From BITS wiki
General transfer format. Identical to [.gff] version 2.
GTF are text files in which genomic annotations (features) are stored per line.
- Ensembl GTF files
- Getting GTF from UCSC
- iGenomes - contains sequences and annotations in GTF for different model organisms
See http://www.ensembl.org/info/website/upload/gff.html See http://cufflinks.cbcb.umd.edu/gff.html