in contrast , transfection of dhfr- cho cells with a vector containing either of two distinct 0.34-kilobase human alphoid dna segments ( and selection to 0.05 to 10.0 microm mtx ) showed an approximately 50 % increase in chromosome number and marked changes in chromosome structure , including one or two dicentric or ring forms per cell .
C0729606
chromosome structure
C0007634
cell