IMGT Web resources

 Here you are: IMGT Web resources > IMGT Education > Questions and Answers

QUESTION 4:

How to make 104 different T cell receptor alpha chains?


ANSWER to question 4:

From the TRA genes to the T cell receptor alpha chains

The TRA V-J rearrangements in the T cells create a combinatorial diversity of 2200-2300 recombinations. One important additional mechanism contributes to the T cell receptor alpha diversity: the N diversity (N, for nucleotides) which results from deletion and/or addition of nucleotides at random by the terminal deoxynucleotidyltransferase and creates, at the V-J JUNCTION, a region not encoded in the germline DNA. In contrast to the immunoglobulin loci, there is no mechanism of somatic mutations in the T cell receptor loci. The TRD locus is nestled in the TRA locus. V-J rearrangements in the TRA locus therefore result in deletion of the TRD genes localized on the same chromosome.


Created: 11/06/2001
Last updated: Wednesday, 29-Jun-2011 17:01:51 CEST
Author: Marie-Paule Lefranc Marie-Paule.Lefranc@igh.cnrs.fr
Editor: Elodie Foulquier