Ext1^{Gt(LST064)Byg}

The gene trap was inserted between exons 1 and 2, resulting in a fusion transcript of exon 1 fused to the gene trap vector sequence. The vector, pGT2TMpfs, contained part of En2, the transmembrane domain of CD4, Beta-geo, IRES, PLAP and pA elements. Northern blot against a cDNA probe for the 3' end of Ext1 showed no 3' mRNA present in mutants. This allele is reported to be a hypomorph (J:92212). (J:91757)