Figure 4. Histological analysis of hind limb, desmoid, epidermal and brain neoplasias of apc TALEN mRNA (40 pg) injected tadpoles and froglets.

The boxed regions in the left panels are shown at higher magnifications in the corresponding panels on the right. (A, B) Tumors associated with the developing hind limb are composed of uniform sheets of densely packed monotonously small, round cells with scant cytoplasm. (C, D) Desmoid tumor composed of spindle shaped or stellate fibroblastic cells interspersed with collagen deposits and with prominent vasculature. (E, F) Epidermoid cyst with neuroblastic elements, morphologically reminiscent of a malignant, poorly differentiated, primitive, embryonal neuroepithelial/neuroectodermal tumor (PNET). (G, H) Brain tumor with the histological characteristics of a medulloblastoma.