Rxrb^tm1Ipc

Genomic sequences encoding the DNA-binding domain in exons 3 and 4 were replaced by a neomycin cassette. RT-PCR analysis on total RNA derived from several tissues of homozygous mice revealed that transcripts corresponding to exon 2 as well as exons 5-9 were present at low levels in homozygous mice. The authors do not rule out the possiblility that some mutant protein could be expressed in homozygotes. (J:30560)