首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 156 毫秒
1.
为研究Na+/H+-exchanger基因在三疣梭子蟹(Portunus trituberculatus)盐度胁迫过程中的功能作用,克隆了三疣梭子蟹Na+/H+-exchanger基因并进行表达分析。结果显示,Na+/H+-exchanger基因(GenBank:KU519329)全长4233 bp,5和3非编码区(UTR)长分别为519和753 bp,开放阅读框(ORF)长2961 bp。编码986个氨基酸,预测蛋白质分子量和等电点分别为110.8 kD和7.42,具有信号肽和典型的Na+/H+-exchanger蛋白结构域,含12个跨膜螺旋;三疣梭子蟹Na+/H+-exchanger基因与普通滨蟹(Carcinus maenas)同源性最高,达到87.2%,系统进化分析也显示该序列与普通滨蟹聚为一支;表达分析显示,三疣梭子蟹Na+/H+-exchanger基因在鳃中表达量最高;在低盐(盐度5、10和20)胁迫过程中,Na+/H+-exchanger基因在0-12h上调表达明显,在24-168h间表达量呈下降趋势;在高盐(盐度50)胁迫初期(0-12h),该基因表达量相对稳定,之后(24-168h)显著下调表达。研究表明低盐显著诱导Na+/H+-exchanger基因的高表达,推测三疣梭子蟹Na+/H+-exchanger基因在低盐环境下发挥重要的渗透调节功能。  相似文献   

2.
盐胁迫对橙色莫桑比克罗非鱼AQP1基因表达的影响   总被引:1,自引:0,他引:1  
水通道蛋白(aquaporin,AQP)是一类细胞膜通道蛋白,能够选择性地高效转运水分子。为研究橙色莫桑比克罗非鱼(Oreochromis mossambicus)AQP1基因在渗透压调控中的作用,该实验克隆了橙色莫桑比克罗非鱼的AQP1基因,并利用实时荧光定量方法(q PCR)分析了该基因在各个组织中的表达分布及其在盐度梯度胁迫(低盐胁迫(22‰)和高盐胁迫(35‰))条件下鳃、肾和肌肉的表达特征。结果显示AQP1基因c DNA全长2 612 bp,开放阅读框(ORF)774 bp,编码258个氨基酸;其DNA序列全长3 215 bp,包含2个内含子,3个外显子。组织分布结果表明,AQP1基因在各组织都有表达,在肾、皮肤和肌肉中表达量相对较高;盐胁迫结果显示,在盐度为22时鳃和肾中表达量在6 h达到峰值,肌肉中在24 h达到峰值;当盐度升至35时,鳃、肾和肌肉表达量均升高。实验结果表明,AQP1基因的表达与盐度密切相关,并参与橙色莫桑比克罗非鱼的渗透压调控。  相似文献   

3.
为了研究水环境中的低盐度对大底鳉(Fundulus grandis)的适应性影响,采用生理和荧光定量PCR方法探讨了盐度为5、2、1、0.5和0.1的情况下,不同饲养时间大底鳉的血浆渗透压,鳃上皮细胞超微结构及通道蛋白m RNA表达的变化。饲养时间小于1 d、盐度小于0.5的胁迫可以导致血浆渗透压明显降低(P0.001);鳃上皮表面泌氯细胞的体积增大、顶隐窝开口扩大或其细胞的形状变为三角形或不规则形。当饲养时间超过3 d时,血浆渗透压以及鳃上皮表面泌氯细胞的形态都恢复到对照组水平(盐度为5);低盐胁迫上调了六种鳃通道蛋白m RNA的表达,并下调了两种鳃通道蛋白m RNA的表达。结果显示:广盐性的大底鳉通过调整鳃上皮的形态及通道蛋白m RNA的表达来维持机体渗透压的平衡状态。  相似文献   

