AUTHOR=Li Huanhuan , Liang Zhixiu , Wu Longping , Ke Yizhou , Que Huayong , Shi Bo 

TITLE=The role of Zip1 and Zip3 in cadmium accumulation in Fujian oyster (Crassostrea angulata)

JOURNAL=Frontiers in Marine Science

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2024.1412127

DOI=10.3389/fmars.2024.1412127

ISSN=2296-7745

ABSTRACT=<p>Oysters are notably susceptible to accumulating substantial amounts of cadmium (Cd), leading to food safety concerns, yet the molecular mechanisms are not fully understood. Previous study identified a significant correlation between polymorphisms in the <italic>Zip1</italic> and <italic>Zip3</italic> of Fujian oyster (<italic>Crassostrea angulata</italic>) and the levels of Cd accumulation. <italic>Zip1</italic> and <italic>Zip3</italic>, belonging to the Zip family, are primarily responsible for the cellular transport of zinc and other metal ions. To delve deeper into their roles in Cd transport within oysters, this research cloned and analyzed the sequences of Fujian oyster <italic>Zip1</italic> and <italic>Zip3</italic>. The open reading frames for <italic>Zip1</italic> and <italic>Zip3</italic> were 960 and 978 bp, respectively, encoding proteins of 319 and 325 amino acids. Following Cd exposure, the expression levels of these genes in the mantle, gills, and other tissues initially increased significantly before decreasing, demonstrating a dose-dependent response. The lowest expression levels were observed in the adductor muscle, with <italic>Zip1</italic> reaching its highest expression in the mantle and <italic>Zip3</italic> in the visceral mass. <italic>In vitro</italic> RNAi experiments revealed that silencing <italic>Zip1</italic> led to a 1.26-fold decrease in new <sup>113</sup>Cd accumulation in the mantle, whereas silencing <italic>Zip3</italic> resulted in a 1.29-fold increase. Immunohistochemistry showed weak expression of Zip1 and Zip3 proteins in the connective tissue of the mantle. In summary, <italic>Zip1</italic> and <italic>Zip3</italic> in Fujian oyster can transport Cd as a substrate, and played different roles in the absorption and efflux of Cd.</p>