史氏鲟外周血细胞的显微及超微结构

采用血细胞计数、光学显微及电子显微技术对二龄史氏鲟外周血细胞的数目、形态及结构进行了研究。二龄史氏鲟红细胞的数目为47.75×104个/mm3,白细胞数目为2.9万个/mm3,其中淋巴细胞所占比率最高。史氏鲟的外周血中除正常红细胞外,还有处于分裂状态及未成熟的红细胞。史氏鲟外周血中的白细胞有四种类型,分别为淋巴细胞、粒细胞、血栓细胞和单核细胞。其中粒细胞有两种,即嗜中性粒细胞和嗜酸性粒细胞。嗜中性粒细胞含有多种形状的核,其中分叶的核数目较多,粒细胞及淋巴细胞均类似于哺乳动物。对史氏鲟外周血细胞细微结构的观察显示:红细胞中具有少量的细胞器;淋巴细胞结构典型;单核细胞较粒细胞稍小且具有较多线粒体;血栓细胞具有梭形和圆形两种,胞质较少,其中梭形的血栓细胞胞质几乎透明;对粒细胞的颗粒按照形状和电子密度进行了分类。     

疥螨消化系统的显微和超微结构观察

疥螨消化系统由咽、食道、中肠、１对侧囊、结肠、直肠、肛门以及唾腺组成。应用透射电镜,可将中肠和侧囊壁上皮细胞分为鳞状细胞期、柱状细胞期、核变性圆细胞期和全变性细胞期等４种不同生理功能状态。可将唾腺细胞分为Ｉ期、Ⅱ期和Ⅲ期等３种不同生理功能时期。食道和中肠及侧囊内含物为絮状物。直肠前段肠壁具有较多微管。     

斑马鱼脾显微与超微结构

应用光学显微镜和透射电镜对斑马鱼(Daniorerio)脾的显微与超微结构进行了观察。光镜结果表明,斑马鱼的脾主要由脾髓和网状组织两部分构成,脾髓分布于整个脾,分为白髓和红髓,但界限不明显,呈混合分布。红髓染色相对较浅,占脾实质的大部分区域,主要由密集的红细胞构成,可见脾窦结构,脾索结构不明显。白髓染色较深,主要由密集的淋巴细胞构成,淋巴细胞的胞核染色较深,呈深紫色。经Gordon-Sweet银染显示网状纤维后,可清晰观察到脾小结,从而可清晰区分红髓与白髓,脾小结与哺乳动物的类似,主要是由密集的淋巴细胞构成。酸性磷酸酶染色可见斑马鱼脾内有大量吞噬性细胞存在。电镜结果显示,红髓分布有不同类型的红细胞、血小板和浆细胞,白髓分布有淋巴细胞、巨噬细胞、单核细胞、嗜中性粒细胞、浆细胞和网状细胞,淋巴细胞胞质内含有多泡体,这可能与淋巴细胞发挥免疫功能有着密切联系。斑马鱼脾与大多数硬骨鱼相似,未观察到椭球这一特殊结构。     

人工雌核发育草鱼外周血细胞的显微及超微结构观察

本文利用光学显微镜、透射电子显微镜、扫描电子显微镜首次对人工雌核发育草鱼的外周血细胞进行了观察。观察结果表明,雌核发育草鱼外周血液中可区分出七种不同类型的血细胞：红细胞、血栓细胞、淋巴细胞、单核细胞、嗜中性粒细胞、嗜酸性粒细胞和嗜碱性粒细胞,这些血细胞的显微及超微结构与已报道过的鲤鱼、鲫鱼、普通草鱼相应血细胞的结构基本相同。     

唐鱼肝脏显微和超微结构观察

应用光镜和透射电镜对繁殖期间唐鱼Tanichthys albonubes肝脏组织的显微和超微结构进行了观察。结果显示,唐鱼肝细胞具单核,中央核仁显著;细胞质内分布着粗面内质网、线粒体、糖原颗粒和脂滴等细胞器和内含物。胆小管由2～3个相邻肝细胞质膜凹陷围成,而肝血窦则由内皮细胞的胞质、成纤维细胞等参与构成。肝细胞与周边细胞通过3种不同方式进行联系:肝细胞之间的紧密连接;与血窦的间接连接;与胆小管的邻接。这些联系方式显示了肝脏具有内分泌腺和外分泌腺功能的特点。研究还发现雌性唐鱼肝脏具有"暗"细胞和"淡"细胞两种类型。本文还讨论了唐鱼肝脏与其他硬骨鱼类肝脏一般组织结构和超微结构的异同点。     

