岳鲤及其双亲(荷包红鲤♀、湘江野鲤♂)LDH同工酶的研究

用聚丙烯酰胺凝胶电泳,结合CS910双波长扫描分析了岳鲤及其双亲(荷包红鲤♀、湘江野鲤♂)6种组织的乳酸脱氢酶同工酶(Lactate Dehydrogenase,LDH)。结果表明:岳鲤及其双亲的LDH同工酶均存在组织特异性;亲本之间LDH同工酶的差异主要表现在肝脏;亲本各组织的大多数LDH同工酶在F_1代得到表现;亲本及F_1代的LDH同工酶可能由基因位点AA′BB′共同控制。本文还讨论了LDH同工酶分析和杂交结果预测的关系。     

Microridges of oral mucosal epithelium in carp,Cyprinus carpio

Summary The surface of carp oral mucosa is characterized by various patterns of microridges about 0.3 m wide, 0.1 m high, and of various lengths. To elucidate the derivation and function of these microridges, the oral epithelium was examined by light- and electron microscopy. Microridges were present only on the surfaces of the superficial cells. Therefore, microridges on renewed superficial cells are presumed to be formed after old superficial cells have been discarded, and the various patterns of microridges found on the cell surface appear to indicate the progress of their development. In thin sections, the outer leaflet of the plasma membranes of microridges stained strongly with ruthenium red, and the underlying cytoplasm was packed with many fine filaments. The superficial cells contained many secretory vesicles that were PAS-positive but Alcian blue-negative at pH 2.5 and pH 1.0. However, after sulfation the vesicles gave a positive reaction with toluidine blue. These vesicles are secreted by exocytosis at the free surface of the cells. After release, the membranes of the vesicles are thought to be utilized for formation of microridges. On the basis of these observations, the possible function of microridges is discussed.This study was supported by grants from the Ministry of Education, Science and Culture, Japan     

大黄蒽醌提取物对建鲤抗应激及生长的影响

将750尾建鲤随机分成5组,第1组为对照组,投喂基础日粮,另外4组为试验组,投喂基础日粮中分别添加0.5%、1.0%、2.0%、4.0%大黄蒽醌提取物。从2005年7月到9月连续投喂70d后,对鱼体进行高密度应激,测定其生长、应激前后血液皮质醇、血糖、溶菌酶等变化。结果表明:与对照组相比,应激前添加大黄蒽醌提取物提高了鱼体增重率、特定生长率、鱼体丰满度、血液溶菌酶活性,降低了饵料系数与鱼体死亡率,但是与大黄蒽醌提取物的添加水平不成线性关系,其中2.0%试验组还显著降低了血液皮质醇。高密度应激1d后,各组血液中的皮质醇、血糖、溶菌酶都有不同程度的增加,其中对照组最高,添加1.0%和2.0%大黄蒽醌提取物的试验组相对较低。应激前后各组鱼的攻毒试验表明:除应激前添加1.0%和2.0%大黄蒽醌提取物的组没有死鱼外,其它各组都有死鱼,其中对照组死亡率最高。因此添加1.0%-2.0%大黄蒽醌提取物提高了机体抗应激能力,并对病原菌感染起一定的保护作用,促进了鱼体生长。     

脆化草鱼(Ctenopharyngodon idellus C.et V)的病理生理生态学

分别就形态、生态和病理学性状对处于脆化终极阶段（LD50≥6．67kg／kgbw）的草鱼与普通草鱼进行比较分析。高度脆化的草鱼在生态学上出现明显变化,体长和体重的指数方程W=al^n显著不同于普通草鱼,DO阈值由平均值O．54mg／L上升到平均值1．68mg／L,CO2麻醉浓度（呼吸抑制值）由194mg／L高浓度下降到52．42～65．36mg／L,Root效应及Broh效应显著改变。解剖分析表明,草鱼脆化过程是渐进性组织病变的生理过程,包括各系统器官的功能性病变,最终使过度脆化的草鱼由于血液循环障碍直接导致死亡。草鱼脆化死亡具有明显的饲料（蚕豆）累积剂量——效应反应的毒理学规律,脆化草鱼的体长与体重的指数方程W=18．1719L^2.4360可作为华南地区商品脆肉鲩标准的参考。研究结果将为脆化草鱼规模化集约养殖和提高脆化草鱼长途运输成活率提供参考。     

