Figure 1. Exo utero surgery. (A) At E15.5, the abdominal cavity of the dam was surgically revealed, and embryos covered with the embryonic membrane were exposed; then, the mandible and maxilla were fixed by suture, while the umbilical cord and placenta were kept intact inside the amnion. (B) Schematic representation of the suture fixation in (A) performed to restrict fetal jaw movement. (C) Sutured (left) and non-sutured (right) embryos obtained at E18.5. Arrows indicate suture fixation with 8-0 nylon.