4.
为研究miR-139555及其潜在靶基因PtNBC(碳酸氢钠协同转运基因)在三疣梭子蟹(Portunus trituberculatus)适应盐度胁迫中的表达调控分析, 利用RACE技术克隆了PtNBC基因, 该基因全长5308 bp, 开放阅读框(ORF)3570 bp, 共编码 1189个氨基酸。利用RT-PCR技术分析miR-139555和PtNBC基因在三疣梭子蟹不同组织及低盐胁迫(11)下的表达规律。组织表达分布结果显示, miR-139555和PtNBC基因均在三疣梭子蟹鳃组织中表达量最高, 与其他组织相比, 有显著差异(P<0.05)。体外双荧光素酶实验表明, miR-139555能够显著抑制PtNBC基因的表达(P<0.001)。低盐胁迫显著影响了miR-139555和PtNBC基因的表达, 且两者间的表达趋势呈现明显的负相关。在低盐胁迫后, miR-139555整体呈现上调表达的趋势且在48h达到最大值, 为对照组的4.9倍(P<0.05), 而PtNBC基因呈现显著下调表达的趋势且各时间点表达量均低于对照组, 在12h表达量最低, 为对照组的0.06倍(P<0.05)。研究结果证明了PtNBC基因是miR-139555的靶基因, miR-139555可能通过调控鳃上皮细胞PtNBC基因的表达发挥重要的渗透压调节功能。  相似文献   

5.
为了解外来物种红耳龟在不同盐度水域中的生存状况,本研究选用体重67.28 g±19.39 g的红耳龟进行为期70 d的不同盐度胁迫实验,分别测定红耳龟在对照组以及盐度为10‰组和20‰组(以下简写为10组和20组)的体重特定增长率和血液生化指标变化.结果表明,盐度10组的体重特定增长率极显著高于对照组和盐度20组(P<0.01),而盐度20组的体重特定增长率略大于对照组,但差异不显著(P>0.05);盐度10组的肌酸激酶(CK)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)、碱性磷酸酶(ALP)的活性显著高于对照组(P<0.05);盐度10组和20组的血糖(Glu)含量显著高于对照组(P<o.05);各盐度组血清渗透压(Osmp)、Na+、C1、K+、Mg2+、血清尿素氮(BUN)、尿酸(UA)含量差异显著(P<0.05);盐度20组Ca2+显著高于对照组(P<0.05).说明红耳龟可通过提高血液中血糖含量及代谢所需的酶活性使得其代谢水平升高,从而为抵抗胁迫提供所需能量;还可以通过提高血液渗透压及无机离子的浓度来适应外界渗透压的升高,从而使其能够在不同盐度水域中生存.本研究为红耳龟对盐度的耐受生理及入侵机理研究提供生理学方面的依据.  相似文献   

6.
探讨了鲻鱼(Mugil cephalus)鳃组织14-3-3a、NKCCla、Apo-14和Na+-K+-ATPaseβ基因对盐度变化的响应表达特性。结果表明:不同盐度处理组对14-3-3a、NKCC1a、Apo-14和Na+-K+-ATPaseβ等4种基因mRNA的表达量与对照组(盐度20)间存在一定的差异性,且各类基因与盐度适应相关性的差异性也较为显著;其中Na+-K+-ATPaseβ和NKCC1a在低盐环境下被显著诱导,表达量上升明显(P0.01),而14-3-3a与Apo-14在低盐环境下表达量均有明显的下调(P0.05);不同盐度处理组与对照组表达量的差异、各基因表达量与盐度的回归关系以及4种基因生物整合标志物响应值的不同,表明Na+-K+-ATPaseβ和NKCC1a相对于14-3-3a和Apo-14更能赋予生物在受到低盐度应激刺激后,产生渗透调节机制,提高生物抵抗环境的胁迫能力;可考虑Na+-K+-ATPaseβ和NKCC1a适宜作为鱼类鳃组织在低盐环境胁迫下调控渗透基因的潜在分子生物标志物。  相似文献   

7.
设定半致死低盐试验组(盐度7)和正常对照组(盐度28)对三疣梭子蟹进行48h的胁迫,检测半致死盐度胁迫下不同时间点三疣梭子蟹组织中抗氧化酶和ATP酶活力的变化。结果显示,随着低盐处理时间的延长,三疣梭子蟹肝胰腺、鳃、肌肉中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活力均呈下降趋势,极显著低于对照组(P0.01),各组织中SOD、CAT活力大小顺序为肌肉肝胰腺鳃;肝胰腺、鳃中谷胱甘肽过氧化物酶(GPX)、谷胱甘肽转硫酶(GST)、谷胱甘肽还原酶(GR)、Na+/K+-ATPase酶和Ca2+/Mg2+-ATPase酶活力也都被抑制,活力极显著下降(P0.01);而对照组在试验期间各组织酶活均较平稳,变化不大。试验结论表明,当盐度下降剧烈,超出机体耐受范围时,三疣梭子蟹生理机能被抑制,酶活力反而下降。  相似文献   

