吉富罗非鱼(♀)与翘嘴鳜(♂)远缘杂交子代的遗传特征分析

为了探究吉富罗非鱼(Oreochromis niloticus,GIFT)(♀)与翘嘴鳜(Siniperca chuatsi)(♂)远缘杂交的可行性,对吉富罗非鱼(♀)×翘嘴鳜(♂)子代的胚胎发育、细胞遗传和分子遗传特征进行了初步研究。杂交子代的胚胎存活率仅为(0.34±0.13)%,通过流式细胞技术对正常存活个体进行了DNA相对含量分析,结果显示杂交子代的DNA含量和吉富罗非鱼的DNA含量无显著性差异。染色体数目和核型分析结果显示,杂交子代的染色体数目是2n=44,核型公式是6sm+24st+14t,染色体臂数(NF)=50。杂交子代的染色体数目与其母本相同,核型与其母本相似,二者与父本明显不同。细胞遗传和分子遗传特征的结果显示,吉富罗非鱼(♀)×翘嘴鳜(♂)子代属于雌核发育个体。     

罗非鱼性别相关微卫星标记的初步筛选

为分析罗非鱼群体的遗传多样性以及筛选与罗非鱼性别相关的微卫星标记。应用24对微卫星引物,使用常规PCR及聚丙烯酰胺凝胶电泳的方法在两个尼罗罗非鱼(Oreochromis niloticus)群体和两个奥利亚罗非鱼(O.aureus)群体中初步筛选到UNH931、GM128、GM201、GM258、GM597以及UNH898共6个与性别相关的微卫星标记。然后使用降落PCR以及毛细管电泳的方法在两个尼罗罗非鱼群体、两个奥利亚罗非鱼群体以及ZY 1、WY 1、YY 1和YY 2型罗非鱼群体中进一步扩增这6个微卫星标记,统计各群体的遗传多样性参数:6个微卫星标记在上述群体共297个样本中检测到95个等位基因,其大小在97~302 bp之间,各位点在各群体等位基因数在1~13个之间,各群体平均观测等位基因数为2.167~9.333,平均有效等位基因数为1.624~4.966,平均观测杂合度为0.324~0.983,平均期望杂合度为0.329~0.782,平均多态信息含量为0.275~0.753;两个尼罗罗非鱼群体、WY 1和YY 2群体达到高度多态(PIC>0.5),两个奥利亚罗非鱼群体、ZY 1和YY 1群体为中度多态(0.25相似文献   

尼罗罗非鱼淀粉酶性质的初步研究

研究了尼罗罗非鱼(Oreochromis niloticus)肝脏淀粉酶的基本性质及金属离子对该鱼淀粉酶活性的影响。结果表明:罗非鱼淀粉酶活力的最适pH是6.5,最适底物浓度是2%。研究金属离子对该鱼淀粉酶活力影响,一价金属离子K+、Li+、Na+对酶活力影响较小;二价金属离子Cu2+对酶活力具有抑制作用,Zn2+对酶活力无明显影响;三价金属离子Al3+对酶活力具有抑制作用,但效果不是很强烈,Fe3+对酶活力具有明显的激活作用;碱土金属Mg2+、Ca2+对淀粉酶活性有激活作用,而Ba2+对酶具有抑制作用;重金属离子Cd2+、Pb2+有明显的抑制作用。     

尼罗罗非鱼与萨罗罗非鱼回交一代与回交二代群体遗传特征的微卫星分析

利用尼罗罗非鱼(Oreochromis niloticus)第二代遗传连锁图谱中微卫星标记,对尼罗罗非鱼♀与萨罗罗非鱼(Sarotherodon melanotheron)回交一代(BC1)和回交二代(BC2)群体遗传特征进行了分析。结果表明,从28个微卫星位点中筛选出9个在尼萨回交一代和回交二代中存在差异的扩增位点,这些多态性位点可作为尼萨回交一代和回交二代群体遗传鉴别的重要依据。尼萨回交一代群体的平均观测杂合度为0.670,多态信息含量为0.423;回交二代群体的平均观测杂合度为0.460,多态信息含量为0.365,回交二代群体的遗传多态性低于回交一代群体。与回交一代相比,尼萨回交二代群体的平均有效等位基因数较为一致(BC1:Ne=2.17,BC2:Ne=2.20),基因型数较为一致,但纯合基因型比例、优势等位基因频率均有明显提高,表明连续回交导致后代遗传同质性提高。     

