Size matters for single-cell C4 photosynthesis in Bienertia.

Bienertia cycloptera belongs to a diverse set of plants, recently discovered to perform C photosynthesis within individual mesophyll cells. How these plants accomplish high photosynthetic efficiency without adopting Kranz anatomy remains unanswered. By modelling the processes of diffusion, capture, and release of carbon dioxide and oxygen inside a typical Bienertia mesophyll cell geometry, we show that a spatial separation as low as 10 μm between the primary and the secondary carboxylases, can, on its own, provide enough diffusive resistance to sustain a viable C pathway at 20 °C, with a CO leakage <35%.

In vivo dynamics of skeletal muscle Dystrophin in zebrafish embryos revealed by improved FRAP analysis.

Dystrophin forms an essential link between sarcolemma and cytoskeleton, perturbation of which causes muscular dystrophy. We analysed Dystrophin binding dynamics in vivo for the first time. Within maturing fibres of host zebrafish embryos, our analysis reveals a pool of diffusible Dystrophin and complexes bound at the fibre membrane.

Studying Smad2 intranuclear diffusion dynamics by mathematical modelling of FRAP experiments.

We combine Fluorescence Recovery After Photobleaching (FRAP) experiments with mathematical modelling to study the dynamics inside the nucleus of both the TGF-β-sensitive transcriptional regulator Smad2, and Green-Fluorescent Protein (GFP). We show how combining modelling with bleaching strips of different areas allows a rigorous test of whether or not a protein is moving via diffusion as a single species. As noted recently by others, it is important to consider diffusion during the bleaching process.