Engineering and Technology Research Center of Shellfish Breeding in Liaoning Province, Dalian 116023, China.
Fisheries College of Jimei University, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Xiamen 361021, China.
Comp Biochem Physiol Part D Genomics Proteomics. 2024 Sep;51:101259. doi: 10.1016/j.cbd.2024.101259. Epub 2024 May 24.
Low temperature in winter poses a threat to the Manila clam Ruditapes philippinarum in North China. However, a number of low-temperature-tolerant clams could survive such condition. It is therefore of interest to explore the survival mechanisms underlying the cold tolerance of R. philippinarum. The Zebra II population of R. philippinarum (Zebra II) from North China and the native Putian population from South China were used as experimental materials. Both populations were stressed with low-temperature and the differences in their survival rates, energy metabolism and transcriptional responses were compared. The results shown that after cold treatment at -1.9 °C, survival rate of Zebra II was higher than that of the Putian group. For both groups, the respiration, ammonia excretion, and ingestion rates continuously decreased till 0 with reductions temperature. In addition, RNA-seq revealed that as compared with the Putian group, there were 3682 up-regulated differentially expressed genes (DEGs) and 3361 down-regulated DEGs in Zebra II group. Moreover, Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that these DEGs were mostly enriched in the purine, pyrimidine, and pyruvate metabolism pathways in Zebra II under low-temperature stress. Furthermore, qRT-PCR analysis further confirmed that Zebra II responded to low-temperature stress through upregulating genes involved in purine, pyrimidine, and pyruvate metabolism pathways. Taken together, all these results indicated that Zebra II has higher cold tolerance than the Putian group. Therefore, Zebra II is capable for overwintering in the intertidal zone of North China.
冬季低温会对中国北方的马尼拉蛤（Ruditapes philippinarum）造成威胁。然而，有一些耐低温的蛤类可以在这种条件下存活。因此，探索菲律宾蛤仔耐低温的生存机制是很有意义的。本研究以中国北方的斑马蛤Ⅱ（Zebra II）种群和中国南方的本地莆田种群为实验材料。对这两个种群进行低温胁迫，比较它们的存活率、能量代谢和转录组响应的差异。结果表明，在-1.9°C的冷处理后，Zebra II 的存活率高于莆田种群。对于这两个种群，随着温度的降低，呼吸、氨排泄和摄食率持续下降至 0。此外，RNA-seq 显示，与莆田种群相比，Zebra II 中有 3682 个上调的差异表达基因（DEGs）和 3361 个下调的 DEGs。此外，京都基因与基因组百科全书（KEGG）分析表明，这些 DEGs 在 Zebra II 中主要富集在低温胁迫下的嘌呤、嘧啶和丙酮酸代谢途径中。此外，qRT-PCR 分析进一步证实，Zebra II 通过上调参与嘌呤、嘧啶和丙酮酸代谢途径的基因来应对低温胁迫。综上所述，这些结果表明 Zebra II 比莆田种群具有更高的耐寒性。因此，Zebra II 能够在中国北方的潮间带越冬。
