Figure 5.

Analysis of Penelope expression in parental strains and reciprocal hybrids. (A) Transfer analysis of RNA isolated from parental strains and dysgenic hybrids using the ³²P-labeled XhoI fragment of Penelope as a probe. Lanes: 1, dysgenic females; 2, dysgenic males; 3, females from the reciprocal cross; 4, males from the reciprocal cross; 5, strain 160 flies; 6, strain 9 flies. The position of the 2.6-kb transcript induced in dysgenic hybrids is indicated by the arrow. (B) Five micrograms of poly(A)⁺-containing RNA isolated either from ovaries or from fly carcasses lacking ovaries was subjected to Northern blot analysis as described above. Lanes: 1, carcasses of females from the reciprocal cross without ovaries; 2, carcasses of dysgenic females without ovaries; 3, ovaries isolated from females of the reciprocal cross; 4, ovaries isolated from dysgenic females. The position corresponding to the 2.6-kb transcript induced in the ovaries is indicated by the arrow. (C) The same blot was rehybridized with a Drosophila actin gene and is shown as a marker for the amount of RNA. The position of the actin RNA is indicated by the arrow.