8.
盐度对卵形鲳鲹幼鱼渗透压调节和饥饿失重的影响   总被引:1,自引:0,他引:1  
区又君  范春燕  李加儿  于娜 《生态学报》2014,34(24):7436-7443
为探讨盐度对卵形鲳鲹(Trachinotus ovatus)渗透压调节的影响,研究了深水网箱养殖的卵形鲳鲹幼鱼鳃Na+-K+-ATP酶(NKA)活性,血浆、鳃和肾渗透压以及饥饿失重在盐度渐变条件下的反应。实验设5个盐度梯度组,分别为5、15、25、30和35。结果显示,鳃NKA活性除盐度15外都呈先下降后升高随之回落并趋于稳定的趋势,在2 d后的各时间节点随盐度变化呈"U"型分布;血浆渗透压在相同盐度下随时间延长呈先升高后下降再升高随后回落并趋于稳定,2 d后在各时间节点与盐度呈正相关关系,盐度30和35组的血浆渗透压显著高于其它盐度组(P0.05);肾脏对盐度变化的渗透调节比鳃敏感,在低盐度时(30以下),鰓和肾共同完成对渗透压的调节,在较高盐度(30以上),肾对渗透压的调节起主导作用。盐度变化对卵形鲳鲹的饥饿失重率有极显著的影响。研究表明,卵形鲳鲹幼鱼对盐度的渗透调节能力较强,在盐度5—35范围内的盐度变化均能适应,一般在1—2 d内可达到稳定,且更适于在低盐度水环境中生活。  相似文献   

9.
血浆视黄醇结合蛋白(Retinol binding protein,RBP)是体内将视黄醇从肝脏转运至靶组织的特异载体蛋白。最近研究发现在盐度升高时肾脏RBP蛋白表达量下降。为了进一步研究香鱼RBP基因mRNA和蛋白表达与盐度应激相关性,从香鱼、肝脏cDNA文库中获得RBP基因cDNA序列。香鱼RBP基因mRNA在肝脏中表达量最高,肾、肠、脑和鳃中表达次之。实时荧光定量RT-PCR结果显示,盐度升高时,RBP基因mRNA表达在不同组织中呈不同下降趋势,其中渗透压调节相关组织鳃、肾中,表达量下降最显著。Western blot实验证实,盐度升高时,香鱼血清RBP蛋白表达量也显著下降。揭示了RBP可能在香鱼盐度适应中有重要作用。  相似文献   

10.
盐度变化会引起头足类动物渗透调节、免疫能力和激素分泌异常等一系列生理应激反应,同时还会引发应激诱导的喷墨行为等异常行为变化,最终可能导致头足类因渗透失衡出现大量死亡。结合头足类苗种繁育过程中因海水盐度波动出现的摄食及行为异常等问题,探究了盐度胁迫对曼氏无针乌贼(Sepiella japonica)行为活跃性、组织结构、渗透调节以及免疫相关酶活性的影响,明确了其对盐度变化的应激反应及适应能力。结果显示:在高盐胁迫下曼氏无针乌贼的行为活跃性显著增加(P<0.05),且倾向于绕水槽壁游动;与21‰组相比,27‰组和33‰组肌肉、鳃和肝脏组织结构呈现较严重的损伤,15‰组的各组织结构无明显变化;随着盐度的升高,鳃中Na+/K+-ATP酶活性呈现先降低后升高趋势(P<0.05);33‰组脑中皮质醇含量显著高于其他处理组(P<0.05);盐度升高或降低均会导致鳃和肝脏中超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化氢酶(Catalase,CAT)活性显著升高(P<0.05),丙二醛(Malondialdehyde,MDA)含量显著增加(P<0.05),溶菌酶(Lysozyme,LZM)活性显著降低(P<0.05)。综合分析认为,曼氏无针乌贼具有较好的耐低盐能力,高盐胁迫会引发其类焦虑行为。此外,在研究设定的15‰-33‰盐度范围内,盐度变化还会引起其渗透调节以及免疫相关酶活性的改变。研究结果为阐释头足类适应盐度波动的调节机理,控制适宜的养殖环境提供了参考依据。  相似文献   

