At which developmental stage does signaling through the pre-B-cell receptor occur?

Signaling through the pre-B-cell receptor occurs during the pre-B cell stage of B-cell development. At this stage, the precursor B cells have successfully rearranged their immunoglobulin heavy chain genes and can express the pre-B-cell receptor on their surface. The pre-B-cell receptor, which consists of the newly synthesized heavy chain pairing with a surrogate light chain, is crucial for several signaling events that promote further differentiation and proliferation of B cells. This signaling is essential for ensuring the viability of the pre-B cells and supporting subsequent light chain rearrangement.

In contrast, the pro-B cell stage is characterized by heavy chain gene rearrangement before the expression of the pre-B-cell receptor begins. The immature B cell stage occurs after the pre-B-cell receptor phase when the immature B cells express a complete B-cell receptor, including both heavy and light chains. The naive B cell is the stage after the immature B cell, representing a mature B cell that has left the bone marrow and has not yet encountered its specific antigen. Each of these stages is distinct in the B-cell maturation process, highlighting the importance of the pre-B-cell receptor in signaling specifically during the pre-B cell stage.