TABLE 2.
Lack of effect of disruption of hH1 on RIP mutations
| Type | Crossa | Relevant genotype | % RIP frequency (mean ± SD)b | No. of progeny analyzed |
|---|---|---|---|---|
| 1 | FGSC 987 × N228 | (+) × al-1+/al-1+ | 47 ± 9 | 1,786 |
| 2 | N1815 × N228 | hH1RIP × al-1+/al-1+ | 77 ± 6 | 2,023 |
| 3 | s-wt × N228 | (+) × al-1+/al-1+ | 66 ± 6 | 6,348 |
| 4 | s-hH1 × N228 | hH1RIP × al-1+/al-1+ | 57 ± 6 | 4,045 |
| 5 | d-hH1 × FGSC 987 | hH1RIP; al-1+/al-1+ × (+) | 69 ± 14 | 3,067 |
| 6 | d-hH1 × N1815 | hH1RIP; al-1+/al-1+ × hH1RIP | 73 ± 11 | 2,870 |
| 7 | d-wt × FGSC 987 | al-1+/al-1+ × (+) | 73 ± 6 | 4,823 |
| 8 | d-wt × N1815 | al-1+/al-1+ × hH1RIP | 74 ± 7 | 4,288 |
Strain N228 has an ectopic duplication of the wild-type al-1+ gene, and FGSC 987 is a wild-type (+) strain. A total of 11 wild-type (s-wt) and 7 hH1RIP (s-hH1) progeny were isolated from a cross between N1815 and FGSC 988. Crosses of s-wt and s-hH1 strains with N228 (type 3 and 4 crosses) were designed to test linkage of the hH1RIP allele with increased RIP frequencies observed in crosses of N1815 and N228 (compare type 1 and 2 crosses). Duplications of al-1+ in wild-type (d-wt) or hH1RIP (d-hH1) progeny were obtained by crossing N1815 and N228 and selecting progeny whose al-1+ copies had survived RIP. Eight d-hH1 and seven d-wt strains were crossed with wild-type or hH1RIP strains (type 5 to 8 crosses).
Because all crosses included a parent with a single al-1 gene, the RIP frequency was calculated as (number of white colonies/total number of colonies) × 200.