B lymphocyte development is often depicted as a linear process that initiates in the fetus and continues in the bone marrow after birth. Based on the dissection of B lymphopoiesis in a PU.1 hypomorphic strain of mice, generated by deletion of a 14kb upstream regulatory element of the Sfpi1 gene, and the transcriptional profiling of fetal and adult B cell progenitors, we establish the existence of three waves of B-1 and two waves of B-2 development and show that each of these waves has distinct transcriptional requirements. In addition to revealing an unappreciated complexity in the development of the humoral immune system, the results provide genetic evidence that the B-1 and B-2 lineages are distinct and a molecular basis for the layering of immune system development. SOURCE: Kenneth Dorshkind (kdorshki@mednet.ucla.edu) -  David Geffen School of Medicine at UCLA

Pluto Bioinformatics

GSE81411: The Genetic Networks that Orchestrate Development of Specific Waves of Fetal and Adult B-1 and B-2 Development are Distinct