拟穴青蟹丝裂原活化蛋白激酶激酶（MAPKK）基因的克隆与表达分析

采用qRT-PCR、RACE等方法,获得了拟穴青蟹丝裂原活化蛋白激酶激酶(MAPKK)基因cDNA全长序列。该基因全长1 558 bp,开放阅读框长度为1 224 bp,编码407个氨基酸残基。同源分析显示,该基因编码的蛋白与昆虫的相似性高达70%,推测MAPKK基因在节肢动物具有较高的保守性。经荧光定量PCR检测,MAPKK基因在拟穴青蟹多个组织中有表达,且在脑神经节和卵巢中表达量较高。在拟穴青蟹卵巢发育过程中,MAPKK基因在卵巢发育期(Ⅲ期)表达量最高,发育期为卵母细胞快速生长期,推测MAPKK具有促进卵母细胞快速生长的作用。     

拟穴青蟹GRP78基因的克隆与应激表达

葡萄糖调节蛋白78(glucose regulated protein 78 ku,GRP78)是热休克蛋白70家族成员之一,在调节蛋白质折叠和维持内质网稳态过程中起着分子伴 侣作用。采用RT-PCR、RACE等技术,首次从拟穴青蟹获得了GRP78的cDNA全长序列。该序列全长2 284 bp,开放阅读框(ORF)为1 962 bp,编码653个氨基酸残基。 同源分析显示,该基因编码的蛋白含有HSP70家族的签名序列,C末端为内质网蛋白滞留信号KDEL,与其他物种具有很高相似性。实时荧光定量PCR结果表明,GRP78 基因在拟穴青蟹多个组织中均有表达。第一期仔蟹在不同的温度和盐度下暴露12 h后,GRP78基因表达量随环境温度升高而增加;在高盐(30)条件下GRP78表达量 较高,进而推测拟穴青蟹GRP78参与蛋白质折叠和环境胁迫的应答。     

拟穴青蟹卵泡抑素相关蛋白基因的克隆和表达分析

卵泡抑素相关蛋白(follistatin related protein,FRP)是一种细胞外基质糖蛋白,该蛋白参与细胞增殖、迁移、组织重塑、胚胎发育、细胞间相互作用等多种生理过程。迄今甲壳动物FRP的研究尚未见诸报道。实验采用RACE技术首次克隆了拟穴青蟹FRP基因部分cDNA序列。该序列长度1 948 bp,FRP肽段含有484个氨基酸残基,包括KAZAL-FS结构域、EFh结构域和两个Ig结构域。系统进化树显示拟穴青蟹FRP基因的分子进化地位与其生物学分类地位一致。半定量PCR及荧光定量PCR结果表明,FRP基因在拟穴青蟹的胸神经团、脑和卵巢中表达。FRP基因在卵巢发育各期的表达量各不相同,卵巢未发育期最高,据此我们推测FRP具有抑制卵巢发育的作用。     

拟穴青蟹Sp-Sox14基因在胚胎发育和性腺发育过程中的表达

为了解Sox14基因在拟穴青蟹胚胎发育和性腺发育过程中可能起到的调控作用,实验从青蟹性腺转录组数据库中得到全长为2558 bp的Sp-Sox14 c DNA序列,该序列编码一个包含427个氨基酸的蛋白,包含一个HMG-box。进化树分析表明,Sp-Sox14与其他节肢动物的Sox14亲缘关系较近。实时定量PCR结果显示,Sp-Sox14在成蟹雌雄各组织中均有不同程度的表达,其中在卵巢和雄蟹心脏中的表达量最高。在胚胎发育过程中,SpSox14在复眼色素形成期的表达量显著高于其他时期。在性腺不同发育阶段,Sp-Sox14在卵黄发生前期(O2)的表达量显著高于卵巢其他发育阶段;而在精巢发育过程中,其表达量在成熟精子期(T3)高于精母细胞期(T1)和精子细胞期(T2)。推测其参与卵巢的前期发育以及精子成熟等过程。整胚原位杂交结果显示,Sp-Sox14在青蟹胚胎复眼色素形成期阳性信号定位于头部以及鄂足附近,在近孵化期定位于复眼附近,幼体孵出期则在头部仍有少量信号,暗示其与青蟹神经器官的形成以及体节附肢的发生有关。     

