G>T transversion VS. T>G transversion? So I'm reading about how mutations in DNA can be caused by oxidative damage. An example of a product of oxidative damage is given: 8-oxo-7-hydrodeoxyguanosine My textbook says that this product frequently mispairs with A, resulting in a high level of **G-->T transversions**. What I'm not understanding is why it's a G-->T transversion. If the 8-oxo-G is pairing with A, resulting an an A-G pair, isn't this a T-->G transversion? Or does the order not matter?

Originally the position had a G:C pair. After the mutation, there is an oxoG:C pair. Upon replication, the strand with C will pair to G and the original pair will be created as expected. However, since oxoG can also pair with A, the strand with oxoG may form an oxoG:A pair. Another round of replication gives the products T:A and oxoG:A. Thus the G in the original strand is replaced by T (ie it is a G$\ce{->}$T transversion).