RNAi screen identifies Jarid1b as a major regulator of mouse HSC activity.

Histone methylation is a dynamic and reversible process proposed to directly impact on stem cell fate. The Jumonji (JmjC) domain-containing family of demethylases comprises 27 members that target mono-, di-, and trimethylated lysine residues of histone (or nonhistone) proteins. To evaluate their role in regulation of hematopoietic stem cell (HSC) behavior, we performed an in vivo RNAi-based functional screen and demonstrated that Jarid1b and Jhdm1f play opposing roles in regulation of HSC activity.

Mapping and functional characterisation of a CTCF-dependent insulator element at the 3' border of the murine Scl transcriptional domain.

The Scl gene encodes a transcription factor essential for haematopoietic development. Scl transcription is regulated by a panel of cis-elements spread over 55 kb with the most distal 3' element being located downstream of the neighbouring gene Map17, which is co-regulated with Scl in haematopoietic cells. The Scl/Map17 domain is flanked upstream by the ubiquitously expressed Sil gene and downstream by a cluster of Cyp genes active in liver, but the mechanisms responsible for delineating the domain boundaries remain unclear.

Genome-wide identification of cis-regulatory sequences controlling blood and endothelial development.

The development of blood has long served as a model for mammalian cell type specification and differentiation, and yet the underlying transcriptional networks remain ill defined. Characterization of such networks will require genome-wide identification of cis-regulatory sequences and an understanding of how regulatory information is encoded in the primary DNA sequence. Despite progress in lower organisms, genome-wide computational identification of mammalian cis-regulatory sequences has been hindered by increased genomic complexity and cumbersome transgenic assays.

Widely spaced alternative promoters, conserved between human and rodent, control expression of the Opitz syndrome gene MID1.

Mutations in the gene MID1 are responsible for the X-linked form of Opitz syndrome, a genetic disorder that primarily affects the development of midline structures. Several mRNA isoforms with variant 5' ends have been reported for MID1, suggesting the presence of alternative transcription initiation sites. However, the genomic organization and expression pattern of the heterogeneous MID1 5'-untranslated regions (UTRs), as well as the promoter regions regulating their transcription, have not been determined.