IJS KOLOKVIJ,sreda, 16. 04. 2014; ob 13. uri; prof. dr. Maria Leptin

[Tanja Debevec]

Vabimo vas na 17. predavanje iz sklopa "Kolokviji na IJS" v letu 2013/14, ki bo v sredo, 16. aprila 2014, ob 13. uri v Veliki predavalnici Instituta »Jožef Stefan«  na Jamovi cesti 39 v Ljubljani. Napovednik predavanja najdete tudi na naslovu http://www.ijs.si/ijsw/Koledar_prireditev, posnetke preteklih predavanj pa na http://videolectures.net/kolokviji_ijs. 

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prof. dr. Maria Leptin

European Molecular Biology Laboratory, Heidelberg, Nemčija

 

Oblika celic in morfogeneza: sub- in supracelični mehanizmi

 

Mehaniko in molekularne mehanizme morfogeneze organov in drugih struktur začenjamo dobro razumeti, manj pa vemo o tem, kako so ti razvojni procesi integrirani v ves organizem. Intuitivno je jasno, da deli telesa ne morejo delovati ločeno in da mora biti njihovo obnašanje koordinirano, če naj vodi do pravilno strukturirane živali, a zaenkrat še ni znano, kako tkiva in celice v organizmu sodelujejo pri doseganju tega cilja. Proces gastrulacije v zgodnjih fazah razvoja embria vinske mušice je posebej primeren za študij tega problema, ker so tako rekoč vsi posamezni procesi, ki potekajo med gastrulacijo, dodobra raziskani in ker poznamo njihovo genetsko kontrolo. Da bi lahko analizirali dinamične interakcije vseh tkiv v telesu, jih moramo snemati v živo z visoko prostorsko in časovno ločljivostjo. Z optičnim mikroskopom smo posneli embrie, ki ekspresirajo fluorescentne markerje, vezane na plazemsko membrano, in napravili popolno 3D rekonstrukcijo s časovno ločljivostjo 20 s. Prva stopnja gastrulacije, nastanek ventralne brazde, vodi z gubanjem epitelija do internalizacije bodočega mezoderma. Ugotovili smo, da pri začetku nastanka brazde nemezodermalne celice ne sodelujejo. Do zmanjšanja površine invaginirajočih se celic pride le s povečanjem površine lateralnih mezodermalnih celic. Ko se mezoderm premakne v notranjost embria, pričnejo v procesu sodelovati tudi lateralne ektodermalne in dorsalne celice. Prve se kot tog, neelastičen segment premaknejo proti ventralni strani. Obenem se dorsalne celice raztegnejo v prečni smeri. Z genetskim in fizičnim manipuliranjem embria smo dognali, da imajo različne populacije celic različne mehanične lastnosti, ki omogočajo diferencialni odziv na sile v brazdi.

Predavanje bo v angleščini.

Lepo vabljeni!

 




We invite you to the 17th Institute colloquium in the academic year 2013/14. The colloquium will be held on Wednesday April 16, 2014 at 1 PM in the main Institute lecture hall, Jamova 39, Ljubljana. To read the abstract click  http://www.ijs.si/ijsw/Koledar_prireditev. Past colloquia are posted on  http://videolectures.net/kolokviji_ijs.

 

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prof. dr. Maria Leptin

European Molecular Biology Laboratory, Heidelberg, Germany

 

Cell shape and morphogenesis: sub- and supracellular mechanisms

 

 

The mechanics and molecular mechanisms of the morphogenesis of organs and other structures are beginning to be well understood, but less is known about how such developmental processes are integrated across the whole organism. While it is intuitively clear that different parts of the body cannot operate in isolation but must coordinate their behaviours to generate a properly structured animal, it has not been tested how all tissues and cells in an organism cooperate to achieve this goal. The process of gastrulation during early Drosophila embryo is particularly well suited for studying this problem, as practically all of the individual processes that occur have been intensively studied and their genetic control has been elucidated. To be able to analyse the dynamic interactions of all tissues in the body, they need to be viewed by live imaging at high spatial and temporal resolution. We have recorded embryos expressing plasma membrane-associated fluorescent markers and have made full 3D reconstructions at 20-second resolution. The first step of gastrulation, the formation of the ventral furrow, internalizes the future mesoderm by epithelial folding. We find that the initial formation of the furrow occurs without participation of non-mesodermal cells. The reduction in cell surface in the invaginating cells is accommodated only by an increase in the cell surface in the lateral mesodermal cells. Once the mesodermal cells translocate towards the interior of the embryo, the lateral ectodermal and dorsal cells begin to participate. The ectodermal cells are displaced as a non-deformable squad towards the ventral side. Simultaneously, the dorsal cells are stretched sideways. Genetic and physical manipulations suggest that the different populations have different mechanical properties that allow the differential responses of the participating cell populations to the forces generated within the furrow.

 

Cordially invited!

 

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