < 0.05)] and lean meat production [larger loin eye area (P < 0.05)]. Moreover, the mRNA expression levels of PPARGC1A among genotypes were significantly different with the highest level of GG genotype. The c.-2885G>T and c.-1402A>T sites showed similar results that had significant effects on the mean cross-sectional area (CSA; P < 0.05), fiber number per unit area (P < 0.05) and loin eye area (P < 0.01). Therefore, we suggest that the c.-2894G>A polymorphism in the 5' upstream region of the porcine PPARGC1A gene can be used as a meaningful molecular marker for simultaneous improvement of lean meat production and quality traits.

Effects of p.C430S polymorphism in the PPARGC1A gene on muscle fibre type composition and meat quality in Yorkshire pigs.

The peroxisome proliferator-activated receptor-gamma coactivator-1A (encoded by PPARGC1A) is involved in the formation of type I fibres. Therefore, the PPARGC1A gene can be considered as a functional candidate gene for muscle fibre type composition and meat quality in pigs. The aim of this study was to investigate the associations of the p.C430S polymorphic site in exon 8 of the PPARGC1A gene with muscle fibre characteristics and meat quality traits. The polymorphism was genotyped by PCR-RFLP using AluI restriction enzyme on a total of 152 Yorkshire pigs. Statistical analyses revealed that the p.C430S genotypes significantly affected number (P < 0.05) and area (P < 0.01) of type I muscle fibre, and were significantly associated with muscle pH (P < 0.001) and lightness(P < 0.01). On the basis of these results, we suggest that the p.C430S polymorphism can induce variation of type I fibre formation in porcine longissimus dorsi muscle and that it can be used as a meaningful molecular marker for better meat quality.

Associations of the variation in the porcine myogenin gene with muscle fibre characteristics, lean meat production and meat quality traits.

Pig breeding is aimed at improving lean meat production ability as well as meat quality, and muscle fibre characteristics may be important for enhancing these traits. Therefore, new molecular markers have been demanded for selecting lean meat production ability and meat quality in live animals. Myogenin belongs to the MyoD gene family, and is a candidate gene responsible for muscle fibre characteristics. We identified a new single nucleotide polymorphism (SNP) site in the 5' upstream region of the myogenin gene (nucleotides C and T). A total of 252 pigs of three breeds were genotyped by polymerase chain reaction-restriction fragment length polymorphism using BspCNI. Additionally, they were genotyped for the previously detected MspI site in the 3'-flanking region (alleles A and B). The CCBB diplotype had the highest frequency over breeds, followed by TCBB and CCAB. The other diplotypes were not found in studied pigs. Association analysis performed for the markers found that the TCBB diplotype has desirable effects on the total number of fibres (p < 0.002), fibre cross-sectional area (p < 0.06), and loin eye area (p < 0.001) than the other diplotypes. Moreover, the diplotype had the highest muscle pH value (p < 0.07) and all meat quality traits were near the upper limit of the normal range as a reddish pink, firm and non-exudative (RFN) pork. Therefore, we suggest that selection for the myogenin diplotypes could improve total muscle fibre number, size and lean meat production ability with good meat quality.

The relation between glycogen, lactate content and muscle fiber type composition, and their influence on postmortem glycolytic rate and pork quality.

This study examined the relation between glycogen, lactate content and muscle fiber type composition, and evaluated their influence on postmortem glycolytic rate and meat quality. Muscle samples were classified based on their glycogen and lactate content at 45min postmortem. Muscles with low glycogen and high lactate levels showed low muscle pH(45min) and high R-values. However, muscles with low glycogen and lactate levels showed normal rates of postmortem glycolysis and normal meat quality. On the other hand, muscles with high glycogen and lactate content showed rapid postmortem glycolysis, paler surface color, higher drip loss, and higher extents of protein denaturation than muscles with high glycogen and low lactate content. These results may be partially explained by muscle fiber type composition. Muscles with low glycogen and lactate content at early postmortem are composed of significantly higher fiber type I and lower fiber type IIB as compared to muscles with high glycogen and lactate content.

Comparing the histochemical characteristics and meat quality traits of different pig breeds.

The purpose of this study was to compare the muscle histochemical characteristics and meat quality traits between Berkshire, Landrace, Yorkshire, and crossbred pigs. A total of 594 pigs were evaluated. A clear difference between histochemical properties was observed from the results for fiber type composition. In Berkshire pigs, the area percentage of type I fibers was higher (P<0.001) and that of type IIb fibers was lower (P<0.05) than those of other breeds. The muscle pH(45min) and pH(24h) were significantly higher in Berkshire pigs. Drip loss and color parameters were significantly different between the breeds (P<0.001). The Berkshire pigs, which showed the highest muscle pH and lowest drip loss and L(∗) values, contained a significantly higher percentage of type I fibers than the other breeds. By comparing the fiber type compositions of the different breeds, the results imply that the longissimus dorsi muscle of Berkshire pigs is more oxidative than that of other breeds. A high pH value in Berkshire pigs is due to a high percentage of type I fibers and a low percentage of type IIb fibers. Based on these results, we conclude that muscle fiber composition can explain in parts the variation of meat quality across and within breeds.

