Quantitative Life Sciences Seminar - 18 February

[Quantitative Life Sciences]

QUANTITATIVE LIFE SCIENCES SEMINAR


*Thursday**, 18 February - 11:00**am*
*****Central Area**, 2nd Floor**- ICTP, old SISSA Building*

Title: "Dynein transmits polarized actomyosin cortical flows to promote 
centrosome separation"

Speaker: Alessandro De Simone - EPFL, Doctoral Program in Molecular Life 
Sciences, Lausanne, Switzerland


Abstract:
Centrosomes are the major microtubule organizing centers of animal cells 
and play a critical role in mitosis to organize the mitotic spindle and 
orchestrate chromosome segregation. The two centrosomes present at the 
onset of mitosis must separate in a timely and accurate fashion along 
the surface of the nucleus to ensure proper bipolar spindle assembly.

The microtubule-associated motor dynein plays a pivotal role in 
centrosome separation, but the underlying mechanisms remain elusive, 
particularly regarding how dynein coordinates this process in space and 
time. Where in the cell do motors act to separate centrosomes? How are 
forces organized to bring centrosomes in opposite directions? And how 
robust is this process?

To address these questions, we have dissected centrosome separation in 
the C.elegans one-cell stage embryo. We have quantitatively measured and 
modeled centrosome separation using a combination of 3D fluorescence 
time-lapse microscopy, image processing and computational modeling. Our 
analysis reveals that centrosome separation is powered by the joint 
action of dynein at the nuclear envelope and at the cell cortex. 
Strikingly, we demonstrate that dynein at the cell cortex acts as a 
force-transmitting device that harnesses polarized actomyosin cortical 
flows initiated by the centrosomes earlier in the cell cycle. This novel 
mechanism elegantly couples cell polarization with centrosome 
separation, thus ensuring faithful cell division.

Web: http://indico.ictp.it/event/7804/





-- 
Erica Sarnataro
Group Secretary
Quantitative Life Sciences
The Abdus Salam International Centre for Theoretical Physics (ICTP)
Trieste,  Italy
Tel. +39-040-2240623
e-mail:qls at ictp.it