Transcriptome study for early hematopoiesis--achievement, challenge and new opportunity.

Hematopoietic stem progenitor cells are the source for the entire hematopoietic system. Studying gene expression in hematopoietic stem progenitor cells will provide information to understand the genetic programs controlling early hematopoiesis, and to identify the gene targets to interfere hematopoietic disorders. Extensive efforts using cell biology, molecular biology, and genomics approaches have generated rich knowledge for the genes and functional pathways involving in early hematopoiesis. Challenges remain, however, including the rarity of the hematopoietic stem progenitor cells that set physical limitation for the study, the difficulty for reaching comprehensive transcriptome detection under the conventional genomics technologies, and the difficulty for using conventional biological methods to identify the key genes among large number of expressed genes controlling stem cell self-renewal and differentiation. The newly developed single-cell transcriptome method and the next-generation DNA sequencing technology provide new opportunities for transcriptome study for early hematopoietic. Using systems biology approach may reveal the insight of the genetic mechanisms controlling early hematopoiesis.