Electron microscopic studies of the developing amphibian thymus.
Electron-microscopic studies of larval Xenopus laevis thymus at three different stages of development are presented. Studies of thymus from 5 and 8 day old larvae (ages when early thymectomy is performed) reveal a relatively undifferentiated rudiment composed of epithelial cells and lymphoid cell precursors. These findings are in marked contrast to ultrastructural observations of 30 day old larval thymus, where there exists a well defined corticomedullary differentiation with an abundance of small lymphocytes in the cortical region.
D000818:Animals; D007814:Larva; D008854:Microscopy, Electron; D009024:Morphogenesis; D013950:Thymus Gland / Q000196:embryology* / Q000648:ultrastructure; D013997:Time Factors; D014981:Xenopus / Q000196:embryology*