Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland.
Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348 Krakow, Poland.
Molecules. 2020 Feb 13;25(4):817. doi: 10.3390/molecules25040817.
In fertilized fish eggs, lipids are an energy reservoir for the embryo development and substrate for organogenesis. They occur in the cytoplasmic area and form lipid droplets (LDs), but also the yolk egg is composed of lipids and proteins. Insight on the LD formation and distribution and their interactions with other cellular organelles could provide information about the role based on the egg development. For non-destructive, macro-scale visualization of biochemical components of fish eggs, such as lipids proteins and water, near-infrared (NIR) imaging is the method of choice. Mid-infrared (MIR) and Raman spectroscopy imaging were used to provide details on chemical composition of LDs and other egg organelles. NIR imaging illustrated main compartments of the egg including membrane, LDs, yolk, relative protein, and lipid content in well-localized egg structures and their interactions with water molecules. In the yolk, a co-existence of lipids and proteins with carotenoids and carbohydrates was detected by Raman spectroscopy. Results showed a prominent decrease of unsaturated fatty acids, phospholipids, and triglycerides/cholesteryl esters content in the eggs due to the embryo development. An opposite trend of changes was observed by MIR spectroscopy for the glycogen, suggesting that consumption of lipids occurred with production of this carbohydrate. The comprehensive vibrational spectroscopic analysis based on NIR, MIR, and Raman imaging is a unique tool in studying in situ dynamic biological processes.
在受精卵中，脂质是胚胎发育的能量储备和器官发生的基质。它们存在于细胞质区域并形成脂质滴（LD），但蛋黄也由脂质和蛋白质组成。了解 LD 的形成和分布及其与其他细胞细胞器的相互作用，可以为基于卵子发育的作用提供信息。对于鱼类卵子的生化成分（如脂类、蛋白质和水）的非破坏性、宏观尺度可视化，近红外（NIR）成像是首选方法。中红外（MIR）和拉曼光谱成像是用于提供 LD 和其他卵子细胞器的化学组成细节的方法。NIR 成像说明了包括膜、LD、蛋黄、相对蛋白质和脂类含量在内的卵子的主要隔室，以及它们与水分子的相互作用。在蛋黄中，通过拉曼光谱检测到了脂类、蛋白质、类胡萝卜素和碳水化合物的共存。结果表明，由于胚胎发育，卵子中的不饱和脂肪酸、磷脂和甘油三酯/胆固醇酯含量显著减少。MIR 光谱对糖原的变化趋势相反，表明在消耗脂质的同时产生了这种碳水化合物。基于 NIR、MIR 和拉曼成像的综合振动光谱分析是研究原位动态生物学过程的独特工具。
