Inbreeding depression and heterosis in various quantitative traits of the guppy, Poecilia reticulata

The present study examines the effects of inbreeding and crossing on various quantitative traits in the guppy, Poecilia reticulata. Effects of inbreeding and crossing were examined in six quantitative traits; body length at birth, survival at day 120, undwarf rate at day 120, body length at day 120, salinity tolerance and high temperature tolerance. Full-sib matings revealed that the amount of inbreeding depression varied from −1.0% to 24.6% among the traits and a significant decrease in survival at day 120 and salinity tolerance was observed. This result indicates that inbreeding reduces the performance for some of the quantitative traits but not all. On the other hand, crosses between genetically different strains showed that the amount of heterosis varied from −1.3% to 42.2% among the six quantitative traits and a significant increase in survival at day 120 and salinity tolerance was observed. The relationship between the amount of inbreeding depression and heterosis supports the theory that the phenomenon of heterosis is the reverse of inbreeding depression, indicating that the traits which have decreased by inbreeding can be recovered by means of crossing.     

栅栏技术在淡腌半干鲈鱼加工工艺中的应用

为确定在实验条件下大口黑鲈 (Micropterus salmoides) 幼鱼适合的麻醉方式与麻醉剂量,研究比较了7种不同质量浓度的MS-222 (40 mg·L^–1、50 mg·L^–1、60 mg·L^–1、70 mg·L^–1、80 mg·L^–1、90 mg·L^–1、100 mg·L^–1)和丁香酚(8 mg·L^–1、10 mg·L^–1、12 mg·L^–1、14 mg·L^–1、16 mg·L^–1、18 mg·L^–1、20 mg·L^–1) 2种常见渔用麻醉剂对体质量为(130±10) g的大口黑鲈幼鱼的静水麻醉效应。静水麻醉实验结果表明：1)随着2种麻醉剂浓度升高,幼鱼入麻时间缩短,复苏时间延长;2)在实验条件下,MS-222与丁香酚的最适麻醉质量浓度分别为70 mg·L^–1和16 mg·L^–1,最适运输质量浓度分别为50 mg·L^–1和10 mg·L^–1。使用最适运输浓度的MS-222和丁香酚对幼鱼进行10 h模拟运输,观察麻醉效应和分析血清生化指标发现：1)麻醉组运输成活率和复苏后24 h成活率均为100%,显著高于无麻醉运输组的80%和60% (P<0.05);2)较之无麻醉运输组和静水对照组,麻醉运输组的丙氨酸转氨酶(ALT)、天门冬氨酸转氨酶(AST)水平显著升高(P<0.05)。在麻醉运输组中,MS-222麻醉组的ALT和AST水平显著高于丁香酚麻醉组(P<0.05)。     

鲤细胞因子多克隆抗体的制备及检测

为从蛋白质水平研究细胞因子在鲤体内免疫应答过程中的合成变化,本研究采用PCR技术克隆TNF-α、IL-1β、IL-6、IL-12、IL-10和TGF-β基因含有部分抗原决定簇的片段,引入双酶切位点Bam HⅠ和HindⅢ后连接至p ET-32a/21a,构建相应的表达载体,制备多克隆抗体。采用ELISA检测抗体效价,并以此作为实验工具,检测经嗜水气单胞菌感染后鲤血清中炎性细胞因子的合成变化。结果显示,基因TNF-α、IL-1β、IL-6、IL-12、IL-10和TGF-β融合蛋白分子量分别约为31.8、31.7、35.3、32.5、18.0和33.6 ku;抗体效价达到2.4×106;在病原菌感染后的不同阶段,促炎细胞因子TNF-α、IL-1β、IL-6、IL-12和抗炎细胞因子IL-10、TGF-β呈现出不同的合成变化。研究表明,制备的抗体具有较高的效价、亲和力和特异性,可用于鲤细胞因子的定量研究,该抗体的获得为鲤免疫应答与细胞因子合成的系统研究奠定了基础。同时,获取的鲤细胞因子TNF-α、IL-1β、IL-6、IL-12、IL-10和TGF-β的抗体亦可用于其他鱼类细胞因子蛋白质水平的定量研究。     