Molecular cloning and characterization of alpha-class glutathione S-transferase gene from the liver of silver carp, bighead carp, and other major Chinese freshwater fishes

Two full-length cDNAs encoding glutathione S-transferase (GST) were cloned and sequenced from the hepatopancreas of planktivorous silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis). The silver carp and bighead carp GST cDNA were 920 and 978 bp in length, respectively, and both contained an open reading frame that encoding 223 amino acids. Partial GST cDNA sequences were also obtained from the liver of grass carp (Ctenopharyngodon idellus), crucian carp (Carassius auratu), mud carp (Cirrhinus molitorella), and tilapia (Oreochromis nilotica). All these GSTs could be classified as alpha-class GSTs on the basis of their amino acid sequence identity with other species. The three-dimensional structure of the silver carp GST was predicted using a computer program, and was found to fit the classical two-domain GST structure. Using the genome walker method, a 875-bp 5'-flanking region of the silver carp GST gene was obtained, and several lipopolysaccharide (LPS) response elements were identified in the promoter region of the phytoplanktivorous fish GST gene, indicating that the GST gene expression of this fish might be regulated by LPS, released from the toxic blue-green algae producing microcystins. To compare the constitutive expression level of the liver GST gene among the six freshwater fishes with completely different tolerance to microcystins, beta-actin was used as control and the ratio GST/beta-actin mRNA (%) was determined as 130.7 +/- 6.6 (grass carp), 103.1 +/- 8.9 (bighead carp), 92.6 +/- 15.0 (crucian carp), 72.3 +/- 7.8 (mud carp), 58.8 +/- 11.5 (silver carp), and 33.6 +/- 13.7 (tilapia). The constitutive expression level of the liver GST gene clearly shows that all the six freshwater fishes had a negative relationship with their tolerance to microcystins: high-resistant fishes (phytoplanktivorous silver carp and tilapia) had the lowest tolerance to microcystins and the high-sensitive fish (herbivorous grass carp) had the highest tolerance to microcystins. Taken together with the reciprocal relationship of constitutive and inducible liver GST expression level in some of the tested fish species to microcystin exposure, a molecular mechanism for different microcystin detoxification abilities of the warm freshwater fishes was discussed.     

Environmental correlate of the testicular events in a major carp Catla catla in an annual reproductive cycle

Current communication describes annual testicular events in free-living Indian major carp Catla catla and their probable environmental synchronizer(s). The study was initiated with month-wise evaluation of gametogenic and steroidogenic status of the testis, and thus dividing the annual testicular cycle into the preparatory spawning (November to March), the pre-spawning (April to June), the spawning (July to August) and the post-spawning (September to October) phases. An exhaustive statistical analysis of the data on the studied variables of testicular functions and various components of the environment indicated seasonal fluctuations of photoperiod as the major environmental factor associated with the seasonal reproductive activity of this carp. Ambient temperature appeared as a dependent variable of photoperiod, and thereby, may have substantial influences on the development of testis in Catla catla. Rainfall, on the other hand, showed significant correlation only with the peak reproductive activity, i.e. the act of spawning. Collectively, it appears logical to surmise that photo-thermal conditions may act as proximate and rainfall may play a role of ultimate environmental factor in the regulation of annual testicular events in Indian major carp Catla catla.     

