Ca. Mallick et al., REARRANGEMENT AND DIVERSITY OF T-CELL RECEPTOR BETA-CHAIN GENES IN THYMOCYTES - A CRITICAL ROLE FOR THE BETA-CHAIN IN DEVELOPMENT, Cell, 73(3), 1993, pp. 513-519
Thymocytes from mice congenitally deficient for TCR alpha chain synthe
sis were examined for the status of their TCR beta chain genes, by DNA
sequencing and by a novel technique that analyzes populations of gene
rearrangements. TCR beta chain genes were predominantly productively
rearranged, in contrast with the statistical prediction for a quasi-ra
ndom rearrangement process. Therefore, productive TCR beta chain gene
rearrangement appears to be a critical step in thymocyte maturation, i
ndependent of TCR alpha chain expression. Moreover, the beta chain gen
e rearrangements in TCRalpha-/- mice are typical of those found in the
thymus and periphery of normal mice. Thus, the extent of junctional d
iversity is a property of TCR genes that is imposed prior to selection
on the mature alphabeta TCR.