网箱养殖大黄鱼"白肝病"防治初探

2000年4至9月，宁德地区网箱养殖大黄鱼出现大面积，大规模死亡，其主要症状为肝脏严重失血，肝组织受损，呈黄白色，并伴有烂鳃等症状，根据临床表现、检查诊断、，并结合治疗效果。本文将该病初步命名为“白肝病”现结合该病的防治，及对其产生的可能原因作初步探讨。     

黄鳝网箱养殖技术与实施

网箱养殖黄鳝投入少,见效快,具有养殖、暂储与选择季节差价上市的优势,特别适合于家庭养殖.养黄鳝的网箱制作材料一般为聚乙烯线.没有污染的池塘、水库、湖泊、河流都可进行网箱养鳝.黄鳝养殖成功的关键是要选好种苗、喂好饵料、勤于管理、预防病害、适时销售.     

动物消化道微生物培养组学研究进展

自然环境中绝大部分微生物仍"尚未被培养",这极大限制了人们对微生物功能的研究,以及微生物资源的开发和利用.培养组学基于微生物基因组信息获得目标微生物的最佳生存环境,利用膜扩散型培养技术、微流控型培养技术和细胞分选培养技术等从自然环境中分离、培养"尚未被培养"的微生物,并通过高通量组学技术加以鉴定.已成功应用于小鼠、白蚁...     

消化道微生物与动物机体关系(动物营养)研究进展

随着对肠道微生物研究的逐步深入,越来越多的研究结果表明,肠道微生物的种群结构、数量等与动物机体的健康密切相关。医学研究发现肠道微生物种群结构变化与人的胃肠道老化,消化不良、消化性溃疡、结肠癌、大肠肿瘤等疾病有一定的关系。另外,消化道微生物还通过影响机体对营养物质的消化吸收、能量代谢,以及先天性和获得性免疫、生理功能等进而影响动物的生产性能。因此,通过研究机体与其消化道微生物的关系,如:不同生理环境条件下消化道微生物对机体的影响机理;不同生长阶段肠道微生物种群结构、数量的变化;不同的消化道微生物对机体的作用等,将有助于提高动物的生产性能。本文着重总结了近年来有关消化道微生物与动物营养的相关研究报道,旨在说明消化道微生物与机体关系密切,应该引起足够重视。     

雌性罗氏鼢鼠肠道微生物群落与功能预测的初步分析

罗氏鼢鼠(Myospalax rothschildi)是陕西南部农区主要害鼠,研究其与当地环境的相互作用对鼠害防控有重要意义。肠道微生物对宿主行为及生理的调控机制是近年来啮齿类动物防控研究新方向。本研究通过Illumina高通量测序技术,对雌性罗氏鼢鼠的盲肠样品进行16S rRNA V3-V4区的高通量测序,分析性别及食物因素对罗氏鼢鼠肠道细菌多样性的影响。结果显示,雌性罗氏鼢鼠的肠道内容物中的细菌隶属10门9纲11目13属。肠道革兰氏阳性厚壁菌门(Firmicutes)和革兰氏阴性菌类的变形菌门(Proteobacteria)的菌种含量较多;埃希氏杆菌属(Escherichia)、瘤胃球菌属(Ruminococcus)、梭杆菌属(Clostridium)和颤螺旋菌属(Oscillospira)为优势菌群属。PICRUSt预测发现,罗氏鼢鼠的肠道微生物参与草本中药材食物在宿主体内的代谢。本研究首次借助生物信息学技术初步分析了罗氏鼢鼠肠道细菌的多样性及其与环境和遗传因素的相互作用,对当地鼠害防控具有一定的理论指导意义。     