拟穴青蟹Na+/H+ exchanger基因克隆及其在盐度胁迫下的表达分析

克隆了拟穴青蟹(Scylla paramamosain)Na~+/H~+-exchanger基因,其cDNA序列全长3 624 bp,开放阅读框(ORF)长2 886 bp,可编码961个氨基酸,预测蛋白质分子量和等电点分别为110.8 kDa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α螺旋。拟穴青蟹Na~+/H~+-exchanger的氨基酸序列与三疣梭子蟹(Portunus trituberculatus)的一致度最高,达到84.9%;该基因在卵巢中表达量最高,其次是精巢、鳃等;该基因在受精卵时期表达水平最高,大眼幼体时期次之。拟穴青蟹大眼幼体在低盐(盐度7和17)胁迫过程中,Na~+/H~+-exchanger基因在20 min表达水平最高,之后基本恢复到正常表达水平;在高盐(盐度37)胁迫(20 min～2 h)期间,该基因表达水平先下降再逐渐上升。Na~+/H~+-exchanger基因在拟穴青蟹大眼幼体阶段盐度适应中发挥着重要作用,且低盐显著诱导Na~+/H~+-exchanger基因的高表达,推测拟穴青蟹Na~+/H~+-exchanger基因在低盐环境下发挥重要的渗透调节功能。     

拟穴青蟹一种含CTLD结构域基因的克隆及表达分析

从拟穴青蟹(Scylla Paramamosain)中克隆得到一个含有CTLD(C-type lectin-like domain)结构域的C型凝集素基因,经分析未发现同源基因,将其命名为SpCTLD。该基因cDNA序列全长为1 237 bp,包含一个468 bp的开放阅读框,编码155个氨基酸,预测分子量为18.32 kDa,等电点为7.56。经一代测序,该基因在第390位(A390G)和第1 020位(T1020C)含有两个SNP位点。对SpCTLD基因在拟穴青蟹幼体不同时期和组织中的表达模式分析发现,SpCTLD在幼体的各个发育时期均有表达,其中在溞状幼体Ⅴ期表达量最高,仔蟹Ⅰ期次之,仔蟹Ⅱ期最低。对SpCTLD的组织分布分析表明,SpCTLD在鳃中表达量最高,其次为射精管,在血淋巴、肝胰腺等其他免疫组织中也有表达,其中在鳃和射精管的表达量远高于在其他组织中的表达量。副溶血弧菌胁迫实验表明,活菌组的肝胰腺、血淋巴、鳃中的SpCTLD表达量发生显著上调,且都在12 h达到最高。根据研究结果,推测SpCTLD是一种含CTLD结构域的新基因,它可能参与了拟穴青蟹抗细菌反应。该基因的发现丰富了拟穴青蟹C型凝集素相关基因的研究,有利于丰富甲壳动物先天免疫机制的研究。     

拟穴青蟹vasa基因cDNA的特征分析与性腺特异表达

vasa蛋白属于DEAD家族蛋白,是一种RNA解旋酶,在生殖细胞的分化中具有重要作用。本研究从拟穴青蟹卵巢中克隆得到vasa基因cDNA全长(将其命名为Sp-vasa),Sp-vasa序列长度为2 944 bp,其中开放阅读框(ORF)长度为1 899 bp,编码632个氨基酸,具有DEAD-box家族蛋白的7个高度保守的结构域。半定量RT-PCR结果显示,Sp-vasa只在卵巢和精巢中特异表达,在其它组织则未检测到表达。由此可见,vasa属于拟穴青蟹性腺特异表达基因。因此,Sp-vasa基因可有望作为有效的分子指标研究拟穴青蟹原始生殖细胞的起源、迁移以及生殖腺的发生。     

