Cell-based assays

2018 Dec 08


Sat Dec 8 (All day) to Wed Dec 12 (All day)


San Diego, CA, USA
The DRSC & TRiP will be represented at the ASCB|EMBO 2018 conference in the form of a poster that includes information about our collaboration with O. Kanca in the H. Bellen lab at Baylor College of Medicine to tag Drosophila S2R+ cell lines with GFP using a CRISPR-based strategy. We have 'painted' a number of subcellular localizations green with this approach! If you're at the meeting, check out P1482 at Board Number B494, presented by Baolong Xia of the Perrimon lab.
Cartoon of fly host cells with virus or endosymbiotic bacteria

Cell-based RNAi screening helps reveal host-microbe interactions--two new screen reports

November 19, 2018

Laboratories at the Skirball Institute at New York University and the Boyce Thompson Institute at Cornell University reported results of two different cell-based Drosophila RNAi screens in papers published this week. The screens have in common that they looked at interactions between the host insect cells and a microbe -- the endosymbiont Wolbachia in one study and baculovirus in the other. For more, check out the newly published studies. For both these screens, the DRSC provided libraries for screens that were then performed at the host institution.


... Read more about Cell-based RNAi screening helps reveal host-microbe interactions--two new screen reports
Hirotaka Kanoh, Li-Li Tong, Takayuki Kuraishi, Yamato Suda, Yoshiki Momiuchi, Fumi Shishido, and Shoichiro Kurata. 2015. “Genome-wide RNAi screening implicates the E3 ubiquitin ligase Sherpa in mediating innate immune signaling by Toll in Drosophila adults.” Sci Signal, 8, 400, Pp. ra107.Abstract
The Drosophila Toll pathway plays important roles in innate immune responses against Gram-positive bacteria and fungi. To identify previously uncharacterized components of this pathway, we performed comparative, ex vivo, genome-wide RNA interference screening. In four screens, we overexpressed the Toll adaptor protein dMyd88, the downstream kinase Pelle, or the nuclear factor κB (NF-κB) homolog Dif, or we knocked down Cactus, the Drosophila homolog of mammalian inhibitor of NF-κB. On the basis of these screens, we identified the E3 ubiquitin ligase Sherpa as being necessary for the activation of Toll signaling. A loss-of-function sherpa mutant fly exhibited compromised production of antimicrobial peptides and enhanced susceptibility to infection by Gram-positive bacteria. In cultured cells, Sherpa mediated ubiquitylation of dMyd88 and Sherpa itself, and Sherpa and Drosophila SUMO (small ubiquitin-like modifier) were required for the proper membrane localization of an adaptor complex containing dMyd88. These findings highlight a role for Sherpa in Drosophila host defense and suggest the SUMOylation-mediated regulation of dMyd88 functions in Toll innate immune signaling.
Hirotaka Kanoh, Takayuki Kuraishi, Li-Li Tong, Ryo Watanabe, Shinji Nagata, and Shoichiro Kurata. 2015. “Ex vivo genome-wide RNAi screening of the Drosophila Toll signaling pathway elicited by a larva-derived tissue extract.” Biochem Biophys Res Commun, 467, 2, Pp. 400-6.Abstract
Damage-associated molecular patterns (DAMPs), so-called "danger signals," play important roles in host defense and pathophysiology in mammals and insects. In Drosophila, the Toll pathway confers damage responses during bacterial infection and improper cell-fate control. However, the intrinsic ligands and signaling mechanisms that potentiate innate immune responses remain unknown. Here, we demonstrate that a Drosophila larva-derived tissue extract strongly elicits Toll pathway activation via the Toll receptor. Using this extract, we performed ex vivo genome-wide RNAi screening in Drosophila cultured cells, and identified several signaling factors that are required for host defense and antimicrobial-peptide expression in Drosophila adults. These results suggest that our larva-derived tissue extract contains active ingredients that mediate Toll pathway activation, and the screening data will shed light on the mechanisms of damage-related Toll pathway signaling in Drosophila.

Missed us at ADRC 2018? View our workshop slides!

April 19, 2018
Thank you to all those who attended our workshop at last week's Annual Drosophila Research Conference in Philadelphia, PA, USA. It was great to talk fly stocks, cell screens, and bioinformatics with the community. We are here to help and look forward to continued feedback on the resources we are building to empower your research. PDFs of our workshop presentations are attached to this news item. The slides will help you learn more about our in vivo resources for CRISPR, new pooled cell-based CRISPR screen technology, and bioinformatics resources at our facility.  Feel free to contact... Read more about Missed us at ADRC 2018? View our workshop slides!
Cartoon of essential gene pooled screen (made using BioRender.io)

Pooled-format CRISPR screens in Drosophila cells

March 22, 2018

The DRSC/TRiP-FGR is pleased to support collaborations on pooled CRISPR screens using the method recently, reported in eLife by Viswanatha et al.   From the abstract: "... Here, we developed a site-specific integration strategy for library delivery and performed a genome-wide CRISPR knockout screen in Drosophila S2R+ cells. Under basal growth conditions, 1235 genes were essential for cell fitness at a false-discovery rate of 5...

