Figure 1.

Genetic screen for modifiers of His1-dependent adult viability using mis-expression alleles on the second chromosome of Drosophila melanogaster. (A) A genetic cross for screening homozygous viable and fertile EP insertions on the second chromosome. Heterozygous Act5C-GAL4, pINT-H1^4M/SM5 females were mated to P{EP}/P{EP} males, and the ratios of H1-depleted and normal adult progeny were scored based on the balancer phenotypic marker (Cy). Positions of Act5C-GAL4, pINT-H1^4M and P{EP} insertions are indicated by black, gray, and white boxes, respectively. The endogenous gene affected by the UAS promoter in the P{EP} insertion is indicated by a hatched box. (B) A genetic cross for screening homozygous lethal and male sterile EP insertions on the second chromosome. Heterozygous Act5C-GAL4, pINT-H1^4M/SM5 females were mated to P{EP}/SM5 or P{EP}/CyO males, and the ratios of H1-depleted and normal adult progeny were scored based on the balancer phenotypic marker (Cy). (C) Over-represented GO terms and their members among alleles genetically interacting with His1. Gene symbols representing enhancers and suppressors are indicated by red and blue type, respectively. P values are calculated by the hypergeometric test.