Fig. 1. Pygo1 and Pygo2 mutant alleles and expression of Pygo2 in the early mouse eye. (A,C) Gene targeting for Pygo1 and Pygo2 alleles. Green and gray boxes represent coding and non-coding exons, respectively. Light orange box indicates positive selection marker Pgk-Neo. Dark orange bars are frt sites. Blue arrowheads denote loxP sites. The left and right targeting arms (LTA and RTA), N box, PHD domain and nuclear localization signal (NLS) are indicated. Exons are numbered. Black arrows indicate the location of amplification primers used in B,D. (B,D) PCR amplification of genomic DNA or cDNA (the lower panel in D) for Pygo1 (B) or Pygo2 (D) allelic series. (E-J) Immunofluorescence for Pygo2 (E,F,H,I) or Pax6 (G,J) in eye region cryosections from the embryonic stages and genotypes indicated. A gray line between panels indicates that different channels of the same image are displayed. ple, presumptive lens ectoderm; op, optic pit; lp, lens placode; ov, optic vesicle.