Together with the advancements in animal cloning, the ability to efficiently target specific genes in somatic cells would greatly enhance several areas of research. While it has been possible for quite some time to target specific genes in the germ cells of mice, the advancements in somatic cell gene targeting has been slowed for two main reasons. First, the finite lifespan of somatic cells, due mainly to the inability of the somatic cells to regenerate or maintain their telomeres, poses a major problem given the lengthy selection process needed to identify a targeting event. The second problem is the overall inefficiency of homologous recombination. A double strand break or introduction of foreign DNA into a cell can be processed either through the homologous recombination or non-homologous end joining pathways. Of these two, non-homologous end joining is dominant in somatic cells. A two plasmid recombination system was used to study the effects of the manipulation of several non-homologous end joining and homologous recombination pathway molecules on the rates of homologous recombination in porcine fetal fibroblasts. In addition, the effect of telomerase expression, cell synchrony, and DNA nuclear delivery was examined. Results indicate a strong positive relationship between inactivation of p53, cell synchronization, and efficient DNA nuclear delivery in enhancing the rate of homologous recombination. These findings were then applied to an actual locus in the pig, the α1,3 galactosyltransferase gene. Results from these transfections are compared to published accounts of successful targeting at this locus and possibilities for the differences found are discussed.

An investigation of the distribution of porcine reproduction and respiratory syndrome virus (PRRSV) and factors associated with the presence of PRRSV in Ontario from 2004 – 2007 was conducted. Surveys on the presence of clinical signs associated with PRRS, management practices, animal suppliers, and herd location were administered to the managers of 458 PRRSV positive herds and 61 PRRSV negative herds. Open reading frame (ORF) 5 of the PRRSV genome was sequenced from herds with PRRSV. PRRSV positive herds were compared to PRRSV negative herds. Management practices associated with being PRRSV positive were: not washing animal- and feed-delivery vehicles, feed-delivery and animal-transport vehicles visiting multiple herds at one time, allowing a truck driver to enter the barn, not requiring visitors to shower prior to farm entry, and not utilizing all-in all-out flow in gilt and finisher barns. Specific PRRSV restriction fragment length polymorphism (RFLP) genotypes of the ORF5 gene were compared with clinical signs. Herds with RFLP type ‘1-undetermined-4’, ‘1-undetermined-2’ and 1-3-4 were associated with clinical signs in sows and 2-6-2 was associated with finisher mortality compared to herds with vaccine virus. Additionally, genotypes 1-3-4 and 1-8-4 increased in frequency during this study. The between-herd PRRSV similarity of genome and clinical signs were compared. Abortions and stillbirths were associated with similarity in genetic sequences between herds. This relationship did not extend to those herds where vaccine virus was identified. Patterns in space and time of herds with different RFLP types of PRRSV were investigated after accounting for ownership. There was weak evidence to suggest local spread the genotype 1-3-4. The association between genetic similarity and proximity in space, time, ownership, animal, and semen suppliers was tested. Significant correlation was detected for distances up to 30 km. After controlling for ownership, only small associations between breeding stock and semen suppliers and genetic similarity of PRRSV were found. The spread of PRRSV among herds in Ontario cannot be attributed to any one factor. However, similarity in ownership between herds was a key variable indicating that movement of animals, personnel, and vehicles among herds must be measured in future investigations of PRRSV dynamics. / Ontario Pork and the Canada-Ontario Research and Development (CORD) Program and the OMAFRA/University of Guelph agreement

No description available.

