Figure 3. Cell type identification within heterogeneous cultures.

Histological sectioning and H&E staining of a developing embryo 19 h post-ovipositioning (A). Dark regions are cross-sections of the embryo. The rest of the egg contains yolk granules and yolk cells. Yolk cells (vitellophages) are 20–50 µm in diameter and contain a single nucleus, stained dark purple (inset, day 0). These cells are also observed in our cultures, and tend to contain a single, large lipid droplet, as shown in red by Oil Red O staining (B). Myogenic cells are the dominant population present in long-term cultures (C–D). Positive staining of myotubes for insect muscle myosin heavy chain (green) on day 48 confirms mature muscle cell identity. Additionally, sarcomeric striations are visible. Nuclear staining with DAPI (blue) reveals multinucleation Scale bars are as noted.