Lipid Droplet Composition Varies Based on Medaka Fish Eggs Development as Revealed by NIR-, MIR-, and Raman Imaging

Abstract

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.

Rapid and Reliable Assessment of Fish Physiological Condition for Fisheries Research and Management Using Fourier Transform Near-Infrared Spectroscopy

“…These wavenumbers encompass signals from carbohydrates (Beć et al, 2020) and often strong signals from water (Bik et al, 2020). Values between ∼6,500 and 6,000 cm −1 that were retained for only energy density are associated with carbohydrates and lipids (∼6,200-5,800 cm −1 ), as well as proteins (∼6,400 cm −1 ; Beć et al, 2020;Bik et al, 2020). These discrepancies concur with differences in tissue components measured by each method.…”

“…Spectral regions that were most informative in predicting % lipid, HSI, and energy density in fish corresponded with wavenumbers that have been identified from other materials and non-aquatic organisms to differentiate lipids from non-lipids, as well as details among lipid molecules. For example, spectral peaks from ∼4,372 to 4,236 cm −1 that were prominent for % lipid, HSI, and energy density to a lesser degree and are indicative of C-H stretching and bending modes of lipids (Bik et al, 2020). Similarly, ∼7,375 to 7,150 cm −1 is a second overtone region for C-H bonds and exhibits combination bands for lipids and carbohydrates (Beć et al, 2020).…”

“…Wavenumbers between ∼5,400 and 5,000 cm −1 that were prominent in PC analyses as regions of high spectra variability were also informative for % lipid and HSI. These wavenumbers encompass signals from carbohydrates (Beć et al, 2020) and often strong signals from water (Bik et al, 2020). Values between ∼6,500 and 6,000 cm −1 that were retained for only energy density are associated with carbohydrates and lipids (∼6,200-5,800 cm −1 ), as well as proteins (∼6,400 cm −1 ; Beć et al, 2020;Bik et al, 2020).…”

Nutrient Absorption Rate of Oryzias celebensis Embryo

“…Pada telur ikan yang telah dibuahi, terdapat cadangan energi yang digunakan untuk perkembangan embrio yaitu kuning telur dan tetesan minyak besar (oil globule) (Bik et al, 2020). Kuning telur Oryzias latipes terdiri dari lipid dan protein (Iwamatsu, 2004) dan tetesan minyak terdiri dari lemak tak jenuh asam arakidonat, linoleatasam, asam docosahexaenoic dan asam eicosapentaenoic (Bik et al, 2020).…”

Effectiveness of near-infrared spectroscopy as a non-invasive tool to discriminate spectral profiles of in vitro cultured oocytes from goats

“…These interpretations can detect minimal variations and accurately identify alterations in the metabolic spectra between oocytes ( Nagy et al, 2009 ) from young and old animals, based on the differences in maturation rates and embryo production ( Souza-Fabjan et al, 2013 ) as well as the changes in the quality of oocytes recovered by LOPU after repeated hormonal treatments ( Gibbons et al, 2007 ; Avelar et al, 2012 ). Several studies have described the use of spectroscopy on spent culture media for human ( Vergouw et al, 2008 ), mouse ( Ishigaki et al, 2017 ), cattle ( Muñoz et al, 2014 ; Li et al, 2018 ), fish ( Ishigaki et al, 2016 , 2017 ; Bik et al, 2020 ) and goat ( Zhang et al, 2018 ) models. Thus, the use of NIR spectroscopy combined with multivariate analysis may accurately determine a metabolic pattern based on the spectral analysis of the oocyte maturation medium, that can be linked to oocyte subsequent metabolism and viability and improve in vitro culture system for assisted reproduction.…”