Genetic analysis of B cell signaling.

Recent evidence indicates that B lymphocytes are instructed continuously by B cell receptor (BCR) signals to make crucial cell-fate decisions at several checkpoints during their development and humoral immune responses, reinforcing the importance of studies of the BCR signals. One of the best cell lines for these studies is a chicken DT40 B-cell line, because a high propensity of homologous recombination in this cell line allows us to easily take both genetic and biochemical approaches. Here, based upon the recent data, mainly obtained from the DT40 system, we discuss several new aspects on mechanisms by which BCR signals are propagated and modified.