Hematopietic system high resolution transcriptome

Recent advances in high density oligonucleotides microarray technology have generated solutions for molecular profiling of human samples at an unprecedented resolution. We mapped whole blood RNA from healthy volunteers and CD34+ collected by cytapheresis from patients to Exon ST 1.0 microarray probing for most known and predicted human exons. Comparison with a broad panel of solid tissues showed that blood displayed the largest tissue specific signature. This unique expression profile comprised transcripts from every blood cell compartment. Moreover, by scanning the expression of over one million different exons, several transcripts were identified as alternatively transcribed between whole blood and solid tissues, or CD34+ and other tissues. The precision of this expression map, at the exon resolution, and the coverage of every blood cell type and hematopoietic stem cells suggest that it will be possible to link specific whole blood exon signatures to many diseases such as cancer or auto-immune disorders and to discover alternative splicing events specific of mature blood cells or stem cells compartment. 4 samples of whole blood from adult healthy donors and 3 samples of CD34+ cells obtained by selection after cytapheresis.