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Frank Schnorrer

Publications and source records attributed to Frank Schnorrer.

2 recordsLinked to original sources

A genome-wide resource for the analysis of protein localisation in Drosophila

The Drosophila genome contains >13,000 protein coding genes, the majority of which remain poorly investigated. Important reasons include the lack of antibodies or reporter constructs to visualise these proteins. Here we present a genome-wide fosmid library of {approx}10,000 GFP-tagged clones, comprising tagged genes and most of their regulatory information. For 880 tagged proteins we have created transgenic lines and for a total of 207 lines we have assessed protein expression and localisation in ovaries, embryos, pupae or adults by stainings and live imaging approaches. Importantly, we can visualise many proteins at endogenous expression levels and find a large fraction of them localising to subcellular compartments. Using complementation tests we demonstrate that two-thirds of the tagged proteins are fully functional. Moreover, our clones also enable interaction proteomics from developing pupae and adult flies. Taken together, this resource will enable systematic analysis of protein expression and localisation in various cellular and developmental contexts.

Genomics

A versatile two-step CRISPR- and RMCE-based strategy for efficient genome engineering in Drosophila

The development of CRISPR/Cas9 technologies promises a quantum leap in genome-engineering of model organisms. However, CRISPR-mediated gene targeting reports in Drosophila are still restricted to a few genes, use variable experimental conditions and vary in efficiency, questioning the universal applicability of the method. Here, we developed an efficient, two-step strategy to flexibly engineer the fly genome by combining CRISPR with recombinase-mediated cassette exchange (RMCE). In the first step, two sgRNAs, whose activity had been tested in cell culture, were co-injected together with a donor plasmid into transgenic Act5C-Cas9, Ligase4 mutant embryos and the homologous integration events were identified by eye fluorescence. In the second step, the eye marker was replaced with DNA sequences of choice using RMCE enabling flexible gene modification. We applied this strategy to engineer four different loci, including a gene on the fourth chromosome, at comparably high efficiencies, suggesting that any fly lab can engineer their favourite gene for a broad range of applications within about three months.

Developmental Biology