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Time-resolved imaging-based CRISPRi screening

Abstract

Our ability to connect genotypic variation to biologically important phenotypes has been seriously limited by the gap between live-cell microscopy and library-scale genomic engineering. Here, we show how in situ genotyping of a library of strains after time-lapse imaging in a microfluidic device overcomes this problem. We determine how 235 different CRISPR interference knockdowns impact the coordination of the replication and division cycles of Escherichia coli by monitoring the location of replication forks throughout on average >500 cell cycles per knockdown. Subsequent in situ genotyping allows us to map each phenotype distribution to a specific genetic perturbation to determine which genes are important for cell cycle control. The single-cell time-resolved assay allows us to determine the distribution of single-cell growth rates, cell division sizes and replication initiation volumes. The technology presented in this study enables genome-scale screens of most live-cell microscopy assays.

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Fig. 1: Assay workflow.
Fig. 2: Analysis.
Fig. 3: Phenotypic data averaged for each genotype.
Fig. 4: Fork distribution plots and time-resolved phenotypes.
Fig. 5: Cell-to-cell phenotypic variation for each genotype.

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Data availability

The microscopy images and image analysis output associated with the DuMPLING experiments are publicly available at the Image Data Resource (https://idr.openmicroscopy.org/) under the accession number idr0065. Other data from this study are available from the corresponding author upon request.

Code availability

The code used to analyze the DuMPLING microscopy images and generate figures associated with the DuMPLING experiments is provided as Supplementary Software.

References

  1. Jinek, M. et al. A programmable dual-RNA–guided DNA endonuclease in adaptive bacterial immunity. Science 337, 816–821 (2012).

    Article  CAS  Google Scholar 

  2. Adli, M. The CRISPR tool kit for genome editing and beyond. Nat. Commun. 9, 1911 (2018).

    Article  Google Scholar 

  3. Garst, A. D. et al. Genome-wide mapping of mutations at single-nucleotide resolution for protein, metabolic and genome engineering. Nat. Biotechnol. 35, 48–55 (2016).

    Article  Google Scholar 

  4. Wang, H. H. et al. Programming cells by multiplex genome engineering and accelerated evolution. Nature 460, 894–898 (2009).

    Article  CAS  Google Scholar 

  5. Rajagopal, N. et al. High-throughput mapping of regulatory DNA. Nat. Biotechnol. 34, 167–174 (2016).

    Article  CAS  Google Scholar 

  6. Dixit, A. et al. Perturb-seq: dissecting molecular circuits with scalable single-cell RNA profiling of pooled genetic screens. Cell 167, 1853–1866.e17 (2016).

    Article  CAS  Google Scholar 

  7. Adamson, B. et al. A multiplexed single-cell CRISPR screening platform enables systematic dissection of the unfolded protein response. Cell 167, 1867–1882.e21 (2016).

    Article  CAS  Google Scholar 

  8. Jaitin, D. A. et al. Dissecting immune circuits by linking CRISPR-pooled screens with single-cell RNA-seq. Cell 167, 1883–1896.e15 (2016).

    Article  CAS  Google Scholar 

  9. Liu, Z., Lavis, L. D. & Betzig, E. Imaging live-cell dynamics and structure at the single-molecule level. Mol. Cell 58, 644–659 (2015).

    Article  CAS  Google Scholar 

  10. Li, N. et al. Single-molecule imaging and tracking of molecular dynamics in living cells. Natl Sci. Rev. 4, 739–760 (2017).

    Article  CAS  Google Scholar 

  11. Balzarotti, F. et al. Nanometer resolution imaging and tracking of fluorescent molecules with minimal photon fluxes. Science 355, 606–612 (2016).

    Article  Google Scholar 

  12. Liu, T.-L. et al. Observing the cell in its native state: imaging subcellular dynamics in multicellular organisms. Science 360, eaaq1392 (2018).

    Article  Google Scholar 

  13. Baltekin, Ö., Boucharin, A., Tano, E., Andersson, D. I. & Elf, J. Antibiotic susceptibility testing in less than 30 min using direct single-cell imaging. Proc. Natl Acad. Sci. USA 114, 9170–9175 (2017).

