Id4^tm1Fsky

A lacZ-neo cassette replaced sequence encoding HLH domain and most of the C-temrinus of the gene. The cassette was inserted in-frame, allowing the expression of a fusion gene encoding the N-terminal 65 amino acids of Id4 fused to beta-galactosidase. RT-PCR of mutant brain and testis failed to detect mRNA encoding the HLH domain. X-gal staining demonstrated that expression of the fusion gene was similar to expression of the endogenous gene expression (J:98270)