A non-Mendelian factor, [eta⁺], causes lethality of yeast omnipotent-suppressor strains

Summary

Omnipotent suppressors cause translational ambiguity and have been associated with poor growth and inviability. We now report that a non-Mendelian element, [eta⁺], causes this inviability. In [eta⁻] strains the suppressors are not inviable. The [eta⁺] genetic element segregates to about 70% of the meiotic progeny, although almost all of the spores probably have the [eta⁺] phenotype for the first few divisions. Growth on 5 mM guanidine hydrochloride efficiently causes [eta⁺] strains to become [eta⁻]. The [eta⁺] factor has many similarities with the previously described [psi⁺] factor (Cox 1965, 1971). However, [eta⁺] and [psi⁺] differ in their patterns of inheritance, and by the fact that [psi⁺] affects ochre specific and not omnipotent suppressors, while the converse is true of [eta⁺].