An R/Bioconductor library to perform genomic liftover between different genome assemblies with GRanges
and chain
file. Source Code: https://github.com/nahid18/easylift
if (!require("BiocManager", quietly = TRUE))
install.packages("BiocManager")
BiocManager::install("easylift")
To view documentation:
browseVignettes("easylift")
library("easylift")
#> Loading required package: GenomicRanges
#> Loading required package: stats4
#> Loading required package: BiocGenerics
#> Loading required package: generics
#>
#> Attaching package: 'generics'
#> The following objects are masked from 'package:base':
#>
#> as.difftime, as.factor, as.ordered, intersect, is.element, setdiff,
#> setequal, union
#>
#> Attaching package: 'BiocGenerics'
#> The following objects are masked from 'package:stats':
#>
#> IQR, mad, sd, var, xtabs
#> The following objects are masked from 'package:base':
#>
#> Filter, Find, Map, Position, Reduce, anyDuplicated, aperm, append,
#> as.data.frame, basename, cbind, colnames, dirname, do.call,
#> duplicated, eval, evalq, get, grep, grepl, is.unsorted, lapply,
#> mapply, match, mget, order, paste, pmax, pmax.int, pmin, pmin.int,
#> rank, rbind, rownames, sapply, saveRDS, table, tapply, unique,
#> unsplit, which.max, which.min
#> Loading required package: S4Vectors
#>
#> Attaching package: 'S4Vectors'
#> The following object is masked from 'package:utils':
#>
#> findMatches
#> The following objects are masked from 'package:base':
#>
#> I, expand.grid, unname
#> Loading required package: IRanges
#> Loading required package: GenomeInfoDb
#> Loading required package: BiocFileCache
#> Loading required package: dbplyr
Create a GRanges
object, assign a genome to it, and specify chain file
gr <- GRanges(
seqname = Rle(
c("chr1", "chr2"),
c(100000, 100000)
),
ranges = IRanges(
start = 1, end = 200000
)
)
# Here, "hg19" is the source genome
genome(gr) <- "hg19"
# Here, we use the `system.file()` function because the chain file is in the
# package (however if you need to point to any other file on your machine,
# just do 'chain <- "path/to/your/hg19ToHg38.over.chain.gz"'):
chain <- system.file("extdata", "hg19ToHg38.over.chain.gz", package = "easylift")
gr
#> GRanges object with 200000 ranges and 0 metadata columns:
#> seqnames ranges strand
#> <Rle> <IRanges> <Rle>
#> [1] chr1 1-200000 *
#> [2] chr1 1-200000 *
#> [3] chr1 1-200000 *
#> [4] chr1 1-200000 *
#> [5] chr1 1-200000 *
#> ... ... ... ...
#> [199996] chr2 1-200000 *
#> [199997] chr2 1-200000 *
#> [199998] chr2 1-200000 *
#> [199999] chr2 1-200000 *
#> [200000] chr2 1-200000 *
#> -------
#> seqinfo: 2 sequences from hg19 genome; no seqlengths
Call easylift
with GRanges
object, target genome and the chain file.
# Here, "hg38" is the target genome
easylift(gr, "hg38", chain)
#> GRanges object with 300000 ranges and 0 metadata columns:
#> seqnames ranges strand
#> <Rle> <IRanges> <Rle>
#> [1] chr1 10001-177376 *
#> [2] chr19 242824-242864 *
#> [3] chr1 10001-177376 *
#> [4] chr19 242824-242864 *
#> [5] chr1 10001-177376 *
#> ... ... ... ...
#> [299996] chr2 10001-200000 *
#> [299997] chr2 10001-200000 *
#> [299998] chr2 10001-200000 *
#> [299999] chr2 10001-200000 *
#> [300000] chr2 10001-200000 *
#> -------
#> seqinfo: 25 sequences (1 circular) from hg38 genome
To use BiocFileCache
for the chain file, add it to the cache:
chain_file <- "/path/to/your/hg19ToHg38.over.chain.gz"
bfc <- BiocFileCache()
# Add chain file to cache if already not available
if (nrow(bfcquery(bfc, basename(chain_file))) == 0)
bfcadd(bfc, chain_file)
Then, use it in easylift
:
easylift(gr, "hg38")
# or
gr |> easylift("hg38")
To cite package easylift
in publications use:
Al Nahid A, Pagès H, Love M (2023). easylift: An R package to perform genomic liftover. R package version 1.0.0, https://github.com/nahid18/easylift.
