Zinc transporter expression in zebrafish (Danio rerio) during development

Abstract

Zinc is a micronutrient important in several biological processes including growth and development. We have limited knowledge on the impact of maternal zinc deficiency on zinc and zinc regulatory mechanisms in the developing embryo due to a lack of in vivo experimental models that allow us to directly study the effects of maternal zinc on embryonic development following implantation. To overcome this barrier, we have proposed to use zebrafish as a model organism to study the impact of zinc during development. The goal of the current study was to profile the mRNA expression of all the known zinc transporter genes in the zebrafish across embryonic and larval development and to quantify the embryonic zinc concentrations at these corresponding developmental time points. The SLC30A zinc transporter family (ZnT) and SCL39A family, Zir-,Irt-like protein (ZIP) zinc transporter proteins were profiled in zebrafish embryos at 0, 2, 6, 12, 24, 48 and 120 hours post fertilization to capture expression patterns from a single cell through full development. We observed consistent embryonic zinc levels, but differential expression of several zinc transporters across development. These results suggest that zebrafish is an effective model organism to study the effects of zinc deficiency and further investigation is underway to identify possible molecular pathways that are dysregulated with maternal zinc deficiency.

3D imaging of transition metals in the zebrafish embryo by X-ray fluorescence microtomography

“…Based on the scaled MLEM data, we determined a total Zn content of 6.7 ng, which is in good agreement with the average Zn content of ~7.3 ng at 24 hpf reported in the literature. 22 …”

“…28 As the maternally derived yolk stores are the primary source of nutrients for the embryo, this pool supplies all developing tissues and organs with Zn, likely orchestrated through an elaborate network of Zn transporters. 22 For example, the reduced expression of Zip7, a Zn importer of the SLC39 solute carrier family of proteins, led to markedly decreased Zn levels in the eye at 72 hpf whereas the total Zn content of the embryo remained unaltered. 7 In contrast, both Fe and Cu are more concentrated in the yolk syncytial layer (YSL) surrounding the yolk and yolk extension.…”

Adverse effects of parental zinc deficiency on metal homeostasis and embryonic development in a zebrafish model

“…Here we show that parental zinc deficiency causes a significant decline in ZnT8 mRNA expression at 24 and 48 hpf when ZnT8 is expressed in the developing pancreas [39, 75]. ZnT8 has been shown to be involved in insulin processing and dysregulated zinc transporters may lead to glucose tolerance and diabetes [75, 76].…”

“…Reactions were performed using Fast SYBR Green Mastermix (Life Technologies) on 7900HT Fast Real-Time PCR System (Applied Biosystems, Foster City, CA). PCR conditions were programmed as follows: 95°C for 20 s, followed by 40 cycles of denaturing at 95°C for 1 s, annealing and extension at 58°C for 20 s, followed by a dissociation curve at 95°C for 15 s, 60°C for 15 s, and 95°C for 15 s. A dilution series of 10 3 , 10 4 , 10 5 , 10 6 , and 10 7 copies of template DNA served as internal standard for quantification [39]. Data in graphs represent the copy number of the gene of interest, divided by the copy number of the housekeeping gene Odc1 to normalize the genes expression relative to input of cDNA.…”

Topographical Analysis of Reactive Zinc in the Central Nervous System of Adult Zebrafish (Danio Rerio)

“…This feature makes it an appropriate animal model to investigate the pool of chelatable Zn throughout the CNS. A recent study performed by Ho and colleagues 27 reported the expression of Zn transporters in the brain during development, suggesting that Zn may play an important role in this species. Moreover, the zebrafish has also been used as an emergent organism for evaluating seizures 28,29 and hypoxia/ischemia-related phenotypes, 30 two brain disorders associated with Zn dyshomeostasis.…”