摘要:中国对虾经过连续6 代的群体选育, 表现出生长快、抗逆性强等优良的经济性状。选育群体的体长比对 照平均增长8. 40%, 体重增长26. 86%。抗逆性强, 发病率不足10%, 而未经选育的对照池发病率在40% 以 上。对不同世代进行了遗传结构分析, ( 1) 同工酶: 在13 个基因位点中, MDH- 2、GPI 、MPI 、PGM- 2 和PGM- 3 五 个位点呈多态。PGM- 3 位点上的变异程度最高, 其等位基因频率呈递减趋势, 选育群体在MPI 位点上发现c 基因, 其等位基因频率呈递增趋势, 其平均观察杂合度呈依次递减趋势。( 2) RAPD: 对5 个世代进行了RAPD 分析, 各世代间多态性比例呈下降趋势, F6 代保持了F5 水平。遗传分化指数Gst 除F3 与F4 之间遗传分化弱之 外, 其他世代间已发生了中等程度的分化。( 3) SSR: 对5 个世代进行了8 个基因位点分析, 共产生108 个等位 基因, 群体间的杂合度呈下降趋势, F6 保持了F5 水平。遗传分化指数Gst 值均小于0. 05, 说明中国对虾人工选 育群体之间存在一定程度的分化, 但分化较弱。

摘要:利用微卫星技术对中国对虾人工选育群体第1代和第6代群体的遗传多样性进行了分析.对10个微卫星位点进行了扩增,共产生74个等位基因,每个位点产生的等位基因数从3到13不等.在两个群体中,所观察到的等位基因数都比有效等位基因数多.多态信息含量PIC值0.5567～0.8877,说明这10个微卫星位点在中国对虾中具有较高的信息含量.两个群体的平均杂合度分别为0.6400(CP1)、0.6300(CP6),并通过计算基因型的P值,确定了对Hardy-Weinberg平衡的偏离情况.对Fis值的计算表明两个群体内共有5个微卫星位点存在杂合度观察值过剩的现象.两个群体的Shannon多样性指数分别为1.6830、1.7382,整个选育群体(两个群体作为一个群体)的遗传多样性指数为1.7742.从遗传多样性所占的比例来看,96.415%的遗传变异是来自群体内,只有3.585%的遗传变异是来自群体间.两个群体间的相似性系数高达0.9187,彼此间的遗传距离仅为0.0848,体现出人工选育群体的遗传分化程度较低.结果均说明第6代群体还有较大的选育潜力,可以继续保持遗传效应,最终保证选种育种工作的成功.

摘要:利用AFLP技术对连续4年选育的中国对虾抗白斑病毒群体进行了遗传分析,并比较了不同的数据处理方法对遗传学参数的影响.7个EcoRⅠ/ MseⅠ引物组合共产生350个位点,其中202个为多态位点.4代群体的多态位点比例分别为:39.4286%,41.4286%,33.4286%,39.1429%,Nei基因多样性指数分别为:0.1197,0.1259,0.1133,0.1249;4代群体的Shannon多样性指数分别为0.1831,0.1917,0.1702,0.1896.遗传多样性水平除了第3代群体标本明显较低外,其它3代甚为接近,维持在一个恒定的水平.比较了Nei分析、Shannon信息指数分析、AMOVA分析得出的遗传学参数,建议AMOVA分析作为应用AFLP进行群体遗传学分析时首选的统计方法.在AFLP指纹图谱中发现共显性基因座,对其中1个基因座的两个AFLP片段进行了回收、克隆及测序.序列分析表明,多态性是由引物扩增区域内4个核苷酸的插入/缺失导致的,证明了AFLP标记并不完全是显性标记.实验表明AFLP技术灵敏度高,信息量大,适用于分析亲缘关系较近的个体或品系,在中国对虾分子标记辅助育种方面有应用潜力.

摘要:采用PCR方法对所克隆的斑节对虾溶菌酶基因的cDNA进行改造,并克隆至含温控启动子PRPL的大肠杆菌表达质粒pBV220,构建斑节对虾溶菌酶表达载体pBV220-lyz.该质粒转化大肠杆菌后经42℃诱导表达.SDS-PAGE电泳表明,表达产物中有16kD左右的特异性条带,与预期斑节对虾溶菌酶分子量相符.薄层扫描显示,重组斑节对虾溶菌酶约占全菌总蛋白的32%,纯化后的重组斑节对虾溶菌酶占全菌可溶性蛋白的90%左右.比浊法检测复性后产物的生物活性,结果表明重组斑节对虾溶菌酶的最适pH为6.0,最适温度为40℃.测定了重组斑节对虾溶菌酶对溶壁微球菌和几种鱼病原菌菌株的溶菌活力,结果表明,重组斑节对虾溶菌酶对溶壁微球菌、溶藻弧菌和鳗弧菌有较强的溶菌活力,对爱德华氏菌有一定的溶菌活力,对嗜水气单胞菌、副溶血弧菌和大肠杆菌DH5α溶菌活力较弱.

