The major group-specific antigen (gs-a) of avian leukoviruses was detected by radioimmunoassay in extracellular medium of all embryonic cultures prepared from infected chickens. Embryos of birds not carrying an avian ]eukosis virus infection and of chickens from a leukosis-free flock could thus clearly be distinguished from infected ones. Release of group-specific antigen into the extracellular...

Avian leukosis virus subgroup J (ALV-J) is a new type of virus that mainly induces myeloid leukosis (ML) in chickens. To further elucidate the pathogenesis of ALV-J infection and tumor development, expression profiles from the bone marrow tissue of 15 infected and 18 non-infected birds from a local-breed poultry-farm under naturally infected conditions, were analyzed by suppression-subtractive ...

With total dependence on the host cell, several viruses have adopted strategies to modulate the host cellular environment, including the modulation of microRNA (miRNA) pathway through virus-encoded miRNAs. Several avian viruses, mostly herpesviruses, have been shown to encode a number of novel miRNAs. These include the highly oncogenic Marek's disease virus-1 (26 miRNAs), avirulent Marek's dise...

Avian lymphoid leukosis can be induced by lymphoid leukosis viruses belonging to Subgroups A, B, C, and D. The endogenous virus of the chicken (Rous-associated virus type 0) belongs to Subgroup E and has little, if any, potential for inducing lymphoid leukosis. Nearly all chicken flocks are infected with Subgroup A lymphoid leukosis virus. This virus can be transmitted from dam to offspring or ...

Neoplasms of the lymphatic tissue in the bovine species can be classified into two major types according to clinical and epidemiological data: 1. The juvenile form of bovine leukosis, with three different clinical forms: the multicentric, thymic, and cutaneous forms. The juvenile form is rare and shows a random geographical distribution. It has also been called sporadic bovine leukosis. 2. The ...

It has been reported that some strains of transplantable fowl leukosis are capable of inducing sarcomas at the site of inoculation when suitable material is injected intramuscularly or subcutaneously. Observations on this subject have been published bv Oberling and Gu&in (] 8,19, 20), Rothc Meyer and Engelbreth-Ilolm, for strain E.S., (22, 6), Stubbs and Furth, for strain 13, (2~). Histological...

The RNAs of several classes of avian and murine RNA tumor viruses were compared. The 60-70s RNA complex of cloned nondefective avian sarcomaviruses contains only 30-40s RNA species of class a, which are larger than the 30-40s RNA species of class b found in avian transformation-defective or leukosis viruses. The RNA of a recombinant avian sarcoma virus, carrying a host range marker of a leukosi...