Zhang Xiangchao, Xun Xiaogang, Meng Deting, Li Moli, Chang Lirong, Shi Jiaoxia, Ding Wei, Sun Yue, Wang Huizhen, Bao Zhenmin, Hu Xiaoli
MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
Antioxidants (Basel). 2023 May 25;12(6):1150. doi: 10.3390/antiox12061150.
Paralytic shellfish toxins (PST) could be accumulated in bivalves and cause safety problems. To protect public health, bivalves are examined for PST contamination before entering the market, usually by high-performance liquid chromatography (HPLC) or LC-tandem mass spectrometry (LC-MS/MS) in the lab, which needs PST standards not all available and is time-consuming for large sample sizes. To detect PST toxicity in bivalves rapidly and sensitively, a biomarker gene is highly demanded, but the related study is very limited. In this study, we fed a commercially important bivalve, , with the PST-producing dinoflagellate . After 1, 3, and 5 days of exposure, both PST concentrations and toxicity levels in the digestive gland continuously increased. Transcriptome analysis revealed that the differentially expressed genes were significantly enriched in oxidation-reduction process, which included the cytochrome P450 genes (s), type I iodothyronine deiodinase (s), peroxidasin (), and acyl-Coenzyme A oxidase 1 () at day 1 and a superoxide dismutase () at day 5, highlighting the crucial roles of these genes in response to oxidative stress induced by PST. Among the 33 continuously upregulated genes, five showed a significant correlation between gene expression and PST concentration, with the highest correlation present in , the gene encoding Complement C1Q-like protein 4, C1QL4. In addition, the correlation between expression and PST toxicity was also the highest. Further analysis in another aquaculture scallop () indicated that the expression of , the homolog of , also exhibited significant correlations with both PST toxicity and concentration. Our results reveal the gene expression responses of scallop digestive glands to PST-producing algae and indicate that the gene might be a potential biomarker for PST monitoring in scallops, which may provide a convenient way for the early warning and sensitive detection of PST contamination in the bivalves.
麻痹性贝类毒素（PST）可在双壳贝类中蓄积并引发安全问题。为保护公众健康，双壳贝类在进入市场前需检测PST污染情况，通常在实验室中采用高效液相色谱法（HPLC）或液相色谱 - 串联质谱法（LC-MS/MS）进行检测，这需要PST标准品，而并非所有标准品都可获取，且对于大量样本来说耗时较长。为快速、灵敏地检测双壳贝类中的PST毒性，迫切需要一种生物标志物基因，但相关研究非常有限。在本研究中，我们用产PST的甲藻喂养一种具有重要商业价值的双壳贝类扇贝。暴露1、3和5天后，消化腺中的PST浓度和毒性水平均持续升高。转录组分析表明，差异表达基因在氧化还原过程中显著富集，其中包括第1天的细胞色素P450基因（多个）、I型碘甲状腺原氨酸脱碘酶（多个）、过氧化物酶（Peroxidasin）和酰基辅酶A氧化酶1（Acyl-Coenzyme A oxidase 1），以及第5天的超氧化物歧化酶（Superoxide dismutase），突出了这些基因在应对PST诱导的氧化应激中的关键作用。在33个持续上调的基因中，有5个基因的表达与PST浓度之间存在显著相关性，其中编码补体C1Q样蛋白4（C1QL4）的基因C1QL4相关性最高。此外，C1QL4表达与PST毒性之间的相关性也最高。在另一种养殖扇贝栉孔扇贝中的进一步分析表明，C1QL4的同源基因C1ql4的表达与PST毒性和浓度也均呈现显著相关性。我们的研究结果揭示了扇贝消化腺对产PST藻类的基因表达响应，并表明C1QL4基因可能是扇贝中PST监测的潜在生物标志物，这可能为双壳贝类中PST污染的早期预警和灵敏检测提供一种便捷方法。
