Jinhua Pigs Research Articles

Molecular cloning and expression analysis of the GNAS gene in pig and porcine fibroblast cells.

The Alpha subunit of the stimulatory guanine nucleotide-binding protein (GNAS) is a complex imprinted gene. The major product of the GNAS gene is the α-subunit of the guanine nucleotide-binding protein (Gas), which plays a key role in multiple signal transduction pathways. Gas is required for the production of the receptor-stimulated intracellular cyclic adenosine monophosphate (cAMP). It has been demonstrated that an increase in the concentration of the intracellular second messenger cAMP promotes apoptosis in different tumor entities. Mutations of GNAS have also been identified in many tumors. This study aimed to investigate the expression pattern and the apoptosis effect in fibroblast cells for porcine GNAS. The results show that GNAS mRNA was detected in a wide range of tissues, especially in the longissimus dorsi muscle and thyroid gland. The developmental pattern of GNAS mRNA in the thyroid gland of Jinhua pigs was then examined; however, there was no significant difference (P > 0.05) among any of the stages. GNAS gene expression was relatively stable in the thyroid gland during the entire growth and development process. The developmental pattern of GNAS mRNA in the longissimus dorsi muscle was significantly different among the various developmental stages (P < 0.01). GNAS mRNA was strongly expressed at 60 days, 90 days, and 150 days after birth, whereas the expression level was very low during the embryo stages. Target RNA interference of GNAS in porcine fibroblast cells leads to lower mRNA expression of Bcl-2, Fas, and Caspase-3, which are recognized as apoptosis related markers.

Changes in gut microbial populations, intestinal morphology, expression of tight junction proteins, and cytokine production between two pig breeds after challenge with Escherichia coli K88: A comparative study1

This study hypothesized that the gut microbial populations, intestinal morphology, and cytokine production are differentially altered in 2 different pig breeds, namely, Chinese native Jinhua pigs and European Landrace pigs, after orally challenge with enterotoxigenic Escherichia coli (ETEC) K88. A total of 12 Jinhua pigs and 12 Landrace pigs were allocated to either the nonchallenged or the challenged groups (6 pigs per group). The challenged pigs were orally administered ETEC K88, and their nonchallenged counterparts were given sterile Luria-Bertani broth. Selected gut microbial populations, intestinal morphology, mRNA expression of tight junction proteins, and the levels of ileal cytokines and secretory immunoglobulin A (sIgA) production were measured in Jinhua and Landrace pigs. The results showed that the challenged Jinhua pigs exhibited a significantly (P < 0.05) lower incidence of diarrhea compared with their Landrace counterparts. The Escherichia coli (E.coli) population and the percentage of E. coli in the total bacteria population were increased in response to ETEC K88 challenge in both Jinhua and Landrace pigs. The challenged Landrace pigs shed more E. coli (P < 0.05) and had higher percentage of E. coli in the total bacteria population in the colon (P < 0.05) compared with their Jinhua counterparts. Both pig breeds tended to exhibit greater villous atrophy and crypt depth reduction in all of the intestinal segments with challenge. The expression of tight junction proteins decreased in response to ETEC K88 challenge in both pig breeds. The levels of the proinflammatory cytokines interferon (IFN)-γ, tumor necrosis factor-α, and IL-6 and the secretion of sIgA were positively altered whereas the levels of the anti-inflammatory cytokine IL-4 and transforming growth factor (TGF)-β were negatively altered by ETEC K88 challenge in both breeds. Jinhua pigs exhibited significantly higher levels of IFN-γ and TGF-β (P < 0.05) in the challenged group. Our findings provide valuable evidence to explain the differences in the intestinal physiology between Jinhua and Landrace pigs; that is, Jinhua pigs appeared to show better growth performance, a lower incidence of diarrhea, and a lower extent of immune activation in response to ETEC K88 challenge and a higher Lactobacillus population, a higher percentage of Lactobacillus in the total bacteria population, a higher ratio of Lactobacillus to E. coli, and higher levels of tight junction proteins with and without challenge.

