氨氮胁迫对拟穴青蟹组织器官中SOD及GPX活性的影响

采用实验生态学的方法,探讨海水中分别添加氨氮（以氯化铵作为氨氮源）0（对照组,C0组）、10（C10组）、20（C20组）、30（C30组）、40 mg/dm3（C40组）,胁迫24、48、72、96 h对拟穴青蟹（Scylla paramamosain）各组织器官中SOD、GPX活性的影响.结果表明,拟穴青蟹鳃中SOD活性,除C40组外,其余各组在胁迫24、48 h随氨氮含量升高而升高,胁迫72、96 h则随氨氮含量升高而下降（p〈0.05）,C40组的则随胁迫时间延长而一直呈下降趋势;各组拟穴青蟹鳃、肝胰腺和肌肉的SOD活性变化趋势相同,鳃和肌肉SOD活性最高均出现在胁迫48 h,肝胰腺SOD活性最高则在胁迫72 h.各组拟穴青蟹鳃GPX活性在胁迫24、48和72 h随氨氮含量升高而下降,胁迫96 h随氨氮含量升高而增大;各组拟穴青蟹肝胰腺和肌肉GPX活性变化与肝胰腺SOD活性变化趋势相似,胁迫48 h,C40组拟穴青蟹肝胰腺GPX活性最高.氨氮胁迫显著影响拟穴青蟹生理效应.     

荧光分光光度法测定海洋生物中的谷胱甘肽

对应用荧光分光光度法测定海洋生物中还原型谷胱甘肽（GSH）含量的方法进行了研究，并测定了分属于鱼、虾、贝、藻的10种海洋生物中谷胱甘肽的含量。利用邻苯二甲醛与GSH反应构成的荧光体系，在激发波长为365nm，发射波长为425nm的条件下，方法的回收率为99．22％-99．69％，变异系数为2．16％。应用此方法测得10种海洋生物中谷胱甘肽的含量为：红笛鲷（Lutjanus sanguineus）0．399mg／g，银鲳（Pampus argenteus）0．352mg／g，大海鲢（Megalops cyrinoides）0．561mg/g，尖紫蛤（Sanguinolaria acuta）0．289mg/g，菲律宾蛤仔（Ruditapes philippinarun）0．287mg／g，墨吉对虾（Penaeus merguiensis）0．892mg／g，凡纳滨对虾（Litopenaeus vannamei）1．434mg／g，囊藻（Colpomenia sinuose）0．221mg／g，石莼（Ulva lactucal）0．727mg／g，马尾藻（Sargassum muticum）0．137mg／g。     

同型半胱氨酸水平与脑梗死患者MTHFR基因C677T多态性之间的相关性研究

目的 探讨研究同型半胱氨酸（homocysteine,Hcy）水平与脑梗死患者亚甲基四氢叶酸还原酶（MTHFR）基因C677T的多态性之间的相关性。方法 选择2012年2月~2015年8月期间在笔者医院住院就诊的450例脑梗死患者作为研究组,其中糖尿病患者181例,非糖尿病患者269例,另外选择285例笔者医院门诊部健康的体检人员作为对照组,分别采用焦磷酸测序的方法检测分析MTHFR基因C677T的多态性,并分析各基因型与Hcy水平之间的相关性。结果 脑梗死组与健康对照组的MTHFR基因型分布之间的差异具有统计学意义（P<0.05）,脑梗死组T基因的频率明显比对照组高,差异有统计学意义（χ²=13.67,P=0.00）。脑梗死组患者的Hcy浓度明显高于健康对照组,差异有统计学意义（t=12.71,P=0.00）。脑梗死组患者各MTHFR基因型患者的Hcy水平之间比较,差异有统计学意义（F=17.68,P=0.00）。非糖尿病脑梗死患者的Hcy水平明显高于糖尿病脑梗死患者,差异有统计学意义（t=2.97,P=0.00）,非糖尿病组TT型的Hcy浓度明显高于糖尿病组,CC型的Hcy浓度明显低于糖尿病组,差异均有统计学意义（t=5.67,2.18;P=0.00,0.03）。糖尿病性脑梗死患者和非糖尿病脑梗死患者中,MTHFR基因为TT型的Hcy水平明显高于CC型和CT型,差异均有统计学意义（P<0.05）,而CC型和CT型的Hcy水平之间比较差异无统计学意义（P>0.05）。结论 脑梗死患者比健康人的MTHFR基因C677T的T等位基因频率高,且脑梗死患者的MTHFR基因C677T为TT基因型时血清中Hcy的水平更高,由此判断TT基因型可能是脑梗死发生的危险因素。     

南极衣藻（Chlamydomonas sp.ICE-L）谷胱甘肽还原酶基因的原核表达及其条件优化

采用RT-PCR技术克隆南极衣藻GR基因ORF全长cDNA,然后经酶切、连接等步骤构建其原核表达载体;并对其表达的诱导时间、IPTG浓度、温度进行了优化,以期获得较大量的酶蛋白。结果表明,将构建的原核表达载体pET-GR导入大肠杆菌BL21,可以高效表达融合蛋白;且表达的蛋白均以包涵体的形式存在;经SDS-PAGE电泳...     

