Infection into paramecia of metagons derived from other mate-killer paramecia

Abstract

1. It has been shown that metagons, gene-controlled units necessary for maintenance of mu particles inParamecium aurelia, can be extracted from cells containing one or both of the dominant genesM₁andM₂, and reinfected into other paramecia. Provided the latter contain mu particles before infection, the introduced metagons resume their normal function of maintaining the mu particles.2. Homogenates containing metagons have been fractionated in various ways. The metagon activity is found in the sediment after centrifuging at 105,000 g. for 90 min., and is retained after deoxycholate treatment removing the microsomal membranes, and after phenol extraction removing the ribosomal protein. By lowering the magnesium concentration, some metagon activity passes from the microsomes into the supernatant.3. Metagon activity in RNA fractions is destroyed by ribonuclease at a concentration of 5 μg. per ml.4. The metagons both in extracts and inside the cells appear often to be aggregated in clumps, the individual units of which are each functionally active in maintaining mu particles in living cells.5. It is concluded that the metagon may be considered as a very stable and repeatedly functioning form of ‘messenger’ RNA.