    Article  CAS  Google Scholar 

  14. Hammar, P. et al. Direct measurement of transcription factor dissociation excludes a simple operator occupancy model for gene regulation. Nat. Genet. 46, 405–408 (2014).

    Article  CAS  Google Scholar 

  15. Wang, P. et al. Robust growth of Escherichia coli. Curr. Biol. 20, 1099–1103 (2010).

    Article  CAS  Google Scholar 

  16. Lawson, M. J. et al. In situ genotyping of a pooled strain library after characterizing complex phenotypes. Mol. Syst. Biol. 13, 947 (2017).

    Article  Google Scholar 

  17. Emanuel, G., Moffitt, J. R. & Zhuang, X. High-throughput, image-based screening of pooled genetic-variant libraries. Nat. Methods 14, 1159–1162 (2017).

    Article  CAS  Google Scholar 

  18. Wallden, M., Fange, D., Lundius, E. G., Baltekin, Ö. & Elf, J. The synchronization of replication and division cycles in individual E. coli cells. Cell 166, 729–739 (2016).

    Article  CAS  Google Scholar 

  19. Si, F. et al. Mechanistic origin of cell-size control and homeostasis in bacteria. Curr. Biol. 29, 1760–1770 (2019).

    Article  CAS  Google Scholar 

  20. Ghatak, S., King, Z. A., Sastry, A. & Palsson, B. O. The y-ome defines the 35% of Escherichia coli genes that lack experimental evidence of function. Nucleic Acids Res. 47, 2446–2454 (2019).

    Article  CAS  Google Scholar 

  21. Schneiders, T. & Levy, S. B. MarA-mediated transcriptional repression of the rob promoter. J. Biol. Chem. 281, 10049–10055 (2006).

    Article  CAS  Google Scholar 

  22. Ranefall, P., Sadanandan, S. K. & Wählby, C. Fast adaptive local thresholding based on ellipse fit. In 2016 IEEE 13th International Symposium on Biomedical Imaging (ISBI) 205–208 (2016).

  23. Magnusson, K. E. G., Jalden, J., Gilbert, P. M. & Blau, H. M. Global linking of cell tracks using the Viterbi algorithm. IEEE Trans. Med. Imaging 34, 911–929 (2015).

    Article  Google Scholar 

  24. Olivo-Marin, J.-C. Extraction of spots in biological images using multiscale products. Pattern Recognit. 35, 1989–1996 (2002).

    Article  Google Scholar 

  25. Jaqaman, K. et al. Robust single-particle tracking in live-cell time-lapse sequences. Nat. Methods 5, 695–702 (2008).

    Article  CAS  Google Scholar 

  26. Keyamura, K. et al. The interaction of DiaA and DnaA regulates the replication cycle in E. coli by directly promoting ATP DnaA-specific initiation complexes. Genes Dev. 21, 2083–2099 (2007).

    Article  CAS  Google Scholar 

  27. Katayama, T., Kasho, K. & Kawakami, H. The DnaA cycle in Escherichia coli: activation, function and inactivation of the initiator protein. Front. Microbiol. 8, 2496 (2017).

    Article  Google Scholar 

  28. Saxena, R., Fingland, N., Patil, D., Sharma, A. K. & Crooke, E. Crosstalk between DnaA protein, the initiator of Escherichia coli chromosomal replication, and acidic phospholipids present in bacterial membranes. Int. J. Mol. Sci. 14, 8517–8537 (2013).

    Article  Google Scholar 

  29. Camara, J. E. et al. Hda inactivation of DnaA is the predominant mechanism preventing hyperinitiation of Escherichia coli DNA replication. EMBO Rep. 6, 736–741 (2005).

    Article  CAS  Google Scholar 

  30. Fujimitsu, K., Senriuchi, T. & Katayama, T. Specific genomic sequences of E. coli promote replicational initiation by directly reactivating ADP-DnaA. Genes Dev. 23, 1221–1233 (2009).

    Article  CAS  Google Scholar 

  31. Kasho, K. & Katayama, T. DnaA binding locus datA promotes DnaA-ATP hydrolysis to enable cell cycle-coordinated replication initiation. Proc. Natl Acad. Sci. USA 110, 936–941 (2013).

