Fig. 1. pcm¹⁴ is a null allele of pcm.

(A) The genomic region of the pacman gene and the alleles pcm⁵, pcm¹³ and pcm¹⁴, created by imprecise excision of P{EP}EP1526. Green boxes represent exons of pacman, blue boxes represent wild-type genomic DNA sequences unaffected by the imprecise excisions and thin red lines indicate regions of the genomic DNA that are deleted in each allele. pcm⁵ is a hypomorphic allele (Grima et al., 2008; Jones et al., 2013) that consists of a 516 bp deletion causing the remainder of the coding region to be out of frame (red box). pcm¹³ is also a hypomorphic allele consisting of a 2,222 bp deletion extending in both directions from the P-element insertion site. pcm¹⁴ is a 3,501 bp deletion extending 3,068 bp into the 3′ of pacman, removing exons 7–11 and part of exon 6, as well as the 5′ region of CR43260. (B) The domains of Pacman proteins encoded by each allele. (C,D) When cultured at 19°C, pcm⁵/Df(1)ED7452 flies become stuck when eclosing from their pupal cases. Df(1)ED7452 is a 17,963 bp deficiency that removes four genes including pacman. Similar results are obtained for pcm⁵/Df(1)JA27 which removes at least 69 genes including pacman. The same phenotype is produced when pcm⁵/pcm¹⁴ flies are cultured at 19°C, showing that pcm¹⁴ is a null allele.