iGenetics 3rd Edition by Peter Russell

Exercise 5

An autopsy of a cat that died from feline sarcoma revealed neoplastic cells in the muscle and bone marrow but not in the brain, liver, or kidneys. To gather evidence for the hypothesis that the virus FeSV contributed to the cancer, Southern blot analysis was performed on DNA isolated from these tissues and on a cDNA clone of the FeSV viral genome. The DNA was digested with the enzyme Hin dIII, separated by size on an agarose gel, and transferred to a membrane. The resulting Southern blot was hybridized with a 32 P-labeled probe made from a 1.0-kb Hin dIII fragment of the feline fes proto-oncogene cDNA. The autoradiogram revealed a 3.4-kb band in each lane, with an additional 1.2-kb band in the lanes with muscle and bone marrow DNA. Only a 1.2-kb band was seen in the lane loaded with Hin dIII-cut FeSV cDNA. Explain these results, including the size of the bands seen. Do these results support the hypothesis?