Blk^tm1Tara

Sequences encoding the essential portion of the kinase domain in exon 8 were replaced with a neomycin resistance gene via homologous recombination. Gene expression was not detected in splenic B-cells from homozygous mutant animals via Northern blot, but RT-PCR analysis detected transcripts containing exons 1-4. However, Western blot using antibodies directed against the N-terminal region of the protein did not detect any translation product from the truncated transcript. (J:60221)