Abstract: The piggery industry is very important in Canada, but localized production of large quantities of swine slurry causes severe environmental problems such as aquatic pollution and emissions of methane, a potent greenhouse gas. There are many technologies that can reduce the impact of these issues, but biofiltration is the only viable process that can treat both pollutants. The main objectives of this thesis are to study the biofiltration of methane at concentrations representative of the piggery industry and to achieve the simultaneous treatment of methane and swine slurry with a single biofilter. Laboratory-scale experiments were used to better understand the biofiltration of methane from the piggery industry. Using an inorganic filter bed, it was possible to reach a maximum elimination capacity of 14.5 ± 0.6 g·m -3 ·h-1 for an inlet load of 38 ± 1 g·m -3 ·h-1 . The removal efficiency was relatively stable with the methane concentration and the biofilter satisfied first order kinetics. By decreasing the nitrate concentration in the nutrient solution, a concentration of 0.1 gN·L-1 proved to be sufficient for proper biofilter operation. Furthermore, once all inorganic sources of nitrogen were removed, the presence of microorganisms capable of fixing atmospheric nitrogen was established. Carbon and nitrogen mass balances suggested that the carbon accumulated within the biofilter was probably used for the production of storage compounds rather than for cell synthesis. The viability of simultaneously treating methane and swine slurry was demonstrated by using an innovative biofilter design to overcome the inhibition of methane biodegradation by swine slurry. Although generally less efficient than the biofiltration of methane alone, an elimination capacity for methane of 18.8 ± 1.0 g·m -3 ·h-1 was obtained with this system at an inlet load of 46.7 ± 0.9 g·m -3 ·h-1 . Pure fungal strains were used in an attempt to improve performance, but no significant increase in the methane removal efficiency was observed. For swine slurry treatment, average removal efficiencies of 67 ± 10 % for total organic carbon and 70 ± 7 % for ammonium were achieved. The influence of the slurry supply was analyzed and the ideal supply method found in this study was 6 doses of 50 ml per day. Pilot-scale tests carried out directly on a pig farm were used to validate the results obtained in the laboratory for the treatment of methane from swine house ventilation air. After a start-up period of 30 days, removal efficiencies up to 83% were observed for a methane inlet load of 1.6 ± 0.8 g·m -3 ·h-1 . Treated swine slurry was tested as a replacement for the synthetic nutrient solution, but due to inhibitory compounds in the treated slurry, the results were not satisfactory. For the simultaneous treatment, the methane removal efficiency only dropped from 58 ± 5% to 53 ± 8% when slurry was supplied to the biofilter. By integrating the results obtained in this study with modern farming techniques, the piggery industry could reduce its greenhouse gas emissions and treat part of the nutrients in swine slurry.||Résumé: L'industrie porcine est très importante au Canada, mais les conditions d'entreposage et l'épandage excessif du lisier de porc contribuent respectivement aux émissions de méthane, un puissant gaz à effet de serre, et à la pollution de l'eau. II existe de nombreuses techniques pour atténuer ces problématiques, mais le procédé de biofiltration s'impose comme étant capable de traiter le méthane et le lisier. Les objectifs principaux de cette thèse sont d'étudier la biofiltration du méthane à des concentrations représentatives de l'industrie porcine et d'effectuer le traitement simultané du méthane et du lisier de porc dans un même biofiltre. Des essais expérimentaux à l'échelle laboratoire ont permis de mieux comprendre la biofiltration du méthane issu de l'industrie porcine. En utilisant un lit filtrant inorganique, il a été possible d'atteindre une capacité d'élimination maximale de 14,5 ± 0.6 g[indice supérieur .]m[indices supérieurs -3.]h[indices supérieurs -1] pour une charge à l'entrée de 38 ± 1 g[indice supérieur .]m[indices supérieurs -3.]h[indices supérieurs -1]. L'efficacité d'enlèvement était relativement stable en fonction de la concentration de méthane et le biofiltre présentait une cinétique de premier ordre. En diminuant la concentration de nitrate dans la solution nutritive, une concentration de 0,1 gN[indice supérieur .]L[indice supérieur -1] s'est avérée suffisante pour assurer l'opération adéquate du biofiltre. De plus, en éliminant tout apport d'azote inorganique, la présence de microorganismes capables de fixer l'azote atmosphérique a été établie. Des bilans de masse sur le carbone et l'azote ont illustré que le carbone accumulé dans le biofiltre était utilisé pour la production de matières de stockage plutôt que pour la synthèse cellulaire. La viabilité de traiter simultanément le méthane et le lisier a été démontrée en utilisant un design innovateur de biofiltre pour éviter l'inhibition de la biodégradation du méthane par le lisier. Quoique généralement moins performant que la biofiltration du méthane seul, ce système a permis d'obtenir une capacité d'élimination de méthane de 18.8 ± 1.0 g[indice supérieur 1]m[indices supérieurs -3.]h[indices supérieurs -1] pour une charge de 46.7 ± 0.9 g[indice supérieur .]m[indices supérieurs -3.]h[indices supérieurs -1]. Des souches pures de champignons ont été utilisées afin d'améliorer la performance, mais aucun effet significatif n'a été observé. Pour le traitement du lisier de porc, des taux d'enlèvement moyens de 67 ± 10 % pour le carbone organique total et de 70 ± 7 % pour l'ammonium ont été obtenus. L'influence de l'alimentation en lisier a été analysée et le mode d'alimentation idéal fut de 6 doses de 50 ml par jour. Des essais à l'échelle pilote effectués directement sur une ferme porcine ont permis de valider les résultats obtenus au laboratoire pour le traitement du méthane dans l'air de ventilation d'un bâtiment d'élevage. Après une phase de démarrage de 30 jours, des efficacités d'épuration jusqu'à 83% ont été observées pour une charge de méthane à l'entrée de 1.6 ± 0.8 g[indice supérieur .]m[indices supérieurs -3.]h[indices supérieurs -1]. Du lisier de porc traité a été testé pour remplacer la solution nutritive synthétique, mais dû à la présence de composés inhibiteurs dans le lisier traité, les résultats obtenus n'étaient pas satisfaisants. Pour le traitement simultané, l'efficacité d'épuration du méthane a seulement diminué de 58 ± 5% a 53 ± 8 % lorsque le lisier a été alimenté au biofiltre. En intégrant les résultats de cette étude aux techniques agricoles modernes, l'industrie porcine pourrait réduire ses émissions de gaz à effet de serre et traiter une partie des nutriments du lisier de porc.