    Article  CAS  Google Scholar 

  32. Goldbeter, A. & Koshland, D. E. Jr. An amplified sensitivity arising from covalent modification in biological systems. Proc. Natl Acad. Sci. USA 78, 6840–6844 (1981).

    Article  CAS  Google Scholar 

  33. Babic, A., Lindner, A. B., Vulic, M., Stewart, E. J. & Radman, M. Direct visualization of horizontal gene transfer. Science 319, 1533–1536 (2008).

    Article  CAS  Google Scholar 

  34. Keseler, I. M. et al. The EcoCyc database: reflecting new knowledge about Escherichia coli K-12. Nucleic Acids Res. 45, D543–D550 (2017).

    Article  CAS  Google Scholar 

  35. Goodall, E. C. A. et al. The essential genome of Escherichia coli K-12. mBio 9, e02096-17 (2018).

    Article  Google Scholar 

  36. Jiang, H. & Wong, W. H. SeqMap: mapping massive amount of oligonucleotides to the genome. Bioinformatics 24, 2395–2396 (2008).

    Article  CAS  Google Scholar 

  37. Markham, N. R. & Zuker, M. in Bioinformatics, Volume II: Structure, Function and Applications (ed. Keith, J. M.) Ch. 1, 3–31 (Humana Press, 2008).

  38. Jones, D. L. et al. Kinetics of dCas9 target search in Escherichia coli. Science 357, 1420–1424 (2017).

    Article  CAS  Google Scholar 

  39. Baba, T. et al. Construction of Escherichia coli K‐12 in‐frame, single‐gene knockout mutants: the Keio collection. Mol. Syst. Biol. 2, 2006.0008 (2006).

    Article  Google Scholar 

  40. Cherepanov, P. P. & Wackernagel, W. Gene disruption in Escherichia coli: TcR and KmR cassettes with the option of Flp-catalyzed excision of the antibiotic-resistance determinant. Gene 158, 9–14 (1995).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This work was supported by the Knut and Alice Wallenberg Foundation (2017.0291 and 2016.0077), the European Research Council (616047) and the Swedish Research Council (VR)(642-2013-7841 and 2016-06213). We are grateful to I. Barkefors for help with the manuscript and figures, to P. Karempudi for making microfluidic molds and to the Dan Andersson lab for kindly sharing E. coli strains.

Author information

Authors and Affiliations

Authors

Contributions

J.E. conceived the DuMPLING method and SeqA application. D.C. developed cloning methods, and designed and made the strain library. J.E. and M.J.L. managed the project. D.F. and M.J.L. developed phenotyping methods. J.L. and M.J.L. developed genotyping methods. D.F. built the microscope. J.L. and M.J.L. performed microscopy experiments. S.Z. and D.F. developed the image analysis pipeline. S.Z. and D.F. analyzed the DuMPLING data. D.J. performed repression measurements and NGS growth rate experiments. J.E., M.J.L., D.C. and D.F. wrote the paper with input from all authors.

Corresponding authors

Correspondence to Michael J. Lawson or Johan Elf.

Ethics declarations

Competing interests

The DuMPLING technology is patented with European patent no. EP3167061 (B1).

Additional information

Peer review information Rita Strack was the primary editor on this article and managed its editorial process and peer review in collaboration with the rest of the editorial team.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Integrated supplementary information

Supplementary Fig. 1 Layout of the microfluidic chip.

Image adapted from (Baltekin et al. 201713). The holes punched in the PDMS before bonding it to the PDMS are 2.0 (media in, front channel), 7.0 and 8.0 (waste port, front channel), 5.1 and 5.2 (waste port, back channel), 2.1 and 2.2 (cell loading or waste port, front channel).

Supplementary Fig. 2 Test strain CRISPRi growth assay.

Identical line style indicates three replicate cultures from three different colonies of the same plasmid construct in the test strain. No sgRNA: Negative sgRNA control plasmid pGuide-empty. lacY sgRNA: sgRNA against lacY from plasmid pGuide-P1-lacY. Glucose or lactose was used as supplemental carbon source and dCas9 expression/CRISPRi was induced with aTc (+ aTc). This assay was carried out once.

