Genetic control of drug resistance: assignment of ama-1 to Chinese hamster chromosome 7, confirmation of assignment of genes coding for TK, GALK, and ACP to chromosome 7, and tentative assignment of TPI to chromosome 8.

The gene which specifies a subunit of RNA polymerase II, ama-1, is assigned to chromosome 7 in the Chinese hamster. The assignment of genes coding for TK, GALK, and ACP to chromosome 7 is confirmed, with a provisional regional assignment of TK and GALK to 7q. On the basis of one clone with six subclones, a provisional assignment of TPI to Chinese hamster chromosome 8 is made. With the assignment of tk and ama-1 to chromosome 7 in the CHO cell line Ama1, this chromosome is shown to have two selectable markers.