Cd3e^tm1Lov

A section of the genome encoding a 3' portion of exon 5, intron 5 and whole of exon 6, encoding the extracellular and transmembrane domains, was replaced by a floxed neo cassette. Northern blot analysis of total RNA obtained from thymocytes showed an absence of Cd3e transcript and reduced levels of Cd3d and Cd3g transcript in homozygous mutant mice. The downregulation of the delta and gamma polypeptides was believed to be due to the reverse transcriptional orientation of the neo transgene having an effect on the enhancer for Cd3d and Cd3g. To eliminate this effect, Cd3etm1.1Lov was generated by breeding mice possessing this allele with cre expressing mice. (J:72144)