Fig. 7. Transposable element display analysis of progeny arising from a cross between individuals heterozygous for a non-autonomous piggyBac element and a Mos1 vector containing the piggyBac transposase gene under the regulatory control of the hsp70 promoter of Drosophila melanogaster and individuals homozygous for kh^w. These progeny were selected for analysis because their eye color phenotype was different from the parental phenotype, suggesting that a transposition resulting in a position-dependent alteration in the phenotype had occurred. Progeny from two parental lines are shown (40D, 40L). The piggyBac element inherited through the germ line yields an intensely labeled PCR product (arrow). P refers to the parental insect. Numbered lanes contain results from individual progeny. No evidence of germ-line movement is present. Some of the progeny analyzed were themselves heterozygous for the non-autonomous element and the transposase-expressing Mos1 vector (h). In these heterozygotes, there was no evidence for somatic transposition of the elements. Molecular size markers, in base pairs, are shown.