拟赤梢鱼卵巢早期发育与sox3基因cDNA克隆及表达分析

为初步阐明拟赤梢鱼(Pseudaspius leptocephalus)卵巢发育特征及sox3 (sry related high mobility group box 3)基因在其卵巢发育过程中的作用,本研究通过组织切片观察了拟赤梢鱼卵巢早期发育过程,利用RACE技术克隆了该鱼sox3基因cDNA全长序列,并进行生物信息学分析;利用实时荧光定量PCR技术分析了sox3基因在拟赤梢鱼不同组织及性腺不同发育时期的表达模式。结果显示,拟赤梢鱼卵巢在孵化后45 d分化形成,160 d时由Ⅰ期进入Ⅱ期,孵化后360 d,卵巢仍处于Ⅱ期。拟赤梢鱼sox3基因cDNA全长为1 800 bp (GenBank登录号：MT952206),编码299 个氨基酸,存在保守的HMG (histidine, methionine, glycine-rich)结构域。氨基酸序列比对和系统进化树分析结果显示,拟赤梢鱼SOX3蛋白与斑马鱼(Danio rerio)和翘嘴鲌(Culter alburnus)亲缘关系最近。此外,sox3基因在拟赤梢鱼卵巢中表达量最高,其次是脑和眼睛,在精巢和其他组织中微量表达;在性腺分化过程中,sox3基因在卵巢中表达量显著高于未分化性腺和精巢,在卵巢发育阶段表达量不断升高,而在精巢中持续低水平表达。综上,本研究推测sox3基因主要参与拟赤梢鱼卵巢的分化和发育。     

拟穴青蟹14-3-3基因全长cDNA的克隆及组织表达分析

采用RT-PCR及RACE技术,从拟穴青蟹眼柄组织中克隆获得14-3-3基因cDNA全序列.序列分析结果表明:拟穴青蟹14-3-3基因全长1112bp,开放阅读框长744 bp,编码由247个氨基酸组成的蛋白,分子量为28.086 ku,等电点为4.675.与其他物种14-3-3基因氨基酸序列进行同源性比较分析显示,拟穴青蟹14-3-3基因与斑节对虾14-3-3基因同源性最高(95％),依次为墨吉对虾(93％)、苜蓿切叶蜂(92％).聚类分析表明,拟穴青蟹14-3-3基因氨基酸序列与斑节对虾、墨吉对虾紧密聚为一支.经荧光定量检测,拟穴青蟹14-3-3基因在肝胰腺和肌肉中的表达量较高,其次为鳃、眼柄、心脏和肠,在胃中表达最少.盐度骤变实验结果表明:盐度胁迫24 h后,盐度的下降(5)或者上升(15、20、25、30)都引起了14-3-3基因在鳃中的表达量极显著上升(P＜0.01),盐度变化的幅度越大,14-3-3基因的表达量越多.实验结果为进一步深入研究14-3-3基因的功能及调控机理奠定基础.     

拟穴青蟹泛素基因的克隆及其在性腺发育过程中的表达

在实验室所构建的拟穴青蟹(Scylla paramamosain)EST文库基础上筛选出泛素基因(Ubquitin,Sp-Ub)片段,利用RACE技术克隆其全长cDNA序列,并对其结构进行分析;利用实时定量PCR技术检测该基因在雌蟹各组织及性腺不同发育阶段中的表达情况。结果显示,Sp-Ub基因全长555 bp,编码154个氨基酸,其第1~76个氨基酸为高度保守的泛素结构域,第101~147的氨基酸残基为典型的核糖体蛋白S27a的保守区域;预测的泛素结构域二级结构由5个延伸链,1个α-螺旋及其连接的无规卷曲构成,Sp Ub三维结构由1个α-螺旋以及5个β片层。多重比对表明不同物种的泛素结构域和核糖体蛋白S27a结构域在进化过程中高度保守。定量PCR结果显示,Sp-Ub在鳃中的表达水平最高,卵巢次之,各组织间的表达无显著性差异,说明Sp-Ub基因在各组织中的表达恒定,且具有普遍作用;在卵巢发育过程中,Sp-Ub在O5期的表达水平最高,O1、O4期次之,O2期表达量最低且与O5期具有显著差异(P<0.05);在精巢发育过程中,Sp-Ub在T2期的表达量最高,其次为T1期,T3期表达最低且与T2期具有显著差异(P<0.05)。本研究结果说明了Sp-Ub对拟穴青蟹生殖细胞的生长和发育可能具有重要作用。本研究将为甲壳动物性腺发育调控的分子机制奠定基础。     

