Progress 10/01/12 to 09/30/13
Outputs
Progress Report Objectives (from AD-416): Determine the etiology and molecular and biological characteristics of spontaneous avian leukosis-like tumors in broiler breeder chickens. Approach (from AD-416): Standard virological assays using chicken embryo fibroblasts to propagate and prepare a working stock of ALV-E isolates obtained from AVIAGEN breeders will be used. The entire genome of two selected isolates (ADOL- AF-227 and ADOL-AF-229) will be sequenced and compared with published sequences of prototype ALV-E and any mutations or variations will be determined. The pathogenicity of the ALV-E isolates will be determined in ADOL Rapid Feathering Susceptible (RFS) chicken line (susceptible to all subgroups of ALV including subgroup E) and the influence of vaccination with various MD vaccine viruses will be determined. This experiment will be repeated in commercial chickens that are vaccinated with various Marek�s disease vaccine viruses. The cell type involved in these tumors will be determined using histopathology, immunohistochemistry and immunofluorescent assays. A pyrosequencing assay will be used to assess the TVB genotypes of commercial broiler breeder chickens (200 chickens) in order to determine the genetic susceptibility of the commercial chicken lines to ALV-E. Using gene expression analysis by microarrays, and by using DNA Southern blotting and hybridization, the tumors induced in ADOL RFS and commercial chickens (20 samples) will be molecularly characterized and the oncogene involved will be determined. Based on the results of these studies, methods such as testing and identifying breeders affected with this virus and elimination of positives will be proposed to reduce or eliminate these tumors. We will also generate information regarding a) genetic susceptibility of Aviagen breeders to ALV-E; and b) role of certain serotypes MD vaccine and in ovo vaccination in development of these spontaneous tumors. This information will be provided to Aviagen for consideration in their breeding and MD vaccination programs. This project is directly linked to Specific Cooperative Agreement 3635- 32000-016-05S titled �Further Studies of Spontaneous Avian Leukosis-Like Tumors in Chickens.� Pyrosequencing assay of blood DNA from 250 commercial broiler breeder chickens was completed, and the TVB genotype in the commercial chicken lines was determined. A high titer pool of a subgroup E avian leukosis virus (ALV-E) named AF-229 (isolated from a commercial chicken line) is being cloned and prepared for sequencing; once sequenced, we will compare its sequence with that of prototype ALV-E, Rous Associated Virus-0.
Impacts
(N/A)
Publications
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Progress 10/01/11 to 09/30/12
Outputs
Progress Report Objectives (from AD-416): Determine the etiology and molecular and biological characteristics of spontaneous avian leukosis-like tumors in broiler breeder chickens. Approach (from AD-416): Standard virological assays using chicken embryo fibroblasts to propagate and prepare a working stock of ALV-E isolates obtained from AVIAGEN breeders will be used. The entire genome of two selected isolates (ADOL- AF-227 and ADOL-AF-229) will be sequenced and compared with published sequences of prototype ALV-E and any mutations or variations will be determined. The pathogenicity of the ALV-E isolates will be determined in ADOL Rapid Feathering Susceptible (RFS) chicken line (susceptible to all subgroups of ALV including subgroup E) and the influence of vaccination with various MD vaccine viruses will be determined. This experiment will be repeated in commercial chickens that are vaccinated with various Marek�s disease vaccine viruses. The cell type involved in these tumors will be determined using histopathology, immunohistochemistry and immunofluorescent assays. A pyrosequencing assay will be used to assess the TVB genotypes of commercial broiler breeder chickens (200 chickens) in order to determine the genetic susceptibility of the commercial chicken lines to ALV-E. Using gene expression analysis by microarrays, and by using DNA Southern blotting and hybridization, the tumors induced in ADOL RFS and commercial chickens (20 samples) will be molecularly characterized and the oncogene involved will be determined. Based on the results of these studies, methods such as testing and identifying breeders affected with this virus and elimination of positives will be proposed to reduce or eliminate these tumors. We will also generate information regarding a) genetic susceptibility of Aviagen breeders to ALV-E; and b) role of certain serotypes MD vaccine and in ovo vaccination in development of these spontaneous tumors. This information will be provided to Aviagen for consideration in their breeding and MD vaccination programs. This project is directly linked to Specific Cooperative Agreement 3635- 32000-016-05S titled �Further Studies of Spontaneous Avian Leukosis-Like Tumors in Chickens.� In order to determine the genetic susceptibility of the commercial chicken lines to subgroup E avian leukosis virus (ALV-E), blood DNA from 200 commercial broiler breeder chickens is being processed for pyrosequencing assay to determine the TVB genotypes in the commercial chicken lines. An ALV-E named AF-229 isolated from the commercial chicken lines is being passaged in susceptible chicken embryo fibroblasts of ADOL lines RFS and 15B1 to obtain a high titer working pool for sequencing; once sequenced, we will compare its sequence with that of prototype ALV-E, Rous Associated Virus-0.
Impacts
(N/A)
Publications
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