香溪河水系大型底栖动物的群落结构及生态位

2005年7月～2006年6月对三峡水库湖北库区最大支流香溪河的大型底栖动物进行定量采集,并对所得数据进行了数理统计分析及生态位分析.结果表明,香溪河水系大型底栖动物物种丰富度在不同季节、不同支流间差异均显著;密度在各季节间差异显著.四节蜉、高翔蜉、锯形蜉、朝大蚊和扁蜉生态位较宽;Tetropina sp.、短尾石蝇、黑蝇生态位较窄.四节蜉、高翔蜉、锯形蜉、朝大蚊与其它分类单元生态位重叠值较大,黑蝇、短尾石蝇、直突摇蚊、Tetropinasp.与其它分类单元生态位重叠值较小.相对丰度和生态位宽度对生态位重

鲤鱼多态性EST标记的筛选与特性分析

表达序列标签(Expressed sequence tag,EST)标记在基因组作图和分子标记辅助育种研究中具有重要价值。筛选和开发可用于遗传作图的鲤鱼多态性EST标记,对研究鲤鱼的基因组结构、遗传多样性研究和遗传育种有重要意义。本研究根据GenBank数据库中鲤鱼EST序列设计了67对EST引物,有47对在鲤鱼基因组DNA中成功扩增得到稳定的特异性条带,经单链构象多态性(SSCP)分析,12对(25.5%)引物扩增的EST在1个鲤鱼回交家系中具有多态性,其中6个为鲤鱼功能基因,5个与斑马鱼(Danio

三峡库区四条支流藻类多样性评价及“水华”防治

应用多样性指数、丰富度指数和均匀性指数对长江4条支流水域的藻类多样性进行了评价.比较了4条支流春、秋两季浮游藻类优势种、细胞密度和生物量等指标,对三峡蓄水后库区“水华”成因进行了初步分析.结果表明,4条支流的营养水平均属于中-富营养型,童庄河的水质最差,其次为香溪河和青干河,九畹溪的水质较好.春季硅藻的种类数多,绿藻种类数少;秋季则相反.藻类细胞密度的最高值出现在香溪河(6.036×106个/L),生物量的最高值出现在童庄河(19.997mg/L).2项指标的最低值均出现在九畹溪.在春季,童庄河还出现了拟

稀有鮈鲫β-肌动蛋白基因片段的克隆及其同源性分析

采用RT-PCR方法,从稀有鮈鲫肌肉组织中分离和克隆出β-肌动蛋白基因cDNA部分序列,长度为1 029 bp,编码343个氨基酸残基.序列分析表明,该cDNA序列与其他物种β-肌动蛋白基因同源性非常高.RT-PCR能够检出该基因在稀有鮈鲫肌肉、眼、脑、心脏、肝、肠、鳃、睥、卵巢等组织中广普表达,在胚胎不同发育时期持续恒量表达.并基于已知的鱼类β-肌动蛋白基因序列构建了进化树.

铲鲟微卫星引物对中华鲟的适用性研究

将 2 1对铲鲟 (ScaphirhynchusplatorynchusRafinesque)的微卫星引物在中华鲟 (AcipensersinensisGray)基因组DNA上进行PCR扩增 ,1 4对 (约占 67% )引物得到了扩增产物 ,其中有 1 0对 (约占 48% )表现为多态性 ,但只有 2对 ( 9 5 % )引物Spl 1 0 0和Spl 1 68的多态性较高 ,且带型清晰 ,可直接作为分子标记应用于相关的研究。此外 ,对具有特异性扩增 ,但有Stutterband现象的 4对引物的部分

草鱼的体液免疫应答及抗体产生细胞

以草鱼出血病病毒和牛血清白蛋白 (BSA)为抗原接种草鱼 ,比较了草鱼对两种抗原的体液免疫应答情况。结果显示 ,在接种了BSA的草鱼中 ,14d后检测到抗体 ,其效价在 2 8d达到峰值 ;而接种了出血病病毒的草鱼 ,在 2 1d后检测到抗体 ,抗体效价在 35d达到峰值。用FITC BSA检测免疫BSA草鱼的抗体产生细胞 ,探讨了抗体产生效价与抗体细胞数量的关系。

用污染指示菌评价城市水体污染的研究

选择湖南省常德市江北城区水体为代表开展本项研究。结果表明，水体中污染指示菌，总大肠菌群（ＴＣ）和粪大肠菌群（ＦＣ）密度同ＢＯＤ＿５负荷以及综合污染指数Ｐ呈高度正相关。所以，污染指示菌指标，特别是粪大肠菌群指标足综合评价城市污水，尤其是生活污水污染的一个必不可少的重要参数。对该城区水体细菌污染的评价结果是，生活污水排放愈集中的地区，细菌污染愈严重。其中护城河水的ＴＣ密度超出我国地面水Ⅲ级标准４个数量级；ＦＣ密度超过ＷＨＯ娱乐用水标准３个数量级。护城河是细菌污染最严重水体。包括滨湖公园内湖在内的接纳生活污水多