摘要:利用光镜和电镜对中国龙虾叶状幼体发育早期(Ⅰ～Ⅳ期)消化道的组织学、组织化学和超微结构进行了研究.消化道可分为前肠、中肠和后肠.前肠包括口、食道和胃.消化道壁由粘膜层、结缔组织层、肌肉层和外膜组成.除中肠外,其余消化管壁上皮均覆盖有几丁质层.消化道结构随幼体发育逐渐复杂化.口部的口器发达.食道壁内褶形成四个食道嵴.贲门胃的结构简单,至Ⅳ期幼体只有胃磨齿的雏形;幽门胃内具有由栉状刚毛组成的腺滤器,其结构与过滤功能逐渐完善.中肠上皮细胞具微绒毛,胞质中富含胞器.后肠有六个纵嵴.各段管壁上皮细胞内的胞器以线粒体与内质网居多.在各期幼体消化道中,几丁质层具较多的多糖类物质,中肠上皮细胞含少量糖原;肌细胞内含丰富蛋白质,幽门胃与中肠上皮的含量次之.还探讨了龙虾幼体消化道的结构与功能的关系.

摘要:采用PHA活体注射结合秋水仙素培养,取点带石斑鱼全肾,低渗处理,空气干燥制片法制作染色体标本,对染色体进行Giemsa染色、C带及Ag-NORs等系列研究.结果表明:(1)点带石斑鱼2n=48,核型组成为48t,NF=48,没有异型性染色体分化;(2)在最小一对染色体的着丝粒与其染色体臂之间,靠近着丝粒部位有明显的次缢痕;(3)在间期核中,通过银染表现出核仁的数目为1～4个,1个核仁的间期核数目最高,多达55%,4个核仁的间期核数目占2%;(4)50%有丝分裂中期相能观察到Ag-NORs,Ag-NORs主要出现在第24对同源染色体上,第5对同源染色体也可观察到,但其它染色体上则没有;(5)Ag-NORs的数目在不同的细胞中表现出多态性,数目为1～4个,出现4个Ag-NORs的频率最低(6.8%),出现2个Ag-NORs的频率最高(58.1%);(6)第24对同源染色体近着丝粒的臂内具次缢痕,是Ag-NORs所在的区域,该区域分布有大量的结构异染色质,即Ag-NORs与C带强阳性呈现严格的同步对应;(7)点带石斑鱼所有染色体着丝粒为阳性C带,而且第24对染色体几乎整个染色体臂都呈C带阳性,着色强度与该对染色体上的着丝粒C带相同.最后讨论了核型演化规律和Ag-NORs、C带的发生机制.

摘要:采用透射电子显微镜对我国南海细薄星芒海绵体内微生物的分布进行了观察研究,同时结合海绵的结构特点与摄取营养的方式对分布特点进行了分析讨论.研究证明:在细薄星芒海绵体内除骨骼外的细胞间中质层、细胞内、海绵内腔等部位均分布着形态多样的微生物,其中海绵中质层是共(寄)生微生物最为丰富的地方.海绵微生物的分布特点与海绵腔状多孔的结构以及依靠过滤海水获取营养的方式有关,这对于将来揭示微生物在海绵体内的聚集机制及其与环境的关系具有重要价值.

摘要:1998-1999年及2001-2002年对北部湾海域进行了6个航次生态环境综合调查.利用调查资料,以种为聚类变量进行了毛颚类的组群分析,结果表明北部湾毛颚类可分为3个组群.组群I及组群II为北部湾的主要组群.组群III组成种类和出现数量最少,为次要组群.组群I是一类分布广但适温盐范围较低,与北部湾高温、低盐的沿岸流关系较为密切的组群;而组群II则适温盐范围较高,与北部湾高温、高盐的外海水关系较为密切.

