Characterization of trace metal content in the developing zebrafish embryo

Abstract

Trace metals are essential for health but toxic when present in excess. The maintenance of trace metals at physiologic levels reflects both import and export by cells and absorption and excretion by organs. The mechanism by which this maintenance is achieved in vertebrate organisms is incompletely understood. To explore this, we chose zebrafish as our model organism, as they are amenable to both pharmacologic and genetic manipulation and comprise an ideal system for genetic screens and toxicological studies. To characterize trace metal content in developing zebrafish, we measured levels of three trace elements, copper, zinc, and manganese, from the oocyte stage to 30 days post-fertilization using inductively coupled plasma mass spectrometry. Our results indicate that metal levels are stable until zebrafish can acquire metals from the environment and imply that the early embryo relies on maternal contribution of metals to the oocyte. We also measured metal levels in bodies and yolks of embryos reared in presence and absence of the copper chelator neocuproine. All three metals exhibited different relative abundances between yolks and bodies of embryos. While neocuproine treatment led to an expected phenotype of copper deficiency, total copper levels were unaffected, indicating that measurement of total metal levels does not equate with measurement of biologically active metal levels. Overall, our data not only can be used in the design and execution of genetic, physiologic, and toxicologic studies but also has implications for the understanding of vertebrate metal homeostasis.

Copper signalling: causes and consequences

“…Brain copper concentrations were inversely correlated with age. It is worth noting that measurements of total copper levels may not necessarily reflect the biologically active metal pools [ 84 ].…”

A Systematic Analysis of Metal and Metalloid Concentrations in Eight Zebrafish Recirculating Water Systems

“…The Cu, Mn, and Zn metal content in early embryos has been suggested to be set by the maternal contribution and only increases once zebrafish develop to the stage where they can acquire nutrients through the diet or the environment. 57 The concentrations of Cu, Mn, and Zn reported in the study of Thomason et al indicated that relatively low concentrations are required for fish younger than 30 dpf, suggesting that the concentrations of the CRWS shown in this study might be sufficient for normal biological processes in larval and juvenile zebrafish.…”

Manganese Exposure Induces Cellular Aggregates and the Accumulation of β-Catenin in Skin of Zebrafish Embryos

“…Zebra sh has been widely used to investigate the effects of Mn, including a manganism model (Altenhofen et , 2020). It has been shown that Mn content levels increase in the zebra sh after 5 days-post-fertilization (dpf), when they start to feed from external sources (Thomason et al, 2017). Interestingly, at this developmental stage the larvae increase sensitivity to Mn exposure (Altenhofen et al, 2017;Bakthavatsalam et al, 2014;Hernández et al, 2015;Tu et al, 2017).…”