Real-time visualisation of developing chick embryos cultured in transparent plastic films from the blastoderm stage until hatching.

Real-time visualisation of chick embryo development occurring inside an opaque eggshell is a major goal of developmental biology. This goal was partially achieved when 3-day-old embryos recovered from fertilised shelled eggs, preincubated in a conventional incubator, hatched after the egg contents had been transferred into shell-less embryo culture systems constructed of transparent plastic film placed in a plastic cup. However, the hatchable shell-less embryo culture systems described thus far cannot be used to visualise the dynamic morphological changes associated with the emergence of major organ systems during the first 3 days of embryo development, as the blastoderm area needs to be covered with an opaque membrane.

PDZD8-FKBP8 tethering complex at ER-mitochondria contact sites regulates mitochondrial complexity.

Mitochondria-ER membrane contact sites (MERCS) represent a fundamental ultrastructural feature underlying unique biochemistry and physiology in eukaryotic cells. The ER protein PDZD8 is required for the formation of MERCS in many cell types, however, its tethering partner on the outer mitochondrial membrane (OMM) is currently unknown. Here we identified the OMM protein FKBP8 as the tethering partner of PDZD8 using a combination of unbiased proximity proteomics, CRISPR-Cas9 endogenous protein tagging, Cryo-Electron Microscopy (Cryo-EM) tomography, and correlative light-EM (CLEM).

Motion of VAPB molecules reveals ER-mitochondria contact site subdomains.

To coordinate cellular physiology, eukaryotic cells rely on the rapid exchange of molecules at specialized organelle-organelle contact sites. Endoplasmic reticulum-mitochondrial contact sites (ERMCSs) are particularly vital communication hubs, playing key roles in the exchange of signalling molecules, lipids and metabolites. ERMCSs are maintained by interactions between complementary tethering molecules on the surface of each organelle.