Biochemical and genetic studies of avian reoviruses /
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| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1991.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy Link to ProQuest copy |
| Abstract: | Reassortants were obtained from cells coinfected with strains 883 and 176 that exhibited the most divergent electropherotypes, in vitro growth and pathogenic properties. Electrophoretic analysis of purified viruses and infected cell lysates identified 10 primary translation products (λ1, λ2, λ3, μ1, μ2, μNS, σ1, σ2, σNS , and σ3)(149 - 39 kDa). μ2 and μNS were posttranslationally cleaved yielding μ2C and μNSC/μNSCs, whereas λ1 was likely modified through a mechanism other than proteolytic cleavage to yield λ1m. μNS appeared to have two alternative cleavage sites. None of the 13 viral proteins of 883 and 176 comigrated on the gel. By analyzing viral proteins of reassortants, protein-coding assignment of each of the 10 genome segments of 883 and 176 was determined. These coding relationships are L1 [to] λ1/ λ1m , L2 (or L3 of 883) [to] λ2, L3 (or L2 of 883) [to] λ3, M1 [to] μ1, M2 [to] μ2/μ2C , M3 [to] μNS/μNSC, S1 [to] σ3 , S2 [to] σ2, S3 [to] σ1 and S4 [to] σNS. Nine small-size viral proteins (35 - 13 kDa) were also identified. Six of them were primary translation products, suggesting that certain genome segment(s) of avian reovirus may encode more than one protein. In coinfections, certain genome segments were observed to be preferentially selected. This is shown to be due to the enhanced growth properties of viruses (reassortants) having the selected genome segment(s). Defective-interfering (DI) panicles lacking one (S1) or two genome segments (S3 and S4) were detected during serial passage of coinfection progeny. The progeny containing the DI panicles encapsidated subgenomic dsRNA segments or Dl RNAs derived from the corresponding segment(s) that were deleted. Analysis of the progeny possessing S1 deletion showed that the S1 segment was responsible for the posttranslational cleavage of μNS, and the subgenomic segment SGS1- 1 derived from the S1 segment was transcribed and expressed. Differences between 883 and 176 in infectious yield, induction of CPE and plaque morphology are shown to be determined by the SI segment... |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Veterinary Microbiology." |
| Physical Description: | xvii, 226 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |