Rap1a^tm1Tze

A targeting construct was made by replacing a 420-bp region encoding the N-terminal 19 amino acids, which include conserved residues and part of the GTP-binding motif, with an internal ribosome entry site (IRES)/LacZ/ neomycin cassette. Shortened mRNAs for the locus were detected in tissue of homozygous mice. These resulted from an alternative splicing site 5' of the neomycin cassette and an alternative ATG start site that would result in a 51 amino acid truncated protein. However, no protein was detected in immunoblot analysis of thymus and spleen extracts so the authors concluded this was a null allele. LacZ staining was evident in E12.5 embryos. (J:144145)