Imaging cytoplasmic lipid droplets in vivo with fluorescent perilipin 2 and perilipin 3 knockin zebrafish

Cytoplasmic lipid droplets are highly dynamic storage organelles; their rapid synthesis, expansion, and degradation, as well as their varied interactions with other organelles allow cells to maintain lipid homeostasis. While the molecular details of lipid droplet dynamics are currently a very active area of investigation, this work has been primarily performed in cultured cells and in vitro systems. By taking advantage of the powerful transgenic and in vivo imaging opportunities afforded by the zebrafish model system, we have built a suite of tools to allow lipid droplets to be studied in real-time from the subcellular to the whole organism level. Fluorescently-tagging the lipid droplet associated proteins, perilipin 2 and perilipin 3, in the endogenous loci, permits visualization of lipid droplets in the intestine, liver, lateral line and adipose tissue. Using these transgenic lines we have found that perilipin 3 is rapidly loaded on intestinal lipid droplets following a high fat meal and then largely replaced by perilipin 2 a few hours later. These powerful new tools will facilitate studies on the role of lipid droplets in different tissues and under different genetic and physiological manipulations.