Breed difference of porcine Sirtuin 1, adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL)

In the current study, we investigated the breed difference of Sirt1 gene expression in liver and pancreas between Jinhua pigs (a local fatty breed of China) and Landrace (a leaner breed). In addition, the gene expression of lipid metabolism enzymes adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL) has also been examined. Results showed that the serum triglyceride (TG), and total cholesterol (TCHO) concentration of Jinhua pigs were greater than Landrace while the serum glycerol in Jinhua pigs was lower at the age of 180d. The serum leptin concentration was also greater in Jinhua pigs. Compared with Landrace, the mRNA level and protein abundance of Sirt1 were lower both in liver and pancreas in Jinhua pigs. Consistent with Sirt1 expression, in liver and pancreas, the mRNA expression of lipolitic enzymes ATGL and HSL was always lower in Jinhua pigs than Landrace respectively. Furthermore, similar results were found in 60d pigs. The mRNA levels of Sirt1, ATGL and HSL were decreased in 60d Jinhua pigs comparatively. These results indicated that porcine Sirt1, as well as ATGL and HSL gene expressions are different between fatty and leaner pigs. This will provide useful information for better known of Sirt1 function in fat deposition.

Effects of cannabinoid receptor 1 (brain) on lipid accumulation by transcriptional control of CPT1A and CPT1B

CB1 (also known as CNR1), a main receptor for cannabinoids acting at PPARs, can enhance fat deposition. Carnitine palmitoyltransferase-1 (CPT1), an enzyme responsible for the transport of long-chain fatty acids for β-oxidation, is closely related to fat deposition. Whether CB1 can regulate intramuscular adipocytes lipid accumulation through regulation of CPT1 is unclear. Based on the investigation of tissue- and breed-specific CPT1A and CPT1B mRNA expression levels in Jinhua and Landrace pigs, we studied the effects of CB1 on lipid accumulation and CPT1B expression by treating porcine intramuscular adipocytes with CB1 antagonist Δ9-THC and antagonist SR141716. Results showed that muscle CPT1 mRNA was expressed at higher levels in the longissimus dorsi and subcutaneous fat. Liver CPT1A mRNA expression levels were higher in the pancreas, duodenum and liver. Compared with Landrace pigs, CPT1A and CPT1B in the longissimus dorsi of Jinhua pigs were significantly higher and positively correlated with intramuscular fat content. However, for subcutaneous fat, CPT1 levels were significantly lower and negatively correlated with body fat percentage. Δ9-THC significantly increased CB1 mRNA levels and lipid accumulation but decreased CPT1A and CPT1B mRNA levels. Conversely, SR141716 reduced CB1 mRNA levels but increased CPT1A and CPT1B mRNA levels, resulting in decreased lipid accumulation. The CPT1 antagonist etomoxir did not affect CB1 expression, suggesting that CB1 is likely upstream of CPT1A and CPT1B. Meanwhile, PPARA expression was greatly decreased when CPT1A and CPT1B were inhibited and enhanced when CPT1A and CPT1B were activated. Taken together, these data indicate that CB1 can affect intramuscular fat deposition by regulating both CPT1A and CPT1B mRNA expression, with the PPARA signal pathway likely playing a major role in this process.

