Genetic mapping of two murine loci that influence the development of IL-4-producing Thy-1dull γδ thymocytes

IL-4-producing gamma delta cells belong to a novel subset of gamma delta lymphocytes that expresses a very restricted repertoire of TCRs. To gain a deeper insight into the development and in vivo functions of these cells, we have analyzed the genetic control of their representation in the thymus. Using an intercross between C57BL/6 and DBA/2 mice we found two loci on chromosomes 13 and 17-named LadT1 and LadT2, respectively-with marked influence in their development. The LadT2 locus does not appear to be the MHC locus. The region identified on mouse chromosome 13 contains the structural genes for TCR gamma as well as the IL-9 gene, which has been suggested as a candidate gene influencing the complex pathogenesis of asthma.