IMGT Index

Here you are: IMGT Web resources > IMGT Index

Cassette

A cassette corresponds to the organization of small units at the genomic DNA level. Cassettes are found, for example, for chondrichthyes (shark, skate) Ig-Heavy (IGH) genes and for teleostei Ig-Light-Iota (IGI) genes.

Chondrichtyes IGH cassettes

Chondrichtyes IGH cassettes comprise V-GENE, D-GENE, J-GENE and C-GENE.
The V-D-J rearrangements seem to occur only within a given cassette and not between cassettes.
The number of cassettes may reach several hundreds and may be localized on different chromosomes.
In the chondrichthyes IGH cassettes partial V-D (~VD) or V-D, D-J (~VD,DJ) rearrangements or complete V-D-J (~VDJ) rearrangements are observed in the genomic DNA of any cell of the organism. This is in constrast with other vertebrates in which V-D-J rearrangements only occur in cells belonging to the B and T lineage, for the IG and TR genes respectively.
It is probable that partially joined ~VD or ~VD,DJ DNA can complete the V-D-J rearrangement in B cells and be transcribed into fully rearranged cDNA (#c).

Teleostei IGI cassettes

Teleostei IGI cassettes comprise V-GENE, J-GENE and C-GENE.
The V-J rearrangements seem to occur only within a given cassette and not between cassettes, but this needs to be confirmed by more data.
Two cassette types are defined, depending from the orientation of transcription of the V-GENEs relative to the J-GENE and C-GENE,
- Cassette type 1: The V-GENE(s) is (are) in inverted orientation of transcription relative to the J-GENE and C-GENE,
- Cassette type 2: The V-GENE(s) is (are) in the same orientation of transcription relative to the J-GENE and C-GENE.

The 'cassette' concept is part of the 'CLASSIFICATION' concept of IMGT-ONTOLOGY[1]

Reference:
[1]	Giudicelli, V. and Lefranc, M.-P., Bioinformatics, 15, 1047-1054 (1999) PMID: 10745995, LIGM:221

See also:

Created: 01/07/2002
Last updated: Wednesday, 29-Jun-2011 17:02:00 CEST
Authors: Dominique Scaviner and Marie-Paule Lefranc
Editors: Géraldine Folch, Nathalie Bosc, Chantal Ginestoux
Contact: Marie-Paule Lefranc

Software material and data coming from IMGT server may be used for academic research only, provided that it is referred to IMGT®, and cited as "IMGT®, the international ImMunoGeneTics information system® http://www.imgt.org (founder and director: Marie-Paule Lefranc, Montpellier, France)." References to cite: Lefranc, M.-P. et al., Nucleic Acids Research, 27, 209-212 (1999) Cover of NAR; Ruiz, M. et al., Nucleic Acids Research, 28, 219-221 (2000); Lefranc, M.-P., Nucleic Acids Research, 29, 207-209 (2001); Lefranc, M.-P., Nucleic Acids Res., 31, 307-310 (2003); Lefranc, M.-P. et al., In Silico Biol., 5, 0006 (2004) [Epub], 5, 45-60 (2005); Lefranc, M.-P. et al., Nucleic Acids Res., 33, D593-D597 (2005) Full text; Lefranc, M.-P. et al., Nucleic Acids Research 2009 37: D1006-D1012; doi:10.1093/nar/gkn838 Full text.
For any other use please contact Marie-Paule Lefranc Marie-Paule.Lefranc@igh.cnrs.fr.

IMGT founder and director: Marie-Paule Lefranc Marie-Paule.Lefranc@igh.cnrs.fr
Bioinformatics manager: Véronique Giudicelli Veronique.Giudicelli@igh.cnrs.fr
Computer manager: Patrice Duroux Patrice.Duroux@igh.cnrs.fr
Webmaster: Chantal Ginestoux Chantal.Ginestoux@igh.cnrs.fr

Citing IMGT | Warranty disclaimer and copyright notice | Privacy policy and advertisement policy