不同碳源对球孢鱼腥藻生长的影响

本文研究了有机碳源和无机碳源对球胞鱼腥藻生长的影响,结果表明:有机碳源中葡萄糖以0.5—1.0μg/mL、蔗糖以5.0μg/mL促进其生长效果最好;无机碳源中,碳酸钠以10.0—15.0μg/mL、碳酸氢钠以10.0μg/mL效果最好。葡萄糖和蔗糖的浓度高低对球孢鱼腥藻叶绿素a的含量没有明显影响,但前者略高于后者。碳酸钠和碳酸氢钠的浓度在5.0μg/mL时均提高了叶绿素a含量。四种碳源都提高了球孢鱼腥藻的同氮活性,有机碳源中蔗糖优于葡萄塘,无机碳源中碳酸钠优于碳酸氢钠。

武汉东湖生态系中浮游物的营养结构

本工作主要探讨东湖水柱浮游物的颗粒有机物在营养结构上量的关系。定量测定武汉东湖浮游物的干重、无灰重及浮游动、植物生物量并进行相应的碳、氮、磷分析。1983和1984两年东湖浮游物总颗粒有机碳现存量(mg/m~3)分别为3993与2819(Ⅰ站),2958与1856(Ⅱ站);总颗粒有机氮为762与584(I站),565与369(Ⅱ站);总颗粒有机磷为105与56(Ⅰ站),59与37(Ⅱ站)。颗粒有机碎屑碳一般占浮游物总颗粒有机碳的50％,占浮游生物活体碳的61％—104％。与浮游植物生物量碳相比,有机碎屑碳

Comparative responses in rare minnow exposed to 17 beta-estradiol during different life stages

Present in the excrement of humans and animals, 17 beta-estradiol (E-2) has been detected in the aquatic environment in a range from several nanograms to several hundred nanograms per liter. In this study, the sensitivities of rare minnows during different life stages to E-2 at environmentally relevant (5, 25, and 100 ng l(-1)) and high (1000 ng l(-1)) concentrations were compared using vitellogenin (VTG) and gonad development as biomarkers under semistatic conditions. After 21 days of exposure, VTG concentrations in whole-body homogenates were analyzed; the results indicated that the lowest observed effective concentration for VTG induction was 25 ng l(-1) E-2 in the adult stage, but 100 ng l(-1) E-2 in the larval and juvenile stages. After exposure in the early life stage, the larval and juvenile fish were transferred to clean water until gonad maturation. No significant difference in VTG induction was found between the exposure and control groups in the adults. However, a markedly increased proportion of females and appearance of hermaphrodism were observed in the juvenile-stage group exposed to 25 ng l(-1) E-2. These results showed that VTG induction in the adult stage is more sensitive than in larval and juvenile stages following exposure to E-2. The juvenile stage may be the critical period of gonad development. Sex ratio could be a sensitive biomarker indicating exposure to xenoestrogens in early-life-stage subchronic exposure tests. The results of this study provide useful information for selecting sensitive biomarkers properly in aquatic toxicology testing.

DE-71-induced apoptosis involving intracellular calcium and the Bax-mitochondria-caspase protease pathway in human neuroblastoma cells In vitro

Polybrominated diphenyl ethers (PBDEs) are used extensively as flame-retardants and are ubiquitous in the environment and in wildlife and human tissue. Recent studies have shown that PBDEs induce neurotoxic effects in vivo and apoptosis in vitro. However, the signaling mechanisms responsible for these events are still unclear. In this study, we investigated the action of a commercial mixture of PBDEs (pentabrominated diphenyl ether, DE-71) on a human neuroblastoma cell line, SK-N-SH. A cell viability test showed a dose-dependent increase in lactate dehydrogenase leakage and 3-(4,5-dimethylthia-zol-2-yl)-2,5-diphenyl-tetrazolium bromide reduction. Cell apoptosis was observed through morphological examination, and DNA degradation in the cell cycle and cell apoptosis were demonstrated using flow cytometry and DNA laddering. The formation of reactive oxygen species was not observed, but DE-71 was found to significantly induce caspase-3, -8, and -9 activity, which suggests that apoptosis is not induced by oxidative stress but via a caspase-dependent pathway. We further investigated the intracellular calcium ([Ca2+](i)) levels using flow cytometry and observed an increase in the intracellular Ca2+ concentration with a time-dependent trend. We also found that the N-methyl d-aspartate (NMDA) receptor antagonist MK801 (3 mu M) significantly reduced DE-71-induced cell apoptosis. The results of a Western blotting test demonstrated that DE-71 treatment increases the level of Bax translocation to the mitochondria in a dose-dependent fashion and stimulates the release of cytochrome c (Cyt c) from the mitochondria into the cytoplasm. Overall, our results indicate that DE-71 induces the apoptosis of ([Ca2+](i)) in SK-N-SH cells via Bax insertion, Cyt c release in the mitochondria, and the caspase activation pathway.