Salinity is an important environmental factor that has a profound impact on the growth, reproduction, survival, and development of mollusk. To investigate the molecular changes in response to acute low-salinity stress, the clams were transferred from 25‰ to 8‰. According to the exposure times of 0, 12, 24, 48, 72, 96, and 120 h, the treatment consisted group T0 (the control), T1, T2, T3, T4, T5, and T6, respectively. Gills were collected, and then transcriptome analysis was conducted. Compared to the control, 3008 DEGs were obtained, including 1127 up-regulated and 1881 down-regulated genes, respectively. Up-regulations of 924, 176, 11, 6, 3, and 7 DEGs, and down-regulations of 1216, 416, 157, 59, 23, and 10 DEGs were observed in T6, T5, T4, T3, T2, and T1 groups, respectively. The related molecular biological processes, and potential functions were explored from enrichment analyses, including energy metabolism, material metabolism, and immune responses. There were 13, 10, 16, 30, 62, and 97 KEGG pathways enriched in T1, T2, T3, T4, T5, and T6 groups, respectively. 13 genes down-regulated, and only one gene up-regulated were found in more than four groups. In addition, the verification of the expression changes of the candidate genes (PCK1, IAP, BIRC2, and LOC102459116) provided insights into responses to salinity change in the gills of the clams. This will be of great value in understanding the molecular basis of low-salinity adaptation in the clam.

盐度是重要的环境因素，对软体动物的生长，繁殖，存活和发展具有深远的影响。为了研究对急性低盐度胁迫响应的分子变化，将蛤从25‰转移到8‰。根据0、12、24、48、72、96和120 h的暴露时间，治疗分别包括T0组（对照组），T1，T2，T3，T4，T5和T6。收集，然后进行转录组分析。与对照相比，获得了3008个DEG，分别包括1127个上调基因和1881个下调基因。在T6，T5，T4，T3，T2和T6中观察到924、176、11、6、3和7个DEG的上调，而1216、416、157、59、23和10个DEG的下调。 T1组分别。相关的分子生物学过程，通过富集分析探索了潜在功能，包括能量代谢，物质代谢和免疫反应。在T1，T2，T3，T4，T5和T6组中分别有13条，10条，16条，30条，62条和97条KEGG通路富集。在四个以上的组中发现了13个基因被下调，而只有一个基因被上调。另外，验证候选基因的表达变化（PCK 1，IAP，BIRC2和LOC102459116）提供了对蛤g中盐度变化的响应的见解。这对于了解蛤中低盐度适应的分子基础将具有重要价值。