1 ZEBRAFISH: GAINING POPULARITY IN LIPID RESEARCH Maarit Hölttä-Vuori * , Veijo T.V. Salo *, Lena Nyberg †, Christian Brackmann † , Annika Enejder † , Pertti Panula * , and Elina Ikonen *1 * Institute of Biomedicine/Anatomy, Haartmaninkatu 8, 00140 University of Helsinki, Finland, and † Chalmers University of Technology, Department of Chemical and Biological Engineering, SE-412 96 Göteborg, Sweden 1 To whom correspondence should be addressed (e-mail elina.ikonen@helsinki.fi) Running title: Zebrafish in lipid research Key words: zebrafish, lipid, model organism, imaging, lipidosis, cholesterol Abbreviations used: CNS, central nervous system; dpf, days post fertilization; FIT, fat- inducing transcript; HDL, high density lipoprotein; HMG-CoA, 3-hydroxy-3-methyl- glutaryl-coenzyme A; LXR, liver X receptor; LDL, low density lipoprotein; MTP, microsomal transfer protein; NBD, nitrobenzoxadiazole; NPC, Niemann Pick type C; OSBPL, oxysterol-binding protein like, PPAR, peroxisome proliferator-activated receptor; PUFA, polyunsaturated fatty acid; S1P, sphingosine-1-phosphate; SREBP, sterol-regulatory element binding protein; TG, triacylglycerol; VLDL, very low density lipoprotein; YSL, yolk syncytial layer