Green fluorescent protein (GFP) expression patterns in the olfactory epithelium of GFP transgenic cloned Jinhua pigs

Domestic pigs possess a well-developed sense of smell. However, the morphology of the porcine olfactory epithelium (OE) is poorly understood. Recently, several strains of transgenic cloned pigs that are presumed to ubiquitously express green fluorescent protein (GFP) have been created. Thus, the purpose of this study was to elucidate the features of porcine OE using the tissues of GFP transgenic cloned pigs. Based on observations of Hematoxylin and Eosin staining and measurements of thickness, porcine OE tissue portions were classified into three categories (thick, standard, and thin). Cryosections revealed that the prominent GFP signals were expressed in olfactory sensory neurons (OSN), Bowman's glands, and olfactory nerve. A few GFP-expressing sustentacular cells were seen; however, the intensity of GFP fluorescence was slight. In the thick portion, numerous GFP-expressing polygonal OSN that did not possess dendrites were found. In the standard portions, GFP-expressing cells had longitudinal dendrites. A few GFP-expressing cells were found in the thin portion. In the thick and standard portions, most of the prominent GFP-expressing cells were positive for olfactory marker protein. Moreover, double immunofluorescence staining with boiled GFP and Sox2 antibody revealed that GFP expression patterns in OSN are synchronized with Sox2 immunoreactive patterns.

The phylogenetic status of typical Chinese native pigs: analyzed by Asian and European pig mitochondrial genome sequences

China is one of the most diverse countries, which have developed 88 indigenous pig breeds. Several studies showed that pigs were independently domesticated in multiple regions of the world. The purpose of this study was to investigate the origin and evolution of Chinese pigs using complete mitochondrial genomic sequences (mtDNA) from Asian and European domestic pigs and wild boars. Thirty primer pairs were designed to determine the mtDNA sequences of Xiang pig, Large White, Lantang, Jinhua and Pietrain. The phylogenetic status of Chinese native pigs was investigated by comparing the mtDNA sequences of complete coding regions and D-loop regions respectively amongst Asian breeds, European breeds and wild boars. The analyzed results by two cluster methods contributed to the same conclusion that all pigs were classified into two major groups, European clade and Asian clade. It revealed that Chinese pigs were only recently diverged from each other and distinctly different from European pigs. Berkshire was clustered with Asian pigs and Chinese pigs were involved in the development of Berkshire breeding. The Malaysian wild boar had distant genetic relationship with European and Asian pigs. Jinhua and Lanyu pigs had more nucleotide diversity with Chinese pigs although they all belonged to the Asian major clade. Chinese domestic pigs were clustered with wild boars in Yangtze River region and South China.

Distinctive genes determine different intramuscular fat and muscle fiber ratios of the longissimus dorsi muscles in Jinhua and landrace pigs.

Meat quality is determined by properties such as carcass color, tenderness and drip loss. These properties are closely associated with meat composition, which includes the types of muscle fiber and content of intramuscular fat (IMF). Muscle fibers are the main contributors to meat mass, while IMF not only contributes to the sensory properties but also to the plethora of physical, chemical and technological properties of meat. However, little is known about the molecular mechanisms that determine meat composition in different pig breeds. In this report we show that Jinhua pigs, a Chinese breed, contains much higher levels of IMF than do Landrace pigs, a Danish breed. We analyzed global gene expression profiles in the longissimus dorsi muscles in Jinhua and Landrace breeds at the ages of 30, 90 and 150 days. Cross-comparison analysis revealed that genes that regulate fatty acid biosynthesis (e.g., fatty acid synthase and stearoyl-CoA desaturase) are expressed at higher levels in Jinhua pigs whereas those that regulate myogenesis (e.g., myogenic factor 6 and forkhead box O1) are expressed at higher levels in Landrace pigs. Among those genes which are highly expressed in Jinhua pigs at 90 days (d90), we identified a novel gene porcine FLJ36031 (pFLJ), which functions as a positive regulator of fat deposition in cultured intramuscular adipocytes. In summary, our data showed that the up-regulation of fatty acid biosynthesis regulatory genes such as pFLJ and myogenesis inhibitory genes such as myostatin in the longissimus dorsi muscles of Jinhua pigs could explain why this local breed produces meat with high levels of IMF.

