Figure 3.
Fluorescence recovery rates of YFP-actin in premyofibrils (a) and mature myofibrils (b) of cultured skeletal myotubes in control medium and in the presence of jasplakinolide. Note the dramatic decreases in the rates of YFP-actin recovery after the photobleaching in the presence of jasplakinolide (lower curves a, b). (c) Calculations of mobile fractions of YFP-actin reveal dramatic decreases of both fast and slow mobile fractions in the presence of jasplakinolide in premyofibrils and in mature myofibrils.