Porcine Species Research Articles

Brucellosis in Argentina

Brucellosis has been recognized in Argentina since the 19th century. Several studies demonstrated the presence of the disease in most of the domestic species. Actually, the estimate of prevalence is that between 10 and 13% of the farm animals are infected with bovine brucellosis with an individual rate of 4–5%. The annual economical losses have been estimated at US$ 60,000,000. The control of bovine brucellosis began in 1932 and successive resolutions have been issued since then. The current resolution indicates that B. abortus S19 is mandatory in female calves between 3 and 8 months of age. The vaccine strain B. abortus RB51 was provisionally approved but only for cattle older than 10 months of age. The brucellosis control program consists principally of test and slaughter. This methodology has been successful mainly in the dairy farms that have the incentive due to increased pricing because of obtaining a low prevalence of the disease. Brucellosis has been found in porcine, caprine, ovine and canine species. All Brucella species have been found in the country. Human brucellosis is an important disease and a national coordinated diagnostic net has been formed to better control the disease in man.

Lactoferrin gene expression and regulation: an overview.

Lactoferrin is highly conserved among human, mouse, bovine, and porcine species. The numbers of amino acids encoded by 15 of the 17 exons in these species are identical, and in 12 locations, they have identical codon interruptions at the intron-exon splice junctions. However, lactoferrin expression is both ubiquitous and species, tissue, and cell-type specific. It is differentially regulated through multiple signaling pathways such as steroid hormone, growth factor, and kinase cascade pathways. Comparing the lactoferrin gene promoters from different species, common and different characteristics are observed. The human, mouse, bovine, porcine, and bubaline (African antelope) promoters all contain a noncanonical TATA box with an adjacent Sp1 site. Both human and mouse have multiple steroid hormone response elements, while none are found in the other species studied, suggesting that the lactoferrin gene is differentially regulated among different species by steroid hormones. Several transcription factors have been identified that are crucial for the expression of the lactoferrin gene during differentiation of the myeloid cells and in estrogen and epidermal growth factor regulation. This article provides an overview on lactoferrin expression and regulation in different species.

CDNA sequence of porcine thioredoxin.

Several mammalian thioredoxin cDNA sequences, namely that of human, macaca, ovine, bovine, equine and murine have been already registered in the Genbank database; but that of porcine is still not known. In this communication, we report the full-length cDNA sequence of porcine thioredoxin as determined by RT-PCR method. We also compared the protein sequence of thioredoxin from various mammals. Multialignment of the amino acid sequences between porcine and other mammalian species revealed that the sequences are highly conserved. Only one difference exists between the amino acid sequences of porcine and bovine thioredoxin.

Porcine troponin I: a thermostable species marker protein

In this study, we confirmed our previous hypothesis that the 24 kD thermostable skeletal muscle protein (TSMP) recognized by a panel of porcine-specific monoclonal antibodies (MAbs) is skeletal troponin I (sTnI). The TSMP and sTnI purified from porcine muscle have identical electrophoretic mobilities, isoelectric characteristics, and specific antigenicities. The heterogeneity of sTnI between porcine and other species, and between porcine sTnI and other troponin subunits or cardiac isoforms can be immunologically differentiated by the MAbs. Heat treatment of sTnI up to 126 °C for 120 min did not diminish its solubility and antigenicity. The antigenic specificity and thermal stability of sTnI indicate its potential as a thermostable species marker for the identification of the origin of meats in severely heated products.

Effects of meal intake on materno-foetal exchanges of energetic substrates in the pig.

Catheters were implanted in 18 gilts at 99 days of pregnancy to study the effects of meal intake on uterine and umbilical uptake of energetic substrates in the conscious pig. Blood samples were withdrawn at 105 days of pregnancy from 10 min before and up to 90 min after feeding of a 2.5-kg meal. Plasma glucose was 2.2 to 2.5 times lower and blood lactate 2 to 3 times higher in the foetus than in the sow. Glucose and lactate increased after the meal. Their umbilical uptake amounted to 0.32 and 0.26 mmol x L(-1), respectively. Fructose was found in large amounts in foetal plasma (4.3 mmol x L(-1)), but it did not seem to be metabolised by the foetus. Meal intake decreased plasma levels of FFA and glycerol in the sows, whereas they increased in the foetuses. A small FFA and glycerol umbilical uptake was recorded (14 and 6 micromol L(-1), respectively). Most features of the materno-foetal exchanges in the porcine species resemble those of other species, especially ruminants.