Effect of breed on the expression of Sirtuins (Sirt1-7) and antioxidant capacity in porcine brain

Sirtuins, NAD-dependent histone deacetylase (HDAC), are correlated to aging and antioxidant. The aim of this study was to determine breed differences of porcine Sirtuins expression and antioxidant capacity in brain between Jinhua pigs (a fatty breed of China) and Danish Landrace pigs (a leaner breed). Effect of age on Sirtuins’ expression was also investigated. At the age of 180 days, the mRNA levels of Sirt1, as well as Sirt2 and Sirt4, in Jinhua pigs were greater, but the mRNA levels of Sirt3, Sirt5, Sirt6, and Sirt7 of Jinhua pigs were lower compared with Danish Landrace pigs. Likewise, at the same BW of 64 kg, the mRNA levels of Sirtuins, except Sirt5 and Sirt7, in Jinhua pigs were greater than Danish Landrace pigs. Meanwhile, Jinhua pigs possessed higher antioxidants activity than Danish Landrace pigs either at the same age or at the same BW. Furthermore, mRNA levels of Sirtuins were decreased with age in brain of the two breeds from 30 to 120 days. The results indicated that Sirtuins expression in brain was different between fatty and lean pigs, and Sirtuins expression may be correlated to antioxidant capacity. In addition, age could down-regulate Siruins expression in porcine brain.

Polymorphisms in porcine TRH and TRHR gene and associations with growth and fatness traits

Thyrotropin-releasing hormone (TRH), produced in the hypothalamus and stimulating secretion of thyrotropin from the pituitary, is central in regulating the hypothalamic–pituitary–thyroid (HPT) axis. The number of TRH receptors (TRHR) expressed on the surface of target cell is a crucial factor influencing the magnitude of TRH response. The objective of this study was to identify the DNA polymorphisms existing in pig TRH and TRHR gene and to evaluate their associations with porcine growth, carcass and meat quality traits. Six polymorphisms in TRH and seven in TRHR gene in total were identified by re-sequencing. Among the polymorphisms, TRH ss325994920 was a missense mutation at TRH precursor residue 173 causing Val>Met (GTG>ATG) and would generate mutant pFE22/pSE14 peptides which are non-TRH peptides derived from the TRH precursor and have roles in regulating hormone ACTH and PRL. Allele frequencies of the polymorphisms were evaluated in four Western and two Chinese pig breeds (N=228). Opposite alleles prevailed in Western pigs and Chinese pigs at loci ss325994933, ss325994918, ss325994923, ss325994924 and ss325994925, and existence of high linkage disequilibrium blocks in all six breeds were observed. A resource population (N=409) based on crosses of Pietrain and Jinhua pigs were used for the association tests. TRH gene was significantly (P<0.05) associated with intramuscular fat content, BFT at shoulder and ADG from 150 to 180days old, while TRHR gene was significantly associated with head weight and ADG from 90 to 120days in the Pietrain×Jinhua resource population. Thus, it was suggested that TRH and TRHR could be the candidate genes for growth, meat quality and fatness traits. As extended linkage disequilibrium existed in resource populations, the association results obtained in the present study need further verification. Though verifying test in Yorkshire (N=57), Landrace (N=27) and Duroc (N=30) showed no significant results, the sample number might not be big enough to be statistical powerful. Peripheral tissue expression profile of porcine TRH mRNA was also investigated in this study. Co-expression of TRH and its receptor TRHR in the same tissue, especially in fat tissue, indicated the possibility of the existence of local paracrine/autocrine regulations of TRH on respective peripheral tissue.

Polymorphism of the porcine CGA gene and its association with growth and carcass traits

Glycoprotein hormones in the pituitary gland affect a myriad of biological processes such as development, growth, metabolic control and gametogenesis. The quantitative trait loci (QTL) near their common glycoprotein α subunit gene (CGA) have been reported inconsistently. The aim of this study was to dissect potential genetic factors for these unstable results and validate the association or linkage relationship of CGA gene with growth and carcass traits. By resequencing all the exons and part of the introns of the porcine CGA gene, 22 polymorphisms in total were identified in this study. Five single nucleotide polymorphism (SNP) markers were chosen and evaluated in six pure-bred pig breeds (n = 228). Breed-specific haplotypes were found and a map of the porcine CGA polymorphisms’ evolution history was inferred. A resource family (n = 365) with different genetic backgrounds from those used in other papers was used to perform an association study. The resource family was created based on crosses of Pietrain and Jinhua pigs (Central China type pigs). Results indicated that a low correlation between haplotype blocks may abolish each other’s effects. Moreover, a significant association of SNP C-925T with growth rate and back-fat thickness in this study confirmed the existence of previously reported QTL. SNP C-925T and SNP A+15599G could be useful linkage markers and SNP C-925T may also be a candidate causative SNP for the corresponding traits. Further investigation for variants within of the CGA promoter region and their association with growth rate and back-fat traits is suggested. Keywords: Common glycoprotein α subunit gene, haplotype, SNP, tetra-primer ARMS, swine

Association of pig UCP3 gene mutations and back fat thickness in the sixth and seventh rib

Accumulated studies have documented extensive links between UCP3 polymorphisms and pig productive traits, and quantitative trait loci linkage results, on the other hand, provided extensive evidences showing that UCP3 was in the core of several QTLs for carcass and meat quality traits. In this research, we screened two substitutions in coding sequence and one 9-base continuous mutated site in 3'UTR of pig UCP3 gene using the reference population of 293 pigs which were F (2) generation of hybrids between Chinese native Jinhua pigs and European Pietrain. The two missense mutations of G1406A in Exon 3 and T3602C in Exon 5 which led to changes in the G150R and M259T, respectively, were digested by SmaI and introduced Tth111I separately for genotype analysis, and the 9-base continuous mutated site in the 3'UTR was analyzed by an AvaI cleavage. As a result, the 9-base continuous mutated site of 3'UTR manifested significantly close association with the backfat thickness at the sixth and seventh rib, but the polymorphisms of G1406A and T3602C were not associated significantly with any of the seven carcass traits. The same results were shown by RT-qPCR and western blotting. These findings inferred that UCP3 probably has tissue-specific effects on pig carcass traits.

Mapping, expression and regulation of the TRα gene in porcine adipose tissue

Thyroid hormone receptors (TR) are members of the nuclear receptor superfamily. There are at least two TR isoforms, TRα and TRβ. The TRα isoform plays a critical role in mediating the action of thyroid hormone in adipose tissue. We mapped the porcine TRα gene to chromosome 12 p11-p13, by using the ImpRH panel. We examined tissue-localization of TRα and determined expression patterns of TRα in porcine adipose tissue with quantitative real-time PCR. TRα was expressed in all tissues, including heart, liver, spleen, stomach, pancreas, brain, small intestine, skeletal muscle, and subcutaneous adipose tissue. In the adipose tissue, the expression of TRα decreased postnatally. Compared to Yorkshire pigs, Jinhua pigs had significantly lower expression levels of TRα gene in the subcutaneous fat tissue. The expression levels of β2-AR, HSL and ATGL were also significantly lower in Jinhua pigs than in Yorkshire pigs. However, no significant differences in PPARγ and SREBP-1C expression levels were found between Jinhua and Yorkshire pigs. Incubation of porcine adipose tissue explants with high doses of isoproterenol (100 and 1000 nM) significantly increased the expression levels of TRα. We conclude that there is considerable evidence that TRα plays an important role in fat deposition in porcine adipose tissue.