Two monoclonal antibodies for the recognition of Mytilus spp. larvae: studies on cultured larvae and tests on plankton samples

Monoclonal antibodies (mAbs) were generated against 2-day-old mussel larvae in an attempt to develop a rapid and rigorous method for the identification of mussel larvae in field plankton samples. Previously, we have shown that two of these mAbs recognised Galician Mytilus galloprovincialis obtained from monospecific cultures, but did not recognise the larvae of other bivalve species present in that area. To assess the possibility of using these mAbs in routine assays for measuring the abundance of mussel larvae in plankton, studies on cultured mussel larvae, at different stages of development, and tests on bivalve larvae from plankton samples were carried out. Initially, to see whether the two mAbs also recognise other mussel larval stages, they were tested against mussel larvae of different ages obtained from monospecific cultures. The results indicate that both antibodies stain all the stages tested, even 1-month-old postlarvae. In addition, we also demonstrate that these mAbs also recognise other forms of Mytilus. Both antibodies bind to M. galloprovincialis larvae from the Mediterranean Sea and M. edulis larvae. Finally, and more significantly, studies on field plankton samples were performed to confirm if both mAbs are really mussel-specific, and do not cross-react with larvae of any other bivalve species existing in the plankton. The results presented here clearly indicate that our two monoclonal antibodies specifically recognise the mussel larvae in field plankton samples from different geographical regions, but not the larvae of any other bivalve species. Thus, these monoclonal antibodies could be used for routine monitoring of mussel larvae in plankton samples from different sources.     

Generation of mouse monoclonal antibodies specific to tilapia immunoglobulin using fish immunoglobulin/BSA complex for monitoring of the immune response in Nile tilapia Oreochromis niloticus

The simple immunoprecipitation method was used to isolate tilapia immunoglobulin (Ig) for immunization in order to produce monoclonal antibodies (MAbs) specific to tilapia Ig. First, the tilapia antiserum against bovine serum albumin (BSA) was prepared by peritoneal injection of BSA into tilapia, and the tilapia anti‐BSA antiserum was used to precipitate BSA to form the Ig/BSA immune complex. The Ig/BSA immune complex was then injected into Swiss mice for hybridoma production. After fusion, three hybridoma clones producing MAbs specific to the tilapia antibody were selected by dot blot and Western blot. All MAbs (101A, 59G, and 11A) were bound specifically to the heavy chain of immunoglobulin M (IgM). The MAbs 101A and 59G demonstrated twofold higher affinity than MAb 11A and the commercialized antibody. However, MAbs 11A could also bind to the heavy chain of IgM in Asian seabass, Lates calcarifer, as well. These MAbs can be used to monitor the immune responses of individual fish by indirect ELISA upon exposure to various antigens.     

卵黄抗体对凡纳滨对虾生长、免疫及抗VpAHPND感染的影响

为探讨特异性卵黄抗体抗致急性肝胰腺坏死病副溶血弧菌 (Vibrio parahaemolyticus associated with acute hepatopancreatic necrosis disease, VpAHPND) 感染的效果及其机制,防控对虾急性肝胰腺坏死病 (Acute hepatopancreatic necrosis disease, AHPND),本研究以添加不同剂量VpAHPND卵黄抗体制剂 (0、0.2%和0.5%) 的饲料投喂凡纳滨对虾幼虾,测定对虾的生长率和存活率、对虾肝胰腺免疫酶活力和免疫基因相对表达水平,通过浸浴感染实验测定免疫对虾抗VpAHPND感染的能力。生长实验结果显示,免疫28 d后,免疫组与未添加卵黄抗体制剂的对照组对虾在平均生长率、特定生长率和存活率方面均无显著性差异。免疫功能实验结果显示,免疫14 d后,与对照组相比,0.2%免疫组对虾肝胰腺的酚氧化酶 (PO)、超氧化物歧化酶 (SOD)、溶菌酶 (LZM) 活力显著升高,抗菌肽 (Crustin) 基因的相对表达水平也显著升高,而β-1,3-葡聚糖结合蛋白-脂蛋白 (β-GBP-HDL) 基因的相对表达水平则显著降低。浸浴感染实验结果显示,0.2%免疫组对虾的存活率显著高于对照组;0.2% VpAHPND卵黄抗体制剂对凡纳滨对虾的相对免疫保护率为63.77%。研究表明,口服卵黄抗体不会对凡纳滨对虾的生长和存活产生不良影响,0.2%的VpAHPND卵黄抗体制剂通过提升凡纳滨对虾的PO、SOD、LZM活力和Crustin基因表达水平,增强凡纳滨对虾的免疫功能,从而提高对虾抗VpAHPND感染的能力,具有很强的应用潜力。本研究为使用特异性卵黄抗体防控AHPND提供了依据,也为其作用机制研究提供了参考。     

