MODIFICATION OF TRAITS IN MOSAICS FROM BINUCLEATE EGGS OF HABROBRACON

¹ From the Zoölogical Laboratory, University of Pittsburgh, and the Marine Biological Laboratory, Woods Hole, Massachusetts

Mosaic males from heterozygous mothers have shown clear-cut mosaicism for the recessive eye colors cantaloup and white. Orange, however, shows intergradation with black of wild type and ivory shows complicated types of modification and intergradation. A similar condition obtains in the case of gynandromorphs. Males have shown clearcut mosaicism for sixteen other traits. As regards either fused or stumpy legs, however, there is much modification, with evidence that influence is from wild type tissue on the same side of the body, but not on the opposite side. Further evidence is presented indicating that gynandromorphs show maternal traits in male parts of body while female parts are biparental. Maternal contribution to male and female parts may be different. A male mosaic has been found which is best explained as a haplo-diplont, being in part biparental. A mosaic male from a mother heterozygous for four linked genes indicates such a combination of traits that two crossovers must have taken place in the tetrad, one between two strands, one between the other two, in the egg from which this male developed.