Association of PPARγ2 polymorphisms with carcass and meat quality traits in a Pietrain x Jinhua F2 population

The PPARγ2 gene is a key regulator of both proliferation and preadipocyte differentiation in mammals. Herein its genotype and allele frequencies were analyzed using PCR-SSCP in eight pig breeds (N = 416). Two kinds of polymorphisms of the PPARγ2 gene were detected, including a previously reported shift SNP A177G (Met59Val) in exon 1 and a novel silent mutation G876A in exon 5. The results revealed that European pig breeds carry a higher allele A frequency at the A177G locus and a fixed GG genotype at the G876A locus. Allele A at the G876A locus was only found in Jinhua pigs. The association between haplotype (A177G/G876A) and carcass and meat quality traits was analyzed in a Pietrain x Jinhua F2 population (N = 248). The PPARγ2 gene was found to be significantly associated with backfat thickness at the shoulder (p < 0.05), 6–7th ribs (p < 0.01), last rib (p < 0.01), gluteus medius (p <0.05) and ham weight (p < 0.01). Significant effects of different haplotypes on ham weight and backfat thickness at the 6–7th ribs, last rib, and gluteus medius were also observed.

Comparisons of different muscle metabolic enzymes and muscle fiber types in Jinhua and Landrace pigs1

Western and indigenous Chinese pig breeds show obvious differences in muscle growth and meat quality, however, the underlying molecular mechanism remains unclear. The main objective of this study was to evaluate the breed-specific mechanisms controlling meat quality and postmortem muscle metabolism. The specific purpose was to investigate the variations in meat quality, muscle fiber type, and enzyme activity between local Jinhua and exotic Landrace pigs at the same age (180 d of age), as well as the same BW of 64 kg, respectively. We compared differentially expressed muscle fiber types such as types I and IIa (oxidative), type IIb (glycolytic), as well as type IIx (intermediate) fibers in LM and soleus muscles of Jinhua and Landrace pigs using real-time reverse-transcription PCR. Furthermore, the metabolic enzyme activities of lactate dehydrogenase, as well as succinic dehydrogenase and malate dehydrogenase, were used as markers of glycolytic and oxidative capacities, respectively. Results showed that Jinhua pigs exhibited greater intramuscular fat content and less drip loss compared with the Landrace (P < 0.01). Meanwhile, the mRNA abundance of oxidative and intermediate fibers was increased in Jinhua pigs, whereas the glycolytic fibers were more highly expressed in the Landrace (P < 0.01). In addition, Jinhua pigs possessed greater oxidative capacity than that of the Landrace (P < 0.05). These results suggested that the increased expression of the oxidative and intermediate fibers and greater activities of oxidative enzymes in Jinhua pigs were related to meat quality as indicated by a greater intramuscular fat and reduced drip loss. Based on these results, we conclude that muscle fiber composition and postmortem muscle metabolism can explain, in part, the variation of meat quality in Jinhua and Landrace pigs. These results may provide valuable information for understanding the molecular mechanism responsible for breed specific differences in growth performance and meat quality.

Breed difference and regulation of the porcine Sirtuin 1 by insulin1

Sirtuin 1 (Sirt1) plays an important role in fat metabolism. In the current study, we examined the breed differences in Sirt1 between Jinhua pigs (a fatty breed of China) and Landrace pigs (a leaner breed). In addition, the effect of insulin on the gene expression of Sirt1 and the major lipase, adipose triglyceride lipase (ATGL), and hormone-sensitive lipase (HSL) in fat metabolism was also studied in vitro. Compared with the Landrace pigs, the BW of Jinhua pigs was less (P < 0.01), whereas the body fat content were greater (P < 0.01). The protein content and the mRNA abundance of Sirt1 in Jinhua pigs were less (P < 0.01) in subcutaneous adipose tissues compared with the Landrace pigs. Likewise, the mRNA abundance of ATGL and HSL were also less (P < 0.01) in Jinhua pigs. In vitro, treatment with a different dose of insulin (10, 50 and 100 nM) decreased (P < 0.01) glycerol release and the mRNA abundance of Sirt1, ATGL, and HSL in porcine adipocytes. Likewise, treatment with 50 nM insulin for 24 and 48 h also decreased (P < 0.05) glycerol release and the expression of Sirt1, ATGL, and HSL in porcine adipocytes. Furthermore, insulin and Sirt1-specific small interfering RNA treatment decreased (P < 0.01) the expression of Sirt1, ATGL, and HSL compared with the control or insulin treatment. These results indicate that insulin may regulate transcription of Sirt1, ATGL, and HSL in porcine adipocytes and provide information for manipulating these gene expressions in regulating fat metabolism in pigs.

