February 2016 - This Month in JoVE: Photoconvertible Proteins, Gold Nanoparticles, PET Principles, and Bone Marrow Microenvironments

Abstract

Here's a look at what's coming up in the February 2016 issue of JoVE: The Journal of Visualized Experiments. In JoVE Developmental Biology, the transparent, rapidly developing zebrafish embryo is ideal for visualizing developmental processes. When cells of interest are labeled with fluorescent photoconvertible proteins, they allow precise tracking of defined structures-highlighting specific cells while leaving other transgenic cells in the dark. Beretta et al. have established the photoswitchable monomeric orange (PSmOrange) system for zebrafish. This protein's orange-to-red spectrum allows it to visible in existing transgenic lines expressing green fluorescent protein (GFP). Microinjection of nuclear-targeted PSmOrange mRNA labels all cell nuclei with orange/red fluorescence, and targeted photoconversion switches its emission spectrum to far red. The quantum efficiency and stability of PSmOrange makes it a superb cell-tracking tool for living zebrafish during embryonic development and disease. In JoVE Chemistry, few materials have found as many uses in so many diverse fields as gold nanoparticles. Their applications range from biological sensors to radio frequency-based cancer treatments. Gold nanoparticles are valued for their unique structural, optical and electronic properties. These special attributes caught the interest of Oliver Smithies, who won the Nobel Prize in Physiology or Medicine in 2007. This month, he and his colleagues describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles, and present models that can predict particle size with great accuracy. In JoVE Engineering, we look at the principles of positron emission tomography (PET), a non-invasive technique for imaging the body's inner tissues and organs. Montano-Zetina and Villalobos-Mora present a guide for constructing a simple, homemade PET system for fully characterizing its basic working principles. This prototype demonstrates the primary functions of PET, and serves as an elegant model for teaching its principles to the academic public. In JoVE Medicine, it is well established that the bone marrow microenvironment provides a haven for hematopoietic diseases. This month, Slone et al. use cell types from the bone marrow niche in an in vitro co-culture model. This supports the generation of a subpopulation of chemoresistant tumor cells. These calls can be used to investigate the underlying pathways of tumor development and to test novel therapeutic strategies. You've just had a sneak peek of the February 2016 issue of JoVE. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments.