Figure 6.

Somite architecture and cell death in wild-type and Mll−/− E10.5 embryos. Hematoxylin and eosin staining of lateral sections and TUNEL staining of transverse sections. (A) wild-type somites; note normal morphology of somite epithelium indicated by arrows. (B) Mll−/− somites demonstrating disrupted epithelial boundaries ventrally. (C) Normal cell death in wild-type somites revealed by TUNEL. (D) Cell death in Mll−/− somites; note the relative sparing of spinal ganglia (sg) and neural tube (nt). Arrows indicate areas of apoptosis. (Scale bars = 50 μm.)