Breed difference and regulation of the porcine adipose triglyceride lipase and hormone sensitive lipase by TNFα

Adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL) are major novel triglyceride lipases in animals. The aim of this study was to determine if there are differences in the porcine ATGL (pATGL) and HSL genes between Jinhua pigs (a fatty breed) and Landrace pigs (a leaner breed). In addition, the effect of TNFalpha and pATGL-specific siRNA (pATGL-siRNA) on the expression of pATGL and HSL in porcine adipocytes was also examined. Compared with Landrace pigs, the body weight (BW) of Jinhua pigs was lower (P < 0.01), while intramuscular fat content (in the longissimus dorsi muscle), as well as the back fat thickness and body fat content were higher (P < 0.01). The expression of pATGL and HSL mRNA in Jinhua pigs was lower (P < 0.01) in subcutaneous adipose tissue, and greater (P < 0.01) in longissimus dorsi muscle compared with Landrace pigs. In vitro treatment of porcine adipocytes with TNFalpha decreased (P < 0.01) the glycerol release and the gene expression of pATGL, HSL and PPARgamma in porcine adipocytes. Furthermore, transfection with pATGL-siRNA significantly decreased (P < 0.01) the expression of pATGL, while it had no effect on the expression of HSL. Treatment with 25 ng/ml TNFalpha in conjunction with pATGL-siRNA significantly decreased (P < 0.01) the expression of pATGL and HSL in cultured porcine adipocytes. These results provide useful information to further the understanding of the function of pATGL and HSL in porcine lipid metabolism, which should be applicable to the regulation of fat deposition and improvement of meat quality.

Distribution of Escherichia coli F4 adhesion phenotypes in pigs of 15 Chinese and Western breeds and a White Duroc×Erhualian intercross

Diarrhoea in newborn and weaned piglets is mainly caused by enterotoxigenic Escherichia coli (ETEC) with fimbriae F4. To investigate the prevalence of resistance to three fimbrial strains, F4ab, F4ac and F4ad, among Chinese indigenous pigs and Western commercial pigs introduced into China, we determined the ETEC F4 adhesion phenotypes in 292 pure-bred piglets from three Western commercial breeds and 12 Chinese indigenous breeds, and a total of 1093 adult pigs in a White DurocxErhualian intercross, by an in vitro microscopic adhesion assay. All the Tibet and Lantang pigs and a majority of the Erhualian and Rongchang pigs were resistant (nonadherent) to ETEC F4 whereas all the Laiwu pigs and most of the Jiangquhai and Tongcheng pigs were susceptible (adhesive) to at least one of the F4 strains. Yushan Black pigs were uniformly resistant to F4ab, and Jinhua pigs were predominantly resistant to F4ac. Susceptible and resistant animals were observed in the other breeds, indicating that diarrhoea caused by ETEC F4 could be prevalent in these breeds. This study confirmed the existence of eight previously reported F4 adhesion patterns, and supported the assumption that the three F4 receptors are encoded by distinct loci. Expression of the weakly adherent phenotype was observed in six pure-bred piglets and 90 adult F(2)/F(3) animals, and the inheritance of this phenotype and its correlation with susceptibility to disease are still not known.