Die Gefriertrocknung von Rinderkot

Fatty acids in fish can arise from two sources: synthesis de novo from non‐lipid carbon sources within the animal, or directly from dietary lipid. Acetyl‐CoA derived mainly from protein can be converted to saturated fatty acids via the combined action of acetyl‐CoA carboxylase and fatty acid synthetase. The actual rate of fatty acid synthesis de novo is inversely related to the level of lipid in the diet. Freshwater fish can de‐saturate endogenously‐synthesized fatty acids to monounsaturated fatty acids via a A9 desaturase but lack the necessary enzymes for complete de novo synthesis of polyunsaturated fatty acids which must therefore be obtained preformed from the diet. Most freshwater fish species can desaturate and elongate 18:2(n‐6) and 18:3(n‐3) to their C20 and C22 homologues but the pathways involved remain ill‐defined. Cyclooxygenase and lipoxygenase enzymes can convert C20 polyunsaturated fatty acids to a variety of eicosanoid products. The dietary ratio of (n‐3) to (n‐6) polyunsaturated fatty acids influences the pattern of eicosanoids formed. The ß‐oxidation of fatty acids can occur in both mitochondria and peroxisomes but mi‐tochondrial ß‐oxidation is quantitatively more important and can utilise a wide range of fatty acid substrates.     

Orally administered LPS enhances head kidney macrophage activation with down-regulation of IL-6 in common carp (Cyprinus carpio)

Immunostimulants represent a promising aquaculture tool for enhancing disease and stress resistance in cultured fish. Moreover, the term and dose for acting immunostimulants is an important thing for fish farmer. This study investigated the immune parameters of common carp after oral administration of LPS (5, 10, 20 μg/kg/days) for 30 and 60 days, which is considered to be the proper time period for acting in aquaculture. Phagocytic and bactericidal activities of head kidney macrophages and serum lysozyme activities were significantly enhanced in LPS-fed carp. Orally administered LPS augmented the expression of interleukin (IL)-1β and TNF-α mRNAs but reduced the expression of IL-6 mRNA in head kidney. Although LPS was detected in the serum and liver after a high-dose (>15 mg/kg) oral administration, it was not detected by administered LPS-specific ELISA after a low-dose (<20 μg/kg) administration. It is speculated that orally administered LPS enhances the eliminating functions of head kidney macrophages with down-regulation of IL-6.     

新疆伊犁河鲫鱼遗传多样性初步研究

为了解我国西北地区野生鲫鱼的遗传多样性,鲫鱼样品从新疆伊梨河中采用小型拖网捕获。通过解剖观察性腺鉴定性别;采用碘化丙啶（PI）染色,经流式细胞仪测定血细胞核DNA含量;采用非变性聚丙烯酰胺凝胶电泳,考马斯亮蓝染色分析血清转铁蛋白多态性。结果表明：新疆伊梨河鲫鱼群体为具雌、雄的两性个体的群体;伊犁河鲫鱼血细胞核DNA平均含量为(5.315±0.215) pg/个细胞核,血细胞核DNA含量约为二倍体彩鲫DNA含量的1.53倍,与银鲫血细胞核DNA含量相当;在所采集的鲫鱼样品中共发现9种转铁蛋白表现型, 由7个等位基因调控,等位基因频率依次为Tf a0.063、Tf b0.063、Tf f0.095、Tf g0.169、Tf c0.174、Tf e0.175和Tf d0.270。基因型频率分别为Tf cd0.043、Tf cdf0.043、Tf abdg0.043、Tf def 0.087、Tf ce0.13、Tf de0.13、Tf df0.13、Tf abeg0. 13和Tf cdg0.26。综合分析,伊犁河现存野生鲫鱼为银鲫,且具有两性融合生殖能力。伊犁河鲫鱼表现出的遗传特性可能与该特定水环境有关。     

Biomanipulation: a review of biological control measures in eutrophic waters and the potential for Murray cod Maccullochella peelii peelii to promote water quality in temperate Australia

Biomanipulation is a method of controlling algal blooms in eutrophic freshwater ecosystems. The most common approach has been to enhance herbivores through a reduction of planktivorous fish and introduction of piscivorous fish. The method was originally intended to reduce grazing pressure on zooplankton, thereby increasing grazing pressure on phytoplankton to increase water clarity and promote the growth of aquatic macrophytes. Biomanipulation has received considerable attention since it was proposed in 1975 where innovative approaches and explanations of the processes have been developed. Although many successful biomanipulation exercises have been conducted internationally, it has received comparatively little attention in the Southern Hemisphere and has not been trialled in the southern temperate climate of South Australia. This is a review to speculate upon the criteria for and against the application of biomanipulation in southern temperate Australia using the native species Murray cod (Maccullochella peelii peelii) and to suggest future research.