Before revision:  Here, we study the myosin-V driven active diffusion of vesicles in mouse oocytes, where this process plays a key role in nuclear positioning during development, and combine an experimental and theoretical framework to extract molecular-scale force kinetics in-vivo (motor force, power-stroke, and velocity) . We find that myosin-V induces rapid kicks of duration \tau \sim 300 \mus resulting in an average force of F \sim 0.4 pN on vesicles  .
After revision:  Here, we study the myosin-V driven active diffusion of vesicles in mouse oocytes, where this process plays a key role in nuclear positioning during development, and combine an experimental and theoretical framework to extract molecular-scale force kinetics in-vivo (motor force, power-stroke, and velocity) of the in-vivo active process. Assuming a single dominant process, we find that the nonequilibrium activity induces rapid kicks of duration \tau \sim 300 \mus resulting in an average force of F \sim 0.4 pN on vesicles .