Species-specific PCR for the identification of ovine, porcine and chicken species in meat and bone meal (MBM)

BSE, first identified in the UK in 1986 is thought to have arisen from feeding scrapie infected Meat and Bone Meal (MBM), produced under sub-optimal conditions, to cattle. For quality and safety reasons there is a requirement for a good analytical test for the surveillance of processed MBM. This study describes species-specific PCR assays for the identification of ovine, porcine and poultry species in MBM. A comparison between two distinct DNA extraction methods, i.e. the silica-guanidiumthiocyanate DNA isolation procedure and a commercial DNA extraction kit, is also presented. Application of this technology to species identification in industrial MBM was investigated as part of this study.

Comparison of the regulatory regions of the α1,3galactosyltransferase gene between murine and porcine species

Comparison of the regulatory regions of the α1,3galactosyltransferase gene between murine and porcine species

Development of a DNA-based assay for species identification in meat and bone meal

Restrictions on the use of meat and bone meal (MBM) as a feed ingredient were introduced by the European Commission as a result of the BSE crisis. This paper describes the development of species specific PCR assays to detect bovine, ovine, porcine and poultry species content in MBM. A simple lysis based extraction procedure and a commercial DNA extraction kit were evaluated using simulated samples of rendered material for performance in terms of yielding DNA that is amenable to PCR amplification. From a small cohort of commercially produced samples ( n=7) the application of species specific PCR assays was used to determine the species content of these samples returning an accuracy of 72.5 and 60% for the two selected extraction procedures. Using the simple lysis method, with single species rendered material, a inclusion rate of 0.3% for the bovine and ovine primers and 1% for the porcine primers in MBM containing another reference species was detectable.

A RESEARCH NOTE: DETECTION OF ADULTERATION IN PROCESSED TRADITIONAL MEAT PRODUCTS

ABSTRACT Nondeclared protein addition is one of the most frequent adulterations used in meat products. Meat substitution with an unspecified specie, usually of less quality, is a fraudulent act in the industry and could have economic and health repercussions. In this study, we used an immunodiffusion assay in agar gel to identify bovine, porcine, equine and avion species in two slightly processed meat products, uncooked commercial hamburger and Mexican sausage (chorizo). Analysis of 40 samples from local food stores was performed. Undeclared equine specie was detected in 9 of the 23 of the hamburger meat samples. In Mexican sausage undeclared equine and porcine specie were also found in 5 of the 17 samples. These results showed violations in practices of the regional meat industry. It is suggested that regulatory agencies institute programs to ensure that meat products are properly labeled to protect consumers.

Cell-specific localization of the cholecystokininA receptor in the porcine pancreas.

Cholecystokinin (CCK) produced in the mucosa of the upper small intestine exerts several biological functions. Its secretion in physiological amounts is modulated by the interaction of extracellular regulators and by binding to intracellular receptors of the target cells. The relative affinity of CCK to its receptor has been characterized in various biological and pharmacological studies and it is now well established that CCK has a higher affinity to the CCKA than to the CCKB receptor. Furthermore CCK influences the secretion of pancreatic enzymes in several species but very little is known about the relationship between CCK and the islet hormone-producing cells in the pig pancreas. The localization of this receptor at the cellular level showed conflicting results in animal studies and has not been described in pigs. The aim of the present study was to characterize the precise cellular location of the CCKA receptor in the porcine pancreas. Polyclonal antiserum was raised against the N-terminal epitope of the CCKA receptor molecule and used for localization studies. Using immunohistochemistry on methanol/acetic acid-fixed, paraffin-embedded pancreas, the CCKA receptor could successfully be localized in islet cells. Parallel staining of serial sections with antibodies directed against insulin and glucagon revealed colocalization with glucagon in alpha cells. No immunoreaction was found in the exocrine pancreas. Our results support the concept that in the porcine species the stimulation of the exocrine pancreas is mediated by the CCKB rather than the CCKA receptor, as it is known for the rat species.