摘要:在20℃下测定了双齿围沙蚕的常规代谢和标准代谢的昼夜变化规律.按沙蚕体湿重分别设置S[0.50?0.05g]、M[0.90?0.05g]、 L[1.50?0.05g]3个组,投喂人工合成的牙鲆饵料,结果表明:(1)常规代谢和标准代谢均随体重的增加而降低,符合幂函数方程R＝aWb,b值分别为-0.5988、-0.4817;(2)在标准代谢的昼夜变化中,S、M、L各组表现出相同的规律,即夜间代谢增强,白天相对低缓;(3)对双齿围沙蚕常规代谢和标准代谢昼夜变化的比较表明,S、M和L组特殊动力代谢的峰值分别为3.936、1.5222和1.2853 mg?(g?h)-1,持续时间相近,S、M、L总耗能分别为:271.62、73.56和70.56J?g-1.

摘要:以Cd2 浓度1.25mg?kg-1腹腔注射染鲫,以富含T、B、NK细胞及单核细胞的鲫外周血单个核细胞(PBMC)为效应细胞,用亚显微形态分析、单细胞凝胶电泳(SCGE)、DNA凝胶电泳和流式细胞术(FCM)等方法进行Cd2 诱导鲫PBMC凋亡的研究.电镜显示染镉细胞的染色质边聚、中聚并向胞浆突出和断裂,胞浆内细胞器结构不清晰并见许多大小不等的空泡;对照细胞的核呈马蹄形,染色质分布均匀,胞浆内细胞器结构清晰可辨.SCGE显示染镉细胞呈现DNA边聚化的彗星小头及DNA片段移动形成的彗星尾,对照细胞的核骨架边缘清晰;染镉处理14、17和21d的细胞凋亡率分别为19.4%、16.4%和5.6%,明显高于对照组(1.1%)(P<0.05).DNA凝胶电泳显示染镉细胞出现180～220bp整数倍的DNA梯状带,14和17d的梯状带较21d明显;对照细胞的DNA为一条带.FCM显示染镉细胞的亚二倍体峰清晰可见,对照细胞的亚二倍体峰几乎看不见;染镉处理14、17和21d的亚二倍体峰细胞量分别为17.5%、23.6%和8.2%,明显高于对照组(1.4%)(P<0.05).因此,体内染镉可诱导鲫PBMC凋亡并在14～17d达到峰值,21d时则可能由于DNA的损伤修复而得以缓解,由此推测镉诱导鲫PBMC凋亡是其致细胞病变死亡的重要表现形式之一,低浓度镉致鲫免疫系统损伤,极有可能通过直接诱导免疫细胞凋亡而实现.

摘要:建立了尼罗罗非鱼血浆内氯霉素的反相液相色谱测定法(RT-HPLC),并研究了以50 mg?kg-1剂量的氯霉素单次给药后,不同水温、不同年龄尼罗罗非鱼血浆中药代动力学的差异.结果表明,RT-HPLC法检测血浆中的氯霉素基线走势平稳,药峰与杂质峰分离良好,在空白血浆样品中添加0.25,2.5和12.5 μg?mL-1标准品,3个水平的平均回收率可达(90.47?3.42)%,且变异系数小于10%;日内精密度和日间精密度均较高,平均变异系数分别为1.199%和1.770%.研究揭示,水温和年龄对氯霉素在尼罗罗非鱼血浆中的药代动力学有一定的影响.水温升高,氯霉素在罗非鱼血浆中吸收、分布和消除速度则明显加快,26℃下T1/2 ka仅为18℃的1/3,T1/2α和T1/2β也明显缩短,Tp不到18℃的一半,CLs是18℃的1.74倍;氯霉素在一龄罗非鱼血浆中的吸收速度比二龄罗非鱼快,达峰时间短,消除速度明显减慢,但分布半衰期和曲线下面积(AUC)大小二者比较接近.鉴于CAP毒性强,在对水产品中的CAP残留进行监控时,应以养殖水温较低、年龄较小者作为监控的重点,以确保水产品的安全.

