Functional Studies Of SLC39A7Gene During The Early Embryogenesis In Zebrafish

Zinc is an essential trance element which is required for organism, approximately300of metal-containing enzymes of six major functional level functions in mammals, it play need zinc as the main structural component or cofactor. It closely related in the early development, brain function, bone growth, rapid reproductive health, immune response function, endocrine regulation, protein and nucleic acid metabolism etc. Many effects caused from zinc deficiency include poor appetite, growth retardation, skin changes, mental lethargy, delayed wound healing, neurosensory disorders, and cell-mediated immune disorders etc. So study zinc transporter protein, explore the complexity of the zinc ion homeostasis is particularly important to the maintenance of zinc absorption, storage and excluded the balance of the process.In recent years, the zebra fish has become one of the best model for an emerging developmental biology and human disease spinal animal. It has a unique advantage in the embryonic development and human disease models. Such as its eggs in vitro fertilization, transparent embryos, rapid organ development. The whole process of the in vivo dynamic blood circulation can be observed under the microscope. And each mating spawning a larger number of eggs in vivo large-scale pilot drug screening etc.We investigated the ZIP7gene expression patterns during zebrafish early embryonic development. Real-time PCR assay showed that ZIP7mRNA was richly detected maternally during embryogenesis. Whole-mount in situ hybridization assay showed that ZIP7mRNA was expressed ubiquitously during12hour post-fertilization (hpf), however, at the24hpf and the later stages, ZIP7mRNA was only detected in eyes. Using a morpholino-antisense (MO) gene knockdown approach, ZIP7knockdown showed several malformations such as smaller eyes, an enlarged pericardial region, and campylorrhachia. Furthermore, re-injection of a MO-resistant form of ZIP7mRNA which was cloned and transcriped in vitro to "rescue" the MO-induced defects, implying that Z1P7played a role in eyes development especially during early embryonic development. Hatching the ZIP7knockdown embryos with zinc in Egg water could "rescue" the MO-induced defects as well. Besides, Synchrotron Radiation-X Ray Fluorescence (SR-XRF) showed the distribution of zinc in ZIP7-MO-injected embryos was changed, and the concentration of zinc in brain and eyes was reduced. These experiments suggest that ZIP7loss-of-function affects eye formation during zebrafish early embryonic development. Which provides a novel insight into the role of ZIP7in vivo. Our results reveal that ZIP7is a critical member in the ZIP family of zinc transporters, which plays indispensable roles in maintaining zinc homeostasis and organism development especially in eyes, brain, and gills. These findings will be helpful for the understanding of mechanisms of zinc homeostasis and diseases resulting from defects in proper zinc homeostasis...