Fig. 4. Lrig3 is required for NC formation in animal caps downstream of Pax3 and Zic1. (A,A') L3MO inhibits NC marker induction by Chordin (Chd) plus Wnt3a in animal caps. Embryos were injected with 300 pg Chd, 1 ng Lrig3, 30 ng L3MO, 300 pg Chd + 300 pg Wnt3a, 300 pg Chd + 300 pg Wnt3a + 30 ng L3MO, or with 300 pg Wnt3a + 300 pg Chd +1 ng Lrig3. Gene expression was assayed by RT-PCR. (B) NC induced by co-injection of Pax3 and Zic1 was inhibited by L3MO. Pax3 (200 pg) and Zic1 (200 pg) each, alone or with 30 ng L3MO were injected, and assayed as in A. AC, uninjected animal caps. RT-, without reverse transcriptase.