Spatial variation of intestinal skatole production and microbial community in Jinhua and Landrace pigs

AbstractBACKGROUND: An excessive accumulation of skatole in pigs is a major contributor to boar taint. Intestinal skatole concentrations may vary among different pig segments and breeds. The objective of this study was to evaluate the spatial variation of intestinal skatole production and the microbial community in local Jinhua and exotic Landrace pigs.RESULTS: For both breeds, skatole concentration increased towards the rectum and segment had a significant effect on skatole (P &lt; 0.001). The caecal skatole concentration in Landrace was significantly lower than proximal, distal colonic and rectal skatole levels (P &lt; 0.05). Compared with Jinhua pigs, the rectal skatole and proximal and distal colonic indole levels were significantly higher in Landrace pigs (P &lt; 0.05). Volatile fatty acids were significantly affected by breed except for isobutyrate and isovalerate (P &lt; 0.05), with higher butyrate level and lower pH in Landrace pigs (P &lt; 0.05). There were no significant differences in mitosis and apoptosis for the two breeds. The denaturing gradient gel electrophoresis profile showed differences between breeds and segments within one breed, though some bands were common to all samples.CONCLUSION: The higher skatole levels in Landrace pigs may be not associated with higher intestinal apoptosis. The results suggested that pig genotype plays a role in the establishment of the host‐specific microbiota and that the variations in fermentation patterns are more likely to explain differences in intestinal skatole production. Copyright © 2009 Society of Chemical Industry

Developmental changes of carcass composition, meat quality and organs in the Jinhua pig and Landrace

The present study was aimed to compare the developmental changes of carcass composition, meat quality characteristics and organ weight in pigs of different breeds. Six pigs (sex balance) of each breed were slaughtered at 35, 80 and 125 days of age, respectively. The carcass was chilled and the left carcass side was dissected into bone, lean meat, fat and skin; additionally, organ weight and meat quality parameters were observed. Carcasses of the Jinhua pig were lighter (P < 0.001), contained less lean meat percentage (P < 0.01) and more carcass fat percentage (P < 0.05) than did carcasses of the Landrace. L*-values were lower in Jinhua pigs than in Landrace at 125 days of age (P < 0.05), but the Jinhua pig had higher a*-values compared with Landrace at the age of 80 days (P < 0.01) and 125 days (P < 0.01), respectively. In addition, Jinhua pigs showed lower colour scores (P < 0.05), higher intramuscular fat (IMF) percentage (P < 0.05), less marbling scores (P < 0.05) and lower drip loss (P < 0.05) than Landrace. For organ weight, Jinhua pigs had higher relative heart weight at the age of 80 days (P < 0.05) and 125 days (P < 0.001), and higher relative liver weight at 125 days of age (P < 0.01) than that of Landrace. In addition, the relative kidney weight was heavier (P < 0.001) in the Jinhua pig than in the Landrace during the whole experiment. These results indicated that developmental changes of carcass composition, meat quality parameters and organ weight displayed breed differences. Jinhua pigs were fatter than Landrace but the former had better quality characteristics in the meat.

Profile of new green fluorescent protein transgenic Jinhua pigs as an imaging source

Animal imaging sources have become an indispensable material for biological sciences. Specifically, gene-encoded biological probes serve as stable and high-performance tools to visualize cellular fate in living animals. We use a somatic cell cloning technique to create new green fluorescent protein (GFP)-expressing Jinhua pigs with a miniature body size, and characterized the expression profile in various tissues/organs and ex vivo culture conditions. The born GFP-transgenic pig demonstrate an organ/tissue-dependent expression pattern. Strong GFP expression is observed in the skeletal muscle, pancreas, heart, and kidney. Regarding cellular levels, bone-marrow-derived mesenchymal stromal cells, hepatocytes, and islet cells of the pancreas also show sufficient expression with the unique pattern. Moreover, the cloned pigs demonstrate normal growth and fertility, and the introduced GFP gene is stably transmitted to pigs in subsequent generations. The new GFP-expressing Jinhua pigs may be used as new cellular/tissue light resources for biological imaging in preclinical research fields such as tissue engineering, experimental regenerative medicine, and transplantation.