抄録
In the present study the change in strain specificity and transplantability was investigated in the MY-mouse sarcoma in relation to the alteration from diploidy to tetraploidy of stem-cells.
In early transplant generations, the present tumor was transplantable to mice of SMA, DM and some other strains and characterized by stem-cells of a near-diploid complex. On the other hand, this tumor failed to grow in mice of C3H, DBA/Ma, A, SWR and Swiss albino which were imported from the United States. After the 94th transplant generation, this tumor became transplantable to mice of various strains such as DM, D103, SMA, S4, SK, SL, SF, C57L, C57BL, C58, DBA/Ma, C3H, A, SWR, Swiss albino, sps, dd and dba. At the same time the tumor stem-cells showed a change in chromosome number from near-diploidy to near-tetraploidy. Morphological analysis of chromosomes revealed that the near-tetraploid cells seemed to be derived from near-diploid cells through the mechanism of chromosomes duplication. The evidence obtained indicates that changes have occurred in the stemline chromosomes in association with changes in tumor properties during serial transfers.
