升温与聚苯乙烯微塑料复合暴露对长牡蛎血细胞功能、免疫基因表达和能量代谢的影响

为阐明全球气候变暖和微塑料复合胁迫对长牡蛎(Crassostrea gigas)免疫应答、氧化应激和能量代谢的影响,本研究采用3个微塑料(microplastics, MPs)水平[无微塑料、小粒径聚苯乙烯微塑料(SPS-MPs,6μm)和大粒径聚苯乙烯微塑料(LPS-MPs,50～60μm)]和2个温度水平(20℃和25℃)对长牡蛎进行了为期21 d的单一和复合暴露,检测分析了各组长牡蛎血细胞功能[吞噬活性、活性氧(reactive oxygen species,ROS)含量]、糖原含量以及免疫相关基因表达的变化。研究结果表明,SPS-MPs暴露能增加长牡蛎血淋巴细胞中ROS含量,降低血细胞吞噬活性,揭示SPS-MPs毒性作用更强。升温与微塑料的协同作用增加了长牡蛎消化腺组织中的糖原含量。实时荧光定量PCR结果显示,升温与SPS-MPs复合暴露组长牡蛎消化腺组织通过上调热休克蛋白90 (heat shock protein90, HSP90)、核因子κB抑制蛋白(inhibitor of NF-κB, IκB)和p53基因表达量进行免疫应答;升温与微塑料的拮抗作用增加了鳃组织p53基...     

浅谈防城港市农田福寿螺发生趋势及防治对策

阐明了防城港市农田福寿螺发生趋势,并指出福寿螺发生程度逐年加重的四大原因,提出了以农业防治为基础。生物控制、人工防除和化学防治相结合的综合防治策略。     

太平洋牡蛎三倍体诱导及苗种培育技术研究

本文报道了采用细胞松弛素B（CB）诱导太平洋牡蛎三倍体的研究结果。研究结果表明，CB浓度为0．25mg／L，处理时间约20分钟，诱导三倍体的倍化率可达75％，至D型幼虫的孵化率为40－50％。1992－1996年其培育出三倍体贝苗1846．4万枚。     

硒化牡蛎多糖制备及其抗氧化和抗肿瘤活性研究

亚硒酸钠和牡蛎多糖合成硒化牡蛎多糖(SeOPS),纤维素DE-52分离纯化,红外光谱结构表征。DPPH·,ABTS+和·OH清除作用及铁还原力测定SeOPS抗氧化活性。MTT法检测SeOPS抑制肿瘤细胞增殖能力,采用流式细胞术检测SeOPS对细胞周期和凋亡的影响。结果表明,SeOPS具有清除DPPH·和ABTS+作用,IC50值分别为7.102 mg/m L和2.243 mg/m L。·OH及铁还原力清除效果与牡蛎多糖(OPS)无显著差别。SeOPS阻滞人宫颈癌(Hela)细胞G0/G1期及肝癌(HepG2) S期的发育,诱导细胞凋亡,从而抑制肿瘤细胞的增殖。     

2003-2012年秘鲁外海茎柔鱼资源丰度年间变化分析

茎柔鱼是世界上重要的经济头足类,也是我国大陆鱿钓渔业最重要的捕捞对象之一。根据中国大陆鱿钓船2003-2004年、2006-2012年9年的渔业生产统计数据和卫星遥感获得的海洋环境数据,利用广义线性模型(generalized linear model,GLM)和广义加性模型(generalized additive model,GAM)对秘鲁外海茎柔鱼的资源丰度进行CPUE标准化,分析秘鲁外海茎柔鱼资源丰度年际变化。经显著性检验,得到最终选择加入模型的自变量有年、月、纬度、经度、叶绿素浓度、年与经度交互项、年与纬度交互项、月与经度交互项、月与纬度交互项共9个自变量。GAM结果表明,模型自变量对因变量的决定系数高达42.3%。标准化后CPUE与名义CPUE变化趋势相同,年平均值略低于名义CPUE,2003-2012年秘鲁外海茎柔鱼资源丰度年间变化较大,资源丰度最高的年份为2004年,GLM标准化后的平均CPUE为7.94 t/d;资源丰度最低的年份为2007年,GLM标准化后的平均CPUE为3.28 t/d。     

Electrophysiological Evaluation of Pacific Oyster (Crassostrea gigas) Sensitivity to Saxitoxin and Tetrodotoxin

