To investigate the role of CD45 protein tyrosine phosphatase in γδ T cell development,we exa-mined whether Vγ3 dendritic epidermal T cells (DETC),a subset of γδ T cells uniquely reside in the murine epidermis were altered in the CD45-gene -deficient mice.In situ immunolabelling on epidermal sheets demonstrsted that the CD45-deficient mice had a normal density and immunophenotype of Vγ3 DETC in comparison to the wild-type control mice.RT-PCR revealed that similar levels of Vγ3 TCR mRNA were present in the epidermis of both CD45-deficient mice and wild-type controls.FCM showed no significant difference in the proportion of Vγ3 T cells in the epidermal cells between the two genotypes.In addition, the frequency of Vγ2 T cells, another subset of γδT cells in lymph nodes was normal in CD45-deficient mice.These results indicate that althouh CD45 is crucial for the development of αβΤ cells,it might be not necessary for the thymic maturation of γδ T cells including Vγ3 DETC and Vγ2 T cells.