Question

Which of the following statements regarding the process of differential splicing of primary RNA transcripts encoding immunoglobulins is incorrect?

a. It does not require rearrangement of genomic DNA sequences.
b. It underlies the production of both membrane-bound IgM and IgD in naive B cells.
c. It is the mechanism involved in isotype switching.
d. It occurs during B-cell differentiation into plasma cells when antibodies are produced in their secreted form.
e. It permits the production of different types of protein originating from the same RNA transcript.

Answer 1

The incorrect statement is that differential splicing is involved in isotype switching; instead, isotype switching involves DNA rearrangement, while differential splicing is an RNA processing mechanism producing different protein isoforms from the same mRNA transcript.

Step-by-step explanation:

The statement regarding the process of differential splicing of primary RNA transcripts encoding immunoglobulins that is incorrect is: It is the mechanism involved in isotype switching. Differential splicing is a RNA processing mechanism that results in the production of different protein isoforms from the same mRNA transcript, without requiring DNA rearrangement. In contrast, isotype switching does involve DNA rearrangement and is distinct from the process of differential splicing. This process allows a B-cell to produce different immunoglobulin classes with the same antigen specificity. Isotype switching occurs after the activation of B-cells and is mediated by activation-induced cytidine deaminase (AID). Therefore, alternative splicing is related to the production of different forms of the same immunoglobulin (e.g., membrane-bound or secreted forms), but not the changing of immunoglobulin classes, which is achieved by isotype switching.