Fig. 2.

Change in gene expression in the exocrine pancreas during metamorphosis. (A–D and I–L) In situ hybridization with amylase (A–D) and Ptf1a (I–L) probes. Every mRNA encoding a “terminally differentiated” exocrine protein that we have tested is extinguished at metamorphic climax (NF62) to the same extent as these 2 mRNAs (see discussion). (E–H) Although amylase mRNA is extinguished at climax, amylase protein was still detected by immunohistochemistry, confirming the dedifferentiation stages of previously differentiated exocrine cells. (Scale bar: 40 μm.)