Genomic characterization of the porcine CRTC3 and the effects of a non-synonymous mutation p.V515F on lean meat production and belly fat.

cAMP-responsive element-binding protein (CREB)-regulated transcriptional coactivator 3 (CRTC3) is well known to be related to obesity in humans and mice. However, the effects of CRTC3 have not been studied in pigs. Here, we characterized the structure of the porcine CRTC3 gene and identified single nucleotide polymorphisms (SNPs) in its coding region. Moreover, mRNA expression profiles of CRTC3 in muscle and fat tissues were examined. Of the 40 identified SNPs, the p.V515F mutation, located on exon 16, was genotyped in 368 Yorkshire pigs. The p.V515F mutation was significantly associated with lean meat production ability, including reduced back fat thickness (P=0.0317) and loin eye area (P=0.0174). Moreover, the SNP was significantly associated with differences in intermuscular fat (P=0.0092), total muscle area in the belly (P=0.0108), and total fat percentage in the belly (P=0.0298). Taken together, our results suggest that the p.V515F mutation affects to lean meat production ability and amount of belly fat.

Early Focal Segmental Glomerulosclerosis as a Cause of Delayed Graft Function With Combined Acute Antibody Rejection: A Case Report.

Focal segmental glomerulosclerosis (FSGS) is the most common form of post-transplant glomerulonephritis. We describe a case where a biopsy proved that early recurrence of FSGS on postoperative day 1 was the cause of delayed graft function. A 39-year-old man, on hemodialysis for 15 years due to polycystic kidney disease, received a cadaveric renal transplantation. On postoperative day 1, his hourly urine output decreased from 700-800 mL to 50 mL. The graft biopsy showed a mild acute kidney injury confusing nephrotic syndrome. On postoperative day 45, his creatinine level increased to 3.02 mg/dL with severe proteinuria. A kidney biopsy showed focal segmental glomerulosclerosis. On postoperative day 120, his creatinine level elevated again, concomitant with proteinuria. A kidney biopsy showed FSGS with antibody-mediated rejection. After plasmapheresis, his creatinine level decreased to 1.3 mg/dL with mild proteinuria. Once active in the allograft, de novo FSGS is a potentially aggressive process. In this case, it could be managed because of an accurate diagnosis and appropriate treatment.

Enterobacter cloacae-Related Necrotizing Fasciitis After Peritoneal Dialysis in Delayed Graft Function: A Case Report.

INTRODUCTION: Necrotizing fasciitis is an uncommon soft-tissue infection that involves the superficial fascia, subcutaneous fat, and deep fascia. Herein, we report the first case of Enterobacter cloacae-related necrotizing fasciitis after peritoneal dialysis in delayed graft function. CASE: A 58-year-old man, who was a hepatitis B-viral carrier and had atrial fibrillation, received cadaveric renal transplantation with peritoneal dialysis and encountered delayed graft function. On postoperative day 5, we tried hemodialysis via the right jugular dialysis catheter. However, he was unable to endure the hemodynamic changes during hemodialysis, showing rapid ventricular rhythm on electrocardiography. On postoperative day 7, we changed to peritoneal dialysis. However, he presented with fever and pain on his left flank and lower extremity. His white blood cell count and C-reactive protein levels were suddenly elevated. According to the abdomen computed tomography scan, there were subcutaneous fluid and air in the left flank and anterolateral pelvic wall. We performed peritoneal dialysis catheter removal, debridement, and drainage of the left external oblique muscle fascia. In a culture, Enterobacter cloacae was identified. After receiving meropenem for 2 months, his wound healed and delayed graft function was recovered. CONCLUSION: Peritoneal dialysis of delayed graft function seems to be effective in reducing the incidence and severity of delayed recovery of renal function after renal transplantation in some reports. However, it is necessary to be cautious when dealing with a rapidly developing and life-threatening soft-tissue infection, such as necrotizing fasciitis. To reduce mortality rates, early diagnosis, recurrent surgical debridement, and aggressive therapy are mandatory.

Abscess of Native Kidney Caused by Carbapenem-Resistant Acinetobacter baumannii (CRAB) in Renal Transplantation: A Case Report.

BACKGROUND: Abscess of native kidney is a rare postoperative event after renal transplantation. This report describes a case of back pain, fever and pyuria caused by carbapenem-resistant Acinetobacter baumannii (CRAB) in a patient who underwent renal-transplantation. CASE REPORT: A 40-year-old man, presenting with hypertension and renal failure, underwent renal transplantation 1 month previously. He developed sudden intense back pain and fever (39°C). There was normal blood flow in graft kidney but there were the swelling and cyst of right native kidney. We aspirated the pus in native kidney and performed the native nephrectomy. The carbapenem-resistant Acinetobacter baumannii (CRAB) was isolated as in pus and native kidney. We performed the tigecyline monotherapy during 3 weeks. He recovered without complication after treatment. CONCLUSIONS: To our knowledge, no report in the literature to date describes abscess in native kidney secondary to CRAB in a renal transplant. Infections caused by CRAB have become critical for immunosuppressed patients. The presence of complication greater risk, by an organism whose pathogenicity and virulence are not yet elucidated should determine an aggressive empirical antimicrobial therapy.

