Data and code from: Imaging flow cytometry enables label-free cell sorting of morphological variants from populations of the unculturable bacterium Pasteuria ramosa
Data files
Nov 21, 2025 version files 1.17 MB
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README.md
2.46 KB
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vocelleetal_analysis_v2.html
1.14 MB
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vocelleetal_analysis_v2.Rmd
19.25 KB
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vocelleetal_data_v2.csv
5.83 KB
Abstract
Bacterial populations often display remarkable morphological heterogeneity. Flow cytometric cell sorting (often called FACS) is an important tool for understanding this diversity. FACS allows researchers to obtain pure samples of each morphological variant (or morphotype) that is present within a mixed population of cells and thus permits each morphotype to be phenotyped. In FACS, cells are first labeled with fluorescent markers such as antibodies or transgenic constructs, and then separated out based on their possession of these labels. However, since the development of fluorescent labels requires a priori knowledge of bacterial biology, it is often impossible to apply FACS to understudied and/or unculturable bacteria. This challenge has limited our capacity to investigate the biology of bacterial size and shape in all but a small, largely culturable subset of bacterial taxa. Here, we present an innovative strategy that permits label-free cell sorting of bacterial morphotypes, using an unculturable, pleiomorphic pathogen (Pasteuria ramosa) as a model bacterium. We show that imaging flow cytometry (IFC) can be used to systematically identify light-scattering and autofluorescence “signatures” of bacterial morphotypes, on which basis cell sorting can be conducted. Critically, our IFC-enabled cell sorting strategy yields samples of sufficient purity (> 90 %) for common downstream analyses e.g., “-omics” analyses. Our work represents an innovative application of IFC and provides an economical, widely applicable solution to a central problem in the study of bacterial diversity.
Dataset DOI: 10.5061/dryad.1g1jwsv86
Description of the data and file structure
Daphnia magna were experimentally infected with the bacterial parasite Pasteuria ramosa, which produces morphologically distinct stages ("morphologies") during its life cycle. Hosts were culled at various points post-infection. The composition of the P. ramosa cell population was analyzed using both an Attune Cytpix imaging flow cytometer and a (non-imaging) Influx cell-sorter ("pre-sort analysis"). The Influx cell-sorter was used to sort different target morphologies. The composition of the resulting sorted sample was then assessed using the Attune Cytpix, to quantify the purity of the sorted sample ("post-sort" analysis). For the sake of efficiency, a random sample of events was inspected.
Full details of the methods are given in the publication.
Files and variables
File: vocelleetal_analysis_v2.Rmd
Description: R Markdown file containing the code used to generate the Figure 2 & Table S4 of the manuscript.
Note that Figure 1 was generated using proprietary FCS Express software and Microsoft Powerpoint.
File: vocelleetal_data_v2.csv
Description: Spreadsheet containing details of each sort and the results of the post-sort validation analysis.
Variables
- sample_name: unique sample name
- run_date: date sample analyzed using the Influx cell-sorter
- gs_conf: gating strategy
- gs_id: unique gating strategy id
- target: Pasteuria morphology that we aimed to sort.
- e_in: number of "events" in the sample analyzed via the Influx.
- e_out: number of "events" in the sorted sample.
- e_attune: number of "events" from the sorted-sample analyzed via the Attune.
- e_validated: number of event-images inspected for validation purposes
- b_target: number of Pasteuria cells of the target-morphology observed in validation subset
- non_b: number of non-bacterial events observed in observed in validation subset
- b_nontarget: number of non-target Pasteuria observed in validation subset
- notes: Operator notes on morphologies observed during post-sort analysis
File: vocelleetal_analysis_v2.html
Description: HTML output of the R file vocelleetal_analysis.Rmd
Code/software
The data was analyzed using R software, version 4.2.
The code, which includes details of the packages required, is provided as a .Rmd file.
