Effects of salinity fluctuation frequency on the osmolarity, Na+-K+-ATPase activity and HSP70 expression in juvenile chinese shrimp, Fenneropenaeus chinensis

Experiments were conducted to examine the effects of salinity fluctuation frequency on the osmolarity, Na⁺-K⁺-ATPase activity and HSP70 of Chinese shrimp Fenneropenaeus chinensis with initial wet body weight of 1.460 g ± 0.091 g. The salinity in the control group (D0) was 28 throughout the experiment, whereas treatments D2, D4, D6 and D8 were subjected to different salinity fluctuation frequencies of 2, 4, 6 and 8 d, respectively. The salinity in treatments D2, D4, D6 and D8 was kept at 28 for 2, 4, 6 and 8 d, respectively, decreased abruptly to salinity 24, lasted for another 2 d, and then was raised to its initial value 28. This was a complete salinity fluctuation cycle that afterwards repeated itself. After 32 days, the osmolarity in treatments D2, D4, D6 and D8 was significantly lower than that in treatment D0 (P<0.05). There were significant differences in both muscle and eyestalks HSP70 expression among groups. The HSP70 expressions in muscle and eyestalks in group D4 were 61.4% and 57.0% higher, respectively, than that in the control group D0 (P<0.05). There were, however, no significant differences in gill or hepatopancreas Na⁺-K⁺-ATPase activity between the treatments and the control.     

盐度、pH对鮸鱼幼鱼鳃丝Na+-K+-ATPase活力的影响

本文研究了盐度、pH变化对娩鱼(Miichthys miiuy)幼鱼鳃丝Na~ -K~ -ATPase活力的影响。结果表明:盐度、pH变化对娩幼鱼鳃丝Na~ -K~ -ATPase活力的影响显著(P<0.05)。在盐度变化(22.185→6.570)2 d内,各处理组鳃丝Na~ -K~ -ATPase活力随着处理时间的增加而逐渐下降,而在盐度变化(22.185→30.060)4 d内,各处理组鳃丝Na~ -K~ - ATPase活力随着处理时间的增加而逐渐升高。所有处理组在2 d或4 d后Na~ -K~ -AT- Pase活力逐渐升高或下降,到第8 d趋于稳定。在pH变化(7.1←8.1→9.6)4 d内各处理组鳃丝Na~ -K~ -ATPase活力随着处理时间的增加而呈峰值变化,表现为向低pH和向高pH变化分别于6 h和12h达到最大值,至第4 d后逐渐恢复正常;在pH变化4～8 d以后,不同pH环境下娩鱼幼鱼鳃丝Na~ -K~ -ATPase活力无明显差异(P>0.05)。     

Effects of salinity on embryonic and larval development of Chinese mitten crab Eriocheir sinensis(Decapoda: Brachyura) and salinity-induced physiological changes

To investigate the effects of salinity on early development of Chinese mitten crab ( Eriocheir sinensis ), and the salinity tolerance mechanism of embryos, different developmental stages of embryos (gastrula, eyespot and pre-hatching stage), and hatched stage I zoea and megalopa, were exposed to a range of salinities (1, 5, 10, 15 (control), 20, 25, 30, 35 and 40). Hatching, survival and molting were monitored. Effects of 24-hour hypersaline (35) and hyposaline (1) stress on egg diameter, water content, Na +/K +-ATPase (NKA) activity, and crustacean hyperglycemic hormone (CHH) gene mRNA expression in embryos and megalopa, are reported. Embryos are more tolerant of low (≤ 5) than high (≥25) salinities, with optimum ranges for gastrula and pre-hatching stage embryos being 5-20, and for eyespot embryo and stage I zoea, 10-20. Most megalopa can molt to the first juvenile instar by day 5 at salinities between 1 and 40, whereas molting of megalopa stages was delayed at 40. Hypersaline conditions resulted in a loss of moisture, reduction of egg volume, and a signifi cant increase in NKA activity and CHH mRNA expression at some developmental stages. Hyposaline conditions did not affect moisture content or egg volume, but resulted in decreased NKA activity and CHH mRNA expression in embryos. For megalopa stages, NKA activity was significantly upregulated following both hypo- and hypersaline stress. Our results suggest high salinity will inhibit development and hatching of E. sinensis embryos, and low salinity will affect the survival of their stage I zoea. Increased NKA activity in embryos and megalopa stages might indicate a hyporegulation response under hypersaline conditions. These findings provide useful information for spawning ground protection of indigenous E . sinensis and enrich the knowledge of embryonic tolerance mechanisms of hyperregulating crustaceans following osmotic stress.     

盐度胁迫对小黄鱼(Larimichthys polyactis)抗氧化酶、非特异性免疫酶和Na+/K+-ATP酶活力的影响

为了研究不同盐度对小黄鱼生理的影响,以人工养殖的4月龄小黄鱼(体质量为(12.6±3.1)g)为实验对象,将在自然海水(对照组盐度为22.1)中养殖的小黄鱼转入到盐度为5(低盐组)和34.5(高盐组)的海水中进行急性盐度胁迫处理10 d,测定并分析肝脏中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、碱性磷酸酶(AKP...     

