Final answer:
Successful rearrangement of the α-chain locus in T cells results in the deletion of the δ-chain locus, due to their chromosomal proximity and the genetic rearrangement process that involves DNA recombinase. This process allows every T cell to express a distinct receptor type, providing diversity for antigen recognition in the immune response.
Step-by-step explanation:
Successful rearrangement of the α-chain locus leads to the deletion of the δ-chain locus. During the genetic rearrangement process, the T cell receptor (α-chain) and (δ-chain) loci are located within the same chromosomal region. Therefore, when the α-chain is successfully rearranged, it often physically deletes the δ-chain locus. This is vital for ensuring that each T cell expresses a single type of receptor.
The DNA recombinase enzyme is responsible for this rearrangement, and it facilitates the random excision of V (Variable), J (Joining), and sometimes D (Diversity) gene segments to create a unique variable region in T cell receptors or B cell receptors (BCRs) that can bind diverse antigens. The vast combinations of genetic segments allow for the generation of a wide variety of antigen receptors, which is essential for the adaptive immune response.