Induction of apoptosis in a flounder gill cell line by lymphocystis disease virus infection

Lymphocystis disease virus (LCDV), a large icosahedral DNA virus classified to the iridovirus family, is the causative agent of lymphocystis, a disease which occurs in marine and freshwater fish species and is characterized by formation of papilloma-like lesions on the surface of the skin. In vitro, LCDV infection causes flounder gill cells, an adherent cell line, to exhibit an obvious cytopathic effect (CPE). In order to test whether apoptosis is responsible for the observed CPE, cells infected with LCDV at a multiplicity of infection (m.o.i.) of 5 PFU per cell were examined at various time intervals for the appearance of apoptotic signs. Nuclear fragmentation, DNA laddering and caspase activation were observed in the infected cells at the time (i.e. 10 days post-infection) when an intensive CPE was observed. These findings demonstrate that LCDV is capable of inducing apoptosis in vitro, which is different from the result of LCDV infection in vivo, and consequently suggest an intricate LCDV-host interaction.     

太平洋牡蛎生理活动的季节变化

以大窑湾养殖太平洋牡蛎离体鳃为材料,周年观察鳃片的匍匐速度以及鳃片在不同盐度海水中和无氧状态下的耐受力。以此作为生理活动指标,描述了其季节变化。显示繁殖季节牡蛎的生理活动下降。同时发现本海区牡蛎鳃缘附有大量真枝螅,对牡蛎鳃纤毛的活动和生长有一定影响。     

946中草药添加剂防治淡水鱼细菌性烂鳃病的比较

[目的]对946中草药添加剂防治淡水鱼细菌性烂鳃病效果进行比较试验,为大面积淡水鱼养殖筛选有效药物及防治细菌性烂鳃病提供理论依据。[方法]选择混养淡水鱼塘,分别应用946中草药添加剂、生石灰、畜用红霉素和空白对照组进行比较试验,观察其对淡水鱼细菌性烂鳃病的防治效果。[结果]应用946中草药添加剂和畜用红霉素鱼塘的鱼未发生细菌性烂鳃病;而应用生石灰和未添加药物的空白鱼塘内的鱼均发生严重的烂鳃病。[结论]946中草药添加剂对淡水鱼烂鳃病有明显的防治效果。     

红枫湖鱼类资源及空间分布的水声学调查研究

于2010年9月～12月和2011年3月～6月对贵阳市红枫湖的鱼类资源进行了调查,捕获鱼类28种,分属于4目6科;鱼类的体长为5.68～116.41 cm,优势体长组为11.00～30.00 cm,其中小型鱼体和中大型鱼体占多数。2011年6月运用BioSonics DT-X（200 kHz）鱼探仪对鱼类密度进行了水声学探测,平均密度为（51.64±36.49）×10-3尾.m-3,不同区域的鱼类密度分布有显著性差异,最大值出现在将军湾[（97.25±12.35）×10-3尾.m-3],最低值位于红枫湖大坝[（14.90±2.56）×10-3尾.m-3],从大坝到将军湾鱼类资源量总体上呈现逐步增长的趋势。红枫湖鱼类分布水层主要在6～15 m,不同水层的鱼类密度分布存在显著差异。     

贝氏高原鳅鳃结构的观察

为了解贝氏高原鳅鳃的结构与其功能的关系,同时为其人工养殖积累基础资料,应用光学显微镜和扫描电镜对贝氏高原鳅(Trilophysa bleekeri)鳃的组织结构进行观察。结果表明,鳃耙短钝;鳃丝末端膨大;鳃小片互生排列在鳃丝两侧;鳃丝呼吸面上皮细胞薄,高度血管化;非呼吸面由上皮细胞彼此相连。氯细胞数量较少,多分布在鳃小片基部。表明,贝氏高原鳅的鳃表面形态结构与其呼吸作用、摄食作用等功能相适应。     

Detection of Neoparamoeba perurans by duplex quantitative Taqman real-time PCR in formalin-fixed, paraffin-embedded Atlantic salmonid gill tissues

