I have mapped my data against hg19 reference with chromosome names following 1,2,3 etc .I have also customized annotations files, ENSMBLE with chromosome names 1,2,3 etc. I see chromosome IDs in BSgenome.Hsapiens.UCSC.hg19 following chr1,chr2 format. How do I import my custom gtf annotations file in to biomart? [[alternative HTML version deleted]]