急性病毒性鲫鳃出血病的病理变化

病毒性鲫(Carassius auratus)鳃出血病的突发流行可导致鱼高致死率,使中国部分养鱼场近些年受到重创。为了充分认识这种鱼病的发生发展过程,我们结合PCR、光学显微镜和透射电镜,对病鱼头肾等组织的病变及病毒分布情况进行了分析。注射自然发病鱼的组织滤液(病毒悬液),能使正常鲫感染,且出现与自然发病鲫相同的症状及高致死率;病原有典型疱疹病毒的形态特征(故称为鲫疱疹病毒,Ca HV)。经PCR扩增对已知鲤科疱疹病毒主要衣壳蛋白(MCP)基因进行检测,可确定Ca HV存在于被感染鱼的肝、脾、肾和头肾组织中。对组织病理变化及不同时序进行比较,结果表明Ca HV感染会引起鲫这些组织不同程度病变,而鳃和头肾的病理变化有显著时序相关性。在头肾细胞中还观察到大量Ca HV颗粒,预示鲫头肾是Ca HV侵染和复制的主要靶器官。     

Malformations of the gill filaments of the ruffe Gymnocephalus cernuus (L.) (Pisces) caused by echinostomatid metacercariae

In parasite surveys of fishes from Lake Balaton and its tributaries in Hungary, infections with metacercariae of a species of the digenean genus Echinochasmus (Trematoda: Echinostomatidae) were found in seven species of fish. In ruffe, Gymnocephalus cernuus, malformations of the gill filaments apparently caused by these infections were observed. These malformations were in the form of bifurcations of the filaments at about their mid‐length. At the point where the filaments bifurcate, an Echinochasmus metacercaria was always embedded in the cartilaginous ray of the gill filament. All specimens of the ruffe were found to be infected by these metacercariae, and each ruffe specimen was infected by 30–300 metacercariae. Such a bifurcation was found in all of the ruffe specimens, but, apart from these gill malformations, the metacercariae produced only local changes in the cartilage. In the other six infected fish species, only local signs were observed in the cartilage. Experimental infections of chicks with metacercariae resulted in the finding of the sexual adult (marita) of an unidentified species of Echinochasmus. ITS sequences of the adult and metacercaria corresponded with each other, and also with a cercaria isolated from a gravel snail (Lithoglyphus naticoides), with a 99.5–100% similarity.     

Testate amoeba Rhogostoma minus Belar, 1921, associated with nodular gill disease of rainbow trout,Oncorhynchus mykiss (Walbaum)

The case study targeted to determine the aetiology of nodular gill disease (NGD) of farmed rainbow trout. The methods included microscopical examination of gill material in fresh, culturing of isolated organisms, histology, transmission electron microscopy and molecular biology identification. The results revealed an intravital colonization of fish gills by the testate amoeba Rhogostoma minus Belar, 1921. Rhogostoma infection was found in all fish examined microscopically (15/15); in contrast, naked amoebae related to fully developed NGD lesions were found in minority of these fish (5/15). They belonged to four genera, Acanthamoeba, Vermamoeba, Naegleria and Vannella. Results presented in this study contribute to the mosaic of findings that contrary to amoebic gill disease of marine fish turn attention to the possibility of the heterogeneous, multi‐amoeba‐species and multifactorial aetiology of NGD.     

First detection of koi herpesvirus from koi,Cyprinus carpio L. experiencing mass mortalities in Iran: clinical,histopathological and molecular study

Koi herpesvirus (KHV) is the aetiological agent of an emerging disease (KHVD) associated with mass mortalities in koi and common carp and reported from at least 30 countries. We report the first detection of KHV from koi in Iran using clinical, histopathological and molecular studies. KHV‐infected fish showed reduced swimming activity, sunken eyes and increased mucus production on skin and fins. On post‐mortem examination, gill necrosis was observed in the majority of fish. Histopathologically, the gill showed diffuse necrosis of the branchial epithelial cells. Margination of chromatin was detected in gills, kidney, heart, spleen, intestine and brain. In addition, sequence analyses of the TK gene, ORF 136 and marker I and II, demonstrates that Iranian KHV isolates were identical and classified as variant A1 of TUSMT1 (J strain) and displayed the I⁺⁺II⁺ allele of this Asian genotype.     

红龙鱼鳃部肿瘤的初步研究

对红龙鱼(Scleropages formosus)鳃部肿瘤进行了病理切片研究。结果表明,该肿瘤是由外界不良因素长期刺激导致的腺体大量分泌,纤维素、蛋白、炎症细胞大量分泌纤维化而成的疏松结蹄组织囊肿性肿瘤。     

盐度、pH对文蛤肌肉、鳃、外套膜HSP70基因表达的影响

为探讨池塘养殖文蛤的适宜盐度和pH范围,以β-actin为内参基因,采用实时荧光定量聚合酶链式反应技术,检测不同盐度(16、18、20、22、24)和pH(6.7、7.7、8.7、9.7、10.7)梯度下文蛤肌肉、鳃、外套膜中HSP70基因mRNA的表达水平。结果显示,盐度16、18、22、24处理组肌肉中HSP70基因的表达量显著高于盐度20的对照组(P0.05);除盐度18组鳃和盐度24组外套膜HSP70基因的表达量与对照组差异不显著外(P0.05),16、18、22、24盐度组鳃和外套膜中HSP70基因的表达量均显著高于对照组(P0.05)。pH 6.7、7.7、9.7、10.7处理组肌肉、鳃、外套膜中HSP70基因的表达量与pH为8.7的对照组差异显著(P0.05)。试验结果表明,超出一定盐度、pH范围,可显著诱导文蛤肌肉、鳃、外套膜中HSP70基因的过量表达,研究结果可为池塘文蛤的健康养殖提供参考。     

鳃的功能组学研究进展和趋势

鳃是水生动物主要的呼吸器官。虽然部分水生动物的鳃结构不同（如鱼和虾蟹）,但其主要功能均为气体交换和渗透压调节等。本文旨在对近年来鳃的功能组学的主要研究结果进行归纳和总结,特别是不同的环境因子（重金属的污染物、寄生虫细菌、盐度、亚硝酸盐等）胁迫下水生动物鳃的转录组测序分析,以及鳃在不同环境因子胁迫下的蛋白组学和代谢组学的研究,揭示环境因子改变对水生动物鳃相关的基因表达变化、生理生化状态变化、分子通路和生理功能的影响,旨在为鱼类的健康养殖提供新的思路和方向。     

Effects of natriuretic peptides on the gill vasculature of a hagfish, Eptatretus cirrhatus

An isolated, perfused gill pouch preparation and myography were used to determine responses of the branchial vasculature of a hagfish to the mammalian natriuretic peptides, rANP and CNP. In the isolated gill pouch preparation afferent perfusion pressures increased in the first 5 min of exposure to low concentrations (10^–14 to 10^–10M) of ANP and CNP and then decreased below starting values by 15 min. At higher concentrations the depressor response prevailed and natriuretic peptides switched the flow away from the efferent artery to the venous route, which would fill the peribranchial sinus in vivo. At low concentrations ANP increased circumferential tensions in afferent branchial arterial rings. At higher concentrations afferent and efferent branchial arteries relaxed in response to ANP and CNP.