Experiment / E51ULM9R6Massively Parallel Splicing Assay (MPSA / MaPSy)

Bovine Vex-seq splicing variant validation in MAC-T cells

Functional impact of splicing variants in the elaboration of complex traits in cattle

The authors transfected the allele-resolved Vex-seq plasmid library into immortalized bovine mammary epithelial MAC-T cells in three biological replicates. The library contained positive controls, bovine GWAS candidates (Var.GWAS), and prediction-enriched bovine variants (Var.P); exon inclusion was quantified as PSI and the alternate-minus-reference change as ΔPSI.

Processed tables are specific to each experiment. Column names, units, measurements, and table structure are not standardized across the database. Check this experiment’s column definitions and quality-control notes before comparing or combining data.

Perturbation & assay details

Basal / Untreated

Vex-seq used an episomal modified pcAT7-Glo1 reporter. Each synthesized construct contained a test exon of 13–98 nt carrying the REF or ALT allele, 50 nt of upstream intron and 20 nt of downstream intron, four sequence barcodes per test sequence, and invariant vector sequences containing MfeI/SpeI sites. The study subset comprised the positive-control, Var.GWAS, and Var.P portions of the pooled library. MAC-T cells were transfected in triplicate with 2 µg PL2 and 6 µL Lipofectamine 2000 per well and harvested 48 h later. UMI-tagged cDNA was sequenced; reads aligning to transcripts with or without the test exon were counted to calculate PSI (%), and ΔPSI is the ALT PSI minus REF PSI.

Processed data

50 rows per page. Click a cell to inspect its full value.

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Filters apply to this table only. The CSV download contains the complete processed table; filtered rows are available through the API.

Column dictionary · 39 definitions
dataset
Source library stratum: Positive control, Var.GWAS, or Var.P.
variant_id
rsID for GWAS/prediction variants; deterministic control key for positive controls without an rsID.
rsid
dbSNP rs identifier; blank for positive controls without one.
species
Species represented by the tested construct.
chromosome
Chromosome reported in the source spreadsheet.
position
1-based variant position reported in the source spreadsheet.
ref_allele
Reference allele in the Vex-seq construct.
alt_allele
Alternative allele in the Vex-seq construct.
gene_symbol
Gene symbol associated with the tested variant.
ensembl_gene_id
Ensembl gene identifier.
variant_consequence
Source/Ensembl variant consequence; positive-control annotations are joined from the bona fide SDV sheet when coordinates match.
vex_seq_region
Test-region genomic interval and orientation used for the Vex-seq construct.
variant_strand
Test-region strand parsed from the Vex-seq region field.
spliceai_consequence
SpliceAI consequence label, when available.
spliceai_score
SpliceAI score for the variant; positive-control values are taken from the corresponding control annotation when available.
spliceai_position
Relative position associated with the reported SpliceAI consequence.
pangolin_score
Signed Pangolin splice-strength score.
pangolin_position
Relative position associated with the Pangolin score.
gerp_score
GERP conservation score from the Var.GWAS or Var.P source sheet.
positive_control_validation_method
Previously reported validation method for a positive-control splice-disrupting variant; blank for study candidate variants.
associated_breeds
Semicolon-separated breeds associated with this rsID in Supplementary Data 5.
associated_phenotypes
Semicolon-separated phenotypes associated with this rsID in Supplementary Data 5.
gwas_imputation_r2
Semicolon-separated imputation r² values from Supplementary Data 5; entries follow the associated breed/phenotype records.
gwas_alt_frequency
Semicolon-separated ALT allele frequencies from Supplementary Data 5; entries follow the associated breed/phenotype records.
gwas_effects
Semicolon-separated breed|phenotype|effect records from Supplementary Data 5.
gwas_effect_sem
Semicolon-separated breed|phenotype|effect-SEM records from Supplementary Data 5.
gwas_p_values
Semicolon-separated breed|phenotype|p-value records from Supplementary Data 5.
gwas_logp
Semicolon-separated breed|phenotype|−log10(p) records from Supplementary Data 5.
cell_line
MAC-T immortalized bovine mammary epithelial cell line used for this child experiment (Cellosaurus CVCL:U226).
ref_psi_mean
Mean percent-spliced-in (PSI) for the REF allele across the three MAC-T transfection replicates.
alt_psi_mean
Mean percent-spliced-in (PSI) for the ALT allele across the three MAC-T transfection replicates.
delta_psi
ALT PSI minus REF PSI in percentage points.
delta_psi_sd
Standard deviation of ΔPSI across the three transfection replicates, when reported by the source.
delta_psi_p_value
Two-tailed Student's t-test p-value for the REF/ALT ΔPSI comparison.
delta_psi_fdr
False-discovery rate for ΔPSI calculated across the PL2 library by the authors.
splicing_call_fdr_0_05
Derived call using the paper's ±5 percentage-point and FDR <0.05 criteria: SDV_gain_inclusion, SDV_loss_inclusion, or not_SDV_at_FDR_0.05.
source_file
Raw supplementary workbook from which the row was extracted.
source_row
Physical Excel row number in source_file.
qc_status
Indicates that the row was in an author post-QC analyzed sheet and passed the package's cell-line readout filter.

Quality control

The paper removed barcode constructs with barcode mutations, fewer than 85% correct MiSeq reads for the associated test sequence, absence from PL1, synthesis errors, or no PL2 reads. UMI duplicates were removed from transcript reads; barcodes with fewer than 10 RNA-seq reads were discarded. Variants were retained for ΔPSI only when at least two expressed barcodes were available for each allele in each transfection experiment and PSI was greater than zero for at least one allele. The authors' analyzed sheets retain 183/210 Var.GWAS and 121/146 Var.P variants after these filters. Package QC additionally requires a numeric REF PSI mean, ALT PSI mean, and ΔPSI for this cell line, yielding 318 rows (20 positive controls, 179 Var.GWAS, and 119 Var.P); non-significant variants are retained.

Curation notes

Vex-seq is the authors' terminology; it is categorized here as a Massively Parallel Splicing Assay because the readout is allele-dependent exon inclusion rather than generic reporter expression. This child experiment uses the same pooled library as the HEK293T child experiment but has a separate MAC-T biosample. The final table is variant-level and includes the author's source-row provenance; the raw oligo/barcode designs are in supplementary_data_7_vexseq_oligonucleotides.xlsx. Positive controls include bovine and human constructs, while the primary study target is Bos taurus. Human control coordinates in the positive-control workbook may refer to GRCh37/hg19 rather than ARS-UCD1.2. Raw FASTQ files were intentionally not packaged.

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