Infection of subgroup J avian leukosis induces erythroblasts and lymphoblasts in Chinese local breed chickens

Abstract

Anaemia, emaciation, increased mortality and decreased egg production were observed in 21 birds in a Chinese
local breed flock infected naturally at 240 days old. Macroscopically, the spleen and kidneys were enlarged. There were
diffuse, multifocal white foci on the surface of the liver, lungs and ovaries. Histopathological examination
demonstrated typical lymphosarcoma cells and erythroblasts in the lungs, spleen, liver, kidneys and ovaries. The
results of polymerase chain reaction (PCR) showed that avian leukosis virus subgroup J (ALV-J) was positive in the
liver, spleen and ovaries. Immunofluorescence assay results further confirmed the presence of ALV-J antigen in the
liver, kidneys and ovaries. Sequence analysis of the specific nucleotides fragments demonstrated that the viruses were
closest to the United Kingdom (UK) prototype strain virus HPRS-103 (97.8% to 98.2%). This is the first report of
erythroblasts and lymphoblasts caused by ALV-J in Chinese local breed chickens.