Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2008
Publication Date: 9/30/2008
Citation: Hunt, Henry D., Fadly, Aly M., Silva, Robert F., Zhang, Huanmin. 2008. Survey of Endogenous Virus and TVB* Receptor Status of Commercial Chicken Stocks Supplying Specific-Pathogen-Free Eggs. Avian Diseases. 52(3):433-440. Interpretive Summary: Avian leukosis virus (ALV) is an economically important virus infection that can cause cancer like disease and other production problems in chickens. Previous observations suggest that the virus is changing (mutating) at a higher rate, however, information regarding the ability of ALV to recombine with other subgroups of ALV viruses is not known. The chicken’s endogenous virus genes can influence the rate of mutation and are therefore a risk factor for producing emerging disease. The endogenous ALV (ALVE) profile of commercial chicken lines that supply specific pathogen free (SPF) cells to the poultry vaccine manufacturers and biologic testing agencies was analyzed. This analysis revealed these cells have the potential to induce changes in ALV. The information is essential to poultry breeders who supply SPF embryonated eggs and/or cells to vaccine manufacturers. Recommendations are made to remove this potential problem ALVE gene from the commercial chicken lines producing SPF materials.
Technical Abstract: The ALVE endogenous virus and the ALVE receptor status of six commercial lines supplying specific pathogen free eggs were analyzed. Commercial lines A, E and F contained replication competent ALVE inserts. Line A was fixed for ALVE21 and lines E and F were segregating for ALVE10. In addition ALVE1 was detected in all lines. Lines B, D and F were essentially fixed for the TVB*S1 allele that confers susceptibility to ALVE while lines A, C, B and E were resistant containing either the TVB*S3 or TVB*R alleles. The implications of these findings for vaccine manufactures and regulatory agencies are discussed.