Paternal inheritance of a daughterless sex ratio factor

Abstract

Here we report an unusual case of extrachromosomal inheritance in the parasitic wasp, Nasonia vitripennis. It was accidentally discovered during attempts to select for genetic variability in the sex ratio produced by females of this wasp. The trait, henceforth termed ‘Daughterless’ (Dl), is transferred paternally and causes the mates of carrier males to produce only sons. The effect is not due to mortality of female offspring but rather to an increase in the number of male offspring. Dl can be shown to be extrachromosomally inherited by experimental use of the haplodiploid sex determination of this wasp. After introduction at low frequency, the trait increases to predominance in an experimental population within a few generations. The Dl trait is of theoretical interest because of its paternal inheritance, and may have practical applications as a biological control agent in pest organisms with haplodiploid sex determination.