Supplementary Fig. 3 Comparison of relative abundances of genotypes in DuMPLING and NGS experiments.

Horizontal axis: Relative abundance of each strain as measured by next generation sequencing. (Raw sequence counts given in Supplementary Table 2) Vertical Axis: Relative abundance of each strain in the microfluidic chip. (The number of measurements for each genotype is equal to its number of traps as given in Supplementary Table 1.) Colors of dots indicate the growth rate of each genotype as estimated by NGS.

Supplementary Fig. 4 Quantified genotype probe fluorescence.

Histogram of average cell pixel intensity per trap after background reduction in logarithmic scale. The lower intensity fluorescence peaks are fitted to Gaussians (solid red line) and genotypes are determined when the probe fluorescence signal reaches above 7 times the standard deviations (dashed red lines) of the fitted Gaussians. See the Image analysis subsection on Genotyping in the Methods for details of how to determine genotypes.

Supplementary Fig. 5 Estimating initiation volume.

A. (left) Fork distribution plot of ref strain (same data as Fig. 3e). Horizontal is SeqA-YFP cluster location along the long axis of the cell, vertical is cell size, color indicates the probability of finding a SeqA-YFP foci at a given position along the cell long axis for a given cell size. Initiation size (red dashed line) corresponds to the average of individually tracked replication forks. (right) Estimating initiation size (dashed red line) by fitting an error function (solid red line) to bulk data (blue squares) from the regions |x|>0.44 μm in the forkplot. B. (left) Same as Fig. 2c. (right) Estimating initiation size (dashed red line) by fitting a Gaussian (solid red line) to the relative histogram of single cell initiation sizes. C. Same as Fig. 3f in main text.

Supplementary Fig. 6 Fork plot distributions for replica experiments of library subpool 1.

r stands for the run number, n stands for the number of traps detected for each genotype. Dashed and solid lines as defined in Fig. 3e. The range of the horizontal and vertical axes is the same for each fork distribution and the same as in Figs. 3e and 4g.

Supplementary Fig. 7 Fork plot distributions for replica experiments of library subpool 2.

r stands for the run number, n stands for the number of traps detected for each genotype. Dashed and solid lines as defined in Fig. 3e. The range of the horizontal and vertical axes is the same for each fork distribution and the same as in Figs. 3e and 4g.

Supplementary Fig. 8 Fork plot distributions for replica experiments of library subpool 3.

r stands for the run number, n stands for the number of traps detected for each genotype. Dashed and solid lines as defined in Fig. 3e. The range of the horizontal and vertical axes is the same for each fork distribution and the same as in Figs. 3e and 4g.

Supplementary Fig. 9 Fork plot distributions for replica experiments of library subpool 4.

r stands for the run number, n stands for the number of traps detected for each genotype. Dashed and solid lines as defined in Fig. 3e. The range of the horizontal and vertical axes is the same for each fork distribution and the same as in Figs. 3e and 4g.

Supplementary Fig. 10 Fork plot distributions for replica experiments of library subpool 5.

r stands for the run number, n stands for the number of traps detected for each genotype. Dashed and solid lines as defined in Fig. 3e. The range of the horizontal and vertical axes is the same for each fork distribution and the same as in Figs. 3e and 4g.

Supplementary Fig. 11 Fork plot distributions for replica experiments of library subpool 6.

r stands for the run number, n stands for the number of traps detected for each genotype. Dashed and solid lines as defined in Fig. 3e. The range of the horizontal and vertical axes is the same for each fork distribution and the same as in Figs. 3e and 4g.

Supplementary Fig. 12 Correlations between replica DuMPLING experiments.

Correlation plots for normalized average growth rate (Pearson correlation = 0.86, n=215 different strains where growth rates were estimated in both run 1 and run 2), normalized average birth size (Pearson correlation = 0.78, n=215 different strains where birth sizes were estimated in both run 1 and run 2) and normalized average initiation size (Pearson correlation = 0.74, n=191 different strains where initiation sizes were estimated in both run 1 and run 2) between duplicate experiments. Deviations by more than 0.1 from the straight line where run 1 = run 2 are indicated by names. The number of data points used to estimate each average in the three different panels is given in Supplementary Table 1. Reference control strain (ref) is indicated with red dots.

