Diploid Tissue Derived from Accessory Sperm in the Honey Bee.

T H E entry of more than one sperm into the egg of the honey bee at fertilization IS normal. A zygote is formed by the fusion of the pronucleus of one of the sperm with that of the egg; the pronuclei from the accessory sperm undergo abortive division and then disintegrate after the second cleavage of the zygote ( NACHTSHEIM 191 3) . Fertilized eggs, with certain exceptions (MACKENSEN 1951; ROTHENBUHLER 1956,1957; WOYKE l962,1963a, b) develop into females; unfertilized eggs, again with certain exceptions (ONIONS 1912; MACKENSEN 1943; TUCKER 1958), develop into males. Bees with both male and female body parts appear occasionally among the normal bees of a colony. These sex-mosaics or gynandromorphs were studied intensively ( ROTHENBUHLER, POLHEMUS, GOWEN and PARK 1949; ROTHENBUHLER, GOWEN and PARK 1952; ROTHENBUHLER 1956,1957) and it was demonstrated that they originate through the cleavage of accessory sperm nuclei along with zygotic cleavage in the cytoplasm of fertilized eggs. Cleavage cells derived from sperm are haploid and give rise to male structures; those derived from the zygote are diploid and are progenitors of female structures. Of the several occurrences of gynandromorphs which must have originated in some other fashion (MACKENSEN 1951; ROTHENBUHLER 1956, 1957; TUCKER 1958; WOYKE 1962) there were some reported by ROTHENBUHLER which could have been due to the union of two accessory sperm. One such case involved the mating of a homozygous ivoryeyed queen to hemizygous cream-eyed drones. Ivory and cream are indistinguishable white eye mutants, recessive to normal black eye and neither allelic nor linked to each other. Male eye facets are distinguishable from female eye facets in the upper three fourths of the compound eyes by their larger size, and can be recognized in mixtures of male and female facets. Male compound eyes are much larger and more bulbous than female eyes, and the two eyes meet at the middorsal line, whereas female eyes do not. In general, patches of male eye facets can be distinguished from female eye facets by gross observation. As was expected, the female eye facets of both the normal workers and the gynandromorphs of this mating were black and both the normal and gyandromorphic male eye facets were white. In some gyandromorphic individuals, however, the compound eyes consisted at least in part of white female eye facets, instead of black. ROTHENBUHLER suspected that these facets were cream