Alternative titles; symbols
Cytogenetic location: 22q11.2 Genomic coordinates (GRCh38): 22:17,400,001-25,500,000
Immunoglobulins (Ig) are the antigen recognition molecules of B cells. An Ig molecule is made up of 2 identical heavy chains (see 147100) and 2 identical light chains, either kappa (see 147200) or lambda, joined by disulfide bonds so that each heavy chain is linked to a light chain and the 2 heavy chains are linked together. The kappa and lambda light chains have no apparent functional differences. Each Ig lambda light chain has an N-terminal variable (V) region containing the antigen-binding site and a C-terminal constant (C) region, encoded by a C region gene (IGLC1; 147220), that provides signaling functions. The lambda light chain V region is encoded by 2 types of genes: V genes and joining (J) genes (see 147230). Random selection of just 1 gene of each type to assemble a V region accounts for the great diversity of V regions among Ig molecules. The lambda light chain locus on chromosome 22 contains approximately 30 functional V genes, followed by approximately 4 functional J genes. Due to polymorphism, the numbers of functional V and J genes differ among individuals (Janeway et al., 2005).
Mraz et al. (2012) reported that the gene for microRNA-650 (MIR650; 615379) is located within the leader exon (exon 1) of the lambda light chain V genes of the V2 family. By expression analysis in chronic lymphocytic leukemia (CLL) samples and bioinformatic analysis, they found that MIR650 and its host gene used the same promoter region for their transcription. However, since MIR650 could also be expressed in cell types other than B cells, Mraz et al. (2012) suggested that the promoter serves as a potent enhancer element for MIR650.
The Ig lambda light chain V gene cluster is located within the Ig lambda light chain locus on chromosome 22q11.2 (Emanuel et al., 1985; Frippiat et al., 1995).
Quantitative DNA fiber mapping (QDFM) allows direct visualization of bound probes at their respective positions along larger DNA molecules (Weier et al., 1995). Specific probes are hybridized to individual stretched DNA molecules. Duell et al. (1997) evaluated the use of QDFM for the large-scale physical mapping of the rather unstable, repeat-rich 850-kb region encompassing the IGLV gene segments. They concluded that compared to other methods commonly used with physical map assembly, QDFM is a rapid, versatile technique delivering unambiguous data necessary for map closure and preparation of sequence-ready minimal tiling paths.
Richl et al. (2008) reported that some V lambda genes were overexpressed in nonproductive neonatal and adult human B-cell repertoires, whereas others were overexpressed in productive repertoires. The selection of the productive V lambda repertoire appeared stable between neonates and adults, suggesting that the selection may be driven mainly by autoantigens, as newborns have not been exposed to exogenous antigens.
Anderson, M. L. M., Goyns, M. H., Geurts van Kessel, A. H. M., Young, B. D. Regional mapping of two human immunoglobulin V-lambda genes and analysis of the V-lambda locus in chronic myeloid leukaemia. Nucleic Acids Res. 13: 5761-5770, 1985. [PubMed: 3862074] [Full Text: https://doi.org/10.1093/nar/13.16.5761]
Duell, T., Wang, M., Wu, J., Kim, U.-J., Weier, H.-U. G. High-resolution physical map of the immunoglobulin lambda variant gene cluster assembled by quantitative DNA fiber mapping. Genomics 45: 479-486, 1997. [PubMed: 9367672] [Full Text: https://doi.org/10.1006/geno.1997.4954]
Emanuel, B. S., Cannizzaro, L. A., Magrath, I., Tsujimoto, Y., Nowell, P. C., Croce, C. M. Chromosomal orientation of the lambda light chain locus: V-lambda is proximal to C-lambda in 22q11. Nucleic Acids Res. 13: 381-387, 1985. [PubMed: 3923432] [Full Text: https://doi.org/10.1093/nar/13.2.381]
Frippiat, J.-P., Williams, S. C., Tomlinson, I. M., Cook, G. P., Cherif, D., Le Paslier, D., Collins, J. E., Dunham, I., Winter, G., Lefranc, M.-P. Organization of the human immunoglobulin lambda light-chain locus on chromosome 22q11.2. Hum. Molec. Genet. 4: 983-991, 1995. [PubMed: 7655473] [Full Text: https://doi.org/10.1093/hmg/4.6.983]
Janeway, C. A., Jr., Travers, P., Walport, M., Shlomchik, M. J. Immunobiology: The Immune System in Health and Disease. (6th ed.) New York: Garland Science Publishing (pub.) 2005. Pp. 103-106, and 135-139.
Mraz, M., Dolezalova, D., Plevova, K., Kozubik, K. S., Mayerova, V., Cerna, K., Musilova, K., Tichy, B., Pavlova, S., Borsky, M., Verner, J., Doubek, M., Brychtova, Y., Trbusek, M., Hampl, A., Mayer, J., Pospisilova, S. MicroRNA-650 expression is influenced by immunoglobulin gene rearrangement and affects the biology of chronic lymphocytic leukemia. Blood 119: 2110-2113, 2012. [PubMed: 22234685] [Full Text: https://doi.org/10.1182/blood-2011-11-394874]
Richl, P., Stern, U., Lipsky, P. E., Girschick, H. J. The lambda gene immunoglobulin repertoire of human neonatal B cells. Molec. Immun. 45: 320-327, 2008. [PubMed: 17675156] [Full Text: https://doi.org/10.1016/j.molimm.2007.06.155]
Weier, H.-U. G., Rhein, A. P., Shadravan, F., Collins, C., Polikoff, D. Rapid physical mapping of the human trk protooncogene (NTRK1) gene to human chromosome 1q21-22 by P1 clone selection, fluorescence in situ hybridization (FISH), and computer-assisted microscopy. Genomics 26: 390-393, 1995. [PubMed: 7601468] [Full Text: https://doi.org/10.1016/0888-7543(95)80226-c]