The development and the application of a quantitative duplex real‐time PCR for the detection of Neoparamoeba perurans and the elongation factor α 1 gene (ELF) of Atlantic salmon, Salmo salar L., and rainbow trout, Oncorhynchus mykiss (Walbaum), are described. A set of primers and probe was designed to amplify a 139‐bp fragment specific to the N. perurans 18S rRNA gene. The test was shown to be very sensitive, being able to detect as little as 13.4 DNA copies per μL corresponding to 0.15 fg of template DNA. In addition, the reaction that detected N. perurans was found to have a high degree of repeatability and reproducibility, to have a linear dynamic range (R² = 0.999) extending over 5 log₁₀ dilutions and to have a high efficiency (104%). The assay was applied to DNA samples extracted from 48 formalin‐fixed, paraffin‐embedded (FFPE) salmon gill tissues showing varying degrees of gill histopathology and amoebic gill disease (AGD)‐type histopathology ranging from absent to severe (each scored 0–3). Neoparamoeba perurans DNA was detected in all the blocks where AGD‐type histopathology was diagnosed microscopically and in 43.6% of the blocks showing signs of gill pathology. The association between parasitic load and gill histopathology and AGD‐type histopathology severity was also investigated. This study also describes the development and the application of a second real‐time PCR for the generic detection of Neoparamoeba spp., Page, 1987. A set of primers and probe conserved among the Neoparamoeba spp. was designed to amplify a 150‐bp fragment within the 18S rRNA gene. Applied to N. perurans‐negative gill tissues, the method was used to exclude the presence of other Neoparamoeba spp. in those blocks where gill pathology was observed microscopically.     

Development of a quantitative real-time PCR for the detection of Tenacibaculum maritimum and its application to field samples

The development and the application of a quantitative real‐time PCR for the detection of Tenacibaculum maritimum are described. A set of primers and probe was designed to amplify a 155‐bp fragment specific to the T. maritimum 16S rRNA gene. The test was shown to be very sensitive, able to detect as little as 4.8 DNA copies number μL^?1. In addition, the assay was found to have a high degree of repeatability and reproducibility, with a linear dynamic range (R² = 0.999) extending over 6 log₁₀ dilutions and a high efficiency (100%). The assay was applied to DNA samples extracted from 48 formalin‐fixed paraffin‐embedded (FFPE) Atlantic salmon, Salmo salar, gill tissues showing varying degrees of gill pathology (scored 0–3) and from 26 jellyfish samples belonging to the species Phialella quadrata and Muggiaea atlantica. For each sample, the bacterial load was normalised against the level of the salmonid elongation factor alpha 1 (ELF) detected by a second real‐time PCR using previously published primers and probe. Tenacibaculum maritimum DNA was detected in 89% of the blocks with no signs of gill disease as well as in 95% of the blocks with mild‐to‐severe gill pathology. Association between bacterial load and gill pathology severity was investigated. T. maritimum DNA was detected at low level in four of the 26 jellyfish tested.     

Pb2+对泥蚶鳃、肝脏等组织结构的影响

为了进一步了解重金属Pb对贝类的毒性毒理影响,研究了4个暴毒浓度(5、15、45和90μg/L)Pb2+对泥蚶鳃和肝脏组织显微结构的影响,及其中2个高浓度组Pb2+暴毒对泥蚶鳃和肝脏组织超微结构的影响,处理时间为96 h。结果显示,低浓度组Pb2+造成泥蚶鳃丝脱离其相连的软骨组织;高浓度组Pb2+使其鳃丝呼吸上皮细胞出现脱落,鳃腔肿胀、内有血细胞堆积,鳃丝断裂;超微结构分析发现,随着浓度的升高,鳃上皮细胞中次级溶酶体和线粒体数量均增加。Pb对泥蚶肝脏组织的显微结构影响仅见高浓度组肝小管附近有黄色物质沉积,消化管界限缺失,超微结构表明随着浓度的升高,肝细胞内沉积大量的黑色嗜锇性物质,次级溶酶体亦大量增加,细胞胞质及细胞核出现空泡,最后将导致细胞坏死,造成肝细胞永久性损伤。结合其他重金属毒性研究可发现,重金属引起的病理学变化并不具有金属特异性,主要还是氧化胁迫造成的氧化损伤。研究推测,生物体的抗氧化体系在重金属解毒中发挥了重要作用。