Oprm1^tm2.1Loh

The intronic neo cassette was excised from Oprmtm2Loh via in vivo cre mediated recombination, leaving the engineered serine to alanine missense mutation in exon 2 at codon 196 (S196A) intact. S196A affects the fourth transmembrane domain. A radioactive ligand receptor-binding assay showed reduced expression of the mutant protein in homozygous mutant mice, approximately 85% that of the endogenous protein in wild-type mice. The reduced protein expression correlated with reduced levels of transcript. (J:81978)