Characteristics of the marine environment and algal blooms in Gamak Bay

This study was conducted to gain insight into the characteristics of algal blooms in relation to the marine environment of Gamak Bay. From the first known occurrence of algal blooms in 1984 until 2006, 23 causal species have been identified, the most common ones being Prorocentrum sp., Cochlodinium polykrikoides, Chaetoceros sp., Skeletonema costatum, and Heterosigma akashiwo. A principal component analysis indicated that blooms of these species develop under different conditions in terms of water temperature, salinity, precipitation, and insolation. Field data showed Cochlodinium polykrikoides to be favored by high temperatures and to be euryhaline, whereas Skeletonema costatum appeared to be eurythermal and euryhaline. Prorocentrum sp. and Chaetoceros sp. appeared to be stenothermal and stenohaline. Finally, Heterosigma akashiwo appeared at the lowest temperature and highest salinity of the five species and was classified here as stenothermal and stenohaline.     

Antifreeze proteins in the urine of marine fish

Several species of marine teleosts have evolved blood plasma antifreeze polypeptides which enable them to survive in ice-laden seawater. Four distinct antifreeze protein classes differing in carbohydrate content, amino acid composition, protein sequence and secondary structure are currently known. Although all of these antifreezes are relatively small (2.6–33 kd) it was generally thought that they were excluded from the urine by a variety of glomerular mechanisms. In the present study antifreeze polypeptides were found in the bladder urine of winter flounder (Pseudopleuronectes americanus), sea raven (Hemitripterus americanus), ocean pout (Macrozoarces americanus) and Atlantic cod (Gadus morhua). Since the plasma of each of these fish contains a different antifreeze class it would appear that all four classes of antifreeze can enter the urine. The major antifreeze components in the urine of winter flounder were found to be identical to the major plasma components in terms of high performance liquid chromatography retention times and amino acid composition. It is concluded that plasma antifreeze peptides need not be chemically modified before they can enter the urine.     

Delivery of HUFA, probionts and biomedicine through bioencapsulated Artemia as a means to enhance the growth and survival and reduce the pathogenesity in shrimp Penaeus monodon postlarvae

One of the major problems in the shrimp culture industry is the difficulty in producing high-quality shrimp larvae. In larviculture, quality feeds containing a high content of highly unsaturated fatty acids (HUFA) and ingredients that stimulate stress and disease resistance are essential to produce healthy shrimp larvae. In the present study, Penaeus monodon postlarvae (PL15) were fed for 25 days on an unenriched Artemia diet (control; A) or on a diet of Artemia enriched with either HUFA-rich liver oil of the trash fish Odonus niger (B), probionts [Lactobacillus acidophilus (C1) or yeast-Saccharomyces cerevisiae (C2)] or biomedicinal herbal products (D) that have anti-stress, growth-promoting and anti-microbial characteristics. P. monodon postlarvae fed unenriched Artemia exhibited the lowest weight gain (227.9 ± 8.30 mg) and specific growth rate (9.95 ± 0.05%), while those fed the HUFA-enriched Artemia (B) exhibited the highest weight gain and specific growth rate (362.34 ± 12.56 mg and 11.77 ± 0.08%, respectively). At the end of the 25-day rearing experiment, the shrimp postlarvae (PL40) were subjected to a salinity stress study. At both low and high (0 and 50‰) salinities, the group fed the control diet (A) experienced the highest cumulative mortality indices (CMI) 935.7 ± 2.1 and 1270.7 ± 3.1, respectively. Those fed diet D showed the lowest stress-induced mortality, and CMI were reduced by 31.1 and 32.3% under conditions of low and high salinity stress, respectively. A 10-day disease challenge test was conducted with the P. monodon postlarvae (PL40–PL50) by inoculating the shrimp with the pathogen Vibrio harveyi at the rate of 10⁵–10⁷ CFU/ml in all rearing tanks. P. monodon postlarvae fed probiont-encapsulated Artemia diets (C1 and C2) exhibited the highest survival (94.3 and 82.3%, respectively) and lowest pathogen load (V. harveyi) in hepatopancreas (5.2 × 10² ± 9.0 × 10 and 4.6 × 10² ± 9.0 × 10 CFU g⁻¹, respectively) and muscle (2.0 × 10² ± 6 × 10 and 1.7 × 10² ± 8.6 × 10 CFU g⁻¹, respectively) tissues. The shrimp that were fed the unenriched Artemia (Control; A) showed the lowest survival (26.33%) and highest bacterial load in the hepatopancreas (1.0 × 10⁵ ± 5 × 10³ CFU g⁻¹) and muscle (3.6 × 10⁴ ± 6 × 10² CFU g⁻¹). The shrimp fed the herbal product (D)-enriched Artemia also exhibited enhanced survival and reduced V. harveyi load in the tissues tested compared to the control diet (A) group. The results are discussed in terms of developing a quality larval feed to produce healthy shrimp larvae.     

