(alpharetrovirus) A genus of the family RETROVIRIDAE with type C morphology, that causes malignant and other diseases in wild birds and domestic fowl.

(alpharetrovirus) An rna-type retrovirus with a c-type morphology. The viruses have a widespread distribution and include both exogenous (vertical and horizontal transmission) and endogenous viruses of chickens and some other birds. Avian Leukosis virus is the type species. Distantly related endogenous sequences are found in birds and mammals. Virus infections are associated with malignancies and some other diseases such as wasting, and osteopetrosis. Many oncogene-containing members of the genus have been isolated.

(alpharetrovirus) Genus of the family retroviridae with type C morphology that causes malignant and other diseases in wild birds and domestic fowl; widespread vertically and horizontally transmitted exogenous and endogenous viruses; associated with malignancies, wasting, and osteopetrosis.