Summary scheme and brief description of stimulation methods used for adipose conversion and for the generation of different, distinct types of lipid droplets.

<p>Major treatments and involved PLIN proteins are shown. Preadipocytes containing many small LDs are <u>not</u> differentiated for several weeks with AIM containing media as conventionally described (top row; cp. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0090386#pone.0090386.s001" target="_blank">Fig. S1</a>), but <u>only</u> very briefly (1–3 days), giving rise to “Adipocytes” (boxed area). Additional, short OA-treatment leads to “OA-Adipocytes” (boxed area, right side). Treatment with OA only - without AIM stimulation - leads to “OA-Preadipocytes” (bottom). Note the huge heterogeneity of sizes and colors of LDs seen within “OA-Adipocytes”. LDs are endogenously generated at the endoplasmic reticulum and stained positively for perilipin (“Endogenous-LDs”, red). Other LDs are obtained from the exogenous uptake of OA and stained positively for adipophilin, TIP47 and S3-12 (“Exogenous-LDs”, green). Merged LDs by fusion and mixed-type expression are seen by yellow color. The backway arrows indicate possible routes of LDs during lipolysis.</p>