Figure 3. Short periodic tracts of homology induce efficient RIP mutation.

a, The general structure of repeat constructs analyzed in b-f. Each bipartite repeat unit contains 220 base pairs of perfect homology (turquoise) and 200 base pairs of interrupted homology (blue and blue/grey, corresponding to Reference (Ref) and Test segments, respectively). Only the Test segment is allowed to vary between constructs.

b, Mutation profiles for situations of perfect homology (Test = Ref ) and random homology (Test = GFP). Each mutation profile summarizes C/T and G/A transitions found over the entire sequenced region in 30 spores obtained from a single cross.

c, The number of mutations over the total sequenced region for repeat constructs carrying a region of heterology in the middle of the 200-bp test sequence that was otherwise identical to the reference. A[19], a 19-bp dA:dT tract; N[19], a 19-bp tract of random sequence; CA[11], CpA dinucleotide repeated 11 times.

d, Schematic representation of tested partial homologies with the matching periodicity of 11 bp: blue - matched bases, grey - random mismatched bases.

e, The number of mutations in the total sequenced (magenta) and the invariant (green) regions corresponding to Test segments in c. Regression analysis excludes 0H-11N. r represents Pearson's correlation coefficient. The number of analyzed crosses and spores is provided in Table 1.

f, Statistical analysis of critical partial homologies. Mutation count distributions are compared by the two-sided Kolmogorov-Smirnov test: *** P < 0.001; NS P ≥ 0.05.

The number of analyzed crosses and spores is provided in Table 1. Error bars represent s.e.m.