基于线粒体COⅠ和Cytb基因序列的北太平洋柔鱼种群遗传结构研究

为准确掌握柔鱼的种群遗传结构,拟通过线粒体DNA的COI和Cytb基因序列分析方法对柔鱼不同产卵季节群体的遗传多样性和遗传结构进行研究。经PCR扩增与测序分别获得600 bp COI与481 bp Cytb基因序列。基于COI基因序列分析得到的单倍型数、单倍型多样性指数、核苷酸多样性指数及平均核苷酸差异数分别为24、(0.729 ±0.033)、(0.005 70 ± 0.003 25)和3.421。基于Cytb基因序列分析得到的单倍型数、单倍型多样性指数、核苷酸多样性指数及平均核苷酸差异数分别为28、(0.852 ± 0.016)、(0.006 45 ± 0.003 73)和3.101。分析认为, 北太平洋柔鱼2个产卵季节群体均具有较高的单倍型多样性指数和较低的核苷酸多样性指数。单倍型邻接树、两两群体间的F_st值以及AMOVA分析结果均表明, 北太平洋柔鱼2个产卵季节群体间的遗传差异不显著, 不存在显著的群体遗传结构。初步认为, 该海域因缺乏地理上的障碍, 加之北太平洋海流的作用以及柔鱼个体较强的游泳能力, 使得群体之间具有较强的基因流。     

Bioaugmentation in the growth and water quality of livebearing ornamental fishes

Bacillus subtilis isolated from the intestine of Cirrhinus mrigala (Hamilton) was incorporated into the rearing water of Poecilia reticulata (Peters), Poecilia sphenops (Valenciennes), Xiphophorus helleri (Heckel) and Xiphophorus maculatus (Gunther) at four different concentrations (5 × 10⁸ cells ml⁻¹, 5 × 10⁷ cells ml⁻¹, 5 × 10⁶ cells ml⁻¹ and 5 × 10⁵ cells ml⁻¹) and its effect on fish growth performance and survival, water quality parameters and bacterial population of water were assessed. The results showed that the addition of bacterial cells in the rearing water resulted in greater survival and a faster growth rate and, hence, greater length and weight increments of the livebearers. The use of a bioaugmentor in the rearing water of the livebearing fishes resulted in significantly lower (P < 0.05) concentrations of dissolved organic matter and total ammonium nitrogen. The counts of motile aeromonads and total coliforms recorded in the water of bioaugmented tanks were also lower than that in the control tank. Bioaugmentation between 10⁶ and 10⁸ cells ml⁻¹ in the rearing water is sufficient in establishing a bioaugmentor and the use of a higher concentration of bacterial cells did not always lead to significantly better results.     

Henneguya pseudorhinogobii n. sp. (Myxozoa: Myxosporea) parasitizing the gills of the freshwater goby Rhinogobius sp. OR from the Nagara River and redescription of Henneguyarhinogobii

Two types of infection with myxosporean parasites, which were different in cyst size, were found from the gill of Rhinogobius sp. OR collected from the Nagara River, Gifu Prefecture, Japan. A myxosporean forming large-type cysts in the gill filament was morphologically identified as Henneguya rhinogobii. Another myxosporean forming small-type cysts was found to be parasitic in the gill lamella. Average spore sizes of the latter myxosporean were 15.8 (range 14.2–17.8) μm in length, 5.3 (4.7–5.8) μm in width, 6.5 (5.9–7.6) μm in polar capsule length and 34.9 (25.3–42.9) μm in caudal appendage length, which were almost identical to those of H. rhinogobii. However, the two were distinguishable by the location in the gill (intrafilamental or intralamellar) and by the difference in the sequence of SSU rDNA (about 96% similarity). We propose the myxosporean forming intralamellar small-type cysts as Henneguya pseudorhinogobii n. sp. and redescribe H. rhinogobii by morphological and molecular studies.     

