Detection of RefSeq transcripts in intestinal samples by RNA-Seq. (A) Expression of RefSeq annotated transcripts in the intestine. Number of annotated RefSeq transcripts covered in small intestine and/or colon at a detection threshold of 0.01 FPKM. (B) Number of detected condensed genes dependent on sequencing depth (black curve) and graphs depicting regression analysis (red solid and dotted lines). Data depicted from the small intestine data set. (C) Distribution of transcripts with different expression levels. All transcripts were sorted to classes spanning an order of magnitude. Transcripts without coverage or not passing the threshold (see (A)) were classified as absent (abs.). (D) Enrichment of specific gene ontology terms with key function for the investigated tissues and depletion of 'house keepers' in tissue specific transcript subgroups. Numbers represent the count of transcripts supporting the GO term.