永生化尼罗罗非鱼巨噬细胞系的建立及鉴定

为获得具有单一克隆特性的能稳定传代培养的罗非鱼巨噬细胞系,本研究从尼罗罗非鱼腹腔中分离纯化巨噬细胞,采用EB病毒(Epstein-Barr virus,EBV)感染,筛选单克隆细胞的方法建立了尼罗罗非鱼巨噬细胞系,并对其进行了EBV感染鉴定、电镜观察、端粒酶活性检测、致癌性评估、核型分析以及分子生物学鉴定。研究表明,EBV已整合到尼罗罗非鱼巨噬细胞中且稳定表达,经30代稳定传代,该细胞系仍维持较好的增殖状态;该细胞系表面不平滑,有明显的钝圆形突起和细长的伪足,表现为典型的巨噬细胞形态;端粒酶活性显著高于未经感染的巨噬细胞,而与He La细胞差异不显著,且该细胞系不具有致癌性,说明永生化细胞系构建成功。核型分析结果发现,该细胞系具有44条染色体,其核型公式为2 n=2 x=44=4 sm+17 st+1 t。PCR检测发现,该细胞系存在CD33和CD205的转录本,这些都是单核巨噬细胞的标志物,经18S r RNA检测证明该细胞系来自尼罗罗非鱼巨噬细胞。永生化尼罗罗非鱼巨噬细胞系已被成功建立,该细胞系为研究罗非鱼链球菌HSP70-肽疫苗的高保护率,以及罗非鱼的免疫防御机制提供了工具。     

WY型罗非鱼的性别鉴定

以尼罗罗非鱼(Oreochromis niloticus)和奥利亚罗非鱼(O.aurea)为材料,进行WZ♀×XY♂、WZ♀×YY♂、WY×ZY♂、WY×YY♂杂交实验及其子代分析,确认WY型罗非鱼的性别为雌性。     

尼罗罗非鱼1号染色体分离及文库构建方法研究

以尼罗罗非鱼(Oreochromis niloticus)为对象,采用体内注射植物血细胞凝集素(PHA)方式收集有丝分裂后期的鱼体头肾细胞,低渗法制片,运用激光显微分离获得尼罗罗非鱼1号染色体,分离后的单染色体通过特异性酶切和LA-PCR体外扩增,得到500~2 000 bp之间的DNA片段,并通过Southern blot和微卫星标记得到验证。扩增片段通过电泳回收、连接转化、感受态细胞培养等步骤构建尼罗罗非鱼1号染色体微克隆文库,克隆片段长度在300~600 bp之间。     

奥利亚罗非鱼雌性化技术的研究

采用FH激素诱导奥利亚罗非鱼(Oreochromis aurea)雌性化,结果显示:以鱼苗为起始材料,奥利亚罗非鱼雌鱼的转化率为76.5%～89.6%;以胚胎为起始材料,雌鱼的转化率可达到100%,ZZ型合子可完全变成生理雌鱼,卵巢发育正常,具有繁殖功能。     

复方中草药对尼罗罗非鱼非特异性免疫功能的影响

研究了在饲料中添加一种以鱼腥草为主要成分(占40%)的复方中草药制剂对尼罗罗非鱼(Oreochromis niloticus)非特异性免疫指标的影响。将鱼腥草、黄芩、板蓝根、连翘、金银花等10种中草药按一定比例充分粉碎后混匀制成以鱼腥草为主要成分的复方中草药制剂,按质量分数0%(对照组)、1%(A组)、3%(B组)和6%(C组)分别添加到基础饲料中饲喂尼罗罗非鱼,饲养12周。分别在第4、8和12周采集各组尼罗罗非鱼血液,测定相关非特异性免疫指标。结果显示:从第8周开始,B组尼罗罗非鱼血清丙二醛(MDA)含量显著降低,C组尼罗罗非鱼血清溶菌酶(LSZ)活力、超氧化物歧化酶(SOD)活力、一氧化氮(NO)含量显著提高,MDA含量显著降低。在第12周,B组和C组尼罗罗非鱼白细胞吞噬百分比、吞噬指数和血细胞呼吸爆发活力、血清SOD活力、LSZ活力、NO含量都显著提高,MDA含量则显著降低。结果表明:在饲料中添加3%和6%质量分数的以鱼腥草为主要成分的复方中草药制剂均能增强尼罗罗非鱼的非特异性免疫力,其中以添加比例为6%的效果最好。     

