铅暴露对黄河鲤鱼黏液细胞数量和类型的影响

利用阿新蓝过碘酸雪夫染色方法,研究了铅浸泡对鲤鱼黏液细胞的影响。结果表明,铅暴露对于黏液细胞数量的影响是先增后降,方差分析表明,Pb2+0.01、0.1 mg/L组口腔上皮和后肠,0.1 mg/L组鳃丝,以及所有试验组前肠和中肠黏液细胞密度与对照组相比均显著增加(P<0.01或P<0.05),而2 mg/L和5 mg/L组口腔上皮和后肠,0.01、2、5 mg/L组鳃丝上黏液细胞密度与对照组相比均无显著性差异(P>0.05)。铅对于黏液细胞类型的影响是可以促进Ⅱ型黏液细胞,抑制Ⅰ、Ⅲ、Ⅳ型黏液细胞的形成。     

草鱼点状产气单胞菌单克隆抗体的制备与双抗原夹心ELISA法的建立

为了建立一种快速、准确能早期检测草鱼肠炎病原菌的方法,以患病草鱼为材料,制备点状产气单胞菌单克隆抗体(McAb),并鉴定其特异性和抗原表位;采用过碘酸钠方法,以辣根过氧化物酶标记单抗,用试管凝集试验测定其活性;建立点状产气单胞菌McAb的双抗原夹心ELISA检测方法,确定包被单抗和酶标单抗的浓度,并测定其灵敏度和特异性。结果:1)获得了2株特异性强和抗原表位不同的单抗,其ELISA效价为1∶16 000。2)辣根过氧化物酶标记的抗体活性为1∶640。3)建立了包被抗体稀释度为1∶800、酶标抗体稀释度为1∶1 600的双抗原夹心ELISA检测方法,该方法与点状产气单胞菌呈强阳性反应,与近似菌无交叉反应,灵敏性为7×103cfu/mL。结论:制备的点状产气单胞菌McAb的效价高、特异性强;建立的双抗原夹心ELISA方法操作简单、灵敏度高、特异性强,可应用于草鱼肠炎病原体的早期快速检测。     

水库鲮和罗非鱼谷胱甘肽转移酶基因表达量与水中蓝藻含量的关系

采用荧光定量的方法对不同季节广州显岗水库鲮(Cirrhinus molitorella)和尼罗罗非鱼(Oreochro-mis niloticu)肝脏中去毒酶基因谷胱甘肽转移酶GST基因的表达情况,并结合不同季节鱼类摄入蓝藻量进行研究,旨在了解鱼体中GST基因的表达量与水体中蓝藻含量的内在联系。结果表明,4月份水库蓝藻暴发,也是鲮和尼罗罗非鱼摄食产毒蓝藻量最多的月份。GST基因的表达情况是:4月份鲮GST基因表达量比其他月份低,可能与鲮对有毒蓝藻的敏感性和耐受力有关,4月份尼罗罗非鱼GSTA及GSTR2表达量最高;其他月份,鲮GSTT表达量最高,而GSTK表达量较低,尼罗罗非鱼GSTA及GSTR2表达量相对较低。结果表明鲮GSTT在去毒过程中起重要作用,但作为环境检测的生物标记,仅适用于环境中藻毒素较低的情况。尼罗罗非鱼GSTA和GSTR2的表达量与食物中的产毒蓝藻生物量多少成正比,因此,尼罗罗非鱼GSTA及GSTR2可作为环境中藻毒素的生物标记,且尼罗罗非鱼可摄入大量有毒蓝藻,通过GST基因去除有毒蓝藻毒性,可用于生物控藻,改善水质。     

不同供饵条件下网养草鱼生长效果的初步研究

通过对6种不同供饵条件下网箱养草鱼试验结果的分析,探讨了不同供饵条件对草鱼营养生长特性的影响.结果表明:配方合理的草鱼用膨化饲料加适量青料投喂组网箱草鱼生长效果最明显,每尾是均增重高达12.2081;主蛋白饲料豆饼、棉饼、菜饼按1.00∶1.25∶3.75的比例进行配方较合理;试验网箱鱼肌肉、血液、肝脏的总糖、总脂、总蛋白质含量均高于同规格池塘草鱼的相应指标,肝脏总脂含量虽高但非“脂肪肝”.     

