Make GRanges from a GFF/GTF file
makeGRangesFromGFF(file, level = c("genes", "transcripts"), ignoreTxVersion = TRUE, .checkAgainstTxDb = FALSE) makeGRangesFromGTF(file, level = c("genes", "transcripts"), ignoreTxVersion = TRUE, .checkAgainstTxDb = FALSE)
Remote URLs and compressed files are supported.
makeGRangesFromGTF: GTF file extension alias.
Runs the same internal code as
Use GTF over GFF3. We recommend using a GTF file instead of a GFF3 file, when possible. The file format is more compact and easier to parse.
Use Ensembl over RefSeq. We generally recommend using Ensembl over RefSeq, if possible. It's better supported in R and generally used by most NGS vendors.
The GFF (General Feature Format) format consists of one line per feature, each containing 9 columns of data, plus optional track definition lines.
The GTF (General Transfer Format) format is identical to GFF version 2.
The UCSC website has detailed conventions on the GFF3 format, including the metadata columns.
CDS: CoDing Ssequence. A contiguous sequence that contains a
genomic interval bounded by start and stop codons. CDS refers to the
portion of a genomic DNA sequence that is translated, from the start codon
to the stop codon.
exon: Genomic interval containing 5' UTR (
five_prime_UTR), CDS, and
3' UTR (
mRNA: Processed (spliced) mRNA transcript.
makeGRangesFromGFF() supports genomes from these sources:
Ensembl (GTF, GFF3).
GENCODE (GTF, GFF3).
RefSeq (GTF, GFF3).
makeGRangesFromEnsembl() offers native support for Ensembl genome
builds and returns additional useful metadata that isn't defined inside a
If you must load a GFF/GTF file directly, then use
Annotations available from Ensembl and GENCODE are very similar.
The GENCODE annotation is made by merging the manual gene annotation produced by the Ensembl-Havana team and the Ensembl-genebuild automated gene annotation. The GENCODE annotation is the default gene annotation displayed in the Ensembl browser. The GENCODE releases coincide with the Ensembl releases, although GENCODE can skip an Ensembl release if there is no update to the annotation with respect to the previous release. In practical terms, the GENCODE annotation is essentially identical to the Ensembl annotation.
However, GENCODE handles pseudoautosomal regions (PAR) differently than Ensembl. The Ensembl GTF file only includes this annotation once, for chromosome X. However, GENCODE GTF/GFF3 files include the annotation in the PAR regions of both chromosomes. You'll see these genes contain a "_PAR_Y" suffix.
Additionally, GENCODE GFF/GTF files import with a gene identifier containing
a suffix, which differs slightly from the Ensembl GFF/GTF spec
The GENCODE FAQ has additional details.
Refer to the current RefSeq spec for details.
Loading UCSC genome annotations from a GFF/GTF file are intentionally not supported by this function.
We recommend using a pre-built
TxDb package from Bioconductor instead.
For example, load
TxDb.Hsapiens.UCSC.hg38.knownGene for hg38.
For reference, note that UCSC doesn't provide direct GFF/GTF file downloads. Use of the hgTables table browser is required in a web browser.
Select the following options to download hg38:
Dec. 2013 (GRCh38/hg38)
Genes and Gene Predictions
GTF - gene transfer format
<Enter a file name>
file <- pasteURL(freerangeTestsURL, "ensembl.gtf", protocol = "none") ## Genes x <- makeGRangesFromGFF(file = file, level = "genes")#>#>#>#>#>#>summary(x)#>  "GRanges object with 60 ranges and 8 metadata columns"## Transcripts x <- makeGRangesFromGFF(file = file, level = "transcripts")#>#>#>#>#>#>summary(x)#>  "GRanges object with 167 ranges and 16 metadata columns"