Table 3.

Rates and types of changes for nuclear poly(AT) and poly(GT) microsatellites

Microsatellite	Rate of mutation to 5-FOAR (per cell division)	Rate of changes in tract (per cell division)*	Types of alterations
			−2	0	+2	Other†	Total
(AT)16.5	5.1 (4.5–6.4)  × 10−5	1.3  × 10−5	1	1	23	1	26
	2.7 (2.6–3.1)  × 10−5
	3.9  × 10−5
(GT)16.5	4.0 (2.4–5.5)  × 10−5	1.2  × 10−5	4	0	24	1	29
	2.4 (1.9–3.3)  × 10−5
	3.2  × 10−5

^*These rates were determined by multiplying the average rate of mutation to 5-FOA^R by the proportion of 5-FOA^R derivatives that had altered tracts. Most of the 5-FOA^R derivatives that did not have a tract alteration had lost the reporter gene as a consequence of mitotic recombination. 

^† In this class are two 5-FOA^R strains in which the tract had gained more than five repeats.