11.
催乳素受体通过结合催乳素,能调节鱼体渗透压。为研究催乳素受体1(PRLR1)在高盐水体和低盐水体中对军曹鱼(Rachycentron canadum)的渗透调节作用,利用cDNA末端快速扩增(RACE-PCR)技术,获得了军曹鱼PRLR1全长cDNA序列。该基因全长为2629 bp,包含1953 bp的开放阅读框ORF,可编码650个氨基酸。氨基酸序列包含了2个纤维连接蛋白3型结构域(FN3)、保守的WS区和box1。采用qRT-PCR技术,检测不同盐度(10‰、30‰和35‰)条件下鳃、肠、体肾中PRLR1基因mRNA表达情况。结果显示,PRLR1基因在军曹鱼的各个组织中均有表达,其中鳃表达量最高,其次是肌肉、体肾和肠,而在胃、脾、脑和心脏中则微量表达。低盐组、正常组和高盐组中,PRLR1基因的表达量均为鳃最高;肠次之;体肾最低。随着盐度提高,PRLR1基因的鳃、肠和体肾组织表达量变化规律均呈逐步下降趋势。以上结果反映了军曹鱼PRLR1在渗透压器官中的功能差异性,说明PRLR1在军曹鱼渗透压调节上具有重要作用。  相似文献   

12.
On exposure to hyposmotic acidic water, teleost fish suffer from decreases in blood osmolality and pH, and consequently activate osmoregulatory and acid-base regulatory mechanisms to restore disturbed ion and acid-base balances. In Mozambique tilapia Oreochromis mossambicus exposed to acidic (pH 4.0) or neutral (pH 7.4-7.7) freshwater in combination with 0mM or 50mM NaCl, we examined functional and morphological changes in gill mitochondria-rich (MR) cells. We assessed gene expression of Na(+)/H(+) exchanger-3 (NHE3), Na(+)/Cl(-) cotransporter (NCC), vacuolar-type H(+)-ATPase (V-ATPase) and Na(+)/HCO(3)(-) cotransporter-1 (NBC1) in the gills. The mRNA expression of NHE3 and NCC in tilapia gills were higher in acidic freshwater than in that supplemented with 50mM NaCl, while there was no significant difference in mRNA levels of V-ATPase and NBC1. In addition, immunocytochemical observations showed that apical-NHE3 MR cells were enlarged, and frequently formed multicellular complexes with developed deep apical openings in acidic freshwater with 0mM and 50mM NaCl. These findings suggest that gill MR cells respond to external salinity and pH treatments, by parallel manipulation of osmoregulatory and acid-base regulatory mechanisms.  相似文献   

13.
Two electrogenic H(+)-pumps, the vacuolar type H(+)-ATPase (V-ATPase) and the vacuolar pyrophosphatase, coexist at membranes of the secretory pathway of plants. The V-ATPase is the dominant H(+)-pump at endomembranes of most plant cells, both in terms of protein amount and, frequently, also in activity. The V-ATPase is indispensable for plant growth under normal conditions due to its role in energizing secondary transport, maintenance of solute homeostasis and, possibly, in facilitating vesicle fusion. Under stress conditions such as salinity, drought, cold, acid stress, anoxia, and excess heavy metals in the soil, survival of the cells depends strongly on maintaining or adjusting the activity of the V-ATPase. Regulation of gene expression and activity are involved in adapting the V-ATPase on long- and short-term bases. The mechanisms known to regulate the V-ATPase are summarized in this paper with an emphasis on their implications for growth and development under stress.  相似文献   

