Polarization of the honey bee gynandromorphic blastoderm

Honey bee (Apis mellifera L.) gynandromorphs arise because one or more accessory sperms, which normally degenerate, develop into male tissue. Twenty-two external morphological structures were examined in 1555 gynandromorphs from 8 gynandromorph-producing queens. The frequency with which a structure was male (percent male) and its longitudinal position on the blastoderm fate map were examined for each structure. When grouped by body region, there were no significant differences between the head, thorax or abdomen in the frequency at which a structure was male. In the head region, a significant relationship was discovered between the frequency that a structure was male and its longitudinal location on the blastoderm (r = −0.884, F = 35.76, degrees of freedom (DF) = 1 and 10, p < 0.0001). A reasonable contour map of the blastoderm was prepared showing the regions with comparable frequency of structures being found male. The compound eye (73.9%) and lateral ocellus (63.9%) were the structures most frequently male. The mouthparts, for example the labial palp (24.5%), showed the least frequency of being male. A hypothesis based upon previous cytological observations was formulated to explain these results. The diploid zygotic nucleus, which will form the female tissue of a gynandromorph, is near the primordia for the mouthparts when it initiates cleavage. Most of the time the mouthparts primordia on the blastoderm are populated by female cells, and the adult structures are most often female. The compound eye and lateral ocellus primordia are near the cephalic pole where the haploid accessory sperm(s) begin division.