单宁与饲用纤维素酶对湖羊瘤胃微生物菌群的影响

试验旨在利用高通量测序技术研究添加单宁与饲用纤维素酶对湖羊生长育肥期瘤胃微生物菌群结构的影响,为单宁和饲用纤维素酶在反刍动物生产中更好地利用提供理论依据。选用3月龄生长发育良好、平均体重(19.85±1.45)kg的肉用湖羊36只,随机分成对照组和3个处理组,对照组饲喂基础日粮,处理组分别在基础日粮中加入0.1%单宁(单宁组)、0.1%饲用纤维素酶(纤维素酶组)和0.1%单宁+0.1%饲用纤维素酶(混合组),每组3个重复,每个重复3只湖羊。试验期70d,其中过渡期7d,预试期7d,正饲期56d。试验结束后,采集湖羊瘤胃液,提取细菌总DNA,进行PCR扩增后用Illumina Hi Seq 2500测序平台进行高通量测序。结果表明:(1)12个湖羊瘤胃微生物样品测序共获得957 440对序列,平均每个样品产生55 997条clean tags,过滤嵌合体后共产生502 965条effective tags;各组湖羊瘤胃微生物样品的AvgLen均在419～420之间;(2)各组间湖羊瘤胃微生物的Ace指数和Chao1指数差异均不显著(P>0.05);与对照组相比,单宁组、纤维素酶组和混合组湖羊瘤胃微生物的香农指数显著提高(P<0.05);纤维素酶组湖羊瘤胃微生物的辛普森指数较对照组显著降低(P<0.05);(3)在门水平上,单宁组湖羊瘤胃内拟杆菌门(Bacteroidetes)丰度比对照组显著降低(P<0.05);单宁组、纤维素酶组和混合组湖羊瘤胃内厚壁菌门(Firmicutes)丰度较对照组均呈下降趋势,但差异不显著(P>0.05);(4)在属水平上,单宁组湖羊瘤胃内普雷沃菌属-1(Prevotella_1)丰度降低,与对照组、纤维素酶组差异均显著(P<0.05),但与混合组差异不显著(P>0.05);单宁组和纤维素酶组湖羊瘤胃内瘤胃菌属(Rumen_bacterium)丰度较对照组和混合组提高,且与混合组的差异显著(P<0.05)。综合试验结果,在湖羊日粮中同时加入单宁和饲用纤维素酶可以提高湖羊瘤胃内菌群的多样性和丰度,影响瘤胃菌群结构,缓解单宁对拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)菌落的抑制;同时混合添加可以缓解单独添加单宁对纤维素分解的抑制作用;在门水平上各组湖羊瘤胃内优势菌群均为拟杆菌门和厚壁菌门;在属水平上各组湖羊瘤胃内优势菌群均为理研菌科-RC9(Rikenellaceae_RC9_gut_group)、细菌(Bacterium)、普雷沃菌属-1和瘤胃菌属。     

如何识别和防治网箱养殖的"营养不良"症

网箱养鱼常常发生“营养不良”症,影响了网箱养鱼增产增收。怎样正确判断、识别网箱养鱼发生的营养不良症,应采取哪些有效的“进补”措施呢? (一)维生素类营养不良及“进补”要点 1.维生素A类营养不良的症状是鱼类皮肤与眼睛出血,     

