Abstract: Seven genes involved in salinity adaption, including Tenascin-R1 (TN-R1), Tenascin-R2 (TN-R2), Neuronal acetylcholine receptor subunit alpha-3 (CHRNA3）, Fatty acid-binding protein 6(FABP6), Monocarboxylate transporter 2 (SLC16A7), Ficolin-1(FCN1), and Melanotransferrin (Mfi2) were selected based on salty transcriptome database of Apostichopus japonicus. The expression profiles of these 7 genes in different tissues and different periods under low salt stress were analyzed by qRT-PCR. The results showed that the expression levels of TN-R1, SLC16A7, FABP6 and Fcn1 was the highest in the coelomic fluid, followed by respiratory tree and intestinal tissue. No expression of TN-R2 was detected in respiratory tree. The expression levels of CHRNA3 and Mfi2 were the highest in coelomic fluid, followed by intestinal tissue and respiratory tree. The expression levels of these 7 genes increased or decreased during low salt stress. Gene Mfi2 was up-regulated in the coelomic fluid and significantly down-regulated in the respiratory tree and intestinal tissue. The expression of FCN1 in the coelomic fluid reached the highest level after low salt stress for 1.5 h, 669 times higher than that of the control group. The changes of these 7 genes under low salt stress showed that these genes were either directly involved in the metabolic regulation as functional proteins or as a regulated protein to regulate the expression and activity of functional proteins to improve adaption to low salt stress. The results suggest that the salinity adaptation process of sea cucumber is a stress response signal transduction network requiring multiple genes. These results laid a foundation for studying the salinity adaptation mechanism of Apostichpus japonicus.

Key words: Apostichpus japonicus, low salinity stress, salinity related gene, expression analysis

摘要： 从仿刺参Apostichopus japonicus低盐转录组数据库中选取肌腱蛋白-R1 (TN-R1）、肌腱蛋白-R2(TN-R2)、乙酰胆碱受体亚基α-3(CHRNA3）、脂肪酸结合蛋白6(FABP6)、单羧酸转运蛋白2(SLC16A7)、纤维胶凝蛋白1 (Fcn1)、黑素转铁蛋白(Mfi2)共7个盐度调节相关基因， 利用 qRT-PCR 技术分析这7个基因在低盐胁迫下不同组织中的表达水平及表达丰度。结果表明TN-R1基因在仿刺参体腔液中表达水平最高，呼吸树次之，肠表达较低；TN-R2基因在仿刺参体腔液中表达水平最高，在肠中表达较低，呼吸树中不表达。SLC16A7、FABP6、Fcn1、CHRNA3和Mfi2均在体腔液中表达最高。Mfi2基因在体腔液中明显上调表达，在呼吸树组织和肠组织中下调表达，且与对照组均呈显著性差异。Fcn1在体腔液中的表达量在胁迫后1.5 h达到最高，为对照组的669倍，在胁迫48 h之前均呈明显上调。低盐胁迫下这7个基因表达丰度的变化，说明这些基因或作为功能基因直接参与机体的盐度适应的代谢调节，或作为调控基因调节盐度相关功能蛋白的表达和活性来提高仿刺参对低盐胁迫的耐受能力。上述结果表明仿刺参的盐度适应过程是一个需要多基因参与的应激反应信号转导网络，为仿刺参盐度调节适应机制的研究奠定基础。

关键词: 仿刺参, 低盐胁迫, 盐度相关基因, 表达模式分析