Abstract
Karyotypes in several lines of the mouse lymphocytic neoplasm, P388, growing in vivo and in vitro, were examined. Parental ascites line (P388) was characterized by stemline cells with 41 telocentric chromosomes. Modal chromosome number of another ascites subline, P388/L, was 44, all being of telocentric type. Although all chromosomes in these two lines were telocentric, the length of chromosomes was considerably different from that of normal somatic ones. On the other hand, P388/P line, adapted to in vitro culture, was remarkable by a drastic change of karyotype, the new one consisting of telocentric, median and submedian metacentric chromosomes. The majority of cells of this line had 34 telocentric, 11 median metacentric and 4 submedian metacentric chromosomes. Four single-cell clones derived from the P388/P line had similar karyotypes to that of the parental line, but chromosome number, length of chromosomes and arm index of metacentric chromosomes were slightly different. The P388/R-26 line which was developed by reinoculation of culture-adapted cells into mice had also complicated karyotypes like the parental cultured line, but the chromosome number, especially that of metacentric chromosomes, was lower. Based on the above investigations, the relation between chromosome alteration and growth capacity of tumor cells were discussed.
