bulk-rna-seq-deconvolution-with-bulk2single

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Turn bulk RNA-seq cohorts into synthetic single-cell datasets using omicverse's Bulk2Single workflow for cell fraction estimation, beta-VAE generation, and quality control comparisons against reference scRNA-seq.

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npx skill4agent add starlitnightly/omicverse bulk-rna-seq-deconvolution-with-bulk2single

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Bulk RNA-seq deconvolution with Bulk2Single

Overview

Use this skill when a user wants to reconstruct single-cell profiles from bulk RNA-seq together with a matched reference scRNA-seq atlas. It follows
t_bulk2single.ipynb
, which demonstrates how to harmonise PDAC bulk replicates, train the beta-VAE generator, and benchmark the output cells against dentate gyrus scRNA-seq.

Instructions

  1. Load libraries and data
    • Import
      omicverse as ov
      ,
      scanpy as sc
      ,
      scvelo as scv
      ,
      anndata
      , and
      matplotlib.pyplot as plt
      , then call
      ov.plot_set()
      to match omicverse styling.
    • Read the bulk counts table with
      ov.read(...)
      /
      ov.utils.read(...)
      and harmonise gene identifiers via
      ov.bulk.Matrix_ID_mapping(<df>, 'genesets/pair_GRCm39.tsv')
      .
    • Load the reference scRNA-seq AnnData (e.g.,
      scv.datasets.dentategyrus()
      ) and confirm the cluster labels (stored in
      adata.obs['clusters']
      ).
  2. Initialise the Bulk2Single model
    • Instantiate
      ov.bulk2single.Bulk2Single(bulk_data=bulk_df, single_data=adata, celltype_key='clusters', bulk_group=['dg_d_1', 'dg_d_2', 'dg_d_3'], top_marker_num=200, ratio_num=1, gpu=0)
      .
    • Explain GPU selection (
      gpu=-1
      forces CPU) and how
      bulk_group
      names align with column IDs in the bulk matrix.
  3. Estimate cell fractions
    • Call
      model.predicted_fraction()
      to run the integrated TAPE estimator, then plot stacked bar charts per sample to validate proportions.
    • Encourage saving the fraction table for downstream reporting (
      df.to_csv(...)
      ).
  4. Preprocess for beta-VAE
    • Execute
      model.bulk_preprocess_lazy()
      ,
      model.single_preprocess_lazy()
      , and
      model.prepare_input()
      to produce matched feature spaces.
    • Clarify that the lazy preprocessing expects raw counts; skip if the user has already log-normalised data and instead provide aligned matrices manually.
  5. Train or load the beta-VAE
    • Train with
      model.train(batch_size=512, learning_rate=1e-4, hidden_size=256, epoch_num=3500, vae_save_dir='...', vae_save_name='dg_vae', generate_save_dir='...', generate_save_name='dg')
      .
    • Mention early stopping via
      patience
      and how to resume by reloading weights with
      model.load('.../dg_vae.pth')
      .
    • Use
      model.plot_loss()
      to monitor convergence.
  6. Generate and filter synthetic cells
    • Produce an AnnData using
      model.generate()
      and reduce noise through
      model.filtered(generate_adata, leiden_size=25)
      .
    • Store the filtered AnnData (
      .write_h5ad
      ) for reuse, noting it contains PCA embeddings in
      obsm['X_pca']
      .
  7. Benchmark against the reference atlas
    • Plot cell-type compositions with
      ov.bulk2single.bulk2single_plot_cellprop(...)
      for both generated and reference data.
    • Assess correlation using
      ov.bulk2single.bulk2single_plot_correlation(single_data, generate_adata, celltype_key='clusters')
      .
    • Embed with
      generate_adata.obsm['X_mde'] = ov.utils.mde(generate_adata.obsm['X_pca'])
      and visualise via
      ov.utils.embedding(..., color=['clusters'], palette=ov.utils.pyomic_palette())
      .
  8. Troubleshooting tips
    • If marker selection fails, increase
      top_marker_num
      or provide a curated marker list.
    • Alignment errors typically stem from mismatched
      bulk_group
      names—double-check column IDs in the bulk matrix.
    • Training on CPU can take several hours; advise switching
      gpu
      to an available CUDA device for speed.

Examples

  • "Estimate cell fractions for PDAC bulk replicates and generate synthetic scRNA-seq using Bulk2Single."
  • "Load a pre-trained Bulk2Single model, regenerate cells, and compare cluster proportions to the dentate gyrus atlas."
  • "Plot correlation heatmaps between generated cells and reference clusters after filtering noisy synthetic cells."

References

  • Tutorial notebook:
    t_bulk2single.ipynb
  • Example data and weights:
    omicverse_guide/docs/Tutorials-bulk2single/data/
  • Quick copy/paste commands:
    reference.md