Read more about Pooled-format CRISPR screens in Drosophila cells
2018 Apr 13

DRSC & TRiP Workshop at ADRC

1:45pm to 3:45pm


Philadelphia, PA, USA
The DRSC & TRiP will be hosting a workshop at the Annual Drosophila Research Conference in Philadelphia, PA. The workshop is scheduled for Friday, April 13th from 1:45 to 3:45 PM. Come hear from DRSC & TRiP leaders Norbert Perrimon, Jonathan Zirin (organizer), Claire Yanhui Hu, and Stephanie Mohr. At the workshop, you will learn about new opportunities for community nomination and experiments using CRISPR knockout and activation, as well as learn what's new and popular among our online software and database tools. There will be something for everyone -- we will provide information... Read more about DRSC & TRiP Workshop at ADRC
Photo of 384-well assay plates

Congrats to Sung, Shears, and colleagues: "Cytokine signaling through Drosophila Mthl10 ties lifespan to environmental stress"

December 13, 2017

Eui Jae Sung, Stephen Shears, and colleagues have published a research report that includes a screen of dsRNAs from the DRSC reagent collection using S2 cells. We shipped dsRNA reagents to the lab for a screen at their home institution, in addition to providing consultation and data management support. The resulting study by Sung et al. was published on Dec. 11, 2017: Sung EJ, Ryuda M, Matsumoto H, Uryu O, Ochiai M, Cook ME, Yi NY, Wang H, Putney JW, Bird GS, Shears SB, Hayakawa Y. Cytokine signaling through Drosophila Mthl10 ties lifespan to environmental stress...

Read more about Congrats to Sung, Shears, and colleagues: "Cytokine signaling through Drosophila Mthl10 ties lifespan to environmental stress"
Stephanie E Mohr, Kirstin Rudd, Yanhui Hu, Wei R Song, Quentin Gilly, Michael Buckner, Benjamin E Housden, Colleen Kelley, Jonathan Zirin, Rong Tao, Gabriel Amador, Katarzyna Sierzputowska, Aram Comjean, and Norbert Perrimon. 12/9/2017. “Zinc Detoxification: A Functional Genomics and Transcriptomics Analysis in Drosophila melanogaster Cultured Cells.” G3 (Bethesda).Abstract
Cells require some metals, such as zinc and manganese, but excess levels of these metals can be toxic. As a result, cells have evolved complex mechanisms for maintaining metal homeostasis and surviving metal intoxication. Here, we present the results of a large-scale functional genomic screen in Drosophila cultured cells for modifiers of zinc chloride toxicity, together with transcriptomics data for wildtype or genetically zinc-sensitized cells challenged with mild zinc chloride supplementation. Altogether, we identified 47 genes for which knockdown conferred sensitivity or resistance to toxic zinc or manganese chloride treatment, and more than 1800 putative zinc-responsive genes. Analysis of the 'omics data points to the relevance of ion transporters, glutathione-related factors, and conserved disease-associated genes in zinc detoxification. Specific genes identified in the zinc screen include orthologs of human disease-associated genes CTNS, PTPRN (also known as IA-2), and ATP13A2 (also known as PARK9). We show that knockdown of red dog mine (rdog; CG11897), a candidate zinc detoxification gene encoding an ABCC-type transporter family protein related to yeast cadmium factor (YCF1), confers sensitivity to zinc intoxication in cultured cells and that rdog is transcriptionally up-regulated in response to zinc stress. As there are many links between the biology of zinc and other metals and human health, the 'omics datasets presented here provide a resource that will allow researchers to explore metal biology in the context of diverse health-relevant processes.
Figure 2 from Housden et al 2017 PNAS

Variable Dose Analysis: a new DRSC-supported cell screen approach that leverages existing reagents to perform robust screens

December 1, 2017

We are excited to report the publication of a paper from Benjamin Housden and colleagues describing development and use of the Variable Dose Analysis (VDA) approach. Ben developed a way to use existing TRiP shRNA plasmids originally developed for fly stock production in a new, effective approach to high-throughput cell screening.

The VDA approach is particularly useful for combinatorial approaches that are acutely sensitive to assay robustness. The screen Ben and colleagues report focused on synthetic effects in Drosophila tumor model cells.  The...

Read more about Variable Dose Analysis: a new DRSC-supported cell screen approach that leverages existing reagents to perform robust screens
Screenshot of a 2015 Science paper from Payre and colleagues

Francois Payre's plenary talk at ADRC 2017 features results from DRSC cell-based screen

March 30, 2017

Those of us lucky enough to be at the Annual Drosophila Research Conference this morning saw a great talk by Francois Payre about regulation of Shavenbaby by small ORFs. A genome-wide cell-based screen done at the DRSC by Emilie Benrabah identified the mechanism of regulation. As this exemplifies, cell screens can help identify key pathways and factors that can then be followed up with in vivo studies.

J Zanet, E Benrabah, T Li, A Pélissier-Monier, H Chanut-Delalande, B Ronsin, HJ Bellen, F Payre, and S Plaza. 2015. “Pri sORF peptides induce selective proteasome-mediated protein processing.” Science, 349, 6254, Pp. 1356-8.Abstract

A wide variety of RNAs encode small open-reading-frame (smORF/sORF) peptides, but their functions are largely unknown. Here, we show that Drosophila polished-rice (pri) sORF peptides trigger proteasome-mediated protein processing, converting the Shavenbaby (Svb) transcription repressor into a shorter activator. A genome-wide RNA interference screen identifies an E2-E3 ubiquitin-conjugating complex, UbcD6-Ubr3, which targets Svb to the proteasome in a pri-dependent manner. Upon interaction with Ubr3, Pri peptides promote the binding of Ubr3 to Svb. Ubr3 can then ubiquitinate the Svb N terminus, which is degraded by the proteasome. The C-terminal domains protect Svb from complete degradation and ensure appropriate processing. Our data show that Pri peptides control selectivity of Ubr3 binding, which suggests that the family of sORF peptides may contain an extended repertoire of protein regulators.