奶牛养殖发酵床不同深度菌群结构及其应用效果分析

[目的] 分析奶牛养殖发酵床不同深度的菌群结构特征,并对奶牛养殖发酵床的应用效果进行评价。[方法] 比较应用和未应用发酵床养殖模式下垫料中3种常见致病菌的菌落数。比较2年监测期内,应用和未应用发酵床养殖奶牛的肢蹄病发生率、产奶量、乳体细胞数,以及使用3种发酵床垫料补充料（稻壳和干牛粪渣、锯末屑、稻壳粉）的奶牛所产生鲜乳的细菌总数。采集发酵床表层（5 cm）、中层（25 cm）、深层（45~50 cm）样本,测定使用2年后发酵床的基本理化指标;分别利用基于16S rDNA和ITS1的高通量测序法,分析发酵床不同深度细菌和真菌的分布特征;应用生物信息学软件预测发酵床微生物菌群代谢功能。[结果] 发酵床养殖管理模式下,垫料中大肠埃希菌、链球菌、克雷伯菌的菌落数均低于未使用发酵床的垫料。在2年监测期内,应用发酵床养殖的奶牛肢蹄病发生率低于未应用发酵床的奶牛,平均产奶量显著（P<0.05）高于未应用发酵床的奶牛,而生鲜乳体细胞数平均值低于未应用发酵床的奶牛;使用稻壳和干牛粪渣为垫料补充料,奶牛生鲜乳中的细菌总数最少。以稻壳和干牛粪为垫料的发酵床基础参数（温度、含水量、pH值、氨气、硫化氢）在持续稳定运行2年后仍能满足生产需要;发酵床微生态群落以细菌菌群为主,拟杆菌门（Bacteroidetes）和厚壁菌门（Firmicutes）多集中在发酵床中层和深层,放线菌门（Actinobacteria）多集中在发酵床表层;发酵床不同深度样品具有相似的真菌群落组成,发酵后真菌多分布在深层;KEGG 通路富集分析显示,细菌群落对整个发酵床的微生态系统影响较大,垫料中细菌代谢最为活跃,仍有大量真菌菌属有待注释说明。[结论] 应用该发酵床养殖技术,奶牛健康状况和生鲜乳品质均得到改善。     

PCR法筛选大黄鱼微卫星DNA

构建大黄鱼部分基因组DNA文库。以M13通用引物和根据微卫星核心序列所设计的引物，用PER法直接对文库进行扩增，获得15个PER阳性克隆，对阳性克隆测序。测序结果说明，6个阳性克隆中含有微卫星核心序列，用Primer3引物设计软件对侧翼序列进行微卫星引物设计。用6对引物扩增大黄鱼基因组，PER结果经6％聚丙烯酰胺凝胶电泳分析，其中2对引物能得到稳定的扩增。     

Molecular cloning and expression analysis of interferon-inducible transmembrane protein 1 in large yellow croaker Pseudosciaena crocea

In human cells, interferon-inducible transmembrane protein 1 (IFITM1) is a component of protein complexes involved in homotypic adhesion and the transduction of antiproliferative signals. Here, we reported the cloning of an IFITM1 homologue from the spleen of large yellow croaker Pseudosciaena crocea (LycIFITM1). The complete cDNA of LycIFITM1 is 734 nucleotides (nt) encoding a protein of 124 amino acids (aa), with a putative molecular weight of 13.6 kDa. The deduced LycIFITM1 protein is significantly homologous to interferon-inducible transmembrane proteins (IFITMs) in mammals and fish, and has the typical structural features of IFITMs, including two transmembrane domains (residues 43-63 and 90-112, respectively) and one intracellular domain between them (residues 64-89), as well as one conserved protein kinase C (PKC) phosphorylation site (residues 65-67, SIK). Phylogenetic analysis showed that LycIFITM1 formed a cluster with fish IFITM, reflecting a relative distant evolutionary relationship from mammals. LycIFITM1 gene was constitutively expressed in various tissues examined, such as gills, intestine, liver, kidney, heart, spleen, muscle and blood. Upon induction with poly(I:C), LycIFITM1 gene expression was obviously up-regulated in gills, kidney, heart and spleen at 24h after stimulation, suggesting that LycIFITM1 may be involved in the immune response induced by poly(I:C). Time course analysis using real-time PCR showed that the mRNA levels of LycIFITM1 in spleen and kidney were quickly up-regulated by poly(I:C) and reached the peak at 24h post-induction (48.7- and 280.4-fold mRNA increases in spleen and kidney, respectively). The results suggest that the IFITM1 homologue from large yellow croaker may represent a novel member of IFITMs family in fish.     

