Chang Gung University, Center of Molecular Medicine, College of Medicine, Kwei-Shan, Tao-Yuan 333, Taiwan.
J Biomed Opt. 2014 Jan;19(1):011011. doi: 10.1117/1.JBO.19.1.011011.
Lipid is an important energy source and essential component for plasma and organelle membranes in all kinds of cells. Coherent anti-Stokes Raman scattering (CARS) microscopy is a label-free and nonlinear optical technique that can be used to monitor the lipid distribution in live organisms. Here, we utilize CARS microscopy to investigate the pattern of lipid droplets in two live Caenorhabditis elegans mutants (fat-2 and fat-3). The CARS images showed a striking decrease in the size, number, and content of lipid droplets in the fat-2 mutant but a slight difference in the fat-3 mutant as compared with the wild-type worm. Moreover, a nondroplet-like structure with enhanced CARS signal was detected for the first time in the uterus of fat-2 and fat-3 mutants. In addition, transgenic fat-2 mutant expressing a GFP fusion protein of vitellogenin-2 (a yolk lipoprotein) revealed that the enhanced CARS signal colocalized with the GFP signal, which suggests that the nondroplet-like structure is primarily due to the accumulation of yolk lipoproteins. Together, this study implies that CARS microscopy is a potential tool to study the distribution of yolk lipoproteins, in addition to lipid droplets, in live animals.
脂质是各种细胞中血浆和细胞器膜的重要能量来源和必需成分。相干反斯托克斯拉曼散射（CARS）显微镜是一种无标记和非线性光学技术，可用于监测活生物体中的脂质分布。在这里，我们利用 CARS 显微镜研究了两种活秀丽隐杆线虫突变体（fat-2 和 fat-3）中脂质滴的模式。CARS 图像显示，fat-2 突变体中脂质滴的大小、数量和含量明显减少，而 fat-3 突变体与野生型蠕虫相比则略有差异。此外，首次在 fat-2 和 fat-3 突变体的子宫中检测到具有增强的 CARS 信号的非液滴样结构。此外，表达卵黄蛋白原-2（一种卵黄脂蛋白）GFP 融合蛋白的转基因 fat-2 突变体显示，增强的 CARS 信号与 GFP 信号共定位，这表明非液滴样结构主要是由于卵黄脂蛋白的积累所致。总之，这项研究表明，CARS 显微镜是一种潜在的工具，可以研究活动物中除脂质滴以外的卵黄脂蛋白的分布。
