Thesis (Ph. D.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains viii, 174 p. : ill. Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains x, 169 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

This thesis describes the development of serum and whole blood immunodiagnostic assays for Maedi-Visna virus (MVV). All previously described recombinant MVV ELISA assays utilised either the core p25 or transmembrane (TM) proteins alone, or combined, but as individual proteins. The p25 and TM genes of MVV were cloned individually into the pGEX-2T expression vector. Both proteins were expressed as a combined fusion protein in frame with glutathione S-transferase (GST). The purified recombinant antigens (GST-TM and GST-TM-p25) were used to develop a MVV ELISA. Sera from 46 positive and 46 negative sheep were tested using the GST-TM and GST-TM-p25 ELISAs and a commercial p25 EIA kit. A two-graph receiver operating characteristic (TG-ROC) analysis program was used to interpret the data. The GST-TM-p25 ELISA was more sensitive than the commercial assay which is based on the p25 antigen alone and more specific than the GST-TM ELISA. The GST-TM-p25 ELISA showed a sensitivity and specificity of 100%. The human AIDS lentivirus transmembrane (TM) glycoprotein portion of the envelope viral protein has been identified as the antigen most consistently recognised by antibodies. There is suggestive evidence that the same applies to MVV as the GST-TM fusion protein, expressed in E. coli, has comparable sensitivity to the GST-TM-p25 fusion protein, but lacks specificity. However, due to the hydrophobic nature of the MVV TM protein, purification of the expressed fusion protein required lengthy purification protocols. This was despite the fact that only a truncated version of the TM protein was expressed. This prompted investigating an alternative expression system that could possibly circumvent the above mentioned problems. The yeast Pichia pastoris is known to be suitable for the high-level expression of heterologous proteins which are secreted into the culture supernatant. These features made P. pastoris an attractive host for the expression of the hydrophobic TM protein of MVV. However, limited success was achieved as only low expression levels were obtained and detection and quantification was only accomplished by means of ELISA. Evaluation of the diagnostic performance of the P. pastoris expressed MVV TM-polypeptide was performed using a panel of 36 confirmed negative and positive sera, and evaluated using a TG-ROC analysis programme, which yielded an equal Se and Sp of 83%. The use of a novel rapid immunoassay system, which allows the detection of circulating antibodies in whole blood, has been investigated for use as a MVV diagnostic assay. The central feature of this immunoassay lies in a monoclonal antibody against a glycophorin epitope present on all sheep erythrocytes. A Fab'-peptide conjugate was constructed by coupling a synthetic peptide, corresponding to a sequence from MVV TM protein, to the hinge region of the Fab' fragment of the antisheep erythrocyte antibody. Within the limited number of 10 seronegative and 10 seropositive samples the autologous red blood cell agglutination assay had a sensitivity of 90% and a specificity of 80%. Despite the limitations and difficulties encountered, the use of such rapid whole blood immunodiagnostic assays for MVV holds promise. / Thesis (Ph.D.)-University of Natal, Durban, 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.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 139-161).

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 6 uppsatser.

Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves : 172-189). Also available on the Internet.

Thesis (Ph.D.)--Ohio University, November, 2004. / Includes bibliographical references (leaves 115-128)

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains ix, 172 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains iv, 66, [6] p. : ill. Includes abstract. Includes bibliographical references.