Molecular cloning and expression analysis of a CXC chemokine gene from large yellow croaker Pseudosciaena crocea

In the present study, we report the cloning of a CXCL12 chemokine gene homologue from the large yellow croaker Pseudosciaena crocea (LycCXCL12). The complete cDNA of LycCXCL12 is 678 nucleotides (nt) encoding a protein of 97 amino acids (aa), with a putative molecular weight of 11.1 kDa. The deduced LycCXCL12 contains a 22-aa signal peptide and a 75-aa mature polypeptide, which possesses the typical arrangement of four cysteines as found in other known CXC chemokines. It shares 57-68% and 32-36% aa sequence identities to known CXCL12 chemokines in fish species and other vertebrates, respectively. The LycCXCL12 gene was constitutively expressed in all tissues examined although at different levels. Upon induction with poly(I:C) or inactivated trivalent bacterial vaccine, LycCXCL12 gene expression was significantly up-regulated in gills, liver, kidney, spleen and blood at 24 h after stimulation. Time course analysis using real-time PCR showed that LycCXCL12 gene expression reached peak level in spleen and kidney at 12 h or in gills at 24 h post-induction by poly(I:C), while its expression increased to the highest level in kidney at 24h or in gills and spleen at 48 h post-induction by bacterial vaccine, indicating that LycCXCL12 gene expression was differentially regulated by poly(I:C) and bacterial vaccine.     

大黄鱼营养需求研究进展

文章综合论述了近年来大黄鱼营养研究的进展。主要包括:饲料中蛋白质和氨基酸、脂肪和脂肪酸、维生素和矿物元素等的适宜含量;不同蛋白源替代鱼粉以及原料消化率;非营养性添加剂;大黄鱼配合饲料发展现状和研究展望。     

罗源湾养殖大黄鱼虹彩病毒的PCR检测

2012年7月至10月间对从福建罗源湾患“白鳃病”的网箱养殖大黄鱼的鳃丝、肝脏、脾脏、肾脏及性腺等器官组织提取的总DNA进行虹彩病毒PCR检测,经序列分析,从患鱼肝脏、脾脏、肾脏获得的两条病毒DNA基因片段ly1、ly2分别与已报道的大黄鱼虹彩病毒(AY779031)和真鲷虹彩病毒(AB104413)高度相似,患鱼病毒阳性率为10%~65%.由此判断,罗源湾发生“白鳃病”并出现陆续死亡情况的养殖大黄鱼可能与感染虹彩病毒有直接关系.     

三七总皂甙对大黄鱼肾细胞生长及部分免疫相关基因表达的影响

本试验将三七总皂甙(PNS)体外作用于大黄鱼肾细胞,通过活细胞计数和荧光定量PCR检测,初步了解PNS对大黄鱼肾细胞生长及部分免疫相关因子表达的影响。结果显示,40~200μg/mL浓度的PNS对大黄鱼肾细胞生长无明显影响,但浓度达到1 mg/mL以上时,对细胞生长有负面影响;10~1 000μg/mL浓度的PNS对大黄鱼肾细胞Toll样受体5mRNA的表达有一定的上调作用,但对Toll样受体3的表达有一定的下调作用;PNS浓度为10~100μg/mL时对大黄鱼肾细胞碱性磷酸酶的表达无明显影响,但浓度达到1 000μg/mL时对该因子的表达有下调作用;PNS浓度为10μg/mL时对大黄鱼肾细胞溶菌酶的表达无明显影响,但浓度达到100μg/mL以上时对该因子的表达具有一定的下调作用。     

Degradation of scrapie associated prion protein (PrPSc) by the gastrointestinal microbiota of cattle

