Chelates of Gadolinium (Gd), a lanthanide metal, are employed as contrast agents for magnetic resonance imaging and are released into the aquatic environment where they are an emerging contaminant. We studied the effects of environmentally relevant Gd concentrations on the development of two phylogenetically and geographically distant sea urchin species: the Mediterranean Paracentrotus lividus and the Australian Heliocidaris tuberculata. We found a general delay of embryo development at 24 h post-fertilization, and a strong inhibition of skeleton growth at 48 h. Total Gd and Ca content in the larvae showed a time- and concentration-dependent increase in Gd, in parallel with a reduction in Ca. To investigate the impact of Gd on the expression of genes involved in the regulation of skeletogenesis, we performed comparative RT-PCR analysis and found a misregulation of several genes involved in the skeletogenic and left-right axis specification gene regulatory networks. Species-specific differences in the biomineralization response were evident, likely due to differences in the skeletal framework of the larvae and the amount of biomineral produced. Our results highlight the hazard of Gd for marine organisms.

d金属（镧系金属）的螯合物用作磁共振成像的造影剂，并释放到水环境中，在水中它们是新出现的污染物。我们研究了环境相关的Gd浓度对两种系统发育和地理上遥远的海胆物种：地中海Paracentrotus lividus和澳大利亚Heliocidaris tuberculata发育的影响。我们发现受精后24 h胚胎发育普遍延迟，而48 h骨骼生长受到强烈抑制。幼虫中的总Gd和Ca含量显示Gd随时间和浓度的增加而增加，同时Ca减少。为了研究Gd对参与骨骼生成调控的基因表达的影响，我们进行了比较RT-PCR分析，发现骨骼生成和左右轴规格基因调控网络中涉及的几个基因的调控异常。生物矿化反应的物种特异性差异很明显，这很可能是由于幼虫的骨骼骨架和生物矿物质产生量的差异所致。我们的结果突出了Gd对海洋生物的危害。