Test for fused-cell origin of tumors with Mus caroli carrying glucose-6-phosphate dehydrogenase cellular mosaicism.

A test system for examining the fused cell-origin of tumors was developed by application of Mus caroli carrying the X-chromosome inactivation cellular mosaicism for G6PD. A G6PD heterodimer pattern is expected if a tumor is initiated from a fused cell. Among tumors induced by subcutaneous injection of a high dose of MCA, three tumors exhibited a single G6PD phenotype and one tumor exhibited a multiple G6PD phenotype; however, the G6PD heterodimer pattern was not found. Although the results obtained were not conclusive, this system is thought to be useful for detecting a possible fused cell-origin of tumors.