A food-borne origin of the transmission of bovine spongiform encephalopathy (BSE) to cattle is commonly assumed. However, the fate of infectious prion protein during polygastric digestion remains unclear. It is unknown at present, whether infectious prion proteins, considered to be very stable, are degraded or inactivated by microbial processes in the gastrointestinal tract of cattle. In this study, rumen and colon contents from healthy cattle, taken immediately after slaughter, were used to assess the ability of these microbial consortia to degrade PrP(Sc). Therefore, the consortia were incubated with brain homogenates of scrapie (strain 263K) infected hamsters under physiological anaerobic conditions at 37 degrees C. Within 20 h, PrP(Sc) was digested both with ruminal and colonic microbiota up to immunochemically undetectable levels. Especially polymyxin resistant (mainly gram-positive) bacteria expressed PrP(Sc) degrading activity. These data demonstrate the ability of bovine gastrointestinal microbiota to degrade PrP(Sc) during digestion.     

Infectivity of scrapie prion protein (PrPSc) following in vitro digestion with bovine gastrointestinal microbiota

The influence of a complex microflora residing in the gastrointestinal tract of cattle on the prion protein plays a crucial role with respect to early pathogenesis and the potential infectivity of faeces resulting in contamination of the environment. It is unknown whether infectious prion proteins, considered to be very stable, are inactivated by microbial processes in the gastrointestinal tract of animals during digestion. In our previous study it was shown that the scrapie-associated prion protein was degraded by ruminal and colonic microbiota of cattle, as indicated by a loss of anti-prion antibody 3F4 immunoreactivity in Western blot. Subsequently, in this study hamster bioassays with the pre-treated samples were performed. Although the PrP(Sc) signal was reduced up to immunochemically undetectable levels within 40 h of pre-treatment, significant residual prion infectivity was retained after degradation of infected hamster brain through the gastrointestinal microflora of cattle. The data presented here show that the loss of anti-prion antibody 3F4 immunoreactivity is obviously not correlated with a biological inactivation of PrP(Sc). These results highlight the deficiency of using Western blot in transmissible spongiform encephalopathies inactivation assessment studies and, additionally, point to the possibility of environmental contamination with faeces containing PrP(Sc) following an oral ingestion of prions.     

小肽对大黄鱼仔鱼生长和小肠发育的影响及其在低温胁迫下的抗氧化应激效应

本试验分为生长试验和低温胁迫试验2部分.先分别投喂大黄鱼(Larimichthys cro-cea)仔鱼经不同浓度(0、0.5、1.0、2.0和3.0 mL/m3)小肽营养强化后的轮虫和卤虫12 d,以探讨小肽对大黄鱼仔鱼生长和小肠发育的影响;再将大黄鱼仔鱼暴露在温度为12℃的水体中24 h,以探讨小肽对低温胁迫下大黄...     

Cloning and expression of Vibrio harveyi OmpK* and GAPDH* genes and their potential application as vaccines in large yellow croakers Pseudosciaena crocea

Vibrio harveyi is a causative agent of vibriosis in the large yellow croaker Pseudosciaena crocea and causes severe losses to the aquaculture industry in China. The vaccines based on the outer membrane proteins (OMPs) of the pathogens are considered to be the optimum intervention for this disease. In this study, two V. harveyi OMP genes, OmpK* and glyceraldehyde-3-phosphate dehydrogenase (GAPDH*), were cloned, sequenced, and characterized. The recombinant proteins (r-OmpK and r-GAPDH) were expressed by the prokaryotic expression vector pET-30a(+) and purified with nickel-nitrilotriacetic acid affinity chromatography. Western blots showed that rabbit antisera against purified r-OmpK and r-GAPDH specifically reacted with the native OMP of V. harveyi. Large yellow croakers were immunized with r-OmpK and r-GAPDH. Specific antibody titer assessed by enzyme-linked immunosorbent and phagocytosis assays demonstrated that specific and innate immunity was stimulated in response to the OMPs of V. harveyi. Challenge results indicated that vaccination of large yellow croakers with r-OmpK and r-GAPDH increased relative survival (37.7% and 40.0%, respectively) against wild V. harveyi.