Add3^tm2.1Llp

An EGFP-pA cassette was inserted into exon 2, the first coding exon, and an FRT-flanked neomycin selection cassette was inserted into the downstream intron, which was excised by breeding to a mouse with germline expression of FLP1 recombinase, resulting in a null allele with expressed reporter and no neomycin selection sequence. (J:266350)