VLA-Integrin β-1 chain function is not fully conserved between the human and porcine species: implications for xenotransplantation

VLA-Integrin β-1 chain function is not fully conserved between the human and porcine species: implications for xenotransplantation

Engineering the largest RNA virus genome as an infectious bacterial artificial chromosome.

The construction of cDNA clones encoding large-size RNA molecules of biological interest, like coronavirus genomes, which are among the largest mature RNA molecules known to biology, has been hampered by the instability of those cDNAs in bacteria. Herein, we show that the application of two strategies, cloning of the cDNAs into a bacterial artificial chromosome and nuclear expression of RNAs that are typically produced within the cytoplasm, is useful for the engineering of large RNA molecules. A cDNA encoding an infectious coronavirus RNA genome has been cloned as a bacterial artificial chromosome. The rescued coronavirus conserved all of the genetic markers introduced throughout the sequence and showed a standard mRNA pattern and the antigenic characteristics expected for the synthetic virus. The cDNA was transcribed within the nucleus, and the RNA translocated to the cytoplasm. Interestingly, the recovered virus had essentially the same sequence as the original one, and no splicing was observed. The cDNA was derived from an attenuated isolate that replicates exclusively in the respiratory tract of swine. During the engineering of the infectious cDNA, the spike gene of the virus was replaced by the spike gene of an enteric isolate. The synthetic virus replicated abundantly in the enteric tract and was fully virulent, demonstrating that the tropism and virulence of the recovered coronavirus can be modified. This demonstration opens up the possibility of employing this infectious cDNA as a vector for vaccine development in human, porcine, canine, and feline species susceptible to group 1 coronaviruses.

Contrôle chromosomique des populations animales d’élevage

Le contrôle chromosomique des populations animales d’élevage a pour principal objectif d’éviter la mise à la reproduction d’individus porteurs d’anomalies chromosomiques, ces dernières étant généralement responsables d’une dégradation importante des performances de reproduction des individus porteurs ou de leurs conjoint(e)s. La quasi totalité des contrôles (2000/an environ pour l’ensemble des espèces) est réalisée, en France, au sein de l’Unité mixte de recherches INRA-ENVT de Cytogénétique des Populations Animales. Ils concernent principalement les espèces bovine et porcine. Chez les bovins, la recherche de translocation Robertsonienne 1/29 concerne 1000 individus par an environ, dont 90 % sont des jeunes taureaux candidats à l’insémination artificielle. La fréquence de l’anomalie est la plus élevée en race Blonde d’Aquitaine (10,9 %). L’application des techniques de coloration en bandes des chromosomes a permis de mettre en évidence quatre anomalies chromosomiques nouvelles dans cette espèce. Chez le porc, environ 650 contrôles sont effectués annuellement. 80 % sont réalisés avant la mise à la reproduction des animaux et concernent majoritairement les verrats de race pure utilisés dans les centres d’insémination artificielle. Deux systèmes complémentaires de détection des verrats hypoprolifiques complètent le dispositif de contrôle. Vingt-quatre anomalies chromosomiques nouvelles ont été diagnostiquées dans ce laboratoire pour l’espèce porcine, dont 10 au cours des trois dernières années.

Targeted modification of the domestic animal genome

While the technique of homologous recombination, or gene targeting, has led to the generation of transgenic mice of great value to biomedical research, similar approaches are only being developed in other species. With the exception of recent reports on the generation of genetargeted sheep, the technology in domestic animals is still in its infancy (45). The development of techniques for generating large animals with deleted or modified genes will result in the generation of animals of great value to society. While the technical difficulties to achieve gene targeting in domestic species are significant, they are not insurmountable. Potential applications in both the bovine and porcine species are described with particular emphasis on the generation of cattle resistant to bovine spongiform encephalopathy (BSE) and pigs that can be of use in xenotransplantation.

