Biology · Developmental Biology

Following statements are made regarding amphibian embryonic development: A. Fibronectin plays an important role in enabling the mesodermal cells to migrate into the embryo. B. The Organizer secretes proteins that block the BMP signal, which allows the ectodermal cells to become epidermis. C. Wnt signaling causes a gradient of β-catenin along the anterior-posterior axis of the neural plate, which appears to specify the regionalization of the neural tube. D. The more ventral blastomeres in the endoderm have high expression of nodal-related proteins. Which one of the following options represents the combination of all correct statements?