Arap2^{Gt(PT1-ATG)9AVal}

The PT1-ATG gene trap vector has integrated into the endogenous gene immediately downstream of bp 4622. This vector contains the engrailed 2 (En2) splice acceptor sequence joined to a promoterless lacZ (E. coli beta-galactosidase) reporter gene with an ATG translation initiation codon; integration of the construct into an intron results in transcription of a fusion mRNA containing the 5' exons of the trapped gene joined to the lacZ coding sequence. PT1-ATG also contains the neomycin phosphotransferase gene under control of the phosphoglycerate kinase 1 (PGK1) promoter (PGK1-neo). The 9A ES cell clone was selected for chimera production because it exhibited significantly elevated beta-galactosidase activity following exposure to gamma radiation. (J:82809, J:197093)