利用海洋微藻生产富含DHA的单细胞油脂

该文基于CIE-L^*a^*b^*颜色分析系统,采用全自动分光测色仪对热带普通小球藻 (Chlorella vulgaris) 生长过程中的颜色值变化进行监测,同时测定其细胞密度及色素的质量浓度变化并进行相关分析。结果显示,热带普通小球藻生长过程中细胞密度分为接种期、快速生长期、稳定期和衰亡期4个阶段,绿色素和黄色素质量浓度和颜色参数值黄度值(b^*)、色差值(△E)和饱和度(C)均呈增加趋势,而颜色参数值明度值(L^*)、红度值(a^*)、相角(H°)呈降低趋势;颜色参数值与细胞密度、色素质量浓度具有较强的相关性,线性回归模型拟合度较高,在快速生长期尤为显著,其中b^*和△E可作为较佳的指示指标。通过量化热带普通小球藻生长过程中的颜色参数变化,建立非接触性数量及质量动态变化预测模型,可快速准确预测,为提高养殖过程中精细操作及效率提供理论基础。

     

江蓠中类菌孢素氨基酸(MAAs)分离纯化及其成分分析

存在于海洋生物中,尤其是藻类中的类菌孢素氨基酸(mycosporine-like amino acids,MAAs),是一种吸收紫外线的物质,可用于紫外线防护品的原料,具有商业开发的前景.对湛江沿海产江蓠中MAAs进行了分离和结构鉴定,确定江蓠MAAs的主要组成及比例.利用C-18 Sep-Pak固相萃取柱和半制备型HPLC对湛江产江蓠中MAAs成分进行分离纯化.根据化合物的特征、紫外吸收波长和波谱数据鉴定其主要成分的结构,并结合参考文献确定湛江产江蓠MAAs的4种主要成分是palythine、shinorine、palythinol和porphyra-334,其比例约为4.9∶1∶1.2∶9.9.同时,比较了UV法和HPLC法对湛江产江蓠MAAs主要成分porphyra-334含量检测的准确度,建立了两种检测方法的拟合曲线,并通过试验验证,最终确立了HPLC对MAAs主要组成成分的检测方法.     

Feeding has the largest effect on the ammonia excretion rate of the southern rock lobster, Jasus edwardsii, and the western rock lobster, Panulirus cygnus

The total ammonia nitrogen (TAN) excretion of spiny lobsters Jasus edwardsii and Panulirus cygnus, was determined in relation to temperature, body weight, emersion, daily rhythm and feeding. Temperature and body weight had large influences on the rate of TAN excretion. Exponential relationships were found between temperature (T) and TAN excretion of both species. These were described by the following equations: J. edwardsii Log₁₀ TAN=0.041T−3.57 (r²=0.979, F=143.2, P=0.001), P. cygnus Log₁₀ TAN=0.057T−3.90 (r²=0.987, F=302.2, P<0.001). TAN excretions of both species were positively correlated to body weight (W), and the relationships were described by the following equations: J. edwardsii Log₁₀ TAN=0.473 log₁₀ W−1.704 (r²=0.42, F=14.05, P=0.001), P. cygnus Log₁₀ TAN=0.499 log₁₀ W−1.346 (r²=0.69, F=44.18, P<0.001). TAN excretion increased significantly when lobsters were re-immersed after a 30 min period of emersion. However, it returned to pre-emersion levels by the second hour of re-immersion. Daily rhythm resulted in a significantly higher nocturnal TAN excretion rate for J. edwardsii; no daily rhythm was observed for P. cygnus. Feeding had the largest influence on TAN excretion, with maximum increases of 6.28 (J. edwardsii) and 5.60 (P. cygnus) times the pre-feeding level. TAN excretion rates remained significantly higher than the pre-feeding levels for an extended period (26 h, J. edwardsii; 30 h, P. cygnus). Implications for the use of purging tanks in lobster holding facilities and for the design of biofiltration systems are discussed.     

广西罗非鱼链球菌病流行菌株PCR鉴定和PFGE基因型分析

为评估吉富罗非鱼(GIFT Oreochromis niloticus)抗病F₅代的选育效果,以F₀代群体和奥尼罗非鱼(Oreochromis aureus×O.niloticus)作为对照组,对F₅代42个家系的抗病性能及生长性能进行评估。对42个家系进行人工腹腔注射感染无乳链球菌 (Streptococcus agalactiae)后,分别有36个和22个家系的感染成活率比F₀代和奥尼罗非鱼高,各家系的抗病育种值为 – 0.158~0.086;生长性能测定发现,42个家系中有27个家系的绝对增长率大于F₀代;感染成活率与体质量之间的遗传相关系数为 – 0.033。综合分析各个家系的感染成活率、抗病育种值和绝对增长率,筛选出抗病力强且生长速度快的家系7个(2^#、3^#、4^#、6^#、28^#、31^#和35^#),可作为F₆代选育和苗种扩繁的亲本。结果表明,经过5个世代的针对性选育,吉富罗非鱼的抗病性能和生长性能均得到了明显改善,选育效果显著。     

茉莉酸甲酯对雨生红球藻虾青素含量和dxs基因表达的影响

雨生红球藻是一种能产生重要次生代谢产物——虾青素的单细胞绿藻,茉莉酸甲酯( MeJA)等诱导因子可促进植物次生代谢产物的积累.以雨生红球藻为研究对象,研究了不同浓度MeJA对雨生红球藻细胞生长、虾青素含量和dxs基因表达的影响.结果表明,MeJA在抑制雨生红球藻细胞生长和总虾青素产量的积累的同时,却能促进雨生红球藻单位细胞虾青素的合成能力.当MeJA浓度为800 μmol/L时,单位细胞虾青素合成能力可达1.75×10-9mg,相比对照组(1.42×10-9 mg)增加23.24％.RT-PCR分析结果表明,dxs基因的表达受MeJA的诱导,800 μmol/L MeJA处理条件下,dxs基因的表达水平最高.相关分析结果表明,MeJA作用下的雨生红球藻虾青素含量和dxs基因表达量呈正相关,推断dxs基因可能是雨生红球藻虾青素合成的一个关键酶基因,这为进一步通过代谢工程策略提高雨生红球藻虾青素含量提供了一个靶点,也为虾青素规模化生产和探讨虾青素积累的分子机理提供参考.     

A comparison of the population genetics of Lethrinus miniatus and Lutjanus sebae from the east and west coasts of Australia: Evidence for panmixia and isolation

Lethrinus miniatus and Lutjanus sebae are important commercial and recreational species of reef fish. Within Australian waters the former species is less widespread than the latter and has a discontinuous distribution, whilst the latter is continuously distributed in tropical Australian waters. The demographic attributes of these species (e.g. long life span, low rates of natural mortality) make them vulnerable to over-exploitation. Consequently, conservative harvest strategies including no-take zones for these species have been adopted by fisheries management agencies to control exploitation. Information on the genetic stock structure of these species is important for developing specific management strategies. However, little is known about genetic stock structures within and between east and west Australian populations of these species. The current study used the mitochondrial genome hypervariable region 1 (HVR1) of the control region to examine variation between two sites from both the east and west Australian coasts for each species. HVR1 for L. sebae did not differ genetically either within or between coasts (F_st < 0.018, p > 0.15) at the sites studied, suggesting a panmictic population structure. Similarly, L. miniatus did not differ significantly between sites sampled within coast. However, the west coast HVR1 for L. miniatus east and west coast populations, were discrete (F_st of at least 0.92, p < 0.0001). The degree of genetic sub-division between east and west coast populations indicates that they should be managed as discrete stocks. Further, when considering both species, the lower genetic (both haplotype and nucleotide) diversity in three of the four sites on the west coast of Australia, indicates that this region is genetically impoverished and neutrality tests suggest that selection is responsible. Consequently, west Australian populations will be less resilient to perturbations (e.g. fishing, climate change) than east Australian populations, which have higher genetic diversity.     

巨须裂腹鱼水霉菌的分离鉴定及其对脾脏转录组的影响

为分析感染水霉菌对巨须裂腹鱼脾脏转录组的影响,探索水霉菌感染巨须裂腹鱼的分子机制,实验随机选取生活在同一水域中的5尾健康和5尾感染水霉菌的巨须裂腹鱼,采用PDA琼脂培养基和分子生物学方法对巨须裂腹鱼水霉菌进行分离鉴定,并采用Illumina HiSeqTM 2000 高通量测序平台,对健康和感染水霉菌的巨须裂腹鱼脾脏组织进行转录组测序,并对测序数据进行拼接、注释和差异表达基因分析。结果显示,从巨须裂腹鱼皮肤上分离鉴定得到3株水霉菌;转录组数据显示,健康组和感染水霉病组分别获得46 619 504 条和43 912 876 条数据,与健康组相比,感染水霉菌组共有1 889 个基因发生差异表达,其中1 414 个基因上调,475 个基因下调,随机选取6个差异表达基因进行实时荧光定量PCR (RT-qPCR)验证,验证结果与转录组测序一致。对健康组和感染水霉菌组的差异表达基因进行GO功能富集发现,上调基因主要富集于241个功能中,下调基因主要富集于60个功能中,上述基因主要涉及分子功能类、细胞组分类和生物过程类等生理功能;KEGG通路富集分析发现,差异表达基因主要富集在免疫疾病、内分泌和代谢疾病、病毒感染性疾病、消化系统及排泄系统等。研究表明,感染水霉菌会影响巨须裂腹鱼脾脏组织多种基因的表达量,实验结果为进一步探索巨须裂腹鱼水霉菌的感染机制奠定了基础。     

斜带石斑鱼肝细胞分离及原代培养方法的建立

本研究以斜带石斑鱼肝细胞为实验对象,在不同培养条件下进行原代培养,旨在探讨稳定可靠的斜带石斑鱼肝细胞分离及原代培养方法。采用组织块分离法和胰蛋白酶(含EDTA)消化法分离肝细胞,并通过密度梯度离心法分离纯化肝细胞,细胞悬液于DMEM/F-12、M199和L-15培养液中培养;细胞活力及数量采用血球计数板计数,并通过MTT法测定细胞增殖率;同时,测定不同时间培养上清液中乳酸脱氢酶(LDH)活性、白蛋白(ALB)和尿素氮(BUN)的含量,以分析肝细胞生长状态。结果表明,组织块方法不适于斜带石斑鱼肝细胞的培养,未见细胞从组织块中迁出,而胰蛋白酶消化法获得良好稳定的培养效果,细胞产量达到1.6×108个/g肝重,活细胞数达到95%;L-15培养基细胞生长明显优于DMEM/F-12和M199培养基;启动原代培养的48~72 h阶段肝细胞生长代谢旺盛,培养上清液中LDH活性显著降低,ALB和BUN含量显著升高。结果显示,0.25%的胰蛋白酶常温消化法适合斜带石斑鱼肝细胞的分离,斜带石斑鱼肝细胞原代培养的最适培养基为L-15培养基,肝细胞在启动原代培养的48~72 h生长代谢旺盛。     

Effect of infestation with the isopod, Alitropus typus M. Edwards (Crustacea: Flabellifera: Aegidae) on the haematological parameters of the host fish, Channa striatus (Bloch)

Detailed accounts supported by experimental data are furnished regarding the haematological parameters of the host fish, Channa striatus infested by the isopod, Alitropus typus. Results demonstrate that the infested fish become anaemic through loss of blood as shown by a reduction in the total erythrocyte count, haemoglobin content and haematocrit. Considering the mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration and volume index, the anaemia can be designated as macrocytic and hypochromic. The total and differential counts of white blood corpuscles of the infested fish indicate leucopenia coupled with lymphocytosis. The percentages of monocytes, neutrophils and macrophages, which were 0.65%, 0.39% and 1.04%, respectively, after 24 h of infestation, had increased to 2.31%, 4.91% and 2.02%, respectively, after 96 h of infestation and declined thereafter.     

