Fig. 1.

pbx is expressed in irradiation-sensitive cells, the cephalic ganglia and regenerating blastemas. (A) pbx was expressed throughout the parenchyma of whole worms and resembles the pattern observed for neoblast-expressed genes. Twenty-four hours after a 100 Gy dose of γ-irradiation, most pbx-expressing cells are lost, revealing clear expression in the CG. By 48 hours post-irradiation, the distinctive parenchymal expression pattern of pbx was completely lost. (B) pbx expression was broadly observed in both anterior and posterior blastemas of regenerating pieces. Regenerating fragments were γ-irradiated with a dose of 100 Gy at 1 dpa to aid visualization of pbx in cells other than neoblasts. Expression was bilateral in both anterior and posterior blastemas, suggesting expression in the regenerating CNS.