Awardees' Articles

HFSP Long-Term Fellows Gidi Shemer and Bob Goldstein and colleagues

Monday 19th March 2012

Apical constriction is a major mechanism in driving cell shape changes during key developmental events, including gastrulation, formation of the basic germ layers, as well as neural tube closure in vertebrates. Apical constriction is thought to be triggered by contraction of a cytoskeletal network, composed of actin filaments and myosin motor proteins (actomyosin). Here, we show that actomyosin contraction takes place even before cell shape changes are initiated, and that cell shape changes are...

 

HFSP Young Investigator Grant holders Julie Plastino and Laurent Kreplak and colleagues

Monday 19th March 2012

The actin cytoskeleton is the cellular scaffolding that primarily determines the shape and mechanical properties of cell protrusions. We examined the combined effect of two key actin-binding proteins, fascin and VASP, on the mechanical properties of actin comets, test-tube mimics of cell protrusions. We find that the effect of the two molecules together is more than the sum of the individual effects, indicating synergy between the two proteins for increased actin network rigidity.

 

HFSP Career Development Award holder Tatsuya Nishino and Young Investigator Grant holder Iain Cheeseman and colleagues

Friday 16th March 2012

At the eukaryotic centromere, more than 100 proteins participate to build a kinetochore: microtubule-capturing machinery. How the kinetochore is built at the centromere remained elusive. Here, we identified a novel kinetochore complex consisting of CENP-T, -W, -S, -X that form a histone-like heterotetramer and wrap DNA similar to canonical histones. Our results extend the current 'histone-code' hypothesis utilizing histone modifications and histone variants to 'chromatin-code'...

 

HFSP Long-Term Fellow Chieh Hsu and colleagues

Thursday 15th March 2012

GAL genes enhance their own transcription via the transcription factor Gal4p. With synthetic circuits and stochastic simulation, we show that the evolution of the feedback system does not rely on tuning the strength of the Gal4p – promoter interaction to change its activation rate but on the adjustment of bursting kinetics in stochastic gene expression.

 

HFSP Program Grant award holders Ingo Roeder and Tilo Pompe and colleagues

Monday 12th March 2012

The analysis of stem cell fate is key to a better understanding of tissue development and ultimately to develop regenerative therapies. In particular, the impact of the microenvironment on stem cell growth, division, and differentiation is far from being understood. One method to quantitatively study stem cell – microenvironment interactions under controlled conditions is automatic single cell tracking in biomimetic culture systems using time-lapse video microscopy.

 

HFSP Long-Term Fellow Naoki Oshimori and colleagues

Friday 9th March 2012

Regeneration of adult tissue relies on the activation of quiescent stem cells regulated through multiple signals in specialized microenvironments, called stem cell niches. Transforming growth factor beta (TGF-beta) signaling in the hair follicle niche induces specific gene expressions in the stem cells to counteract quiescent signals and drives them into a tissue regenerative state.

 

HFSP Long-Term Fellow Tomomi Kiyomitsu and Young Investigator Grant holder Iain Cheeseman

Thursday 8th March 2012

Mitotic spindle positioning by cortical pulling forces defines the cell division axis and location, which is critical for proper cell division and development. Although recent work has identified developmental and extrinsic cues that regulate spindle orientation, the contribution of intrinsic signals to spindle positioning and orientation remains unclear. Here, we demonstrate that cortical force generation in human cells is controlled by distinct spindle pole and chromosome-derived signals that...

 

HFSP Career Development Award and Program Grant holder Mariano Sigman and colleagues

Wednesday 29th February 2012

The human brain is organized in functional modules. Such an organization poses a conundrum: modules ought to be sufficiently independent to guarantee functional specialization and, at the same time, sufficiently connected to bind multiple processors for efficient information transfer in the whole brain. How is this solved? Here we show a formal solution to this problem is the formation of two networks. A skeleton of strong links forms a highly modular and fragmented structure. This network is embedded...

 

HFSP Long-Term Fellow Fernando Garcia-Moreno and colleagues

Tuesday 28th February 2012

Since evolution is the evolution of embryonic forms, the study of embryonic development is currently the most powerful tool for biologists to understand the evolutionary process. When addressing the question of the origins of the human brain, scientists stumble over the frustrating lack of similarities between the surfaces of brains among mammalian and other vertebrate species. All living mammals present a six layered neocortex, whereas no homologous structure is found in any other vertebrate species...

 

HFSP Long-Term Fellow Shalev Itzkovitz and colleagues

Saturday 25th February 2012

Intestinal crypts display a developmental temporal order in which the establishment of stem cells precedes the expansion of nonstem cells. Optimal control theory predicts that this strategy minimizes the time needed to create a mature crypt.