TABLE 3.
Summary of phenotypes observed for indicated histone allelesa
| Substitution | Growth in absence of wild type | ribosomal DNA silencing | Telomeric silencing | Growth on HU |
|---|---|---|---|---|
| WT H3/H4 | +++ | +++ | +++ | +++ |
| H4 K31A | +++ | ++++ | ++++ | +++ |
| H4 K31R | +++ | +++++ | ++++ | +++ |
| H4 K31Q | +++ | ++++ | ++++ | +++ |
| H4 K59A | ++ | ++ | + | ++ |
| H4 K59R | ++ | +++ | + | +++ |
| H4 K59Q | +++ | ++ | + | ++ |
| H4 K77A | +++ | +++++ | + | +++ |
| H4 K77R | +++ | +++ | +++++ | +++ |
| H4 K77Q | +++ | +++++ | +++ | +++ |
| H4 K79A | +++ | + | + | +++ |
| H4 K79R | +++ | +++ | +++ | +++ |
| H4 K79Q | +++ | + | + | +++ |
| H3 K56A | +++ | + | +++ | + |
| H3 K56R | +++ | +++ | +++ | + |
| H3 K56Q | +++ | + | ++ | ++ |
a
The mutants were analyzed and their phenotypes were scored arbitrarily with respect to wild type. For a given process, wild type was denoted +++, and those mutants with a negative effect were scored as ++ or +, depending on the severity of the mutation. Alleles that induced an increase in silencing are indicated with ++++ or +++++, the latter of which corresponds to almost-complete repression of the reporter gene.