Effect of Salinity on Hemolymph Osmotic Pressure, Sodium Concentration and Na^＋-K^＋-ATPase Activity of Gill of Chinese Crab, Eriocheir sinensis

The effects of salinity on hemolymph osmotic pressure, Na^＋ concentration and Na^＋-K^＋-ATPase activity of gill of Chinese crab Eriocheir sinensis were studied. The results showed that hemolymph osmotic pressure and Na^＋ concentration increased significantly （P〈0.05）, and the Na^＋-K^＋-ATPase activity of gills decreased significantly （P〈0.05） when salinity increased from 0 to 16. The hemolymph osmotic pressure and Na^＋ concentration in each treatment group rose remarkably at 0.125 d or 0.25 d, while the Na^＋-K^＋-ATPase activity of gill reduced gradually with increased experiment time in 3 d. Then the three parameters remained at a constant level after 0.25 d, 0.125 d and 3 d, respectively, and higher hemolymph osmotic pressure, higher Na^＋ concentration and lower Na^＋-K^＋-ATPase activity of gill occurred at higher salinity. The effect of salinity change on protein concentration of hemolymph was indistinct （P〉0.05）; However, the protein concentration decreased gradually with the increase of salinity from 0.25 d to 1d, and then tended to be stable from day 1 to day 15.     

缢蛏(Sinonovacula constricta)耐氨氮关联SNP验证及相关基因NKA在氨氮胁迫下的表达特征分析

为筛查和验证缢蛏(Sinonovacula constricta)耐氨氮相关单核苷酸多态性(SNP)和基因, 为分子标记辅助育种提供参考, 通过竞争性等位基因特异性PCR (KASP)对位于缢蛏NKA基因(Sc-NKA)下游的SNP (g.21062868T＞A)进行验证, 采用实时荧光定量PCR (qRT-PCR)和蛋白免疫印迹(WB)检测高氨氮胁迫下Sc-NKA基因的表达水平, 用免疫荧光技术对Sc-NKA蛋白进行组织细胞定位, 通过RNA干扰探究Sc-NKA基因在氨氮排泄中的作用。结果显示, SNP位点(g.21062868T＞A)与氨氮耐受性状显著相关(P＜0.05); Sc-NKA基因在氨氮胁迫后的mRNA和蛋白表达量均显著增加(P＜0.05); 缢蛏鳃中的柱状细胞和扁平细胞是Sc-NKA蛋白分泌的主要部位, 且在氨氮胁迫后细胞中的蛋白丰度增加; 干扰Sc-NKA基因6~48 h后, 缢蛏血淋巴中氨含量显著升高(P＜0.05),且Na⁺-K⁺-2Cl共转运蛋白1 (NKCC1)的mRNA表达水平显著降低(P＜0.05)。这些研究结果表明, Sc-NKA参与氨氮的排泄过程, 且与NKCC1在氨氮转运中具有协同作用。     

珠江口表层水中Alk,K~ ,Na~ ,Ca~(2 )运移过程的稀释规律

１９９４ 年９ 月１ 日～１１ 日采集珠江口表层海水水样。利用模拟水样和现场水样稀释比与化学要素浓度关系的数学模式,对珠江口表层水Ａｌｋ ,Ｋ＋ ,Ｎａ＋ ,Ｃａ２ ＋ 在运移过程的稀释规律进行了研究,并利用上述模式计算了珠江口表层水样的Ａｌｋ ,Ｋ＋ ,Ｎａ＋ ,Ｃａ２ ＋ 在河海水整个混合过程和相应于各稀释比条件下的转移量。     

中华绒螯蟹鳃上皮Na+-K+-ATPase性质的研究

本文研究了中华绒螯蟹鳃上皮Na^ -K^ -ATPase的性质，并比较了各对鳃丝Na^ -K^ -ATPase的活性大小。结果表明：中华绒螯蟹鳃上皮Na^ -K^ -ATPase的最适温度为40℃，温度高于45℃时酶活急剧下降；最适pH为8．0，并且其活力对pH的变化非常敏感，当pH小于7．5或大于8、25时酶活急剧下降；最适底物和Na^-，K^ ，Mg^2 浓度分别为1．5，75，15，6mmol／l；反应介质中乌本苷浓度达到2mmol／l时，Na^ -K^ -ATPase的活力完全被抑制；中华绒螯蟹后3对鳃丝Na^--K^ -ATPase的活力极显著高于前5对鳃丝的酶活力。     

盐碱土壤修复材料对作物生长影响研究

本实验是利用以牡蛎壳为主要材料的 3种不同用量的盐碱土壤修复材料 ,处理含盐量为 2的低度盐碱土壤 ,对作物油菜的形态及其生理生化指标进行对比测量 ,用以观察此修复材料对盐碱土壤的修复作用。实验表明 ,此修复材料对种植 4 0 d后的油菜的出苗率无显著影响 ,而对叶长、叶宽等形态有明显影响。改良后的盐碱土上生长的油菜的叶绿素含量及叶绿素 a与叶绿素 b的比值均上升 ;叶片类囊体膜 H+ - ATPase活性上升 ,证明此盐碱土壤修复材料对盐碱土壤具一定的修复作用 ,且其修复作用与修复材料的添加用量有关。     

大菱鲆幼鱼鳃小叶软骨组织的超微结构研究

利用电镜技术研究了大菱鲆(Scopthalmus maximus)幼鱼鳃小叶软骨组织的细胞超微结构。研究表明。鳃小叶软骨细胞呈近似的椭圆状，电子密度较低，细胞间有大量的胶原蛋白结构。软骨细胞分为3种类型：新生软骨细胞、成熟软骨细胞和衰老软骨细胞。幼稚软骨细胞体积较小，细胞核较大，具有1个核仁；胞内有丰富的粗面内质网，线粒体数量不多且体积较小；成熟软骨细胞和核的体积均庞大，具有1个核仁；可见少量的粗面内质网和线粒体；衰老软骨细胞细胞核收缩或消失。胞质中出现许多不规则空泡，细胞器很少。细胞间丰富的胶原蛋白结构使鳃小叶软骨组织具有良好的弹性。