干扰素防治草鱼出血病的效果初探

对人工的鲫鱼干扰素防治草鱼出血病的效果进行了初步探讨。结果表明，人工诱导的鲫鱼干扰素确能有效防治草鱼出血病，腹腔注射和药浴浸泡两种匀有一定效果。在病毒感染前使用干扰素处理的效果好于在病毒感染后使用干扰素处理。多次使用干扰素处理的效果好于一次性处理。     

Dietary lysine requirement of juvenile Jian carp (cyprinus carpio var. Jian)

This study was designed to determine the dietary lysine requirement of juvenile Jian carp (cyprinus carpio var. Jian). A total of 990 juvenile Jian carps (initial weight 7.89 ± 0.04 g) were randomly allocated six groups of each three replicates, feeding isonitrogenous (320 g kg^?1 crude protein) and isolipidic (50 g kg^?1 crude fat) diets containing graded levels of coated l ‐lysine, with dietary lysine content ranging from 22 to 69 g kg^?1 of protein, respectively, for 80 days. Final weight, protein deposition and protein production value were significantly improved in response to the increasing levels of dietary lysine up to 59 g kg^?1 of protein and remained nearly constant thereafter. Whole‐body protein content followed a similar pattern as growth parameters in relation to dietary lysine level. Hepatopancreas and intestine protein content, hepatopancreas index (HSI) and intestine index (ISI) were positively affected by dietary lysine level. The dietary lysine requirement of juvenile Jian carp estimated by broken line analysis based on weight gain was 59 g kg^?1 of protein.     

Substrate specificity of carp hepatopancreatic cathepsin S for peptides and myofibrillar proteins

SUMMARY: From 250 g of carp hepatopancreas, 0.29 mg of the purified enzyme was obtained. The bond specificity of cathepsin S for α-neoendorphin and neurotensin was ⁶Arg-⁷Lys and ³Tyr-⁴Glu, respectively. The cleavage sites for insulin B-chain were estimated to be the bonds at ³Asn-⁴Gln, ⁶Leu-⁷Cys, ¹²Val-¹³Glu, ¹³Glu-¹⁴Ala, ¹⁶Tyr-¹⁷Leu, ²²Arg-²³Gly, ²⁴Phe-²⁵Phe and ²⁶Tyr-²⁷Thr. P2 position on these peptides were bulky and hydrophobic amino acid residues such as Phe or Leu, small amino acid residues such as Gly, Ala and Val were also accepted in these positions. Regarding the protein substrates, cathepsin S degraded carp α-actinin, actin, tropomyosin and troponins T and I although the proteolyzing speeds were distinct from one another.     

Mechanism of blood coagulation in common carp (Cyprinus carpio)

In vitro, carp blood was anticoagulated by using MgSO₄ at a final concentration of 22.2 mmol L^?1 and sodium citrate at a final concentration of 11.8 mmol L^?1. The coagulation times for carp plasma diluted by ion‐free water (1:1), and that of carp plasma to which thrombocytes and small lymphocytes were added, were measured at 23 °C using standard methods, and then contrasted with the coagulation times for plasma obtained from chickens and rabbits. The shapes of the thrombocytes and small lymphocytes, which were either wet mounted or stained with hematoxylin and eosin, were observed under a light microscope. We found that: (i) the coagulation reaction of carp blood was significantly (P < 0.01) accelerated by the addition of ion‐free water; (ii) the three types of blood cells (thrombocytes, small lymphocytes and red blood cells) promoted plasma coagulation to a similar extent (P > 0.05); (iii) in carp Mg²⁺ plasma and K₂C₂O₄ plasma, the thrombocytes were usually morphologically normal, but many small lymphocytes were destroyed and became aggregated; (iv) in the citrate plasma, thrombocytes were often aggregated, but the small lymphocytes were usually morphologically normal; and (v) the coagulation time for chicken and rabbit plasma was significantly extended by adding ion‐free water.     

荧光假单胞菌灭活疫苗对草鱼的免疫保护效应

从患病草鱼分离出荧光假单胞菌,制备甲醛灭活全菌苗、高温灭活全菌苗、可溶性蛋白及外膜蛋白疫苗。经腹腔注射草鱼后,研究这些疫苗的免疫保护作用。免疫后于不同时间采集血液,用试管凝集法测定血清抗体滴度。实验结果表明,上述疫苗均诱导较强的免疫应答。抗体峰值出现的先后顺序依次为可溶性蛋白组、外膜蛋白组、甲醛灭活全菌苗组及高温灭活全菌苗组;而抗体峰值从高到低依次为甲醛灭活全菌苗组、高温灭活全菌苗组、可溶性蛋白组及外膜蛋白组。细菌攻毒实验显示,4种疫苗免疫后均产生明显的保护效应。其中,高温灭活全菌苗相对保护率最高,达到75%,甲醛灭活全菌苗、外膜蛋白以及可溶性蛋白的相对保护率分别为70%,70%和65%,说明这些疫苗均可用于预防草鱼赤皮病。此外,实验亦显示血清抗体水平与疫苗保护效应并不完全一致。