11 May

Publication on kinetochore microtubules

Three-dimensional reconstruction of spindle and KMTs

Nature Communications 8, Article number: 15288 (2017) doi:10.1038/ncomms15288

C. elegans chromosomes connect to centrosomes by anchoring into the spindle network

Our paper is published here. We combine large-scale serial electron tomography, live-cell imaging, a new method based on spatial-temporal correlation with numerical modelling to show that the connection between centrosomes and chromosomes is mediated by an anchoring into the entire spindle network.

10 May

Soluble tubulin enriched at centrosome

This week I present a poster at the conference: Actin and microtubule cytoskeleton: bridging scales from single molecules to tissues at Roscoff (France) about:

The concentration of tubulin dimers in centrosomes is above the critical concentration for nucleation

During cell division, the mitotic spindle physically separates the duplicated chromosomes. The spindle is formed by many highly dynamic microtubules. Microtubules are stiff filaments that form by polymerization of tubulin dimers. Here we determine the concentration profile of tubulin dimers by combining electron with light microsocopy data.

Tomographic electron microsocopy is able to identify microtubules in the spindle, but cannot resolve the tubulin dimers. Therefore it provides a quantitative measure of the local concentration of tubulin within microtubules. Read More

20 Mar

Local tubulin concentration in the spindle

Today I present a poster at the DPG (BP 9.13) in Dresden about:

Local tubulin concentrations in the C. elegans metaphase spindle

During cell division, the mitotic spindle physically separates the duplicated chromosomes. The spindle is formed by many highly dynamic microtubules. Microtubules are stiff filaments that form by polymerization of tubulin dimers. Here we determine the concentration profile of tubulin dimers by combining electron with light microsocopy data.

Tomographic electron microsocopy is able to identify microtubules in the spindle, but cannot resolve the tubulin dimers. Therefore it provides a quantitative measure of the local concentration of tubulin Read More

16 Mar

Networking by personal communication

For a scientist there is a need to communicate and discuss research findings. There are many ways to communicate. Besides the written form and a structured oral form—such as a talk or a lecture—informal personal communication is another common way to exchange ideas. Good communication within the scientific community also helps to be well integrated. This clarifies relevant research directions, possibly increases the support of reviewers, and can motivate your own research as you know that somebody else will be interested in your findings. But how do you strike up these conversations? Certainly it helps to do networking by personal communication.

There are different strategies  Read More

10 Oct

Postdocs biophys

We started a weekly postdoc meeting in the biological physics department. We talk about our research, but equally about career topics and professional skills.

12 Jul

Traveling wave in the inner ear

Today I gave a talk at the ICSV23 in Athens about:

The traveling wave in the human inner ear studied by means of a finite-element model including middle and outer ear

The mammalian hearing organ is a remarkable biophysical system, which converts the incoming sound into a neural signal. The main components in the signal chain are the middle ear, the basilar membrane, and the organ of Corti. The middle ear matches the impedance of the liquid filled inner ear to the surrounding air. If a tone reaches the ear, a traveling wave builds up along the basilar membrane, which peaks at a frequency dependent location due to multiple gradients in stiffness and geometry. Atop of the basilar membrane resides the organ of Corti wherein the mechanotransduction process takes place.

Here we study the mechanics of the traveling wave by a detailed three-dimensional finite-element model. The model is based on geometry data from μCT-scans of a human ear and Read More

29 Jun

Microtubules in the spindle

We combined electron tomography, light microscopy, and modelling to gain insights in the arrangement and dynamics of microtubules in C. elegans metaphase spindle. We show that kinetochore microtubules grow from the pole to the midplane and hardly connect directly the pole to the chromosomes.

Our preprint on this tour de force project Kinetochore Microtubules indirectly link Chromosomes and Centrosomes in C. elegans Mitosis written by Stefanie Redemann, Johannes Baumgart, Norbert Lindow, Sebastian Fürthauer, Ehssan Nazockdast, Andrea Kratz, Steffen Prohaska, Jan Brugués, Michael Shelley, Thomas Müller-Reichert is available on bioRxiv.

30 May

Spindle architecture

I present a poster with EM data and EB1 velocity measurements based on spatial-temporal correlations:


A model of mitotic spindle architecture in C. elegans

The mitotic spindle is stable in size and shape during metaphase. However, its building blocks, the microtubules, have an average lifetime that is substantially shorter than the duration of metaphase. To study this stable macroscopic structure assembled by short-lived components, we analyzed the spatial organization and dynamics of microtubules in the first mitotic spindle of the C. elegans embryo.
Read More