人胎儿腓肠神经的显微与超微结构研究

光镜与电镜下研究了２２例人４－足月胎儿腓肠神经，发现：４月龄是形成髓鞘的开始阶段；７月时其数量与足月相近。４月时血－神经屏障已趋完善，血管中见有核红细胞；５月后龄神经束膜完善，可达１６－２０层。４月１０天见肥大细胞存在，即分化在此之前，但颗粒还不成熟。４－足月标本均见轴突和髓鞘变性；亦见无髓纤维囊泡聚积。     

杂色鲍足的显微与超微结构

杂色鲍（Haliotis diversicolor）隶属软体动物门、腹足纲、前鳃亚纲、原始腹足目、鲍科、鲍属。鲍的足是柔韧性很好的器官,它具有运动、支持、感觉与辅助捕获功能,是鲍生活中匍匐和吸附岩石等固着物的重要部位,因其首先接触环境而成为脓疱病、裂壳病、弧菌病等病病原体的主要侵袭部位,这些病可造成十分严重的鲍死亡现象。国内学者对鲍足的研究文献较少,仅有关于皱纹盘鲍（Haliotis discus hannai Ino）足的组织学（崔龙波等,1997）及皱纹盘鲍足的粘液细胞的片断研究（王宜艳等,2004）报道。     

光强对人参叶片显微和超微结构的影响

在５％、２０％和３５％３种透光率棚下,人参叶片的比叶重、叶厚度,单位叶面积的叶肉细胞数目,叶肉细胞表面积和细胞层数随着光强的增加而增加,５０％透光率棚下叶片开始减少,５％和２０％透光率棚下叶片叶肉细胞主要呈横向排列,胞间隙较大,３５％透光率棚下叶片叶肉细胞排列致密,胞间隙变小,靠近上一有皮形成一层呈纵向排列的栅栏状细胞;５０５透光率棚下叶片叶肉细胞为大而圆形,胞间隙变大,排列也不规则。５％透光率棚     

山溪鲵卵黄发生的显微与超微结构

用光镜和透射电镜观察了山溪鲵（Batrachuperus pinchonii)不同发育时期卵母细胞的显微与超微结构,特别注意了与卵黄发生相关的细胞器变化。结果表明,类核周体为线粒体、高尔基体、内质网等膜性细胞器聚集的场所;线粒体自身也可演变成卵黄前颗粒,参与构成卵黄小板的成分;吞饮泡和髓样小体是卵母细胞利用外源卵黄物质的中间媒介。经过与其他动物卵黄发生过程相比较,认为非哺乳脊椎动物卵黄发生是卵母细胞在多种细胞器参与下整体活动的结果,不是经由单一的模式或途径形成,因此呈现发生上的多元化;不同物种在卵黄发生中分别采取与各自相适应的模式或途径。     

北方山溪鲵精子发生不同阶段的显微与超微结构

用光镜和电镜观察了北方山溪鲵(Batrachuperus tibetanus)精子发生过程中各种类型生精细胞的显微与超微结构变化。结果显示,北方山溪鲵在4~8月时处于精子发生期,精子形成在7~8月。成熟精子的结构具有小鲵科精子的一些共同特征,如顶体前端呈三叶草状,尾部由轴纤维、波动膜、轴丝及轴丝旁纤维构成,轴纤维粗大呈圆柱形,尾部无线粒体等。比较分析认为,在两栖类的系统发育中,轴纤维、波动膜和轴丝旁纤维的消失为近裔性状。     

A putative serine protease,SpSsp1, from Saprolegnia parasitica is recognised by sera of rainbow trout, Oncorhynchus mykiss

Saprolegniosis, the disease caused by Saprolegnia sp., results in considerable economic losses in aquaculture. Current control methods are inadequate, as they are either largely ineffective or present environmental and fish health concerns. Vaccination of fish presents an attractive alternative to these control methods. Therefore we set out to identify suitable antigens that could help generate a fish vaccine against Saprolegnia parasitica. Unexpectedly, antibodies against S. parasitica were found in serum from healthy rainbow trout, Oncorhynchus mykiss. The antibodies detected a single band in secreted proteins that were run on a one-dimensional SDS-polyacrylamide gel, which corresponded to two protein spots on a two-dimensional gel. The proteins were analysed by liquid chromatography tandem mass spectrometry. Mascot and bioinformatic analysis resulted in the identification of a single secreted protein, SpSsp1, of 481 amino acid residues, containing a subtilisin domain. Expression analysis demonstrated that SpSsp1 is highly expressed in all tested mycelial stages of S. parasitica. Investigation of other non-infected trout from several fish farms in the United Kingdom showed similar activity in their sera towards SpSsp1. Several fish that had no visible saprolegniosis showed an antibody response towards SpSsp1 suggesting that SpSsp1 might be a useful candidate for future vaccination trial experiments.     

