三倍体雌性虹鳟性腺发育阶段细胞色素相关基因的表达

Cyp19a1b、Cyp11a1、Cyp11b2、Cyp17a1、Hsd3b1等细胞色素相关基因能够调节硬骨鱼类性类固醇的合成,对性腺发育和性别决定产生影响。本研究以全雌三倍体虹鳟(Oncorhynchus mykiss)为研究对象,正常雌性二倍体虹鳟为对照,选取31~68 dpf(days post fertilization)时间段的虹鳟仔鱼脑组织,采用q RT-PCR和酶联免疫的方法研究以上几种基因的表达状况和脑芳香化酶的活性变化,以期探明导致三倍体雌性虹鳟性腺发育异常的关键原因。q RTPCR结果显示,二倍体中Cyp19a1b在30~50 dpf时表达量上调并且维持在较稳定水平,但50~56 dpf时表达量逐渐下调,之后56~68 dpf表达量持续上调;三倍体中Cyp19a1b表达量在30~35 dpf开始上调,35~47 dpf逐渐下调,47~55 dpf开始第二次上调,之后维持在较稳定水平直至68 dpf,但三倍体Cyp19a1b的表达量显著(P0.05)低于同期二倍体的。二倍体Cyp11a1表达量在34 dpf出现峰值,三倍体Cyp11a1在38 dpf时出现峰值。二倍体Hsd3b1表达量在33~42 dpf时维持在较高水平,在38 dpf时出现高峰;三倍体Hsd3b1表达量在47~59 dpf时较高,在49 dpf出现高峰。二倍体中Cyp11b2在37 dpf出现峰值,之后开始下调;三倍体在40 dpf出现峰值,之后逐渐下调,但三倍体Cyp11b2表达量显著低于同期二倍体。二倍体Cyp17a1的表达量在35~46 dpf时逐渐上升,在45 dpf时达到高峰之后直至69 dpf逐渐下降,并且维持在较为平稳的水平上;但是在相同的实验条件下未检测到同一时期三倍体Cyp17a1的表达量。酶联免疫结果显示,在40 dpf时二者的脑芳香化酶活性到达高峰,但在40~60 dpf时期,二倍体虹鳟脑芳香化酶活性显著(P0.05)高于三倍体虹鳟,尤其在45~50 dpf时,该酶活性分别较三倍体的高1.15倍和1.12倍。以上结果表明三倍体虹鳟早期性腺发育迟缓的原因之一是Cyp19a1b、Cyp11a1、Cyp11b2、Cyp17a1、Hsd3b1等基因的表达晚于二倍体,且表达量低于二倍体,造成雌二醇不能正常合成,最终导致性腺发育迟缓。     

图们江陆封型马苏大麻哈鱼的个体繁殖力

为研究马苏大麻哈鱼(Oncorhynchus masou)资源保护策略和人工繁殖技术,对人工养殖的图们江陆封型马苏大麻哈鱼繁殖力进行了研究。选取122尾不同养殖区域卵巢发育Ⅳ-Ⅴ期的马苏大麻哈鱼样本(其中延吉42尾、山东35尾、北京45尾)进行统计分析。试验马苏大麻哈鱼体重209~845 g,平均为(512±206)g;体长17.0~39.5 cm,平均为(26.81±6.53)cm。结果表明,大麻哈鱼的绝对繁殖力410~3 075粒,平均为(1 485±797)粒;体重相对繁殖力1.93~3.64粒/g,平均为(2.72±0.47)粒/g;体长相对繁殖力23.60~77.85粒/cm,平均为(51.35±17.60)粒/cm;Ⅴ期卵巢性腺指数14.85%~27.93%,平均为(20.97±3.57)%;繁殖力随着体重、体长、性腺指数增加而提高(P0.01)。通过人工驯养和移植培育,改变了马苏大麻哈鱼在自然环境下雌鱼卵巢发育不成熟的现象,而且繁殖力明显提高。移植到北京和山东后,其繁殖力极显著高于原产地(P0.01)。国产陆封型马苏大麻哈鱼具有规模化人工繁育的优势,能够为野生种群资源增殖提供苗种补充。     

不同消毒剂对三种鲑科鱼受精卵成活率的影响

在水温4.5±1.3℃下和桶式流水孵化器中,研究了不同浓度过氧化氢水溶液、聚维酮碘、甲醛溶液和二氧化氯对虹鳟（Oncorhynchus mykiss）、金鳟（Oncorhynchus mykiss）和白斑红点鲑（Salvelinus leucomaenis）受精卵至发眼期胚胎的成活率和防治水霉菌等感染的效果。结果表明：二氧化氯处理组与对照组鱼胚胎的发眼率与畸形率差异显著;聚维酮碘处理组鱼胚胎的发眼率虽与对照组无显著差异,但畸形率明显高于甲醛对照组。因此,聚维酮碘和二氧化氯不适于这三种鱼受精卵的消毒。1000 mg.L-1的过氧化氢饱和水溶液（双氧水）与1500 mg.L-1甲醛处理组鱼胚胎的在发眼率无显著差异,但随着药物浓度的增加,其畸形率显著高于对照组。因此,建议鲑鳟鱼受精卵孵化过程中可用1000 mg.L-1双氧水防止水霉菌滋生,提高受精卵的成活率。     

