Bowen Lizabeth, Waters Shannon, Ballachey Brenda, Coletti Heather, Forster Zachary, Li Jie, Jenner Bradley
U.S. Geological Survey, Western Ecological Research Center, Davis Field Station, Davis, CA 95616, USA.
U.S. Geological Survey, Alaska Science Center, Anchorage, AK 99508, USA.
Toxins (Basel). 2025 Apr 11;17(4):194. doi: 10.3390/toxins17040194.
As oceans warm, harmful algal blooms (HABs) are expected to increase, including blooms of , a diatom that produces domoic acid (DA), which is a potent neurotoxin. Regulatory limits for human consumption (0.075-0.1 mg/kg/day; acute exposure) exist for the Pacific razor clam; however, fisheries currently do not have regulatory limits for chronic low-level exposure to DA even though razor clams can retain DA for over a year after an algal bloom. For bivalves, exposure to marine toxins may disrupt important cellular processes, leading to concerns about effects on their overall health and potential population- and ecosystem-level impacts. Transcriptomics was used to identify differentially expressed genes in razor clams (N = 30) from Long Beach, WA, collected prior to, during, and after a DA-producing bloom. Differentially expressed genes were identified that may indicate exposure of razor clams to DA, including clams with tissue DA concentrations that fall below regulatory limits for human consumption. Targeting these genes in real-time PCR assays may provide an early warning system for routine monitoring of DA in clams. Our results suggest DA exposure is associated with physiological responses ranging from decreased immune function to the potential disruption of cell communication, including retinoic acid catabolic processes, cell adhesion, collagen fibril organization, and immune effector processes. This work may also allow us to examine potential drivers of population-level change and whether chronic lower-level exposure to DA negatively impacts razor clam function, consequently affecting individual and population health.
随着海洋变暖，有害藻华（HABs）预计会增加，包括产软骨藻酸（DA）的硅藻藻华，软骨藻酸是一种强效神经毒素。对于太平洋剃刀蛤，存在人类食用的监管限量（0.075 - 0.1毫克/千克/天；急性暴露）；然而，渔业目前对于慢性低水平暴露于软骨藻酸并没有监管限量，尽管剃刀蛤在藻华发生后可以在一年多的时间里留存软骨藻酸。对于双壳贝类而言，暴露于海洋毒素可能会扰乱重要的细胞过程，引发对其整体健康影响以及潜在的种群和生态系统层面影响的担忧。转录组学被用于鉴定来自华盛顿州长滩的剃刀蛤（N = 30）在产软骨藻酸藻华之前、期间和之后所采集样本中差异表达的基因。已鉴定出的差异表达基因可能表明剃刀蛤暴露于软骨藻酸，包括那些组织中软骨藻酸浓度低于人类食用监管限量的蛤类。在实时荧光定量PCR分析中靶向这些基因，可能会为蛤类中软骨藻酸的常规监测提供一个早期预警系统。我们的结果表明，软骨藻酸暴露与从免疫功能下降到细胞通讯潜在破坏等一系列生理反应相关，包括视黄酸分解代谢过程、细胞粘附、胶原纤维组织和免疫效应过程。这项工作还可能使我们能够研究种群水平变化的潜在驱动因素，以及慢性低水平暴露于软骨藻酸是否会对剃刀蛤的功能产生负面影响，从而影响个体和种群健康。