Pacific oysters (Crassostrea gigas) may bio-accumulate high levels of paralytic shellfish toxins (PST) during harmful algal blooms of the genus Alexandrium. These blooms regularly occur in coastal waters, affecting oyster health and marketability. The aim of our study was to analyse the PST-sensitivity of nerves of Pacific oysters in relation with toxin bio-accumulation. The results show that C. gigas nerves have micromolar range of saxitoxin (STX) sensitivity, thus providing intermediate STX sensitivity compared to other bivalve species. However, theses nerves were much less sensitive to tetrodotoxin. The STX-sensitivity of compound nerve action potential (CNAP) recorded from oysters experimentally fed with Alexandrium minutum (toxic-alga-exposed oysters), or Tisochrysis lutea, a non-toxic microalga (control oysters), revealed that oysters could be separated into STX-resistant and STX-sensitive categories, regardless of the diet. Moreover, the percentage of toxin-sensitive nerves was lower, and the STX concentration necessary to inhibit 50% of CNAP higher, in recently toxic-alga-exposed oysters than in control bivalves. However, no obvious correlation was observed between nerve sensitivity to STX and the STX content in oyster digestive glands. None of the nerves isolated from wild and farmed oysters was detected to be sensitive to tetrodotoxin. In conclusion, this study highlights the good potential of cerebrovisceral nerves of Pacific oysters for electrophysiological and pharmacological studies. In addition, this study shows, for the first time, that C. gigas nerves have micromolar range of STX sensitivity. The STX sensitivity decreases, at least temporary, upon recent oyster exposure to dinoflagellates producing PST under natural, but not experimental environment.     

Taurine transporter from the giant Pacific oyster <Emphasis Type="Italic">Crassostrea gigas</Emphasis>: function and expression in response to hyper- and hypo-osmotic stress

ABSTRACT:   Taurine is the primary osmolyte in marine molluscs, whose cellular osmo-conforming process is vital for environmental adaptation because of a lack of osmotic homeostasis. Here, cDNA cloning and expression, and functional analyses of taurine transporter (TAUT) from the giant Pacific oyster are reported on. The deduced amino-acid sequence of oyster TAUT (oyTAUT) showed 47–51% identity to those of vertebrate TAUT, whereas identity among the vertebrates is 78–95%. Functional analysis of oyTAUT expressed in Xenopus oocytes revealed that oyTAUT has a lower affinity and specificity for taurine and a requirement for higher NaCl concentration, compared with vertebrate TAUT. Taken together with similar functional properties of TAUT from mussel, indicated by our previous study, it is possible that these functional features reflect the internal environment of the molluscs (i.e. higher taurine and NaCl concentrations). Oyster taurine transporter mRNA expression was induced by not only hyper-osmotic stress, similar to other TAUT, but also hypo-osmotic stress. It is speculated that the expression in response to hypo-osmotic stress was induced by a substantial decrease in tissue taurine content following the decrease in the internal osmolality.     

茶麸对福寿螺室内毒杀试验

[目的]为田间茶麸防治福寿螺提供依据。[方法]采用不同用量茶麸,在不同施用方法和不同温度下对福寿螺进行毒杀作用试验,探求最佳的施用方法、最经济的施用量和最好的毒杀效果。[结果]比较理想的福寿螺毒杀方法是:在气温比较高条件下(30℃以上),用开水浸泡茶麸,以2000倍的茶麸浸出液浸泡毒杀福寿螺。[结论]茶麸浸出液对福寿螺有很好的毒杀效果。     

小蜂对杨圆蚧的趋性及杨圆蚧挥发物分析

采用四臂式嗅觉仪测定了长棒四节蚜小蜂和黄胸扑虱蚜小蜂对杨圆蚧1龄固定若虫的虫体、介壳、虫体与介壳复合体的趋性。结果表明，介壳和虫体与介壳复合体对两种小蜂具有较强的吸引力。两种小蜂对气味源的剂量都比较敏感。采用敢相色谱－质谱联机分析方法，分析了杨圆蚧1龄固定若虫虫体及介壳所释放的挥发性物质的成分和各组分所占比例，分析表明，虫体和介壳中释放出的挥发性物质均含有9个组分，但这9个组分在虫体和介壳挥发物中的比例略有变异。     

6_二甲基氨基嘌呤诱导太平洋牡蛎三倍体_抑制受精卵第一极体释放

于 1996～ 1997年 ,用 6-二甲基氨基嘌呤 ( 6-DMAP)抑制受精卵第一极体的释放 ,诱导太平洋牡蛎产生三倍体。选用L16( 45)设计 ,进行三因素四水平的正交试验 :6-DMAP浓度 ,设15 0、30 0、45 0和 60 0μmol/L ;诱导时机 (即精卵混合后的时间 ) ,设 10、15、2 0和 2 5min ;诱导持续时间 ,设 10、15、2 0和 2 5min。试验平行重复二次。结果为最高三倍体诱导率为 ( 71.3± 1.2 ) % ,该实验组胚胎孵化率为 ( 5 5 .5± 3.1) % ,D形幼虫畸形率为 ( 10 .7± 1.6) %。根据直观分析结果 ,得出诱导太平洋牡蛎三倍体各因素的最优水平组合 :水温 2 5～ 2 5 .5℃ ,精卵混合 10min时 ,将受精卵浸泡在含 6-DMAP 60 0μmol/L的海水中 15min ;决定三倍体产生的三因素的主次顺序 :6-DMAP浓度→诱导时机→诱导持续时间。 6-DMAP浓度对三倍体诱导率影响显著 ,但诱导时机和诱导持续时间不显著。