Wang Daixia, Liu Xiaochen, Shang Yan, Yu Xuee, Gao Baoquan, Lv Jianjian, Li Jitao, Liu Ping, Li Jian, Meng Xianliang
National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China.
National Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China.
Biology (Basel). 2023 Mar 6;12(3):409. doi: 10.3390/biology12030409.
Ammonia is a significant concern during hatchery culture in brachyuran species, and its accumulation may lead to abortive moulting and large-scale deaths of the early juveniles. To date, the underlying mechanism for ammonia-induced alteration of the moulting process is still unknown. In this study, we aimed to investigate the effects of ammonia on the moulting as well as the potential mechanisms in early juveniles of the swimming crab , an important aquaculture species in China. We evaluated the survival rate and moulting rate of the juvenile crabs (C2) and analyzed the expression pattern of the genes in key components of molt signaling during a complete moulting cycle under different concentrations of ammonia nitrogen (the control group: <0.1 mg/L; the LA group: 5 mg/L; and the HA group: 20 mg/L). The results showed that: (1) the survival rate in the LA and HA groups was lower than that in the control group at the end of the experiment, and moulting death syndrome (MDS) was only observed in the HA group; (2) the moulting rate was higher in the LA group and lower in the HA group compared to the control group; (3) consistent with the results of the moulting experiment, showed decreased expression, and genes related to ecdysteroid synthesis, ecdysteroid receptors, and responsive effectors exhibited increased expression in the LA group compared to the control group; and (4) although expression was upregulated, increased expression of the genes associated with ecdysteroid synthesis, ecdysteroid receptors and downstream effectors still observed in the HA group. Our results indicated that low levels of ammonia can promote moulting in juvenile swimming crabs by inhibiting the expression of and activating moult signaling, whereas high levels of ammonia inhibit moulting and lead to MDS through impairing moult signaling.
在短尾类物种的孵化场养殖过程中，氨是一个重大问题，其积累可能导致幼体蜕皮失败和大规模死亡。迄今为止，氨诱导蜕皮过程改变的潜在机制仍不清楚。在本研究中，我们旨在研究氨对中国重要水产养殖物种——三疣梭子蟹早期幼体蜕皮的影响及其潜在机制。我们评估了幼蟹（C2）的存活率和蜕皮率，并分析了在不同浓度氨氮（对照组：<0.1 mg/L；低氨组：5 mg/L；高氨组：20 mg/L）下完整蜕皮周期中蜕皮信号关键成分基因的表达模式。结果表明：（1）实验结束时，低氨组和高氨组的存活率低于对照组，且仅在高氨组观察到蜕皮死亡综合征（MDS）；（2）与对照组相比，低氨组的蜕皮率较高，高氨组较低；（3）与蜕皮实验结果一致，[此处原文缺失相关基因名称]的表达下降，与蜕皮类固醇合成、蜕皮类固醇受体和响应效应器相关的基因在低氨组中相对于对照组表达增加；（4）尽管[此处原文缺失相关基因名称]表达上调，但在高氨组中仍观察到与蜕皮类固醇合成、蜕皮类固醇受体和下游效应器相关的基因表达增加。我们的结果表明，低水平的氨可通过抑制[此处原文缺失相关基因名称]的表达并激活蜕皮信号来促进三疣梭子蟹幼体蜕皮，而高水平的氨则通过损害蜕皮信号抑制蜕皮并导致MDS。
