氨是影响对虾生存和健康的主要水质因子,其中g是氨毒性的主要效应器官。在这项研究中,我们选择了两种凡纳滨对虾,在30亿个海水中养殖,在3亿个低盐度中驯化,分别,然后在海水和低盐度条件下分别经受14天的氨胁迫,其中3万只低盐度养殖虾是在经过27天的逐渐盐度淡化后,从30万只海水中养殖的虾中驯化的。详细来说,这项研究包括四组,即SC组(氨氮0毫克/升,盐度30),SAN组(氨氮10mg/L,盐度30),LC组(氨氮0mg/L,盐度3),和LAN组(氨氮10毫克/升,盐度3)。氨胁迫持续了14天,然后对其形态结构和生理功能的变化进行了探讨。结果表明,氨气胁迫导致g丝严重收缩,g血管变形甚至破裂。氧化应激的生化指标,包括LPO和MDA含量,以及T-AOC和GST活动,在SAN和LAN组中增加了,而CAT和POD的活性以及抗氧化相关基因的mRNA表达水平(nrf2,cat,GPX,hsp70和trx)下降。此外,与内质网应激有关的基因(ire1和xbp1)的mRNA表达水平,凋亡(casp-3、casp-9和jnk),排毒(gst,ugt,andsult),葡萄糖代谢(pdh,香港,pk,和ldh),和三羧酸循环(mdh,cs,idh,和odh)在SAN和LAN组中降低;电子传递链相关基因的水平(ndh,CCO,andcoi),SAN组bip和sdh基因降低,LAN组升高;SAN组和LAN组ATPase基因水平降低,cytc基因升高。渗透调节相关基因的mRNA表达水平(nka-β,ca,SAN组的aqp和clc)降低,而LAN组的ca基因水平升高;两组的nka-α基因均降低。结果表明,氨胁迫可以影响对虾的生理稳态,可能是通过破坏组织形态,影响氧化还原,ER函数,凋亡,排毒,能量代谢,和渗透调节。
Ammonia is a major water quality factor influencing the survival and health of shrimp, among which the gill is the main effector organ for ammonia toxicity. In this study, we chose two types of Litopenaeus vannamei that were cultured in 30‱ seawater and domesticated in 3‱ low salinity, respectively, and then separately subjected to ammonia stress for 14 days under seawater and low-salinity conditions, of which the 3‱ low salinity-cultured shrimp were domesticated from the shrimp cultured in 30‱ seawater after 27 days of gradual salinity desalination. In detail, this study included four groups, namely the SC group (ammonia-N 0 mg/L, salinity 30‱), SAN group (ammonia-N 10 mg/L, salinity 30‱), LC group (ammonia-N 0 mg/L, salinity 3‱), and LAN group (ammonia-N 10 mg/L, salinity 3‱). The ammonia stress lasted for 14 days, and then the changes in the morphological structure and physiological function of the gills were explored. The results show that ammonia stress caused the severe contraction of gill filaments and the deformation or even rupture of gill vessels. Biochemical indicators of oxidative stress, including LPO and MDA contents, as well as T-AOC and GST activities, were increased in the SAN and LAN groups, while the activities of CAT and POD and the mRNA expression levels of antioxidant-related genes (nrf2, cat, gpx, hsp70, and trx) were decreased. In addition, the mRNA expression levels of the genes involved in ER stress (ire1 and xbp1), apoptosis (casp-3, casp-9, and jnk), detoxification (gst, ugt, and sult), glucose metabolism (pdh, hk, pk, and ldh), and the tricarboxylic acid cycle (mdh, cs, idh, and odh) were decreased in the SAN and LAN groups; the levels of electron-transport chain-related genes (ndh, cco, and coi), and the bip and sdh genes were decreased in the SAN group but increased in the LAN group; and the level of the ATPase gene was decreased but the cytc gene was increased in the SAN and LAN groups. The mRNA expression levels of osmotic regulation-related genes (nka-β, ca, aqp and clc) were decreased in the SAN group, while the level of the ca gene was increased in the LAN group; the nka-α gene was decreased in both two groups. The results demonstrate that ammonia stress could influence the physiological homeostasis of the shrimp gills, possibly by damaging the tissue morphology, and affecting the redox, ER function, apoptosis, detoxification, energy metabolism, and osmoregulation.