Body Mass Parameters, Lipid Profiles and Protein Contents of Zebrafish Embryos and Effects of 2,4-Dinitrophenol Exposure

Abstract

Morphology and physiology of fish embryos undergo dramatic changes during their development until the onset of feeding, supplied only by endogenous yolk reserves. For obtaining an insight how these restructuring processes are reflected by body mass related parameters, dry weights (dw), contents of the elements carbon and nitrogen and lipid and protein levels were quantified in different stages within the first four days of embryo development of the zebrafish (Danio rerio). The data show age dependent changes in tissue composition. Dry weights decreased significantly from 79μgdw/egg at 0hours post fertilization (hpf) to 61 μgdw/egg after 96 hpf. The amounts of total carbon fluctuated between 460 mg g-1 and 540 mg g-1 dw, nitrogen was at about 100 mg g-1 dw and total fatty acids were between 48–73 mg g-1 dw. In contrast to these parameters that remained relatively constant, the protein content, which was 240 mg g-1 at 0 hpf, showed an overall increase of about 40%. Comparisons of intact eggs and dechorionated embryos at stages prior to hatching (24, 30, 48 hpf) showed that the differences seen for dry weight and for carbon and nitrogen contents became smaller at more advanced stages, consistent with transition of material from the chorion to embryo tissue. Further, we determined the effect of 2,4-dinitrophenol at a subacutely toxic concentration (14 μM, LC10) as a model chemical challenge on the examined body mass related parameters. The compound caused significant decreases in phospholipid and glycolipid fatty acid contents along with a decrease in the phospholipid fatty acid unsaturation index. No major changes were observed for the other examined parameters. Lipidomic studies as performed here may thus be useful for determining subacute effects of lipophilic organic compounds on lipid metabolism and on cellular membranes of zebrafish embryos.

A Zebrafish Model of Cryptococcal Infection Reveals Roles for Macrophages, Endothelial Cells, and Neutrophils in the Establishment and Control of Sustained Fungemia

“…After 3 to 5 trial injections at different volumes, the dosage was adjusted after directly assessing the inoculum in larvae. Inocula of between 150 and 250 cryptococcal cells per larva (estimated mass of 50.5 g at 48 hpi [52]) produce an inoculum-to-mass ratio averaging 3.96, comparable to that of previously published mouse infections (1 ϫ 10 5 yeast cells or spores in an ϳ22-g mouse ϭ 4.54). This dosing was also comparable to that for previously published studies in zebrafish (35,36).…”

Lipid dynamics in zebrafish embryonic development observed by DESI-MS imaging and nanoelectrospray-MS

“…These may be packaged into very low density lipoprotein particles for distribution throughout the embryo. Previous studies on zebrafish embryos support this model 38,39 . Moreover, 48 hpf coincides with the development of important organs like liver that allows de novo synthesis to occur 3 .…”

“…Glycerophosphoinositols play crucial role in intracellular signaling, gene transcription, RNA editing, nuclear export, and protein phosphorylation, thus their presence in embryos at early stages of development is not surprising. Hachicho et al estimated that around three quarters of FAs in the zebrafish embryo are in the form of phospholipids, one fifth in neutral lipids, and 3-4% in glycolipids, notwithstanding minor variation across development 39 . In adult zebrafish, PI(38:4) was found by DESI to be localized in the spinal cord area 34 .…”

Linking life‐history theory and metabolic theory explains the offspring size‐temperature relationship

“…Danio reproduces sexually by spawning gametes into the water column where fertilised eggs undergo several stages of development. Embryos rely on yolk supplies in the egg to meet energy requirements for development until post-hatching, when feeding structures form, which occurs approximately 5 days after fertilisation under normal laboratory conditions (Bryson-Richardson et al 2011;Hachicho et al 2015).…”