This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Zambernard, J. Articles by McKinnell, R. G. Search for Related Content PubMed PubMed Citation Articles by Zambernard, J. Articles by McKinnell, R. G.

The Fine Structure of Nuclear and Cytoplasmic Inclusions in Primary Renal Tumors of Mutant Leopard Frogs¹

Department of Pathology, University of Colorado Medical Center, Denver, Colorado (J.Z., A.E.V.), and Department of Biology, Newcomb College, Tulane University, New Orleans, Louisiana (R.G.M.)

This investigation summarizes a study of the incidence and fine structure of primary renal tumors found in mutant leopard frogs (Rana pipiens burnsi). Of 204 winter frogs autopsied from Minnesota and South Dakota, renal tumors were found in 13 animals, an incidence of 6.4%. Light microscopic examination showed that all of the renal tumors had Cowdry Type A nuclear inclusions. The fine structure revealed virus and viral-associated structures previously described in inclusion-containing tumors of wild type leopard frogs. Several features were observed which have not been previously described. These were: (a) long, tubular elements associated with nuclear inclusions containing immature and mature virus particles; (b) immature virus particles within the marginated chromatin; (c) images which suggest more than 1 method of viral release from the nucleus; and (d) the migration of mature virus particles into the lumens of agranular cisternae or vacuoles, during which process the virus is enclosed in an extracapsular envelope. This envelope is formed by a pinching off of a portion of the agranular membrane.

¹ This investigation was supported in part by a USPHS Research Grant CA-05935-03 from the National Cancer Institute to R. G. McKinnell, and by a Viral Training Research Grant 5T1 CA5164-01 from the NIH issued to the Department of Pathology, University of Colorado Medical Center, Denver, Colorado.

Received 2/ 1/66.