Fig. 4

Apoptotic cell death persists and increases in later phases. a TUNEL⁺ cells (green) in control animals are normally distributed throughout larval tissues and is concentrated within the ciliary band epithelium. Nuclei (gray) stained with DAPI. Regenerating anterior (b) and posterior (c) fragments display similar patterns and numbers of TUNEL⁺ cells from 3 h post-bisection (hpb) until 6 days post-bisection (dpb) when there is an increase. d Quantitation of TUNEL⁺ cells in regenerating anterior and posterior fragments shows that there is no significant difference in the number of TUNEL⁺ cells until 6 dpb when a significant increase in apoptotic cells are detected. The difference of the means (i.e., Δ TUNEL⁺ cells) is plotted and significance differences are indicated (Mann-Whitney, p < 3 × 10⁻⁴, red asterisk). n = the number of individuals sampled