Fig. 8. Msxb expression is restricted to non-proliferating DMB. Representative sections from 30- and 72-hour fin regenerates (n=4-6) were processed for detection of msxb (A-H) and shh (I-L) mRNA (red) and PCNA protein (green). Fluorescent sections are counterstained with DAPI to reveal nuclei (blue). (A-D) Note that during blastema formation, a large number of distal blastemal proliferating cells are positive for msxb, while during regenerative outgrowth (E-H), msxb expression is restricted to a small number of non-proliferating DMB cells. Although, msxb and PCNA domains partially overlap, there is no PCNA staining in the DMB. (I-L) The level of shh staining correlates with the end of the blastema proliferation zone and the onset of differentiation (appearance of new scleroblasts, indicated by stars).