A BibTeX entry for LaTeX users is
@Manual{,
title = {easylift: An R package to perform genomic liftover},
author = {Abdullah Al Nahid, Hervé Pagès, Michael Love},
year = {2023},
note = {R package version 1.0.0},
url = {https://github.com/nahid18/easylift},
}
Please note that the easylift
was only made possible thanks to many other R and bioinformatics software authors, which are cited either in the vignettes and/or the paper(s) describing this package.
Please note that the easylift
project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.
sessionInfo()
#> R version 4.5.0 Patched (2025-04-21 r88169)
#> Platform: aarch64-apple-darwin20
#> Running under: macOS Ventura 13.7.1
#>
#> Matrix products: default
#> BLAS: /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/lib/libRblas.0.dylib
#> LAPACK: /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/lib/libRlapack.dylib; LAPACK version 3.12.1
#>
#> locale:
#> [1] C/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
#>
#> time zone: America/New_York
#> tzcode source: internal
#>
#> attached base packages:
#> [1] stats4 stats graphics grDevices utils datasets methods
#> [8] base
#>
#> other attached packages:
#> [1] easylift_1.7.0 BiocFileCache_2.99.0 dbplyr_2.5.0
#> [4] GenomicRanges_1.61.0 GenomeInfoDb_1.45.0 IRanges_2.43.0
#> [7] S4Vectors_0.47.0 BiocGenerics_0.55.0 generics_0.1.3
#> [10] BiocStyle_2.37.0
#>
#> loaded via a namespace (and not attached):
#> [1] SummarizedExperiment_1.39.0 rjson_0.2.23
#> [3] xfun_0.52 bslib_0.9.0
#> [5] httr2_1.1.2 lattice_0.22-7
#> [7] Biobase_2.69.0 vctrs_0.6.5
#> [9] tools_4.5.0 bitops_1.0-9
#> [11] curl_6.2.2 parallel_4.5.0
#> [13] tibble_3.2.1 RSQLite_2.3.9
#> [15] blob_1.2.4 pkgconfig_2.0.3
#> [17] R.oo_1.27.0 Matrix_1.7-3
#> [19] lifecycle_1.0.4 GenomeInfoDbData_1.2.14
#> [21] compiler_4.5.0 Rsamtools_2.25.0
#> [23] Biostrings_2.77.0 codetools_0.2-20
#> [25] htmltools_0.5.8.1 sass_0.4.10
#> [27] RCurl_1.98-1.17 yaml_2.3.10
#> [29] pillar_1.10.2 crayon_1.5.3
#> [31] jquerylib_0.1.4 R.utils_2.13.0
#> [33] BiocParallel_1.43.0 DelayedArray_0.35.1
#> [35] cachem_1.1.0 abind_1.4-8
#> [37] tidyselect_1.2.1 digest_0.6.37
#> [39] dplyr_1.1.4 restfulr_0.0.15
#> [41] bookdown_0.43 grid_4.5.0
#> [43] fastmap_1.2.0 SparseArray_1.9.0
#> [45] cli_3.6.5 magrittr_2.0.3
#> [47] S4Arrays_1.9.0 XML_3.99-0.18
#> [49] filelock_1.0.3 UCSC.utils_1.5.0
#> [51] rappdirs_0.3.3 bit64_4.6.0-1
#> [53] rmarkdown_2.29 XVector_0.49.0
#> [55] httr_1.4.7 matrixStats_1.5.0
#> [57] bit_4.6.0 R.methodsS3_1.8.2
#> [59] memoise_2.0.1 evaluate_1.0.3
#> [61] knitr_1.50 BiocIO_1.19.0
#> [63] rtracklayer_1.69.0 rlang_1.1.6
#> [65] glue_1.8.0 DBI_1.2.3
#> [67] BiocManager_1.30.25 jsonlite_2.0.0
#> [69] R6_2.6.1 MatrixGenerics_1.21.0
#> [71] GenomicAlignments_1.45.0