慢性盐度胁迫对吉丽罗非鱼(尼罗罗非鱼♀×萨罗罗非鱼♂)及其两亲本耐盐性的影响

为深入研究养殖新品种吉丽罗非鱼[尼罗罗非鱼(♀)×萨罗罗非鱼(♂)]的耐盐性能,对吉丽罗非鱼及其两个亲本尼罗罗非鱼和萨罗罗非鱼进行了慢性盐度胁迫实验,分析了3种罗非鱼耐盐性能的差异,建立了盐度胁迫过程中死亡率与致死盐度及时间的回归模型,结果显示:(1)3种罗非鱼的耐盐能力差异显著,吉丽罗非鱼的耐盐性能接近于萨罗罗非鱼,远高于尼罗罗非鱼,耐盐胁迫时3种罗非鱼的平均致死盐度分别为57.9、66.7和18.5.(2)盐度胁迫实验中尼罗罗非鱼个体间死亡时间差异最大,萨罗罗非鱼个体之间差异最小,吉丽罗非鱼介于其间;吉丽罗非鱼和萨罗罗非鱼死亡时间都有极显著的正态负偏移,离群值和极值较多,尼罗罗非鱼有较显著正态正偏移,只有离群值,没有极值.(3)3种罗非鱼盐度胁迫实验中死亡率与死亡时间及盐度之间的回归关系更适合一元回归,吉丽罗非鱼盐度胁迫实验中死亡率(y)与死亡时间(t)的回归模型为增长模型Y=e (-7.694+0.031t)(R2=0.979),死亡率(Y)与盐度(s)的回归模型为二次模型Y =0.542-0.037s +0.001s2(R2=0.950).     

Juvenile growth of two tilapia species in lakes Naivasha and Baringo, Kenya

Abstract –  Tilapia species in East African lakes often form the basis of commercial fisheries, with information on their population biology assisting their management. This study utilised otolith microstructure, with validation by modal progression analysis, to provide growth data for two tilapia species in two Kenyan lakes for the first time. Otolith microstructure revealed the growth rate of Oreochromis niloticus baringoensis , a sub-species endemic to Lake Baringo, was fast compared with populations of Oreochromis niloticus ; mean daily growth rates were >0.50 mm·d⁻¹ in fish between 12 and 53 mm total length. Growth of Oreochromis leucostictus in Lake Naivasha was also relatively fast when compared with the growth rates of other tilapia species, with mean daily growth rates of approximately 0.35–0.48 mm·d⁻¹ in fish between 10 and 56 mm total length. Growth rates of both species were well described by the Gompertz model and were corroborated by modal progression analysis that revealed similar daily growth rates in modes of young-of-the-year fish.     

盐酸诺氟沙星在奥尼罗非鱼体内的生物利用度研究

采用高效液相色谱法分别测定静脉注射和混饲口灌奥尼罗非鱼(Oreochromis aureus×O.niloticus)盐酸诺氟沙星后鱼体血液中该药含量变化,用3P97药动学软件分析药动学参数,计算生物利用度.结果表明,在(25±1)℃水温下,以10 mg/kg剂量对奥尼罗非鱼静脉注射和混饲口灌盐酸诺氟沙星,静脉注射药时...     

Observations on the reproductive performance of three mouth-brooding tilapia species in low-salinity underground water

The reproductive performance and seed production of three mouth‐brooding tilapia species, Oreochromis spilurus (Günther), Oreochromis aureus (Steindachner) and Taiwanese red tilapia hybrid, were compared in low‐salinity underground water (3–5 g L^?1) to select species with the highest reproductive rate. Two‐year‐old males and females having average body weights of 454 and 259 g, respectively, were stocked in 2‐m³ fibreglass breeding tanks (two tanks per species) at 1:3 male to female sex ratio and at average density of three fish m^?2. Seeds (unhatched eggs; yolk‐sac fry and the swim‐up fry) were collected weekly for 112 days. The results showed O. spilurus to have significantly higher (P<0.05) mean spawning parameters expressed as total seed tank^?1 (84 154), seed kg female^?1 day^?1 (284), seed m^?2 day^?1 (190.3) and seed female^?1 day^?1 (76.3), than O. aureus and red tilapia. Monthly seed production in O. spilurus and red tilapia gradually increased from May, peaked in July and declined in August, while in O. aureus, it continued to decrease from May to August. In this study, the observed production levels of seed in O. spilurus were among the highest levels reported for tilapia; therefore, O. spilurus could be selected as a potential candidate for mass seed production in commercial tilapia hatcheries.     