Supplementary information

Supplementary Information

Supplementary Figs. 1–12 and Notes 1–4.

Reporting Summary

Supplementary Video 1

Example of time-lapse fluorescence imaging; one position with segmented cell outlines (yellow) and detected SeqA-YFP clusters (red). The video is truncated in time compared with the complete experiment.

Supplementary Video 2

Collage of time-lapse phase contrast imaging; from 1/3 of the positions in one experiment. The video is truncated in time compared with the complete experiment.

Supplementary Video 3

Collage of time-lapse fluorescence imaging; from 1/3 of the positions in one experiment. The video is truncated in time compared with the complete experiment.

Supplementary Video 4

Fluorescence time-lapse imaging of three cell traps genotyped as ref traps; images are overlaid with segmented cell outlines (yellow) and detected SeqA-YFP clusters (red). There is 2 min between fluorescence images in the experiment. The video playback rate is 7 fps.

Supplementary Video 5

Fluorescence time-lapse imaging of three cell traps genotyped as dedD traps; images are overlaid with segmented cell outlines (yellow) and detected SeqA-YFP clusters (red). There is 2 min between fluorescence images in the experiment. The video playback rate is 7 fps.

Supplementary Video 6

Fluorescence time-lapse imaging of three cell traps genotyped as hda traps; images are overlaid with segmented cell outlines (yellow) and detected SeqA-YFP clusters (red). There is 2 min between fluorescence images in the experiment. The video playback rate is 7 fps.

Supplementary Video 7

Fluorescence time-lapse imaging of three cell traps genotyped as clpP traps; images are overlaid with segmented cell outlines (yellow) and detected SeqA-YFP clusters (red). There is 2 min between fluorescence images in the experiment. The video playback rate is 7 fps.

Supplementary Video 8

Time-lapse phase contrast imaging of three traps with single-gene clpP knockdown cells; there is 5 min between phase contrast images in the experiment. The video playback is at 7 fps.

Supplementary Video 9

Time-lapse phase contrast imaging of three traps with single-gene clpP knockout cells; there is 5 min between phase contrast images in the experiment. The video playback is at 7 fps.

Supplementary Table 1

DuMPLING data and statistics; estimates of mean and CV of growth rate, birth size and initiation size for each genotype in two replicates of the DuMPLING microscopy experiments (shown in two different tabs, ‘run 1’ and ‘run 2’). Each estimate is normalized to the ref strain in each experiment. The table also includes the number of data points used in each estimate (N cells) and the number of traps (N traps) that each detected genotype occupies. For initiation size bulk, the column ‘N cell detections’ implies the total number of detected SeqA-YFP foci used in fitting the initiation size.

Supplementary Table 2

NGS statistics; the number of occurrences of each strain before (t = 0) and after (t = 12 h) pooled competition is indicated, as well as the corresponding fractional abundances calculated from the numbers of occurrences. The resulting changes in relative abundance and relative fitness are also given, calculated as described in Supplementary Note 3.

Supplementary Table 3

Comparison of DuMPLING experiments with single-gene knockdown and knockouts; for nine selected genotypes. Table includes normalized means, normalized CV and the number of data points used to estimate these (N cells).

Supplementary Table 4

List of genes in each of the transcriptional units of the CRISPRi target genes in the DuMPLING library; the table also includes genes in each transcriptional unit that have been reported essential.

Supplementary Table 5

Sequences of CRISPRi spacers, barcodes and oligonucleotides; for each genotype in the DuMPLING library.

Supplementary Table 6

Strains used in this study; includes genotypes and description.

Supplementary Software

Compressed file with all software used to derive and analyze the DuMPLING data.

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Camsund, D., Lawson, M.J., Larsson, J. et al. Time-resolved imaging-based CRISPRi screening. Nat Methods 17, 86–92 (2020). https://doi.org/10.1038/s41592-019-0629-y

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