摘要:为了弄清免疫促进剂增强对虾自身免疫力的作用机理,利用脂多糖 (LPS)、β-葡聚糖 (β-1,3-glucan)、灭活哈维氏弧菌和灭活鳗弧菌对中国对虾血细胞的数量、形态结构以及酚氧化酶 (phenoloxidase,PO) 的产量与活性在刺激前后的变化进行了研究.研究结果表明,经β-葡聚糖、脂多糖、灭活哈维氏弧菌和灭活鳗弧菌刺激后,中国对虾总血细胞的数量分别增多了83.4%、52.0%、73.4%和111.3%,其中,小颗粒细胞的数量分别增多了100.4%、67.3%、57.2%和102.9%,大颗粒细胞的数量分别增多了47%、10%、127%、和173%;同时,PO 的产量分别提高了81.3%、104.7%、29.2%和40.4%,但 PO 的单位酶活性在刺激前后没有显著变化.透射电镜 (TEM) 观察结果显示,中国对虾血细胞的超微结构在免疫刺激前后发生了不同程度的变化.在β-葡聚糖和脂多糖刺激下,小颗粒细胞和大颗粒细胞内糙面内质网 (RER) 和游离核糖体数量明显增多,线粒体数量增加,细胞内分泌颗粒的数量大幅度减少;而透明细胞的超微结构在多糖刺激前后除 RER 及线粒体数量略有增加、核孔复合体数量明显增加外没有显著差异.经灭活哈维氏弧菌刺激后,对虾大颗粒细胞中 RER 增生显著并发生泡状化,核质比明显降低;小颗粒细胞中的 RER 也发生增生且呈泡状化,核质比略有降低;透明细胞中 RER 数量明显增加,线粒体数量显著增加,核质比明显下降;在灭活鳗弧菌刺激下,对虾透明细胞中游离核糖体和线粒体的数量明显增加,核质比下降;小颗粒细胞内 RER 的数量明显增多、潴泡体积扩大,细胞质中分泌颗粒的数量比对照组略有减少,核质比明显下降;大颗粒细胞的超微结构除游离核糖体数量有所增加外,变化并不显著.β-葡聚糖和脂多糖主要用于小颗粒细胞和大颗粒细胞;而灭活鳗弧菌和哈维氏弧菌对大颗粒细胞、小颗粒细胞和透明细胞均有作用.

摘要:白斑综合征可以导致养殖对虾短时间内大面积死亡,是迄今为止对虾养殖业面临的最大挑战.本试验采用巢式PCR法对2001年采自黄渤海的中国对虾几个产卵场群体进行白斑综合征病毒检测,旨在较全面地了解黄渤海野生中国对虾携带病毒状况.各群体的阳性检出率分别为:朝鲜半岛南海岸群体55%;渤海湾群体35%;辽东湾群体94.7%;海州湾群体47.4%.结果显示,中国对虾几个产卵场群体均不同程度地携带白斑综合征病毒.辽东湾产卵场群体阳性检出率明显高于其他群体,推测人工孵化苗种放流、海湾的地理和水质条件与中国对虾的WSSV感染率相关.而中国对虾野生群体携带病毒对于对虾养殖业的影响是不容忽视的,笔者认为,只有从无特异病原(SPF)及抗特异病原(SPR)对虾养殖群体的建立着手才能从根本上避免由于对虾携带病毒而可能导致的病毒性疾病的暴发.同时,应该重视海区污染的治理,减少病毒病暴发的诱因.本试验建立了快速检测WSSV的PCR方法,1pg病毒核酸仍可检测到,为白斑综合征病毒病的防治及早期诊断提供了有效的手段.

摘要:根据已发表的气单胞菌16S rDNA基因序列及气单胞菌气溶素(aerolysin)基因序列,设计了2对引物,建立了检测致病性嗜水气单胞菌的PCR方法.通过对12株气单胞菌的检测,发现16S rDNA引物具有高度的特异性,仅对嗜水气单胞菌扩增阳性.而Aero基因引物检测结果与采用生物学方法(鲜血平板法)检测的结果符合率为97.2%,且具有高度的敏感性,可检测最低1fg 的模板.将16S rDNA与Aero基因结合PCR方法检测致病性嗜水气单胞菌与用致病性嗜水气单胞菌检测试剂盒的符合率为94.4%.该方法的建立为致病性嗜水气单胞菌的检测提供了一种简便、快速的途径,是一种比较实用的致病性嗜水气单胞菌的检测方法.

摘要:用酪蛋白和白鱼粉为蛋白源配制7种蛋白含量为32.07%～45.64%的半精制试验饲料,喂养7组3个重复的翘嘴红鲌幼鱼8周.饲养试验在室内玻璃钢水箱中进行,试验鱼每尾平均初始体重2.88?0.22g,水温为25～29℃.结果显示:蛋白质水平为41.05%的试验组的鱼体增重、特定生长率、饲料效率和蛋白质效率等指标均显著高于其它试验组(P<0.05);对特定生长率(Y)和饲料效率(F)二项指标的二次曲线回归分析求得翘嘴红幼鱼饲料蛋白最适值分别为40.94%和41.35%;饲料蛋白水平对鱼体(全鱼)的水分、粗蛋白和粗灰分的含量无显著影响(P>0.05),而较高水平饲料蛋白会使鱼体脂肪含量明显降低(P<0.05).

