The incidences of endogenous viral genes (ev-genes) and myb-gene polymorphisms were determined in substrains of strains R, M and G which had been divergently selected or susceptibility to tumour formation induced by Rous Sarcoma virus (RSV) of type A and B. Frequencies of myb gene polymorphisms were also determined in two replicates of strains selected for high and low multiple immune response to challenge with Pasteurella multocida and Mycoplasma gallisepticum. Strains R, M and G were found to contain different sets of ev-genes reflecting their distinct genetic origins. Among eleven ev-genes identified, two showed a significantly increased frequency in the susceptible substrains. One was ev-6, which expresses the viral envelope protein of the endogenous avian leucosis, while the other was a new endogenous viral gene New-E, whose phenotype is unknown. A significant increased incidence of ev-4, reported to be a silent ev-gene, was observed in resistant rather than susceptible substrain. Myb gene polymorphisms were assessed using a cDNA probe and a genomic probe yielding 2 and 3 restriction fragment length polymorphisms (RFLPs) respectively. In strains M and G, only one polymorphism (PM5$ sp+$) observed at an Msp I site located downstream of the last of the c-myb exons was found to be significantly co-selected for susceptibility. Analysis of RFLPs of myb-gene in strains selected for high or low multiple immune response did not reveal any significant response to selection. Rather, polymorphisms seemed to reflect a founder effect as revealed by opposite frequencies obtained in the two replicates. DNA methylation, a possible epigenetic mechanism regulating gene expression, was also investigated in the myb-gene. DNA from semen, blood, spleen, liver and thymus was extracted from organs obtained from chickens at different ages.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.56818 |
| Date | January 1992 |
| Creators | Urbani, Nicola |
| Contributors | Kijhnlein, Urs (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Animal Science.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001323979, proquestno: AAIMM87576, Theses scanned by UMI/ProQuest. |
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