Table 1.

Percentage of molecules showing compact conformation^a

	Native (%)	Crosslinked (%)	Native + blebbistatin (%)	Blebbistatin + crosslinking (%)
Tarantula	46	67	ND	ND
Limulus	40	68	ND	ND
Vertebrate skeletal	6	37	42	65

^a The number of molecules showing the compact conformation (apposed heads) in relaxing conditions following different treatments (Figure 5 legend), were counted from five micrographs (each of a 0.75 μm x 0.75 μm region of the EM specimen), in each case. The number of compact molecules is shown as a percentage of the total number of molecules (about 100–150 total in each condition). ND, not determined.