BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//wp-events-plugin.com//6.4.7.2//EN
TZID:Europe/Paris
X-WR-TIMEZONE:Europe/Paris
BEGIN:VEVENT
UID:0-633@lptms.universite-paris-saclay.fr
DTSTART:20181121T110000Z
DTEND:20181121T120000Z
DTSTAMP:20181115T071904Z
URL:http://www.lptms.universite-paris-saclay.fr/seminars/physics-biology-i
 nterface-seminar-jan-brugues-2/
SUMMARY:Physics-Biology interface seminar: Jan Brugues - Amphi BLANDIN du L
 PS de la Faculté des Sciences d’Orsay (Bâtiment 510) - 21 Nov 18 11:00
DESCRIPTION:How to set the proper size and shape of metaphase spindles\nJan
  Brugues (MPI Dresden\, Germany)\nRegulation of size and growth is a funda
 mental problem in biology. A prominent example is the formation of the mit
 otic spindle\, where protein concentration gradients around chromosomes ar
 e thought to regulate spindle growth by controlling microtubule nucleation
 . Previous evidence suggests that microtubules nucleate throughout the spi
 ndle structure. However\, the mechanisms underlying microtubule nucleation
  and its spatial regulation are still unclear. In the first part of the ta
 lk I will present an assay based on laser ablation to directly probe micro
 tubule nucleation events in Xenopus laevis egg extracts. Combining this me
 thod with theory and quantitative microscopy\, we show that the size of a 
 spindle is controlled by autocatalytic growth of microtubules\, driven by 
 microtubule-stimulated microtubule nucleation. The autocatalytic activity 
 of this nucleation system is spatially regulated by the limiting amounts o
 f active microtubule nucleators\, which decrease with distance from the ch
 romosomes. This mechanism provides an upper limit to spindle size even whe
 n resources are not limiting. Once the necessary amounts of microtubules a
 re created\, the activities of motors lead to the proper shape and archite
 cture of spindles. In the second part of the talk I will discuss the origi
 n of motor-mediated stress in spindles.
CATEGORIES:physbio,seminars
LOCATION:Amphi BLANDIN du LPS de la Faculté des Sciences d’Orsay (Bâtim
 ent 510)\, 15 Rue Georges Clemenceau\, orsay\, France
GEO:48.698187;2.181768
X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=15 Rue Georges Clemenceau\,
  orsay\, France;X-APPLE-RADIUS=100;X-TITLE=Amphi BLANDIN du LPS de la Facu
 lté des Sciences d’Orsay (Bâtiment 510):geo:48.698187,2.181768
END:VEVENT
END:VCALENDAR