Islet transplantation has the potential to be an effective treatment for patients with type 1 diabetes. However, a shortage of human donor islets and the need for continuous immunosuppressive therapy currently limit this therapy to patients with brittle type 1 diabetes. Neonatal pigs may provide an unlimited source of islets for transplantation; however, the barrier of islet xenograft rejection must still be overcome. Understanding the mechanism of neonatal porcine islet (NPI) rejection will help to develop targeted therapies to prevent rejection. This thesis studied the early immune cells and molecules involved in NPI xenograft rejection, compared the role of NK cells in two models of islet xenotransplantation and investigated the role of T cell co-stimulatory and adhesion pathways in NPI xenograft rejection. Targeting these aspects of the immune response to NPI xenografts with short-term therapies may play a role in improving NPI xenograft acceptance and induce long-term xenograft survival.

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 62-77). / ix, 77 leaves, bound ill. (some col.), maps (some col.) 29 cm

Bibliography: leaves 148-189. / viii, 189 leaves, [5] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / A transgenic rat model was developed to allow the study of the effects of GH expression, growth regulation and reproductive function. Transgenic rats were created by pronuclear microinjection of a human metallothionein promoter porcine growth hormone (pGH) gene construct. / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1996?

Addendum pasted onto front end-paper. / Bibliography: leaves 176-216. / x, 216 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The aim of this project is to determine why LR3IGF-1 has such divergent effects in two different species. The study investigates the endocrine regulation of IGF-I and IGF binding protein-3 (IGFBP-3) in the pig and determines the effects of IGF-I and LR3IGF-I treatment on porcine IGF-I and IGFBP-3 expression at the gene and protein level. / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1997