Welding characteristics of different albumin species with and without fatty acids

Background and Objective Albumin solders from different species have been used for laser tissue welding without a complete understanding of possible differences between them. The breaking strength of four different species of serum albumin (human, bovine, porcine, and canine), both fatty acid containing (FAC) and fatty acid free (FAF), was determined to evaluate the welding ability of each type of albumin. Study Design/Materials and Methods Acute breaking strengths were determined on canine small bowel by using 50% albumin (FAF and FAC) from human, bovine (BSA), porcine, and canine species. Results BSA-FAC and BSA-FAF had a significantly higher (P < 0.05) breaking strength than all other groups; furthermore, BSA-FAC was significantly higher (P < 0.05) than BSA-FAF. There was no significant difference in breaking strength when FAF albumin was compared with FAC albumin from humans, pigs, or dogs. Conclusion These experimental results show that species-specific and fatty acid–specific differences exist when these albumin solders are used for laser tissue welding. This finding suggests that modifications in albumin could be used to improve results through decreased thermal damage and increased weld strength. Lasers Surg. Med. 27:82–86, 2000. © 2000 Wiley-Liss, Inc.

Demonstration of 16‐Unsaturated C‐19 Steroids (‘Boar Pheromones’) in Tissues of the Male Camel (Camelus dromedarius)

ContentsInvestigations into the role of pheromones in reproductive behaviour have been mainly limited to the boar, with 16‐unsaturated C‐19 steroids playing a major role. Similarities in the mating behaviour of the camel and pig suggest that pheromones may also be important in the camel. The aim of this study was to determine the concentrations of 16‐unsaturated steroids in camel testes and other tissues. Samples of testicular tissue were obtained by castration from six male camels (9–15 years) and 16‐unsaturated steroid content was measured by gas–liquid chromatography (GLC). In addition, samples of the glandula occipitalis (‘poll gland’), g. parotis, g. submandibularis and the palatal flap (‘dulaa’) were obtained from a 10‐year‐old camel and also analysed for steroid content. Results were confirmed by GC‐MS (gas‐chromatography‐mass spectrometry) in selected testicular samples. 5α‐androst‐16‐en‐3‐one could be detected in all testicular specimen (range 0.05–1.28 μg/g tissue) as well as in all the other tissues analysed, with highest concentrations in the glandula occipitalis. 5α‐androst‐16‐en‐3β‐ol was present in most tissues, whereas 5α‐androst‐16‐en‐3α‐ol was detectable at 0.75 μg/g only in one testes which also had the highest level of 5α‐androst‐16‐en‐3‐one. The similarities of these findings to the porcine species suggest a role of 16‐unsaturated steroids as pheromones in the camel. Further experimental evidence however, is required to confirm these findings.

Characterization of porcine and ovine Oesophagostomum spp. by isoenzymatic patterns and restriction-fragment-length polymorphisms (RFLPs)

Four different morphological and biometrical populations of Oesophagostomum have been identified, using classical taxonomy methods, from Sus scrofa domestica (pigs): O. dentatum (Od), O. quadrispinulatum (Oq), O. granatensis (Og), and a fourth population, including individuals with morphological and biometric parameters overlapping these three species that were clasified as Oesophagostomum sp. The G6PD and MDH isoenzymatic patterns did not discriminate between the three species, while GPI showed a diagnostic isoenzymatic pattern for Oq. Og showed identical G6PD, GPI and MDH isoenzymatic pattern as Od. Furthermore, after rDNA amplification by polymerase chain reaction (PCR), the uncut PCR product showed that the ITS2 of these three species had a similar size of 320 base pairs (bp). Restrictionfragment-length polymorphisms (RFLP) were analyzed after digestion of the ITS2 with 13 different restriction enzymes. After electrophoretic separation of the digested PCR products, only one unique differentiating pattern of bands was observed for Od and Oq. This was when Sau3AI was used, while Og showed an identical band pattern to Od. Thus, our studies provided no evidence for the existence of Og and Od as differentiated populations. O. venulosum was isolated from sheep and goat; G6PD and MDH isoenzymatic patterns discriminated this species from porcine species of Oesophagostomum. The ITS2 region appeared as a different band of 380 bp from those observed for porcine Oesophagostomum species.

Sperm-oviduct interaction: induction of capacitation and preferential binding of uncapacitated spermatozoa to oviductal epithelial cells in porcine species.

