Maintenance of kappa particles in cells recently deprived of gene K (stock 51, syngen 4) of Paramecium aurelia

Abstract

1. Heterozygous (K/k) killer paramecia containing kappa particles from stock 51, syngen 4 of Paramecium aurelia were passed through autogamy, and the kk offspring tested for killing ability and for presence of stainable kappa particles at various fission stages.2. After eight fissions, a small proportion of the paramecia were non-killers, and a few lacked stainable particles. After the 12th fission nearly all cells lacked kappa.3. Mild starvation of the kk kappa-bearing paramecia resulted in complete loss of kappa and conversion to non-killers, even when applied to animals only one fission after the loss of gene K at autogamy.4. The results obtained here show some discrepancy with data obtained earlier, both with kappa, and with mu particles in stock 540, syngen 1. The reasons for this discrepancy are at present not clear.