Final answer:
The statement is false; Igα and Igβ genes continue to be expressed after the light chain rearrangement as they are part of the B cell receptor complex necessary for B cell function and antigen recognition.
Step-by-step explanation:
The statement that once the light chain has finished rearrangement, the Igα and Igβ genes are expected to be turned off (no longer expressed) is false. Igα and Igβ genes encode for proteins that are part of the B cell receptor complex, which is essential for the B cell development and antigen recognition post light chain rearrangement.
In germ-line B cells, a process known as V(D)J recombination facilitates the genetic rearrangement of the variable region of the light chain gene, involving the excision and splicing of V and J segments. This DNA recombinase-mediated process is crucial for creating a diverse range of antibodies, with each differentiated B cell producing a unique antibody due to these rearrangements. The Igα and Igβ proteins remain critical for the signaling processes needed for the B cell to function correctly after the antigen-binding site is formed, and thus their expression continues.