Figure 2.

Extensive apoptosis in the epidermis and notochord is associated with tail resorption during natural metamorphosis. (A) H&E staining of tail cross-sections at indicated stages. Magnification, 40×, scale bar: 200 μm, M, muscle; nt, notochord; sp, spinal cord. (B) TUNEL labeling reveals apoptotic cells mainly in the epidermis and notochord at S43 when tail length reduces rapidly (see A). Tail sections at indicated stages were co-stained with TUNEL labeling (green) for apoptotic cells (indicated by white arrows) and DAPI (blue) for DNA. Magnification, 200×, scale bars: 100 μm.