Biology subjects

Stuurman, N.

Publications and source records attributed to Stuurman, N..

3 recordsLinked to original sources

bioRxiv2018

High Numerical Aperture Epi-illumination Selective Plane Illumination Microscopy

Selective-plane illumination microscopy (SPIM) provides unparalleled advantages for long-term volumetric imaging of living organisms. In order to achieve high-resolution imaging in common biological sample holders, we designed a high numerical aperture (NA) epi-illumination SPIM (eSPIM) system, which utilizes a single objective and has an identical sample interface as an inverted fluorescence microscope with no additional reflection elements. This system has an effective detection NA of > 1.06. We demonstrated multicolor and fast volumetric imaging of live cells and single-molecule super-resolution microscopy using our system.

bioengineering↗

bioRxiv2017

High accuracy measurements of nanometer-scale distances between fluorophores at the single-molecule level

To uncover the mechanisms of molecular machines it is useful to probe their structural conformations. Single-molecule Forster resonance energy transfer (smFRET) is a powerful tool for measuring intra-molecular shape changes of single-molecules, but is confined to distances of 2-8 nm. Current super-resolution measurements are error prone at <25 nm. Thus, reliable high-throughput distance information between 8-25 nm is currently difficult to achieve. Here, we describe methods that utilize information about localization and imaging errors to measure distances between two different color fluorophores with [~]1 nm accuracy at any distance >2 nm, using a standard TIRF microscope and open-source software. We applied our two-color localization method to uncover a [~]4 nm conformational change in the \"stalk\" of the motor protein dynein, revealing unexpected flexibility in this antiparallel coiled-coil domain. These new methods enable high-accuracy distance measurements of single-molecules that can be used over a wide range of length scales.

biophysics↗

bioRxiv2017

The actin cytoskeleton governs apical mitosis and daughter cell dispersion in intestinal epithelia

Cell proliferation is critical for maintaining the absorptive, protective and regenerative functions of the small intestine throughout adulthood. Interphase nuclei are positioned near the basal surface of the intestinal epithelium, but during mitosis, chromosomes are located apically. The molecular basis for apical-basal DNA positioning and its consequences for tissue homeostasis are poorly understood. Here, we image and pharmacologically perturb these behaviors in live murine intestinal organoids. We find that apical and basal DNA movements occur as a result of mitosis-coupled actin rearrangements that alter the basolateral shape of dividing cells, while the apical cell surface remains confined by cell-cell contacts that persist throughout mitosis. Strikingly, these polarized shape changes allow neighboring cells to insert between nascent daughters, intermingling cells of different lineages. In summary, polarized rearrangements of the actin cytoskeleton govern the mitotic behavior of intestinal epithelial cells and lead to interspersion of cell lineages.

cell biology↗