14.
Haloferax volcanii and Halomonas elongata have been selected as representatives of halophilic Archaea and Bacteria, respectively, to analyze the responses to various osmolarities at the protein synthesis level. We have identified a set of high-salt-related proteins (39, 24, 20, and 15.5 kDa in H. elongata; 70, 68, 48, and 16 kDa in H. volcanii) whose synthesis rates increased with increasing salinities. A different set of proteins (60, 42, 15, and 6 kDa for H. elongata; 63, 44, 34, 18, 17, and 6 kDa for H. volcanii), some unique for low salinities, was induced under low-salt conditions. For both organisms, and especially for the haloarchaeon, adaptation to low-salt conditions involved a stronger and more specific response than adaptation to high-salt conditions, indicating that unique mechanisms may have evolved for low-salinity adaptation. In the case of H. volcanii, proteins with a typical transient response to osmotic shock, induced by both hypo- and hyperosmotic conditions, probably corresponding to described heat shock proteins and showing the characteristics of general stress proteins, have also been identified. Cell recovery after a shift to low salinities was immediate in both organisms. In contrast, adaptation to higher salinities in both cases involved a lag period during which growth and general protein synthesis were halted, although the high-salt-related proteins were induced rapidly. In H. volcanii, this lag period corresponded exactly to the time needed for cells to accumulate adequate intracellular potassium concentrations, while extrusion of potassium after the down-shift was immediate. Thus, reaching osmotic balance must be the main limiting factor for recovery of cell functions after the variation in salinity.  相似文献   

15.
State-dependent expression of pressure diuresis in conscious rats   总被引:1,自引:0,他引:1  
In 1967, Guyton and Coleman modeled pressure diuresis as the underlying, essential, long-term mechanism that regulates arterial pressure when sodium intake changes. Other mechanisms that influence renal function interact with pressure diuresis to achieve sodium balance and determine the blood pressure. Increases in sodium intake suppress sodium conserving mechanisms and activate natriuretic mechanisms; decreases in sodium intake have the opposite effect. If the Guyton-Coleman model is correct, then pressure diuresis should be more readily detected in animals on a high-salt diet than in animals on a low-salt diet. We measured spontaneous changes in arterial pressure and urine flow in conscious rats fed low-salt (0. 4% NaCl) and high-salt (8.0% NaCl) chow. For 10 rats fed a high-salt diet, arterial pressure and urine flow were positively correlated in 19 of 32 (59%) trials. In 10 rats fed a low-salt diet, a positive correlation was observed in 10 of 33 (30%) trials. Chi-square analysis revealed that differences in Na+ content of the diet were significantly associated with the probability of a positive relationship between blood pressure and urine flow. These results support the hypothesis that the expression of pressure diuresis across time is dependent on the state of sodium balance.  相似文献   

16.
17.
18.
Growth hormone (GH) transgenic fish are at a critical step for possible approval for commercialization. Since this hormone is related to salinity tolerance in fish, our main goal was to verify whether the osmoregulatory capacity of the stenohaline zebrafish (Danio rerio) would be modified by GH-transgenesis. For this, we transferred GH-transgenic zebrafish (T) from freshwater to 11 ppt salinity and analyzed survival as well as relative changes in gene expression. Results show an increased mortality in T versus non-transgenic (NT) fish, suggesting an impaired mechanism of osmotic acclimation in T. The salinity effect on expression of genes related to osmoregulation, the somatotropic axis and energy metabolism was evaluated in gills and liver of T and NT. Genes coding for Na+, K+-ATPase, H+-ATPase, plasma carbonic anhydrase and cytosolic carbonic anhydrase were up-regulated in gills of transgenics in freshwater. The growth hormone receptor gene was down-regulated in gills and liver of both NT and T exposed to 11 ppt salinity, while insulin-like growth factor-1 was down-regulated in liver of NT and in gills of T exposed to 11 ppt salinity. In transgenics, all osmoregulation-related genes and the citrate synthase gene were down-regulated in gills of fish exposed to 11 ppt salinity, while lactate dehydrogenase expression was up-regulated in liver. Na+, K+-ATPase activity was higher in gills of T exposed to 11 ppt salinity as well as the whole body content of Na+. Increased ATP content was observed in gills of both NT and T exposed to 11 ppt salinity, being statistically higher in T than NT. Taking altogether, these findings support the hypothesis that GH-transgenesis increases Na+ import capacity and energetic demand, promoting an unfavorable osmotic and energetic physiological status and making this transgenic fish intolerant of hyperosmotic environments.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号