After mating, inseminated spermatozoa are transported to the oviduct. They attach to and interact with oviductal epithelial cells (OEC). To investigate sperm-OEC interactions, we used chlortetracycline to study the capacitation status of boar spermatozoa in coculture with homologous OEC and cells of nonreproductive origin (LLC-PK1, porcine kidney epithelial cell line). Boar spermatozoa were cocultured with OEC and LLC-PK1 cells for 15, 60, 120, or 240 min. The proportion of capacitated spermatozoa in coculture with the isthmic and ampullar cells increased significantly (p < 0.05) during incubation. However, most spermatozoa in coculture with LLC-PK1 cells or blank (medium only) remained uncapacitated. In addition, preferential binding of uncapacitated, capacitated, or acrosome-reacted boar spermatozoa to OEC and the other cell type was investigated. Our approach was to vary the proportions of uncapacitated, capacitated, or acrosome-reacted boar spermatozoa in suspension using long preincubation and lysophosphatidylcholine treatment of semen prior to a very short incubation with OEC or LLC-PK1 cells. The results showed that the majority of spermatozoa that were bound to OEC or LLC-PK1 cells were uncapacitated and that a significant relationship existed between the relative proportion of uncapacitated spermatozoa in the control samples and those bound to LLC-PK1 cells (r2 = 0.43, p < 0.005). However, there was no correlation between the proportion of uncapacitated spermatozoa in the control samples and the proportion of those bound to isthmic or ampullar cells. In conclusion, the results clearly demonstrated the specific nature of the sperm-OEC interaction in the porcine species. This interaction is initiated by uncapacitated spermatozoa binding to OEC and is continued by the induction of capacitation in cocultured spermatozoa.

Detection of two novel porcine herpesviruses with high similarity to gammaherpesviruses.

Evidence for the existence of porcine gammaherpesviruses was obtained by PCR and sequence analysis. Initially, samples of peripheral blood mononuclear cells (PBMC), spleens, lungs, kidneys and livers of pigs from Germany and Spain were tested with a PCR assay which targets conserved regions of the herpesvirus DNA polymerase gene with degenerate and deoxyinosine-substituted primers. Amplicons of identical sequence were obtained from one spleen and two PBMC samples. This sequence showed a high percentage of identity with the DNA polymerase genes of herpesviruses of the oncogenic subfamily Gammaherpesvirinae. Alignment of amino acid sequences showed the highest identity values with bovine gammaherpesviruses, namely alcelaphine herpesvirus type 1 (68%), ovine herpesvirus type 2 (68%) and bovine lymphotropic herpesvirus (67%). Comparison with pseudorabies virus and porcine cytomegalovirus, which are the only porcine herpesvirus species presently known, showed values of only 41%. PCR analysis of PBMC (n = 39) and spleen (n = 19) samples from German pigs, using primers specific for the novel sequence, revealed a prevalence of 87 and 95%, respectively. In this analysis, three out of eight spleen samples from Spanish pigs were also positive. Subsequent sequencing of the amplicons revealed the presence of two closely related gammaherpesvirus sequences, differing from each other by 8% at the amino acid level. The putative novel porcine herpesviruses, from which these sequences originated, were tentatively designated porcine lymphotropic herpesvirus type 1 and type 2 (PLHV-1 and PLHV-2). When using pig organs for xenotransplantation, the presence of these viruses has to be considered.

Development of gastrointestinal and pancreatic functions in mammalians (mainly bovine and porcine species): influence of age and ingested food

This review summarizes recent advances in knowledge on the development of digestive tissues and their productions as well as mechanisms of regulation in response to age and ingested food in mammalian species (mainly bovine and porcine species). In the first two sections, changes are reported for stomach, pancreas and small intestine, and examined in relation to different situations (colostral, milk feeding and weaned periods). The implication of some regulatory substances (growth factors, gut regulatory peptides and neurohormonal substances) in regulation mechanisms is discussed over these periods. For example, the plasma pattern of several gut regulatory peptides and the expression of their specific receptors could explain certain phenomena of digestive development. Recent cellular and molecular aspects of regulation of the digestive enzyme production are also reported. Finally, an approach to interactions existing between age and ingested food is given in the last section. In conclusion, although some phenomena are well established, it is often difficult to distinguish what the age- and food-dependent events are in the development of the digestive function.