What are VD and J segments?

The process is a defining feature of the adaptive immune system. V(D)J recombination in mammals occurs in the primary lymphoid organs (bone marrow for B cells and thymus for T cells) and in a nearly random fashion rearranges variable (V), joining (J), and in some cases, diversity (D) gene segments.

What is idiotype immunology?

In immunology, an idiotype is a shared characteristic between a group of immunoglobulin or T-cell receptor (TCR) molecules based upon the antigen binding specificity and therefore structure of their variable region.

How many V segments are there?

51 V segments
The human heavy-chain gene-segment pool. There are 51 V segments, 27 D segments, 6 J segments, and an ordered cluster of C-region exons, each cluster encoding a different class of heavy chain. The D segment (and part of the J segment) encodes amino acids (more…)

What is VDJ region?

VDJ recombination is the process by which T cells and B cells randomly assemble different gene segments – known as variable (V), diversity (D) and joining (J) genes – in order to generate unique receptors (known as antigen receptors) that can collectively recognize many different types of molecule.

What is VDJ sequencing?

Here, we describe VDJ sequencing (VDJ-seq), which accurately quantitates immunoglobulin diversity at the DNA level in an unbiased manner. This is accomplished with a single primer-extension step using biotinylated J gene primers.

What is the purpose of VDJ recombination?

When does junctional diversity occur?

The primary antibody repertoire derives its diversity from two sources: combinatorial diversity (mix-and-match usage of V, D, and J gene segments) and junctional diversity [38]. Junctional diversity occurs because the RAG1/2 recombinase makes a covalent hairpin at the coding end.

How do antibody isotypes differ?

In mammals, antibodies are classified into five main classes or isotypes – IgA, IgD, IgE, IgG and IgM. These differ in the sequence and number of constant domains, hinge structure and the valency of the antibody.

Where are the V and C regions located in the lambda gene?

The V and C regions genes are not however immediately adjacent to each other. The organization of the kappa and lambda light chain genes in the germ line of undifferentiated cells is depicted in Figure 1. The lambda gene family is composed of 4 C region genes, one for each subtype of lamda chain, and approximately 30 V region genes.

Are there any genes that differ at the C terminal?

The amino acid sequence of the heavy chains of the membrane and secreted Igs differ only at their C-terminal end: are the same genes implicated in both cases? C

Where are the IGK genes located on the chromosome?

IGK (kappa) genes at 2p11 on chromosome 2. Multiple IGKV genes for the variable region, V (76 genes, of which 31 to 35 are functional); 5 IGKJ genes for the junctional region, J; a single IGKC gene for the constant region, C; the V, J and C genes are separated in the DNA of the genome (‘germline’ configuration of the Ig genes).

Where does the rearrangement of the V-J gene occur?

V-J rearrangements occur at the recombination signals (RS), which include a heptameric sequence (7 nucleotides) and a nonameric sequence (9 nucleotides), separated by a spacer. Each IGKV gene is followed downstream (in the 3′ position) by an RS consisting of a CACAGTG heptamer, and then by a 12-bp spacer, and then an ACAAAAACC nonamer.