What is immunoglobulin rearrangement?

What is immunoglobulin rearrangement?

During early B-cell differentiation in the bone marrow (BM) the variable (V), diversity (D), and joining (J) gene segments of the immunoglobulin (Ig) genes are rearranged in an ordered fashion to generate the primary Ig repertoire.

What is the order of immunoglobulin gene rearrangement?

We found an ordered model for Ig light chain gene rearrangements: the Ig light chain gene recombination process starts within the IGK locus, followed by IGK deletion(s) and rearrangements in the IGL genes. This order of the rearrangements guaranteed allelic exclusion of Ig light chain genes in >90% of CBL cases.

What is DNA rearrangement?

Homologous recombination results in the reassortment of genes between chromosome pairs without altering the arrangement of genes within the genome. In contrast, other types of recombinational events lead to rearrangements of genomic DNA.

Why are permanent rearrangements of DNA important in immunoglobulin genes?

Molecular cloning and structural characterization of the immunoglobu lin gene have shown that DNA rearrangement plays essential roles in the somatic amplification of the immunoglobulin diversity that manifests in two aspects: the ability to bind an enormous number of antigens, and the ability to trigger a variety of …

What causes class switching?

Class switching occurs after activation of a mature B cell via its membrane-bound antibody molecule (or B cell receptor) to generate the different classes of antibody, all with the same variable domains as the original antibody generated in the immature B cell during the process of V(D)J recombination, but possessing …

What is the genetic code for immunoglobulin?

The immunoglobulin heavy and light chains are coded for by three separate gene families each one on a separate chromosome – one for the heavy chain and one for each of the light chain types. Each of these gene families has several V region genes and one or more C region genes.

What is gene rearrangement in immunology?

Gene rearrangement plays a role in determining the sequences in which the genes are joined as the DNA of the immunoglobulin producing cell matures.

What is lymphocyte receptor gene rearrangement?

Instead, we will see that the V regions of the receptor chains are encoded in several pieces—so-called gene segments. These are assembled in the developing lymphocyte by somatic DNA recombination to form a complete V-region sequence, a mechanism known generally as gene rearrangement.

When does DNA rearrangement occur?

Sometimes, chromosome rearrangements happen soon after fertilization. The rearrangement is then copied to all or some of the baby’s cells. During recombination, pairs of chromosomes duplicate, swap pieces, and separate. A complete set of genetic information has 23 pairs of chromosomes.

Which is a likely cause of a chromosome rearrangement?

Chromosome rearrangements can be caused by exposure to radiation, and/or TEs have also been implicated in chromosome rearrangements (Fig. 3.10). Many of these rearrangements can be detected by chromosome painting, FISH, or Giemsa staining.

How does gene rearrangement occur?

Gene rearrangement is a phenomenon in which a programmed DNA recombination event occurs during cellular differentiation to reconstitute a functional gene from gene segments separated in the genome.

How does IgM change to IgG?

Antibody-producing cells undergo a process of differentiation and class switch recombination (CSR) such that the antibodies produced start as immunoglobulin M (IgM) and then switch to IgG and IgA as the concentration of antigen changes and as the cells differentiate.