Reversion of protoplasts and spheroplasts in the yeast Nadsonia elongata

Summary The time rate of regeneration of the cell wall and reversion of protoplasts of the yeast Nadsonia elongata to cells of normal shape and size has been compared with the capability for regeneration of spheroplasts of this yeast. Nearly all protoplasts in a given culture were able to regenerate new walls and had usually reverted to cells of normal appearance by the 30th h of cultivation. Spheroplasts required only half this time to do this. These results can be interpreted as evidence that regeneration of a wall by protoplasts does not depend upon the presence of a cell wall primer, because the proportion of reverting protoplasts (which lack wall remnants) was the same as that of reverting spheroplasts (which possess them). The presence of wall remnants in spheroplasts appears to have merely an accelerating effect on the formation of a new wall and on subsequent reversion of the spheroplasts to complete cells of normal shape and size.