基于MHC\|DAB基因内含子序列的3种虹鳟养殖群体遗传结构分析

虹鳟是当前全球性养殖品种,采用PCR\|SSCP的方法,分析了甘肃金鳟、道氏虹鳟和美国金鳟三个虹鳟养殖群体各30个个体MHC\|DAB基因第2内含子序列（308 bp）的遗传变异。108个阳性克隆经SSCP筛选及测序,共获得11种不同的核苷酸序列（Ⅰ~Ⅺ）,单个个体最多存在4种等位基因。等位基因Ⅱ、Ⅲ、Ⅵ是三个群体共有的;Ⅳ仅存在于道氏虹鳟中;Ⅶ仅存在于甘肃金鳟中;Ⅸ、Ⅹ、Ⅺ仅存在于美国金鳟中。甘肃金鳟、道氏虹鳟、美国金鳟群体内核苷酸多态位点分别为17个、19个、22个,核苷酸多样性指数（Pi）分别为0.005、0.008、0.013,平均核苷酸位点差异数（K）分别为1.200、2.000、3.333。甘肃金鳟群体与道氏虹鳟群体间的遗传距离最小(0.231),与美国金鳟群体间的遗传距离最大(0.539),三个群体间的遗传分化均达到了种群的分化标准（D＞0.05）。群体遗传分化系数GST为0.097,表明变异主要来源于群体内个体间。     

道氏虹鳟同工酶的组织分布及表达

运用聚丙烯酰胺凝胶电泳的方法,初步研究了道氏虹鳟(Oncorhynchus mykiss)的7种同工酶(GDH、SOD、LDH、α-AMY、POD、EST、MDH)在5种组织(眼、心脏、肾脏、肝脏、肌肉)中的分布及位点表达。结果表明,道氏虹鳟除α-AMY外的6种同工酶都具有明显的组织特异性。生化遗传研究发现7种同工酶共记录27个基因座位,多态座位百分数P=29.63%,平均有效等位基因数Ne=1.2963,说明道氏虹鳟的群体遗传多样性在鱼类中处于中等水平。     

In vitro and in vivo effects of some pesticides on glucose-6-phosphate dehydrogenase enzyme activity from rainbow trout (Oncorhynchus mykiss) erythrocytes

We investigated the in vitro and in vivo effects of some pesticides on rainbow trout erythrocyte glucose-6-phosphate dehydrogenase enzyme. The enzyme was purified 1691-fold with a specific activity of 16.235 U/mg protein and a yield of 63%. Cypermethrin, and propoxur inhibited glucose-6-phosphate dehydrogenase enzyme in vitro and deltamethrin inhibited both in vivo and in vitro. The obtained IC₅₀ values for deltamethrin, cypermethrin, and propoxur were 0.63, 1.02, and 12 mM, respectively. The activity of the control was determined as 5.17 ± 0.62 U/g Hb in in vivo studies. The enzyme activities of the groups treated with 0.25 g/L deltamethrin were measured at 6, 12, 24, 48, and 72 h, and found to be 4.32 ± 0.47, 3.57 ± 0.39, 3.47 ± 0.45, 2.86 ± 0.37, and 2.31 ± 0.32 U/g Hb. In vivo experiments showed that deltamethrin significantly inhibited the G6PD enzyme activity after the 48th h (p < 0.05).     

人工养殖硬头鳟鱼卵的营养成分分析

[目的]分析硬头鳟鱼卵营养成分,为综合开发硬头鳟鱼卵产品提供理论依据.[方法]以山泉水人工养殖的硬头鳟成熟卵为研究对象,对其常规营养组成、氨基酸及脂肪酸成分、矿物质及维生素含量进行测定,并对其营养品质进行评价.[结果]硬头鳟鱼卵中粗蛋白含量为25.4%,粗脂肪含量为3.6%;包含人体必需氨基酸8种、非必需氨基酸10种,氨基酸总量为24.32%,必需氨基酸含量为10.79%,占氨基酸总量的44.37%,必需氨基酸总量与非必需氨基酸总量比值(移EAA/移NEAA)为79.75%;谷氨酸含量(3.00%)最高,必需氨基酸中除色氨酸外,其余氨基酸评分均高于联合国粮农组织/世界卫生组织(FAO/WHO)标准,第一限制性氨基酸为色氨酸.硬头鳟鱼卵中共检测到饱和脂肪酸3种,不饱和脂肪酸13种,不饱和脂肪酸含量占脂肪酸总量的84.40%;含有多种人体所需的常量矿质元素(Na、K、Mg、P和Ca)、微量矿质元素(Cu、Zn、Fe、Mn和Se)和维生素(VE、VA、VB1和VB2).[结论]硬头鳟鱼卵具有高蛋白、低脂肪的特点,营养全面且品质优良,可作为保健食品进行开发利用.     

