Radiation-induced Dominant Lethality in Haploid and Diploid Sperm of the Wasp Mormoniella.

I N yeast, more dominant lethality is induced in diploid than in haploid vegetative cells (OWEN and MORTIMER 1956), and this is consistent with the observed increase in X-ray sensitivity of cells of higher ploidy in this organism ( MORTIMER 1958). To study dominant lethality with respect to ploidy in a higher organism, the parasitic wasp Mormoniella was selected. Stocks are available which produce normal haploid males with haploid sperm as well as fertile diploid males with 100 percent diploid sperm. The males can be irradiated and mated with normal females for an unambiguous analysis of dominant lethality in haploid and diploid nuclei.