The initial focus of this PhD project was on comparative gene mapping. Comparative gene mapping is facilitated by consensus PCR primers which amplify homologous gene fragments in many species. As a part of an international co-ordinated programme of comparative mapping in pigs, 47 CATS (Comparative Anchor Tagged Sequence) consensus primer pairs for loci located on human chromosomes 9, 10, 20, and 22, were used for amplifying homologous loci in pigs. After optimization of PCR conditions, 23 CATS products have confirmed by comparison with homologous sequences in GenBank. A French somatic cell hybrid panel was used to physically map the 6 porcine CATS products distinguishable from rodent background product, namely ADRA1A, ADRA2A, ARSA, GNAS1, OXT and TOP1. Of these, the map location of ADRA1A and OXT showed inconsistency with the previously recognised conserved relationship between human and pig. The other four loci mapped to positions consistent with known syntenic relationships. Despite low levels of polymorphism, frequently indistinguishable rodent and porcine products in somatic hybrids and some confusion of identity of gene family members, these CATS primers have made a useful contribution to the porcine-human comparative map. The focus of the project then changed to genetic and molecular characterisation of endogenous retroviruses in pigs and their relatives. Pigs are regarded as a potentially good source of organs and tissues for transplantation into humans. However, porcine endogenous retroviruses have emerged as a possible problem as they can infect cultured human cells. Two main types of pig retrovirus, determined by envelope protein, PERV-A and PERV-B, are widely distributed in different pig breeds and a third less common type, PERV-C, has also been recognised. Endogenous retroviruses were analyzed from the Westran (Westmead transplantation) inbred line of pig, specially bred for biomedical research. Thirty-one 1.8 kb env PCR product clones were sequenced after preliminary screening with the restriction enzymes KpnI and MboI. Five recombinant clones between A and B were identified. 55% of clones (17/31) sequenced had stop codons within the envelope protein-encoding region, which would prevent the retrovirus from making full-length envelope protein recognizable by cell-surface receptors of the virus. The endogenous viruses were physically mapped in Westran pigs by FISH (Fluorescence In Situ Hybridisation) using PERV-A and PERV-B envelope clones as probes. Preliminary FISH data suggest that there are at least 22 PERVs (13 PERV-A and 9 PERV-B) and the chromosomal locations of these in the Westran strain are quite different from European Large White pigs. The sequences and mapping results of inbred Westran pig suggest that there are relatively few PERV integration sites compared with commercial pigs and further that a large proportion of clones are defective due to premature stop codons in the envelope gene. To investigate the relationship of endogenous retroviruses in peccaries and pigs, a set of degenerate primers was used to amplify peccary retroviral sequences. The sequences of two putative retroviral clones showed close homology, albeit with a 534 bp deletion, to mouse and pig retroviral sequences. Also, four non-target sequences were amplified from peccary with the degenerate retroviral primers. They are a part of the peccary cofilin gene, a SINE, and a sequence containing a microsatellite. The peccary endogenous retroviral sequences are significant in that they are the first such sequences reported in peccary species and repudiate old claims in the literature that peccaries do not have C-type retroviral sequences.

Immunological stressors, in the form of clinical and sub-clinical disease are currently controlled using both prophylactic antibiotics in-feed, and therapeutic antibiotic treatment. Respiratory disease, primarily Actinobacillus pleuropneumoniae (App) infection, is recognised as a major factor causing reduced productivity in pigs. This thesis reports investigations into the use of novel immunomodulators in particular Interleukin 4 (IL-4) and Interleukin 1 receptor antagonist (IL-1ra) as alternatives to antibiotics to treat App infection. Immunological and molecular biological assays were used to investigate and accumulate data. An in vitro study undertaken to find potential anti-inflammatory substances, revealed that Interleukin 8 (IL-8) mRNA production stimulated by PMA or LPS in whole pigs' blood was suppressed by IL-4. IL-1ra also suppressed stimulated IL-8 mRNA production by heat killed App bacteria (KB) in vitro. An acute LPS challenge in pigs in vivo however, showed no variation in illness or weight loss between pigs treated prophylactically with anti-inflammatory substance (IL-4 and IL-1ra) and saline treated pigs. The use of plasmids as a delivery system for anti-inflammatory substance did not show promise since it did not enhance growth or prolong the expression of the substances in the pigs. However, in the chronic App challenge model IL-4 and IL-1ra administered prophylactically in vivo showed an ability to improve growth. The therapeutic administration of IL-4 and IL-1ra to App challenged pigs showed no difference in pigs' growth, regardless of the treatment or control administered. To conclude, IL-4 and IL-1ra showed promise when administered prophylactically and improved growth and abrogated disease under conditions of App challenge. However when IL-4 and IL-1ra where administered therapeutically they did not perform as well. Moreover these compounds have potential as a commercial application to reduce the growth reduction caused by disease such as App.