乌苏里江大麻哈鱼（♀）婚姻色差异的生态指征意义

黑龙江大麻哈鱼（Oncorhynchus keta）繁殖群体由鄂霍次克海经俄罗斯境内的黑龙江干流洄游至我国境内即分成黑龙江和乌苏里江两个地理群体。过去大麻哈鱼洄游至我国时婚姻色均较浓艳,但近十年来发现洄游至乌苏里江的大麻哈鱼部分个体婚姻色浓艳,部分婚姻色很浅或无色。为了揭示婚姻色浓淡差异的原因及其对大麻哈鱼繁殖适应性的指征作用,笔者于2011年9月20～29日,对乌苏里江大麻哈鱼回归繁殖群体进行了调查,共采集样品94尾,将其划分为婚姻色浓艳个体组（红色度a＋值〉13）和浅淡个体组（红色度a赤〈7）,进行了两群组间的繁殖生态学参数比较分析。结果表明,浅淡个体的成熟系数（CSI）、卵径、卵重、年龄、体长和体质量均小于浓艳个体,且差异极显著（P〈0．01）;婚姻色浅淡个体的绝对繁殖力显著小于浓艳个体（P〈0．05）;但二者的肥满度指数差异不显著。两群组间各繁殖生态参数间相关关系的差异分析表明,婚姻色浅淡个体性腺发育落后于浓艳个体,表明婚姻色浅淡个体的繁殖适合度低于婚姻色浓艳个体。     

Effect of dietary inclusion of lysozyme on growth performance and plasma biochemical parameters of rainbow trout (Oncorhynchus mykiss)

This study was conducted to evaluate the effect of dietary lysozyme supplementation on growth performance and plasma biochemical parameters of rainbow trout (Oncorhynchus mykiss). Graded levels of lysozyme [0 (control), 150, 300, 450 and 600 mg kg^?1 diet] were fed to fish (initial average weight 7.76 g) for 10 weeks. Dietary lysozyme supplementation regardless of inclusion level generally improved the growth, feed utilization and nutrient retention, but significant differences were mainly observed between the 450 or 600 mg kg^?1 lysozyme group and the control group. Lysozyme supplementation generally decreased the plasma aspartate aminotransferase and alanine aminotransferase (ALT) activities, but significant difference was only observed in the ALT activity between the 450 mg kg^?1 lysozyme group and the control group. In contrast, lysozyme supplementation generally increased the plasma alkaline phosphatase and lysozyme activities, but significant difference was only observed in the lysozyme activity between the 600 mg kg^?1 lysozyme group and the control group. Lysozyme supplementation generally increased the plasma antioxidant activities of enzymes (including superoxide dismutase, glutathione peroxidase and catalase) and total antioxidant capacity, but decreased the plasma malondialdehyde level. These results suggest that dietary 450–600 mg kg^?1 lysozyme inclusion may improve the growth and non‐specific immune response of rainbow trout.     

The effectiveness of adenoviral vectors to deliver and express genes in rainbow trout,Oncorhynchus mykiss (Walbaum)

The efficacy of adenoviral vectors for gene delivery into fish cells, both in vitro and in vivo, was evaluated. Vectors utilized were of human adenovirus serotype 5 (Ad), which are commonly used in human clinical trials, but have not been assessed for gene delivery to fish. Because nothing is known about Ad receptors in fish, both an Ad (Ad5Luc1) with natural tropism for the coxsackie and adenovirus receptor (CAR), as well as an infectivity enhanced Ad (Ad5LucRGD) were included within this study. Gene expression was detected in cell lines using either vector. The levels seen with Ad5LucRGD were much higher than for Ad5Luc1 in most lines except CHSE-214. Transduction of CHSE-214 cells with Ad5Luc1 could be blocked with an excess of a competitive inhibitor, suggesting that these cells possess a CAR homologue thatmediates attachment of Ad, similar to that seen in mammalian cells. In vivo gene delivery was attempted by several methods, with significant expression seen only via intramuscular injection, although infection efficiency was low. Thus it was observed that several teleost cell lines are capable of being infected and one cell line expressed a human serotype adenoviral receptor homologue that aids in Ad infection. Additionally, in vivo studies indicated that muscle tissue of rainbow trout could be infected with Ad vectors, suggesting an alternative gene delivery strategy for this animal.