Cd3g^tm1Amk

Exon 4, which encodes the transmembrane domain, was replaced with a neomycin cassette. In addition a frameshift mutation was introduced into exon 3. Northern blot analysis of homozygous mutant thymocytes showed an absence of normal transcript. The analysis also showed that the expression of the closely related CD3 antigen genes, Cd3d and Cd3g, was not affected in mutant mice. The levels of Cd3z transcript, however, were found to be slightly lower than in wild-type. (J:47013)