Histopathological changes induced by maneb and carbaryl on some tissues of rainbow trout, Oncorhynchus mykiss

Acute toxicity of the pesticides, maneb and carbaryl, to juvenile rainbow trout were evaluated under static-renewal test conditions. Actual concentrations of maneb ranged from 0.10 mg/L to 2.00 mg/L and carbaryl ranged from 0.20 mg/L to 3.90 mg/L. The concentrations of maneb that killed 50% of the rainbow trout (3.27 ± 0.9 g) within 24-h (24-h; LC₅₀), 48-h, 72-h and 96-h were 1.19 ± 0.12, 1.04 ± 0.11, 0.92 ± 0.12 and 0.81 ± 0.14 mg/L (95% confidence limits), respectively. LC₅₀ values of carbaryl for 24-h, 48-h, 72-h and 96-h were 2.52 ± 0.71, 2.16 ± 0.63, 1.71 ± 0.46 and 1.39 ± 0.15 mg/L, respectively. None of the unexposed control fish died and the first fish died 6 h after exposure to maneb (≥1.30 mg/L), and carbaryl (≥2.60 mg/L). Lamellar edema, separation of epithelium from lamellae, lamellar fusion, swelling of the epithelial cells and epithelial cell necrosis were observed on maneb and carbaryl exposed fish. Gills also had scattered areas of focal lamellar hyperplasia. Fish exposed to pesticides had inflammation and focal necrosis in liver, trunk kidney and spleen. Maneb and carbaryl had similar histopathological lesions. In order, the most affected organs were gill, trunk kidney and liver.     

松江鲈鱼皮肤的显微和亚显微结构

采用光学显微镜、扫描电镜和透射电镜,对松江鲈鱼(Trachidermus fasciatus)成体皮肤的显微和亚显微结构进行了观察。结果表明,松江鲈鱼体表不同部位皮肤的厚薄不一,但基本结构相似。皮肤由表皮和真皮层构成。松江鲈鱼的皮肤裸露无鳞,表皮层较薄,由约4～8层细胞构成,主要由复层上皮细胞和黏液细胞及基底细胞组成。表层细胞呈扁平、多边形,细胞之间主要靠桥粒紧密连接,连接处形成增厚的边缘嵴状突起。表皮细胞游离面向内凹陷,表面形成指纹状微嵴。黏液细胞呈圆形或卵圆形,散布在上皮细胞之间。黏液细胞内的黏原颗粒具有椭圆颗粒状、均匀致密的块状和疏松丝状3种不同形态。真皮通过基膜与表皮相连,由稀疏层和致密层构成。真皮结缔组织在腹部较厚而在其他部位较薄。表皮与真皮连接处有色素层,头部、背部、尾柄和体侧皮肤色素细胞分布多,色素层明显,而腹部和颏部皮肤缺少色素。松江鲈鱼黄河群体真皮层中有角质棘状突起,而滦河群体则无。头部、体侧和尾柄处皮肤上还分布有侧线孔和表面神经丘等感觉器官。     

不同发育时期哲罗鱼卵黄的超微结构

应用透射电镜观察了不同发育时期哲罗鱼(Hucho taimen)卵黄的超微结构.根据哲罗鱼卵黄物质在卵母细胞中的加工合成、积累以及卵母细胞中参与卵黄颗粒形成的细胞器的变化,可将该鱼卵黄发生分为4个特征时期,即卵黄发生前期、卵黄泡期、卵黄积累期和卵黄积累完成期.卵黄发生前期是指卵母细胞发育过程中的卵黄物质开始积累前的时期,此时期核仁不断分裂,出现线粒体云和早期的滤泡细胞层、基层和鞘细胞层;卵黄泡期特点主要是细胞器不断变化产生卵黄泡和皮层泡;卵黄积累期的滤泡膜由内向外依次为放射带、颗粒细胞层、基层和鞘细胞层,此时外源性卵黄前体物质不断经过血液汇集于鞘细胞层,后经微胞饮作用穿过胶原纤维组成的基层,经过多泡体作用转运至颗粒细胞内,在细胞内经过加工和修饰形成小的卵黄蛋白颗粒,卵黄蛋白颗粒经微胞饮穿过放射带进入卵母细胞边缘形成的空泡中,不断积累形成卵黄球;进入卵黄积累完成期,卵黄球体积变大,向细胞中心聚集,填满大部分卵母细胞,卵黄积累完毕.     

