10x Genomics
Chromium Single Cell ATAC

Cell Ranger ATAC2.0, printed on 11/17/2024

Release Notes

Cell Ranger ATAC 2.0 (May 3, 2021)

• New wavelet-based peak caller:

  • Eliminates large peaks much larger than 5kb. Peaks have a tighter size distribution around ~ 1kb.
  • Improved detection of cluster-specific peaks.
  • Improved reproducibility between technical replicates.
  • Consistent performance across a range of cell loads.
  • Fixes crashes in the signal-background fitting procedure.

• Change in duplicate marking algorithm:

  • Two read pairs are duplicates if they share the same start, end and cell barcode. Previously, only the start and end were used.
  • Boosts median fragments per cell by as much as 25% at high cell loads.
  • We no longer distinguish between PCR and sequencer duplicates.

• Improved computational performance:

  • Up to 4x faster, 0.5x disk requirements.
  • Complete rewrite of read processing and differential accessibility analysis in Rust.
  • Minimize disk I/O.

• Change to pre-built references:

  • The following additional annotation tracks have been removed:
    • blacklist.bed
    • dnase.bed
    • ctcf.bed
    • enhancer.bed
    • promoter.bed
  • As a consequence, columns in the singlecell.csv output for the corresponding tracks are all zero. Additionally, the on_target_fragments column, which is a sum of TSS, DNAse, enhancer and promoter columns represents the TSS fragments. This value would be lower than expected for this reason.

• Breaking changes to reference package structure:

  • Cell Ranger ATAC 2.0 pipelines cannot be run with a version 1.2 reference. Cell Ranger ARC 1.0+ or Cell Ranger ATAC 2.0 references must be used.
  • Restrictions on the number of contigs or primary contigs in the reference have been eliminated.
  • Change to the config file format to construct a reference using mkref.
  • Primary contigs are now defined to be the set of gene-containing contigs and cannot be specified by the user.
  • Disabled support for URLs in the config file.
  • Disabled support for GFF annotations, annotations must be in GTF format.
  • Eliminated discrepancies between reference checks in mkref and preflight checks in count. Previously, it was possible to pass checks in mkref and fail checks in count.

• Added header lines beginning with # to the fragments.tsv.gz and peaks.bed files that contain version, reference and sample information.

• Eliminated the --downsample option and replaced by --subsample-rate.

• Change to ATAC peak annotation:

  • Annotate peaks using all genes provided in the reference GTF. Previously only certain gene types were used for annotation.
  • The peak column is now split into three columns: chrom, start, end.
  • When a peak has multiple gene annotations, the same peak appears in multiple rows with each annotation. Previously, each row represented one peak and multiple annotations were expressed using ; separators in the same row.

• Change to CSV definition file format for cellranger-atac aggr: eliminated peaks column. Custom peaks may be specified using a --peaks argument at the command line.

• Eliminated normalization mode signal from cellranger-atac aggr.

• Loupe browser files now contain pre-computed K-means clustering for K=2-5 (previously K=2-10).

• Loupe browser files generated by the pipeline can only be opened by Loupe browser version 5.0 or later.

• The web_summary.html file output from cellranger-atac count has been updated to be functionally consistent with that from cellranger-arc count.

• The PLSA algorithm is restricted to use one thread and computational performance is likely to be affected.

• Change to metric names in summary.csv generated by cellranger-atac count.

• Eliminated secondary alignments from the position-sorted BAM.

Cell Ranger ATAC 1.2.0 (November 21, 2019)

• Allow robust handling of GFF3 input in mkref.
• Fix a bug in the pre-generated human references where the Human Pseudoautosomal Region (PAR) genes are filtered out.
• Fix a bug in reporting the erroneous line number of mal-formatted bed file containing comment header lines.
• Fix a bug where the adjusted fragment bounds exceed the size of contig to which the fragment is mapped.
• Fix a bug in peak calling where the initialization of the mixture model fitting involved integer division instead of floating point division.
• Fix an issue in the peak calling algorithm where the mixture components were not always ordered with respect to each other in the same consistent way, leading to occasional stringent peak calls.
• Fix a bug in the interpolation formula used to evaluate the sensitivity of the assay at various downsampled depths.
• Allow better handling of whitespaces in file paths in mkref.
• Add new metrics to metrics.json: median unique fragments per cell overlapping peaks, percentage of genome in peaks, barcode and gel bead multiplet rate.
• Fix a bug in the web summary file where the alert color for cell calls is not consistent with the thresholds.
• Add a feature to the websummary where a guidance message is printed at the top of the html file.
• Mask out barcodes associated with gel bead doublets from the set of barcodes on which cell calling is performed.
• Mask out barcodes associated with barcode multiplets from the set of barcodes on which cell calling is performed.

Cell Ranger ATAC 1.1.0 (April 17, 2019)

• Include new mkref tool to allow building of single-species custom references from fasta and gene annotations.
• Remove metrics related to targeting based on custom files that may not be available for custom genomes.
• Include new reanalyze pipeline to allow rerunning data from a finished pipeline but with custom selection of peaks and barcodes, along with tweaking analysis parameters.
• Include new aggr pipeline to allow aggregating data from multiple pipelines and analyzing it as one dataset.
• Include GC and depth normalized differential enrichment analysis for accessibility of transcription factor binding motifs.
• Include depth normalized differential enrichment analysis for accessibility in peaks.
• Improve peak annotation to include associations of genes with distal peaks.
• Improve performance of motif scanning by setting moderate background nucleotide frequencies for peaks in extreme GC bins.
• Analysis output directory now has enrichment in place of diff_tf.
• Fix an issue in peak calling where signal and noise components of a mixture model get swapped and produces nonsensical threshold. Fixes via changing the mixture model components.
• Fix an issue in peak calling where odds-ratio determines the wrong threshold that would lead to calling entire genome in peaks.
• Replace the default clustering for LSA and PLSA based dimensionality reductions to be spherical k-means in place of k-medoids.
• Add an additional step to filter out low targeting barcodes prior to cell calling, for better cell calling.
• Update references to include transcripts.bed file derived from gene annotations, used in annotating peaks.

Cell Ranger ATAC 1.0.1 (December 17, 2018)

• Fix an issue in which some peak annotations were reversed.
• Update references to fix an off-by-one issue in some tss.bed entries.
• Fix an issue where PLSA would crash on CPUs without AVX support.
• Fix a division-by-zero issue in calculating the background nucleotide % during motif scanning.

Cell Ranger ATAC 1.0.0 (October 29, 2018)

• Initial release.