FIG. 4.

Direction of Tn917 orientation is biased locally but not globally. (A) The insertion of Tn917 into the plus strand (positive orientation) or the minus strand (negative orientation) was noted for each mutant relative to the transposon's location in the genome. (B) The orientation bias of 1,000-bp regions which contained five or more insertions were analyzed by subtracting the number of insertions on the minus strand from the number on the plus strand and dividing by the total. Insertions that occurred multiple times in the same base were counted only once.