The Zuker Collection: A Resource for the Analysis of Autosomal Gene Function in Drosophila melanogaster

Abstract

The majority of genes of multicellular organisms encode proteins with functions that are not required for viability but contribute to important physiological functions such as behavior and reproduction. It is estimated that 75% of the genes of Drosophila melanogaster are nonessential. Here we report on a strategy used to establish a large collection of stocks that is suitable for the recovery of mutations in such genes. From ‫000,27ف‬ F 3 cultures segregating for autosomes heavily treated with ethyl methanesulfonate (EMS), ‫000,21ف‬ lines in which the treated second or third chromosome survived in homozygous condition were selected. The dose of EMS induced an estimated rate of 1.2-1.5 ϫ 10 Ϫ3 mutations/gene and predicts five to six nonessential gene mutations per chromosome and seven to nine alleles per locus in the samples of 6000 second chromosomes and 6000 third chromosomes. Due to mosaic mutations induced in the initial exposure to the mutagen, many of the lines are segregating or are now fixed for lethal mutations on the mutagenized chromosome. The features of this collection, known as the Zuker collection, make it a valuable resource for forward and reverse genetic screens for mutations affecting a wide array of biological functions.T HE search for mutations in genes whose protein generated and now maintain a collection of 12,336 lines with EMS-treated chromosomes, with 6079 lines with products are known is complicated by the uncertainty regarding the phenotypes expected for such mumutagenized second chromosomes and 6257 lines with mutagenized third chromosomes. Here we describe the tations. To search for mutations in a gene encoding a protein of interest, an F 2 screen can be used if a mutant strategy used to generate this collection and report on the features that make it a valuable resource for genetic or chromosome deficiency is available for the locus. In analyses of a wide variety of physiological processes in the absence of a chromosome deficiency, it is necessary Drosophila. to carry out an F 3 screen to produce flies homozygous for a mutagenized chromosome. The interest in this laboratory has been in genes encoding eye-specific pro-MATERIALS AND METHODS teins, the mutations of which are expected to result in viable adults. In the past this approach has been effective Deciding on the optimal level of EMS required us to strive in recovering mutations of a number of genes; however, for a dose high enough to engender a high mutation rate, each recovery required a large F 3 screen involving thoubut not so high as to produce too many homozygous lethal chromosomes. We arbitrarily settled on the criterion that at sands of individual lines (Table 1). least 75% of the treated chromosomes in a run must be homoOn the basis of our knowledge of the Drosophila zygous lethal. The reliable achievement of 75% lethality rephototransduction cascade, we knew that mutations for quired experimentation with mutagenic protocols, in the proevery gene had not yet been generated and that a definicess of which many F ...

The peptidoglycan recognition protein PGRP-SC1a is essential for Toll signaling and phagocytosis of Staphylococcus aureus in Drosophila

“…For phagocytosis mutants, the assay was repeated several times (in Ϸ30-40 animals total) to verify the phenotype. For phenotypic analysis of the picky mutant, the isogenic parental cn bw strain that was mutagenized to generate the mutant (25) was used as the wild-type control.…”

“…By comparing a wild-type PGRP-SC1a with a cysteine-serine mutant PGRPSC1a for rescue of picky phenotypes, we find that the catalytic activity is essential for phagocytosis of live S. aureus, but not for activation of the Toll pathway. To identify genes important for phagocytosis, we screened a collection of ethylmethane sulfonate-induced adult viable mutants (25) using an in vivo phagocytosis assay (1). To determine what a mutant might look like, we first examined the PGRP-LC (ird7) and PGRP-SA (seml) mutants.…”

Lipid flippase modulates olfactory receptor expression and odorant sensitivity in Drosophila

“…1 A-C) (1)(2)(3). Approximately half of the Or67d neurons from these four lines were insensitive to all concentrations of cVA, and those that did respond had severely impaired cVA sensitivity compared with wild-type controls ( Fig.…”

SNMP is a signaling component required for pheromone sensitivity in Drosophila

“…Using a genetic screen, we set out to identify additional components important for cVA sensitivity. We screened Ϸ3,000 mutagenized third-chromosome lines selected for homozygous viability (5). We screened each mutant line for T1 electrophysiological responses to cVA using single sensillum electrophysiological recordings (2,3,6).…”