Abstract
Summary
Ultrathin sections of the pellets formed by ultracentrifugation of plasmas from birds with myeloblastosis and erythroblastosis have been examined by electron microscopy. In the material from both diseases there were observed structures of similar appearance represented by images of round or oval shape consisting centrally of a dense core of about 40 mμ diameter. These were surrounded by a less dense material and were limited by an outer membrane-like structure with a total particle diameter of about 80 mμ. In many instances the limiting membrane appeared to be double. The ultrastructure of these agents of the avian leukemic diseases was very similar, if not identical, to that of the viruses of other chicken neoplasms. No particles of these characteristics were obtained from the plasmas of apparently healthy chickens.
Get full access to this article
View all access options for this article.