A bioinformatics-based update on microRNAs and their targets in rainbow trout (Oncorhynchus mykiss)

MicroRNAs (miRNAs) participate in various vitally biological processes via controlling target genes activity and thousands of miRNAs have been identified in many species to date, including 18,698 known animal miRNA in miRBase. However, there are only limited studies reported in rainbow trout (Oncorhynchus mykiss) especially via the computational-based approaches. In present study, we systematically investigated the miRNAs in rainbow trout using a well-developed comparative genome-based homologue search. A total of 196 potential miRNAs, belonging to 124 miRNA families, were identified, most of which were firstly reported in rainbow trout. The length of miRNAs ranged from 17 to 24 nt with an average of 20 nt while the length of their precursors varied from 47 to 152 nt with an average of 85 nt. The identified miRNAs were not evenly distributed in each miRNA family, with only one member per family for a majority, and multiple members were also identified for several families. Nucleotide U was dominant in the pre-miRNAs with a percentage of 30.04%. The rainbow trout pre-miRNAs had relatively high negative minimal folding free energy (MFE) and adjusted MFE (AMFE). Not only the mature miRNAs but their precursor sequences are conserved among the living organisms. About 2466 O. mykiss genes were predicted as potential targets for 189 miRNAs. Gene Ontology (GO) analysis showed that nearly 2093, 2107, and 2081 target genes are involved in cellular component, molecular function, and biological processes respectively. KEGG pathway enrichment analysis illuminated that these miRNAs targets might regulate 105 metabolic pathways, including those of purine metabolism, nitrogen metabolism, and oxidative phosphorylation. This study has provided an update on rainbow trout miRNAs and their targets, which represents a foundation for future studies.     

Reduction in swimming performance in juvenile rainbow trout (Oncorhynchus mykiss) following sublethal exposure to pyrethroid insecticides

While the lethal toxicity of pyrethroid insecticides to fish is well documented, their sublethal physio-behavioral effects remain poorly characterized. Known pyrethroid-associated changes to insect neuromuscular function may translate into similar effects in fish, thereby altering swimming ability and affecting foraging, predator avoidance, and migration. Three experiments were conducted using critical (U_crit) and burst (U_max) swimming speeds to assess the sublethal effects of the pyrethroids permethrin and deltamethrin in juvenile rainbow trout (Oncorhynchus mykiss). Fish were exposed to deltamethrin (100, 200, or 300 ng/L) or permethrin (1, 2, or 3 μg/L) in water for 4 d, and assessed for swimming performance. Deltamethrin (200 and 300 ng/L) reduced U_crit, but not U_max, while both swim performance measurements were unaffected by permethrin. Subsequent experiments used only U_crit to assess deltamethrin exposure. In a time course experiment, deltamethrin (300 ng/L) reduced U_crit after 1 and 4 d of exposure, but after 7 d of exposure U_crit was fully recovered. Finally, deltamethrin (1, 2, or 3 μg/L) reduced U_crit after 1 h bath exposures similar to recommended protocols for deltamethrin based sea-lice treatment in aquaculture. The real-world implications of the revealed pyrethroid-associated swimming ability reductions in salmon may be important in areas close to aquaculture facilities.     

拟目乌贼精子发生和精子的超微结构

应用扫描电镜和透射电镜观察了拟目乌贼(Sepia lycidas)精子的发生过程和超微结构。结果表明,精子发生经历了精原细胞、初级精母细胞、次级精母细胞、精细胞和成熟精子5个阶段,其中精细胞可以分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ5个时期,精细胞Ⅱ期又可分为前期和后期。细胞核经历了一个横向收缩、纵向拉长的过程,由圆形或椭圆形,变为不规则的纺锤形、稍弯曲的长柱形;核内染色质由絮状,变为絮块状、致密颗粒状、细纤维状、粗纤维状和片层状,直至高电子密度均质状;顶体由圆形,变为头盔形、圆锥形、倒"U"字形,直至子弹头形;线粒体由空泡状经过融合和迁移,变为内嵴丰富的椭球形,形成不完全包围鞭毛的线粒体距。成熟精子全长101.28μm,由头部和尾部组成,头部呈长辣椒状,长7.73μm,宽1.51μm,由顶体和细胞核组成;尾部细长,为93.18μm,为典型的"9+2"结构,由中段、主段和末段三部分组成。     

