Ghsr^tm1Lowl

The insertion of a loxP flanked transcriptional blocking cassette (TBC) into putative intron 1, downstream of the transcriptional start site, created this null allele. The TBC contained a splice acceptor, SV40 polyA signal, SV40 enhancer, a neomycin resistance cassette, two HSV-TK polyA signals, a synthtetic polyA signal/transcriptional pause signal, and another synthetic polyA signal followed by a Myc-associated zinc finger protein-binding site. Cre expression would reactivate the locus by removing the TBC. Mutant brains demonstrated absence of transcript by in situ hybridization. (J:104704)