Fig. 3.

Muscle gene expression in tail-formation stage embryos injected with CiMRFb mRNA. (A) Control embryos are shown in lateral views; injected embryos had no clear axial organization. Numbers of injected embryos examined (N) are indicated at the bottom of the figure. Two representatives from the pool of injected specimens are shown for each marker examined. The apparent hybridization signal in the epidermis of CiMRFb mRNA-injected embryos assayed for TnI mRNA was not observed when these embryos were examined microscopically; therefore, this “signal” is an artifact caused by the intense staining reaction seen in these embryos and by photographing them in glycerol, which renders them somewhat transparent. Scale bar is 100 μm. (B) Embryos cleavage-arrested with cytochalasin B from the 64-cell stage until early tail formation. Injected embryos had an average of 18 acetylcholinesterase positive cells; the number of TnI positive cells in injected embryos could not be determined. Number of injected embryos examined (N) is indicated at the bottom.