Fig. 2. spin is a novel, rotation-specific Fas2 allele. Schematic view of the Fas2 gene and the Fas2^spin p{GawB} P-element insertion (A). Expression of Fas2 in stage 9 (B) and 14 (C) wild-type embryos. In a Fas2^spin lethal revertant allele (Fas2^spinRM1), Fas2 expression is lost (D), while Fas2 expression in the viable Fas2^spin allele is strongly reduced (E), when compared with wild type (compare D with B and E with C). Expression of Fas2 (green) in a wild-type eye imaginal discs starts anterior to the morphogenetic furrow (F, arrowhead), while it is strongly reduced in a Fas2^spin eye imaginal disc (G). (H) Histogram showing the percentage of males with normal genitalia, after expression of Fas2 using a UAS-Fas2 transgene under the control of a heat-inducible GAL4 line. For each time-point, the phenotype of the external genitalia has been determined and the extent of rotation rescue plotted. Heat-shocked males have the following genotype: Fas2^spinR5/Y; UAS-Fas2/HS-GAL4. Fas2^spinR5 is a Fas2^spin excision allele that retains the original Fas2^spin rotation phenotype but lacks GAL4 activity.