Date(s) - 03/26/2012
11:45 am - 12:35 pm
There are two contrasting views on how the centrosome is centered in the cell. One view is that microtubules grow out from the centrosome and push on the cell membrane. The other view is that molecular motors pull along the microtubule length and center the centrosome. We severed single living microtubules with a femtosecond laser. On severing, the minus-ended microtubules bend further, suggesting that microtubules are under tension. On inhibiting dynein activity, microtubules straighten. We propose that dynein pulls on microtubules and pulls the centrosome into place. I will conclude with evidence for how dynein also tugs on the nuclear surface and causes nuclear rotations.