Submitted to: Diseases of Poultry
Publication Type: Book / chapter
Publication Acceptance Date: 1/3/2007
Publication Date: 6/20/2008
Citation: Fadly, A.M., Nair, V. 2008. Leukosis/sarcoma group. In: Saif, Y.M., Fadly, A.M., Glisson, J.R., McDougald, L.R., Nolan, L.K., Swayne, D.E., editors. Diseases of Poultry. 12th edition. Ames, IA: Iowa State University Press. p. 514-568. Interpretive Summary:
Technical Abstract: The leukosis/sarcoma (L/S) group of diseases designates a variety of transmissible benign and malignant neoplasms of chickens caused by members that belong to the family Retroviridae. Lymphoid leukosis has been the most common form of L/S group of diseases seen in field flocks, although myeloid leukosis has also become prevalent. Members of this group of avian viruses are characterized, as are all members of the Retroviridae, by possession of an enzyme reverse transcriptase, which directs the synthesis of the proviral DNA form of the RNA virus that forms part of the retroviral life cycle and from which the family name is derived. These avian retroviruses, including avian leukosis virus (ALV)-related viruses, formerly were placed in a subgenus termed avian type C oncornaviruses, but they recently have been termed alpharetroviruses. Members of this group of viruses have similar physical and molecular characteristics and share a common group-specific antigen. Because of the relationships between these viruses, they are discussed as a group in most parts of this chapter. Sections reflecting the host response (Pathology and Pathogenesis of the Infectious Process) are discussed under the pathologic entities without regard for the properties of the inducing virus (es) other than their inclusion in the L/S group.