Effect of X-Rays on Micronuclear Number in Paramecium aurelia

Abstract

Exautogamous descendants of P. aurelia exposed to X- rays have reduced viability; one suggested factor has been possible reduction in micronuclear no. below the normal 2. Following variable X-ray treatment of 7 populations of Stock OR, variety 1, of P. aurelia, the animals were allowed to multiply for 24 hrs. at 27[degree]C before fixation and staining. Careful counting of micronuclei of individuals in each population indicated that, although more intensive radiation did produce a greater proportion with abnormal micronuclear no., this factor is insufficient to be the major cause of reduced vigor and death after autogamy. Possibly gene mutations or chromosome aberrations (or both) are the responsible factors.