Broad profiling of DNA-binding transcription factor activities improves regulatory network construction in adult mouse tissues.

Molecular systematics involves the description of the regulatory networks formed by the interconnections between active transcription factors and their target expressed genes. Here, we have determined the activities of 200 different transcription factors in six mouse tissues using an advanced mouse oligonucleotide array-based transcription factor assay (MOUSE OATFA). The transcription factor signatures from MOUSE OATFA were combined with public mRNA expression profiles to construct experimental transcriptional regulatory networks in each tissue.

[Comparative study of differentially expressed genes in mouse bone marrow and fetal liver cells].

Hematopoiesis undergoes several migrations from yolk sac to liver and spleen, and finally bone marrow until the end of life. A number of investigations have demonstrated that the hematopoietic microenvironment plays very important role in this process. However, the exact mechanisms remain unknown.

[Screening of differentially expressed genes in the mouse hematopoietic stromal cells after long-term culture].

Hematopoietic stromal cells, being the essential ingredient of the hematopoietic microenvironment, play very important roles in the control and regulation of self-renewal, proliferation and differentiation of hematopoietic stem cells (HSC) via complex interactions of cell-cell, cell-humoral and cell-extracellular matrix. Evidence from in vivo experiment has proved that HSC derived from normal mice could reconstitute hematopoiesis of mice with HSC defects but failed to reconstitute hematopoiesis of those mice with microenvironment defects, showing the importance of hematopoietic microenvironment in the maintenance of hematopoiesis in vivo. A well-known long-term culture (LTC) system established by Dexter demonstrated in another way that stromal cell layer in the system could support ex vivo hematopoiesis for several months, even more than one year under the optimal conditions.