Gene splicing

Gene rearrangement is a process that occurs in the immune system to help it respond to various antigens. This process is crucial for the diversity of the immune response, allowing the body to recognize and respond to a wide range of foreign substances.

Overview

Gene rearrangement involves the reordering of DNA sequences to bring together separate exons, which are the coding regions of a gene. This process is a form of somatic recombination, and it occurs in the lymphocytes of the immune system, specifically in B cells and T cells.

Mechanism

The mechanism of gene rearrangement involves several steps. First, the recombination signal sequence (RSS) is recognized by the recombination activating gene (RAG) complex. The RAG complex then introduces a double-strand break in the DNA at the RSS. The broken DNA ends are then processed and joined together by the non-homologous end joining (NHEJ) pathway.

Role in Immune System

Gene rearrangement plays a crucial role in the immune system. It is responsible for the generation of a diverse repertoire of immunoglobulins and T cell receptors, which are necessary for the immune system to recognize a wide range of antigens. This diversity is achieved through the random combination of different gene segments during the rearrangement process.

Clinical Significance

Abnormalities in gene rearrangement can lead to various immune disorders. For example, severe combined immunodeficiency (SCID) can result from defects in the RAG genes, which are necessary for gene rearrangement. In addition, gene rearrangement is also involved in the development of certain types of cancer, such as leukemia and lymphoma, where it can lead to the activation of oncogenes.

See Also

• V(D)J recombination
• Somatic hypermutation
• Class switch recombination