东太平洋公海茎柔鱼种群遗传结构初步研究

根据2009年7月到10月我国大型鱿钓渔船在东太平洋(81.9°～94.9°W,8.9°N～11.3°S)秘鲁和哥斯达黎加外海作业期间采集的样本,利用线粒体DNA细胞色素b基因的724 bp部分序列,分析了采自秘鲁7个采样点和哥斯达黎加3个采样点的155个个体的序列多样性与种群遗传结构.结果显示,724 bp片段中发现了16个变异位点,155个个体出现43个单倍型.序列多样性分析结果揭示,155个个体的平均单倍型多样性指数为0.873,核苷酸多样性指数为0.003 69.群体间共享6个单倍型,秘鲁外海茎柔鱼群体享有最多特有单倍型(20个).分子方差分析揭示,82.70％的遗传变异性出现在种群内；群体间的FST分析揭示部分秘鲁群体与哥斯达黎加群体,部分秘鲁群体间存在着显著的遗传分化；而哥斯达黎加群体内部不存在显著的遗传分化.     

Influence of the antibacterial herbs, Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia on the survival, growth and bacterial load of Penaeus monodon post larvae

The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 10³ to 3.76 × 10⁵ cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 10⁵ cfu/g). This revised version was published online in August 2006 with corrections to the Cover Date.     

中国明对虾Dscam基因的克隆及其在免疫致敏(类免疫)诱导反应中的表达分析

为了研究对虾免疫致敏过程中Dscam基因的表达规律,实验采用同源克隆和RACE技术获得了中国明对虾Dscam基因c DNA全长序列,并对该序列进行生物信息学分析。结果显示,中国明对虾Dscam基因的c DNA全长为6 624 bp,其中包括171 bp的5′端非编码区,459 bp的3′端非编码区,开放阅读框的长度为5 994 bp,编码1 996个氨基酸。推测该基因编码的蛋白含有一个信号肽、10个Ig结构域、6个FNIII功能区、1个胞质尾区和1个跨膜结构域。同源性分析及系统进化分析表明,Dscam基因与节肢动物的Dscam基因首先聚为一类,且与凡纳滨对虾的同源性最高,为92.4%。连续投喂6 d热灭活白斑综合征病毒(white spot syndrome virus,WSSV)饵料来诱导免疫致敏反应,在0、6和12 d及二次感染后的12、24、48、72和168 h分别取样,用RT-PCR的方法检测中国明对虾Dscam的相对表达量。结果显示,诱导感染组Dscam基因在第12天开始上调,且与阴性对照组和未诱导感染组差异显著;二次感染后24 h,Dscam基因的相对表达量达到最大值,与阴性对照组和未诱导感染组差异显著;48 h后基因表达量开始下降,但表达量仍高于阴性对照组和未诱导感染组。实验表明,中国明对虾存在Dscam基因,并在免疫致敏过程中发挥重要作用。     

抑食金球藻对翡翠贻贝抗氧化酶系统的影响

本研究以单种抑食金球藻及其与亚心形四爿藻的混合藻为实验组,以亚心形四爿藻为对照,探究抑食金球藻对翡翠贻贝超氧化物歧化酶(SOD)活性、丙二醛(MDA)和谷胱甘肽(GSH)含量的影响。结果显示,抑食金球藻显著影响翡翠贻贝的SOD活性、MDA和GSH含量,各实验组均表现出诱导升高与抑制降低交替出现的规律。单种高、中浓度的抑食金球藻在短期(3 h)内即可对翡翠贻贝的SOD活性产生影响,混合藻组中的SOD活性上升较慢,说明亚心形四爿藻可以延滞氧化还原系统的反应时间。各实验组翡翠贻贝GSH含量在2 d内均显著低于对照组,且混合藻组与单种抑食金球藻组相差不大,提示亚心形四爿藻对抗氧化还原损伤并未起到明显的缓解作用。