Chromosome Studies of a Frog Renal Adenocarcinoma Line Carried by Serial Intraocular Transplantation

Summary

Chromosome analyses were made on 1 primary renal adenocarcinoma of Rana pipiens and on 11 intraocular tumors, derived from the primary tumor through serial transplantation in the anterior eye chamber of adult frogs. The transplanted tumors from the second, fourth, sixth, and eighth generations were in culture from 1 to 2.7 years. Changes in chromosome number were observed in 4 transplanted tumors and constituted 3 percent of all the tumor cells examined; metaphases from normal embryonic and adult bone marrow cells were diploid. Nonspecific structural abnormalities were found in 8 of the 11 transplanted tumors; these abnormalities amounted to 14 percent of the tumor samples, whereas a 2 percent incidence of structural abnormalities was present in the normal tissues. The number and mitotic frequency of stromal cells were estimated from serial sections of some of the tumors and were found to be extremely low, which demonstrates that the chromosome studies are based mainly on epithelial cells of the tumor.