曼氏无针乌贼(Sepiella maindroni)sigma-型谷胱甘肽硫转移酶基因的克隆及重组表达

采用EST结合RACE技术进行了曼氏无针乌贼(Sepiella maindroni)sigma-型GST(SmGST)基因的克隆。结果表明,该基因的cDNA全长为838bp,其中5′非编码区为73bp,3′非编码区为150bp,开放阅读框为615bp,编码的蛋白含有204个氨基酸。该基因的氨基酸序列中包含1个典型的GST-N结构域和一个GST-C结构域,与栉孔扇贝和长牡蛎的sigma-型GST的相似度分别为40.3%和39.3%。将该基因的编码区重组到pET-21(a+)载体后在大肠杆菌中得到诱导表达。重组SmGST的GST活力为(12.22±0.92)U/mg蛋白。     

大叶藻微粒体GST基因对温度胁迫响应的分子机制

为了分析鳗草（Zostera marina）中微粒体谷胱甘肽S-转移酶在不同温度下的基因表达规律以及响应机制,本文通过在大肠杆菌中表达ZmGST,纯化重组蛋白以及热稳定性分析,以此为进一步阐述Z. marina的种群退化机制并提供理论依据。总之,鳗草中的微粒体GST的热稳定性和其对温度变化的响应决定了其对温度的耐受范围,并进而影响其恢复力。     

Comparative study on in vitro transformation of paralytic shellfish poisoning (PSP) toxins in different shellfish tissues

Dissected tissues of three shellfish species,the Chinese scallop,Chlamys farreri,Manila clam,Ruditapes philippinarum,and Razor shell,Solen strictu were evaluated for in vitro transformation of paralytic shellfish poisoning(PSP) toxins. Tissue homogenates were incubated with extraction from toxic algae Alexandrium minutum to determine toxin conversion. The effects of heating and addition of a natural reductant(glutathione) on toxin conversion were also assessed. The toxin profile was investigated through high performance liquid chromatography with fluorescence detection(HPLC-FLD) . The evident variations in the toxin content were observed only in Chinese scallop viscera homogenates. The concentration of GTX4 was reduced by 45%(approximately 0.8 μmol/dm 3 ) and 25%(approximately 1 μmol/dm 3 ) for GTX1,while GTX2 and GTX3 increased by six times(approximately 1 μmol/dm 3 ) and 3 times(approximately 0.3 μmol/dm 3 ) respectively. Simultaneously,the total toxicity decreased by 38% during the 48 h incubation period,the final toxicity was 20.4 nmol STXeq/g. Furthermore,heated Chinese scallop viscera homogenates samples were compared with non-heated samples. The concentration of the GTX4 and GTX1 was clearly 28%(approximately 0.53 μmol/dm 3 ) and 17%(approximately 0.69 μmol/dm 3 ) higher in heated samples,GTX2 and GTX3 were four times(0.66 μmol/dm 3 ) and two times(0.187 μmol/dm 3 ) lower respectively. GSH(+) Chinese scallop viscera homogenates samples were compared with GSH(-) samples,the concentration in the GTX4 and GTX1 was 9%(approximately 0.12 μmol/dm 3 ) and 11%(approximately 0.36 μmol/dm 3 ) lower respectively,GTX2 and GTX3 was 17%(approximately 0.14 μmol/dm 3 ) and 19%(approximately 0.006 μmol/dm 3 ) higher respectively. In contrast,there was a little change in the concentration of PSP toxins of Manila clam and Razor shell tissue homogenates. These observations on three shellfish tissues confirmed that there were species-specific differences in PSP toxins transformation. PSP toxins transformation was more pronounced in viscera tissue than in muscle tissue. PSP toxins was possibly interfered by some carbamoylase enzyme,and the activity in Chinese scallop viscera tissue is more remarkable than in the other two species.     

海洋生态系统中碘的分布及形态转化

根据国内外文献总结了海洋生态系统中主要碘形态分布及其相互转化的研究进展。溶解无机态碘的两种主要形式(碘酸根IO3-及碘离子I-)之间随着海水物理化学性质的改变而发生的形态转换是海洋生态学家相对最为关注的热点问题。研究者们对其反应机理开展了各自的研究,认为其中IO3-的还原机理包括:浮游植物生长调控、细菌活动、硫化物及光化学反应;I-的氧化包括光化学途径及细菌活动等。本文还就海洋生态系统中有关碘的深入研究提出了展望。     

Influence of temperature on glutathione level and glutathione-related enzyme activities of Antarctic ice microalgae Chlamydomonas sp.ICE-L

GSH system plays a role in the control of the redox balance state,anti-oxidation and protecting life from injury of ROS(reactive oxygen species).In present paper,the possible GSH system of Chlamydomonas sp.ICE-L has been investigated by evaluating GSH and GSH-related enzymatic responses at different temperatures using spectrophotometer methods.The results showed that the GSH system is correlated positively to low temperature,and other factors but GR are correlated negatively to high temperature.So GSH and GSH-related enzymes play an important role in the adaptation of Antarctic ice microalgae to low temperature.     

三角褐指藻和亚心形扁藻对太平洋纺锤水蚤繁殖与生化指标的影响

采用实验生态的方法,探讨三角褐指藻(Phaeodactylum tricornutum)、亚心形扁藻(Platymonassubcordiformis)对太平洋纺锤水蚤(Acartia pacifica)繁殖及其生化指标的影响.实验结果表明,三角褐指藻对太平洋纺锤水蚤产卵量和卵的孵化率均具有抑制作用,随着投喂时间的增加,太平洋纺锤水蚤的产卵量由15.02±3.15 ind/d下降到3.25±3.15 ind/d(p<0.05),其卵的孵化率由22.88%±2.49%下降到14.84%±1.20%(p<0.05).而投喂亚心形扁藻的太平洋纺锤水蚤其产卵量和卵的孵化率与对照组无显著差异(p>0.05).投喂三角褐指藻后,太平洋纺锤水蚤的超氧化物歧化酶(SOD)活力相对于投喂亚心形扁藻的增加了20.94±0.04μg/mg,其谷胱甘肽过氧化物酶(GPX)活力增加了15.812±1.240 U/mg.这表明相对于亚心形扁藻,三角褐指藻对太平洋纺锤水蚤的抗氧化性酶具有诱导作用.