Thrb^tm3.1Df

Neomycin resistance and lacZ cassettes were targeted into a beta1 isoform-specific coding exon removing 84 codons and the splice donor of the exon. This mutation leaves the beta2 isoform-specific exon intact. Cre-mediated recombination removed the selection cassette. Expression of beta-galactosidase is detected in the cortex and medulla of the adrenals, with expression undetectable by P35 in males but persisting into adulthood in females. RT-PCR confirmed the absence of the beta1 isoform, but presence of the beta2 isoform, in P5 cochlea and P21 pituitary. (J:222168, J:227423)