Figure 1. Schematic diagram of the Pax6-GAL4/VP16 and UAS-lacZ transgene

A GAL4/VP16 cDNA (800 bp) [3] was inserted between a modified Pax6 epithelial promoter (2.3 kb) [10] and an intron and polyadenylation sequence derived from SV40 virus (850 bp) [25]. The lens/cornea enhancer [9] is contained between the BglII/AccI sites (clear bar). SV40 and GAL4/VP16 sequences were used to make riboprobes for detection of transgene expression. An 800 bp BglII fragment from the Pax6 promoter was used for Southern hybridizations (bold line). The UAS-lacZ construct was made by linking 6 tandem copies of the 17 bp UAS with a minimal thymidine kinase (TK) promoter to the lacZ gene to generate UAS-lacZ. The lacZ gene contains a Kozak consensus sequence.