Production of heterozygous and homozygous clones in Nile tilapia

Production of heterozygous and homozygous clones of Nile tilapia (Oreochromis niloticus L.) was successfully carried out. An outbred clonal line was produced by cross-breeding between a viable mitotic gynogenetic female and male (recessive mutation in a sex determining gene). At the same time, an inbred clonal line was produced by gynogenetic reproduction (retention of 2nd polar body) using optimal pressure/heat shock treatments. The heterozygous and homozygous nature of the two types of clonal lines were checked and identified at the adenosine deaminase ADA* marker locus. A model for the large scale production of similar clones is presented. The possible implications of such clonal lines in genetic research and in the culture of Oreochromis spp. are discussed. © Rapid Science Ltd. 1998     

高温诱导对尼罗罗非鱼性别分化及生长的影响

采用自雌鱼口腔中取出受精卵人工孵化的方法建立了尼罗罗非鱼家系20个。受精后9d,将各家系鱼苗分成两份,分别在28℃(对照组)和36℃(高温诱导组)下养殖,诱导处理12d后,统计高温诱导期成活率并将实验鱼转入自然水温下培育,养殖60～120d后对各实验组的雄性率及生长情况进行测定。结果表明,高温处理对仔鱼的成活率没有影响,但能显著提高某些家系的雄性率,如F27(诱导组88%,对照组49%)、F37(诱导组90%,对照组53%)和F41(诱导组91%,对照组53%);高温处理后多数家系的雄性率略有升高,但不显著;有两个家系高温诱导组雄性率低于对照组,分别是F8(诱导组43%,对照组46%)和F35(诱导组29%,对照组38%),这显示了尼罗罗非鱼性别分化受遗传和环境因子共同作用。生长情况测定结果表明,高温诱导对发育初期罗非鱼的生长没有显著影响。本研究结果说明,高温处理能显著提高某些家系的雄性率,高温诱导和家系选择有望成为高雄性率尼罗罗非鱼新品种培育的新的技术手段。     

Passive immunization of tilapia, Oreochromis niloticus (L.), with anti-Streptococcus iniae whole sera

Passive immunization of tilapia, Oreochromis niloticus, was conducted to determine whether anti- Streptococcus iniae whole sera (ASI), heat inactivated anti- S . iniae whole sera (HIASI) and normal whole sera (NWS) were protective when intraperitoneally (i.p.) injected into tilapia. The ASI was produced in tilapia actively immunized (challenged) with virulent S. iniae by i.p. injection. An antibody response against S. iniae was demonstrated by enzyme linked immunosorbent assay (ELISA) and 18% of the immunized fish died because of the S. iniae infection. The actively immunized tilapia demonstrated a secondary antibody response and immunity to S. iniae after challenge with S. iniae by i.p. injection. Survival was 100% in the actively immunized fish. The NWS was obtained from tilapia free of ASI antibody and susceptible to S. iniae infection (40% mortality). In two separate experiments, significantly higher mortality was noted in tilapia passively immunized with NWS (33 and 53%) and phosphate buffered saline (PBS) (30 and 60%), in comparison with mortalities of 0 and 10% or 3.3 and 6.7% in the fish passively immunized with ASI or HIASI 14 days after S . iniae infection by i.p. injection ( P  = 0.0003 and 0.0023). Results suggest that immunity provided by ASI and HIASI was because of antibody against S. iniae . Inactivation of complement in the HIASI treatment further suggests that ASI antibody plays a primary role in immunity against S. iniae infection.     

尼罗罗非鱼β-actin基因启动子的分离及其在真核细胞中的活性验证

采用高保真PCR方法从尼罗罗非鱼(Oreochromis niloticus)基因组DNA中分离出β-actin基因启动子序列,将β-actin基因启动子插入pN1-EGFP构建成真核细胞表达载体pEGFP-β-actin,并通过脂质体转染法将重组载体导入人胚肾上皮细胞HEK 293T,荧光显微镜下观察外源基因EGFP...     

尼罗罗非鱼出肉率与可量性状的相关性

运用统计分析方法研究了吉富品系和埃及品系尼罗罗非鱼(Oreochro misniloticus)2龄成鱼雌、雄个体的出肉率和可量性状之间的相关性。结果显示,尼罗罗非鱼的平均出肉率为38.68%,雄性个体出肉率比雌性个体略高,吉富品系出肉率比埃及品系略高。尼罗罗非鱼出肉率与可量性状间存在较强的线性关系,拟合方程相关系数为0.985。在有显著意义的可量性状相关系数中(P0.01),与肉片质量和出肉率的相关性均最高的可量性状为体质量,相关系数分别为0.964和0.575;其次为体高、体长和体厚。而头长与肉片质量、出肉率均呈负相关关系。雄性个体的相关系数均高于雌性个体,在雄性个体中,出肉率与体质量的相关系数为0.630,与体高的相关系数为0.617,均为中等程度相关。对可量性状之间的比值与出肉率进行相关性分析,相关系数普遍比单个性状高,特别在雄性个体中表现明显。其中相关系数较高的比例组合有身长/头长比值(0.765)、体长/头长比值(0.732)、身长/体厚比值(0.703),均达到较强程度的相关,比单个性状的相关性有明显提高。结果表明,利用可量性状预测罗非鱼的出肉率是可行的。