Biliary lymphoepithelioma-like carcinoma not associated with Epstein-Barr virus.

We report the case of a 64-year-old man who presented with a hepatic mass and macronodular cirrhosis. The pathologic findings revealed a lymphoepithelioma-like carcinoma arising in the hepatobiliary tract that was morphologically identical to nasopharyngeal undifferentiated carcinoma. However, this tumor was not associated with Epstein-Barr virus infection in molecular studies. Macronodular cirrhosis associated with hepatitis C virus was present in the background liver.

Hepatocellular carcinoma with lung metastasis in a 9-year-old-boy.

Hepatocellular carcinoma (HCC) remains chemoresistant and, therefore, the principal treatment of HCC is surgical resection. After a 9-year-old boy with huge HCC with lung metastasis received the 5 cycles of chemotherapy (cisplatin and Adriamycin), the lung metastasis had been resolved completely and the size of HCC in liver had decreased. Right hepatic trisegmentectomy was performed, and then the additional 3 cycles of chemotherapy was given. Currently, the patient shows no recurrence of HCC 42 months after surgical extirpation.

Pneumatic colonic rupture accompanied by tension pneumoperitoneum.

Rupture of the colon caused by high pressure compressed air is a rare, unique and traumatic intra-abdominal injury. As the use of compressed air in industrial work has increased, so has the risk of associated pneumatic injuries from its improper use. Recently we experienced a case of pneumatic rupture of the sigmoid colon accompanied by tension pneumoperitoneum, which caused respiratory distress. The patient's respiration was very rapid with the rate of 44 breaths per minute. On arterial blood gas analysis, pH was 7.40, pO2 68 mmHg, pCO2 44 mmHg, and SaO2 90%. Chest X-ray film showed marked pneumoperitoneum and an elevated diaphragm. The respiratory distress was severe and required immediate relief by emergency decompression peritoneocentesis before surgical intervention consisting of the serosal tear repair, colonic rupture colostomy and abdominal cavity irrigation. A follow up operation 2 months later for colostomy repair completed the patient's recovery.

A case of hemorrhagic gallbladder paraganglioma causing acute cholecystitis.

Gallbladder paraganglioma is a very rare tumor and so far only a few cases have been reported. Most of these were asymptomatic and were found incidentally during operation. Recently, we experienced a gallbladder paraganglioma that gave rise to hemorrhage, which in turn caused acute cholecystitis. Our case involved a 45 year-old female patient complaining of an intermittent right upper abdominal pain. After a preoperative evaluation, cholecystectomy and lymphadenectomy were performed under the impression of gallbladder cancer with acute cholecystitis. Postoperative pathologic examination revealed a hemorrhagic gallbladder paraganglioma accompanied by acute cholecystitis. Immunohistochemical staining of the chief cells for neuron specific enolase, chromogranin and synaptophysin were positive. Sustentacular cells also stained positively for S100 protein.

Effects of variation in porcine MYOD1 gene on muscle fiber characteristics, lean meat production, and meat quality traits.

Three single nucleotide polymorphisms (SNPs) in the porcine MYOD1 gene were used for association analysis and haplotype construction to evaluate the effects of their substitution. Four hundred and three pigs of Yorkshire and Berkshire breeds were used. The mRNA expression levels of MYOD1 were examined. The g.489C>T and g.1264C>A SNPs were significantly associated with several muscle fiber characteristics, the loin eye area, and lightness. Particularly, animals having hetero-genotypes of both sites showed good performance both in lean meat production and meat quality traits. The results of haplotype substitution were similar to the associations of individual SNPs. Moreover, the 2 SNPs had significant effects on mRNA expression. Therefore, the g.489C>T and g.1264C>A SNPs in MYOD1 may be meaningful DNA markers that can be used for improving important porcine economic traits.

The influence of pork quality traits and muscle fiber characteristics on the eating quality of pork from various breeds.

The purpose of this study was to compare parameters associated with pork quality, muscle fiber, and eating quality among various breeds, and to examine if differences in eating quality were associated to pork quality and muscle fiber characteristics. For carcass and pork quality, although there were significant differences among breeds, the values of parameters in all pigs were assigned a normal quality class, a likely outcome of the similarity in the area percentage of type I and IIB fibers. For eating quality, pork loins from Berkshire pigs were more tender and full of pork flavor than Landrace and Yorkshire pigs. Except juiciness and mouth coating, over 20% of the variability in the eating quality parameters can be explained by pork quality traits and muscle fiber characteristics using multiple regression analysis. Furthermore, differences in muscle pH(24h), cooking loss, shear force, and NPPC marbling score could explain a large proportion of variation in eating quality parameters associated with the texture of pork.