This allele was created by transfer of a male alpha-beta T cell nucleus into an enucleated oocyte. A blastocyte was grown and from this an ES cell clone was derived. The two Tcra alleles in this ES cell were recombined with one allele having a productive, in frame recombination and the other a non-productive, out of frame recombination. Only the productive allele containing a Valpha3.1-J30 recombination was propagated and is the one described here. Recombination was determined by Southern blotting and inverted PCR. (J:143006)