Invasion of Ceratomyxa shasta (Myxozoa) and comparison of migration to the intestine between susceptible and resistant fish hosts

The myxozoan parasite Ceratomyxa shasta infects salmonids causing ceratomyxosis, a disease elicited by proliferation of the parasite in the intestine. This parasite is endemic to the Pacific Northwest of North America and salmon and trout strains from endemic river basins show increased resistance to the parasite. It has been suggested that these resistant fish (i) exclude the parasite at the site of invasion and/or (ii) prevent establishment in the intestine. Using parasites pre-labeled with a fluorescent stain, carboxyfluorescein succinimidyl diacetate (CFSE), the gills were identified as the site of attachment of C. shasta in a susceptible fish strain. In situ hybridization (ISH) of histological sections was then used to describe the invasion of the parasites in the gill filaments. To investigate differences in the progress of infection between resistant and susceptible fish, a C. shasta-susceptible strain of rainbow trout (Oncorhynchus mykiss) and a C. shasta-resistant strain of Chinook salmon (Oncorhynchus tshawytscha) were sampled at consecutive time points following exposure at an endemic site. Using ISH in both species, the parasite was observed to migrate from the gill epithelium into the gill blood vessels where replication and release of parasite stages occurred. Quantitative PCR verified entry of the parasite into the blood. Parasite levels in blood increased 4 days p.i. and remained at a consistent level until the second week when parasite abundance increased further and coincided with host mortality. The timing of parasite replication and migration to the intestine were similar for both fish species. The field exposure dose was unexpectedly high and apparently overwhelmed the Chinook salmon’s defenses, as no evidence of resistance to parasite penetration into the gills or prevention of parasite establishment in the intestine was observed.     

Disparate infection patterns of Ceratomyxa shasta (Myxozoa) in rainbow trout (Oncorhynchus mykiss) and Chinook salmon (Oncorhynchus tshawytscha) correlate with internal transcribed spacer-1 sequence variation in the parasite

Ceratomyxa shasta is a virulent myxosporean parasite of salmon and trout in the Pacific Northwest of North America. The parasite is endemic in the Klamath River, Oregon/California, where a series of dams prevent movement of fish hosts between the upper and lower parts of the basin. Ceratomyxa shasta exhibits a range of infection patterns in different fish species above and below the dams. We hypothesised that the variations in infection and disease are indicators that different strains of the parasite exist, each with distinct host associations. Accordingly, we sought to identify strain-specific genetic markers in the ssrRNA and internal transcribed spacer region 1 (ITS-1). We examined 46 C. shasta isolates from water samples and two fish hosts, from June 2007 field exposures at upper and lower Klamath River sites with similarly high parasite densities. We found 100% of non-native rainbow trout became infected and died at both locations. In contrast, mortality in native Chinook salmon was <10% in the upper basin, compared with up to 40% in the lower basin. Parasite ssrRNA sequences were identical from all fish. However, ITS-1 sequences contained multiple polymorphic loci and a trinucleotide repeat (ATC)_0-3 from which we defined four genotypes: 0, I, II and III. Non-native rainbow trout at both sites were infected with genotype II and with a low level of genotype III. Chinook salmon in the upper basin had genotypes II and III, whereas in the lower basin genotype I predominated. Genotype I was not detected in water from the upper basin, a finding consistent with the lack of anadromous Chinook salmon there. Genotype O was only detected in water from the upper basin. Resolution of C. shasta into sympatric, host-specific genotypes has implications for taxonomy, monitoring and management of this significant parasite.     

乌梢蛇精子头部形成的超微结构

摘要：为了解乌梢蛇（Zaocys dhumnades）精子形成的规律,用透射电镜对其头部超微结构进行了观察。结果表明,乌梢蛇精子头部形成可分为4个阶段：阶段Ⅰ,前顶体囊泡内的颗粒物质融合形成1个顶体颗粒而发育为顶体囊泡,随着顶体囊泡的增大,在顶体囊泡与核膜之间形成了致密的纤维物质层。阶段Ⅱ,顶体囊泡变扁平,顶体颗粒分散...