The results showed that only mean wind speeds and sector frequencies from the GWC are the important parameters for the target area.
Then, the following equation was used to calculate the half-sector frequency: # of half-sectored colonies/(# of total colonies–# of fully green colonies) Three independent experiments were performed for each genotype.
(B ) Frequency of half-sectored colonies for the hst3Δ mutant shown in panel A. The half-sector frequency of the hst3Δ mutant was significantly greater (p = 6 × 10−6; Student's t test) than the half-sector frequency of wild type (red dotted line represents the rate shown in Figure 3B ).
Rates of silencing loss as measured by half-sector frequency.
The half-sector frequency of a strain containing the cre gene at HMLα (JRY9628) was significantly different (p = 0.003; Student's t test) from the half-sector frequency of a strain containing the cre gene at HMRα (JRY9629).
Whereas the deletion of HST3 caused a threefold increase in the half-sector frequency of wild type (p = 3 × 10−4; Student's t test), it did not significantly affect the half-sector frequency of the H3 K56Q mutant (p = 0.3; Student's t test) or the surprisingly high half-sector frequency of the H3 K56R mutant (p = 0.06; Student's t test) (Table 1 and Figure 7D).
The half-sector frequency of the wild-type strain containing only one copy of the histone H3 H4 gene pair was significantly higher (p = 0.001; Student's t test) than the half-sector frequency of the strain shown in Figure 3B containing both copies of the histone H3 H4 gene pair (red dotted line) (see Figure 7 figure supplement 2 ).
For both HMLα ::cre - and HMRα ::cre -containing strains, the half-sector frequency of the sir1Δ mutant was significantly higher (p = 2 × 10−4 for HMLα ::cre, p = 7 × 10−7 for HMRα ::cre ; Student's t test) than the half-sector frequency of wild type (red dotted lines represent the rates shown in Figure 3B ).
The half-sector frequencies of the sir1, sir3 and sir4 hemizygotes were significantly higher (*p < 0.05, **p < 0.01; Student's t test) than the half-sector frequency of the wild-type diploid.
Whereas the reduction from two copies of the histone H3 H4 gene pair to one copy did enhance the sectoring phenotype of hst3Δ colonies (compare panels A and C in Figure 7 and panels A and B in Figure 7 figure supplement 1), it did not increase the half-sector frequency in the hst3Δ background as it did in the wild-type background (Table 1 and Figure 7B,D).
Differences between sectoring patterns and half-sector frequencies are considered further in the 'Discussion'.
