Question

The initial stages of B cell development are:

1. Early Pro-B cell
2. Late Pro-B cell
3. Large Pre-B cell.
In terms of H chain genes, when is VDJ rearrangement occurring?

a) Early Pro-B cell
b) Late Pro-B cell
c) Large Pre-B cell
d) Not applicable

Answer 1

VDJ rearrangement of the H chain genes in B cell development occurs during the Late Pro-B cell stage, which is crucial for the generation of antibody diversity and the adaptive immune response.

Step-by-step explanation:

In terms of H (heavy) chain genes, VDJ rearrangement occurs during the Late Pro-B cell stage of B cell development. This genetic rearrangement is crucial for creating a diverse range of antibodies, each capable of binding to a different antigen. This process involves the recombination of variable (V), diversity (D), and joining (J) segments to generate a unique variable region of the antibody's heavy chain. The mechanism is facilitated by an enzyme called DNA recombinase, which brings the gene segments together in various combinations.

The VDJ rearrangement is a critical part of B cell maturation, ensuring that B cells can produce a vast array of antibodies necessary for the adaptive immune response. This diversity allows the immune system to recognize and respond to a multitude of pathogens. Subsequently, B cells expressing successful BCRs undergo further maturation and selection processes in the bone marrow and the spleen before they become fully mature B cells.