Table 14

Growth of Tetrahymena clones after different types of treatment with T₂ (mean cell number/clone)

(Csaba, G., Németh, G., Vargha, P. Development and persistence of receptor “memory” in a unicellular model system. Expl. Cell Biol. 50, 291-294, 1982)

Group/end of weeks	1^st	4^th	9^th	12^th
Treatment once a week	20.5	19.2	18.7	17.5
Treatment only at the beginning	18.5	17.4	16.0	16.8
Control (untreated)	12.2	11.6	12.2	12.0

Each treated group is significant (p<0.01) to control; each once a week treated group is significant to groups treated at the beginning (at least p<0.05) at each time point.

Conclusions:

1. 1.T₂ increases the growth rate of Tetrahymena.
2. This increase is long lasting and after 12 weeks (about 500 generations) also significant.
3. The increase is significantly reduced with progressing time.
4. Repeated treatment has not deeply impressed effect, than a single treatment (hormonal imprinting), however the decrease was less.