Application of aquariological techniques to an intensive fish-rearing process using recycled, warmed water for the production of rainbow trout fry, Oncorhynchus mykiss

Since 1991, the Laboratoire de Biologie Appliquée has been developing a new, intensive fish-rearing process. Based on simple aquariological techniques used at the Nancy Aquarium Tropical, the process involves recycled, warmed (18–20°C) water, and autonomous modular units both technically simple and small in size. Among its applications is the production of rainbow trout fry, Oncorhynchus mykiss. At present, from an initial batch of 100 000 eye-stage embryonated eggs, it allows 85 000 fry of 0·8-1 g to be produced in 60 days for a water consumption of less than 10 m³.     

海月水母螅状体无性繁殖方式观察及一种新发现报道

无性繁殖是水母螅状体有效补充种群数量及扩展栖息地的重要方式,为正确掌握海月水母的无性繁殖方式进而深入了解其生活史,在显微镜下常年观察并详细描述了海月水母螅状体进行匍匐茎生殖、芽体生殖、足囊生殖、繁殖体生殖、纵向分裂生殖和破裂生殖等复杂无性繁殖方式的过程,发现繁殖体生殖可产生浮游态繁殖体芽,在水中漂浮并生长发育成螅状体,新发现一种破裂生殖方式,仅发生在螅状体极度饱食的状态下。对6种无性繁殖方式的行为特征和功能作用进行了对比分析,认为匍匐茎生殖和破裂生殖有利于螅状体种群快速增加个体数量,芽体生殖和纵向分裂生殖有利于子代幼体生长,足囊生殖有利于种群抵御不良的环境条件,繁殖体生殖有利于种群随水流进行长距离迁移,以扩展或转移栖息地。研究表明,不同的繁殖方式是海月水母应对不同环境条件的适应性繁殖对策。     

An indoor solution for mass production of the marine rotifer Brachionus plicatilis Müller fed on the marine microalga Tetraselmis suecica butcher

Mass production of the rotifer Brachionus plicatilis Müller is carried out in a set of 50-liter polyethylene bags in which first the microalga Tetraselmis suecica Butcher is cultured and then the rotifer is grown till most of the algae are grazed.This novel procedure based on a monoxenic production technique, has been conceived with a number of aims in view among which the following should be mentioned: shortest time elapsing between the start and the end of the culture (1 week); minimal care of the cultures; light energy saving for indoor invertebrate mass production systems; unified culture vessel for growing algae and rotifers; accuracy and timing of planned rotifer production. Each bag maintained in the best reported conditions gives over 400 rotifers per ml as final production. Rotifer mass production in plastic bags is better achieved when operated in conjunction with a system of continuous monoxenic cultures of microalgae and of rotifers which provide the inocula.     

Gut contents of silver carp, Hypophthalmichthys molitrix, and the disruption of a centric diatom, Cyclotella, on passage through the esophagus and intestine

The digestibility of algae by stomachless filter-feeding fish has been debated for decades. Results from gut contents and digestive enzyme analysis suggest poor utilization, while the measurement of food assimilation using radiolabeled isotope techniques indicate reasonable assimilation efficiency. Phytoplankton in the gut contents of the planktivorous filter-feeding silver carp were studied during March–May. The fish were cultured in a large net cage in a shallow, hypertrophic subtropical Chinese lake, Lake Donghu. In terms of biomass, the dominant phytoplankton in the fore-gut contents were Cyclotella (average 77.8%, range 69.7–93.5%) and Cryptomonas (average 9.57%, range 0–20.4%). The Ivlev's electivity index E of silver carp was much higher for Cyclotella (1.54) than for Cryptomonas (0.56). The majority of the phytoplankton found in the intestines of silver carp were 8–20 μm, but they were also able to collect particles as small as 4.5–10 μm, smaller than their filtering net meshes, suggesting that the secretion of mucus may play an important role in collecting such small particles. We conclude that disruption of cell walls is principally by the pharyngeal teeth, explaining previous contradictory conclusions.