Transcription factor regulation of B lineage commitment

The past year has provided insight into the mechanisms by which multipotent progenitors commit to differentiation through the B lymphocyte lineage. Mi ce lacking the Pax5 gene develop pro-B lymphocytes but these cells are not uniquely committed to the B lineage as they can give rise to all hematopoie tic cell types if cultured under appropriate conditions. Regulators of lymp hocyte proliferation and survival have also been identified that may allow lymphocytes to respond to information provided by the external environment.