Double minute chromosomes are not centromeric regions of the host chromosomes

Abstract

The SEWA ascites tumor of the mouse contains, in addition to the ordinary chromosomes, a varying number of minute chromatin bodies, called double minutes (dms). Among 394 cells, 43 were without dms, the others had from 1 to 300 dms. The appearance of the dms suggested that they were acentric, which was also supported by the finding that even the largest dms, which were spheres with a diameter larger than the ordinary chromatid breadth, exhibited no C‐heterochromatin in Hoechst 33258 fluorescence nor in C‐banding with the BSG technique. The conclusion was that the dms of the SEWA tumor have not originated from centromeric regions of ordinary mouse chromosomes. © 1976 Mendelian Society of Lund