Table A5 Expected tetrad frequencies (per 1000 tetrads) for the MMR-proficient cross of Table 5
Meiotic pathwayMitotic pathwayObserved per 1000Meiotic pathwayMitotic pathwayCalculated total
6:2B[gD + (1 − g)D/2]BP[g + (1 − g)um]55.515.839.655.5
2:6(1 − B)[gD + (1 − g)D/2](1 − B)P[g + (1 − g)un]64.127.436.764.1
5:30BP(1 − g)(1 − u)8.106.16.1
3:50(1 − B)P(1 − g)(1 − u))8.7010.610.6
  • Since HC ratios are unperturbed by MMR disparity (Detloff et al. 1991), the ratio 5:3/3:5 is B/(1 − B), giving the expectations 5:3 = 6.1 and 3:5 = 10.6. The numbers of 6:2 and 2:6 tetrads contributed by the meiotic pathway were calculated using B = 0.365 and g = 0.08. P = 216, D = 80 from Table A4. These were subtracted from the total observed values to get the mitotic pathway values. From the ratio of mitotic pathway FC numbers, the ratio m/n = 2.2 can be obtained, independently of u, and, thus, independently of any assumption about whether all acts of unwinding render a mismatch eligible for repair. Evaluating u from the sum 5:3 + 3:5 gives u = 0.915.