Mapping the iav locus. A, Deficiency-duplication mapping. The indicated deficiencies and duplication were crossed to iav¹ and scored for ability to complement the locomotor inactivity phenotype. The right edge of the candidate region is defined by the gene ogre, which complements iav and is to the left of Df(1)3196 but is uncovered by Df(1)947 (Curtin et al., 1999). The left edge is defined by the lethal P element insertion l(1)G0254 (Schaefer et al., 1999), which is in the predicted gene CG4094 in 6C10-11 (data not shown). This insertion is not rescued by Dp(1;3)sn[sn13a1], indicating that it is left relative to the duplication. B, The iav candidate region at higher resolution assembled from Flybase (The FlyBase Consortium, 2003). Predicted genes are shown above and below the line representing the genetic region. The circles show P-element insertions, and inverted triangles a-d represent sequence polymorphisms used for recombination mapping (see Materials and Methods). The left extent of the candidate region is defined by the lethal P insertion l(1)G0254 in cytogenetic region 6C5 and the right by the gene ogre in 6E4, because Df (1)3196 (Df(1)Sxl-bt) removes ogre yet complements iav (Curtin et al., 1999). C, CG4536 gene structure and lesions in the iav alleles. Predicted structure of the iav protein and the iav mutant alleles. Gene structure prediction is from Flybase release 3.1 (The FlyBase Consortium, 2003) and from PCR 5′ and 3′ RACE analyses and sequencing.