Fig. 2. OE1 and OE2 mice and embryos display externally visible abnormalities with penetrance varying from severe to non-detected. (A,B) OE1 transgenic mice commonly display defective forelimbs. (C,D) OE2 mice commonly display kinked tails with terminal scabs in newborns. (E-G) Smaller forelimb buds (with dotted green outline) are commonly seen at 10.5 days in OE1 embryos (F) relative to wild type (E) and OE2 (G). Embryos are stained for Mox1 mRNA to facilitate assignment of prevertebral (v) addresses. The OE2 embryo possesses a club-tail.