摘要:采用感官评估、物理、化学、微生物分析方法,对贮藏在不同冷藏条件下的北极虾的质量变化与质量指标进行了研究.保藏方法分别为传统冰块冷却法、液态冰冷却法、盐水-冰混合冷却剂法,贮藏环境温度为 -1.5℃或 1.5℃.研究结果表明,液态冰冷藏法对延缓虾腐败变质的效果比传统冰块冷藏法、盐水-冰混合冷却剂冷藏法好.经过1d的贮藏后发现,无论在-1.5℃还是 1.5℃的环境温度下,保藏在液态冰中虾的挥发性总氮(TVB-N)都有所下降,并且在-1.5℃的环境温度下,其TVB-N值在3d后才回升到刚开始贮藏时的水平,而在其它保藏方法中,虾的TVB-N值始终随贮藏时间的延长而增加;除保藏在液态冰-1.5℃环境中虾的三甲胺(TMA)在贮藏的第1天有所降低以外,其它各试验组虾的TMA值均随贮藏时间的延长而增加.检测结果还表明,保藏在传统冰块及盐水-冰混合冷却剂中虾的细菌总数(TVC)增加最快,其次是保藏在液态冰中1.5℃的环境下.而保藏在液态冰中-1.5℃的环境下,虾的细菌繁殖最慢,并且在贮藏初期,产生了明显的细菌总数降低及细菌繁殖被抑制的现象.采用主要因子分析(PCA)和方差分析(ANOVA)发现,质量指标如TVB-N、TMA、TVC、pH、NH3(电子鼻测量值)和感官评估结果等相互之间存在着良好的相关性.

摘要:对以中国毛虾为原料酶法制备具有抑制血管紧张素转换酶(ACE)活性的酶解产物的方法作了探讨.以体外活性(ACE抑制率)为指标,通过正交试验确定胃蛋白酶的最佳酶解条件为pH2.4、温度41℃、酶量900U?g-1底物、底物浓度8%;酶解产物的IC50为0.65 mg?mL-1,再分别利用Sephadex G-25和Sephadex G-15对其进行进一步分离提纯,IC50降至0.084 mg?mL-1和 0.046 mg?mL-1,活性组分中的疏水性氨基酸含量增高,最终活性产物的分子量分布在700～1900.

摘要:研究了气相色谱法测定水产品肌肉组织中氯霉素残留的前处理方法.在综合分析比较现有国内外有关气相色谱法及气-质法检测动物源性食品中氯霉素残留前处理方法的基础上,对加标溶剂选择及样品提取方式、净化方法、SPE小柱活化方法对回收率的影响,硅烷化的时间等进行了比较研究.结果表明:用蒸馏水作加标溶剂,回收率高,平行性较好,可代替甲醇作为加标溶剂.采用乙酸乙酯作为提取剂,用正己烷脱脂,水溶液直接过SPE小柱(小柱依次用5mL甲醇和5mL水活化)净化,硅烷化试剂衍生20～30min后测定的前处理方法,步骤少,试剂省.该方法0.1～20 μg?kg-1加标水平的回收率为67%～115%,适合水产品中氯霉素残留分析.

摘要:水生甲壳动物的渗透调节机制一直是国内外学者研究的热点,在渗透调节器官的形态结构[1,2]、离子转运调控[3-9]和血淋巴渗透压调节[10,11]以及神经内分泌调控[12,13]等方面已作了大量的研究工作,并取得了许多重要的成果.

摘要:由于海洋捕捞强度的日益加重,海洋渔业资源已严重匮乏.海水增养殖已成为弥补海洋资源的重要途径之一.而随着养殖规模及养殖密度的不断扩大,病害问题日趋严重,已成为制约我国海水养殖业健康可持续发展的重要因素之一.

摘要:Gynogenesis is thought to be a useful method to generate fully inbred line and to initiate monosex culture in teleost fish. This article presents results of a study of gynogenesis of tench, Tinca tinca L. from Eltrix River of Xinjiang, China, induced by the common carp ( Cyprinus carpio ) sperm inactivated with UV irradiation. When cold shocking method was used to prevent exmasion of the second polar body in order to produce gynogenetic diploids, the optimum treated parameters were screened as cold shocking for 20min at 4℃, 5min after insemination. On this condition, 10.23% of the treated eggs survived at feeding stage. A comparative study between the gynogenesis and their parents was made by RAPD technique. 82 random primers of 10 nucleotide long sequence were used in RAPD analysis. The results showed that each primer gives 3- 12 fragments for each sample with the fragment length 330 - 2 460 bp, and the genetic similarity between gynogenesis and their mother was 97.4 %, while the genetic similarity between gynogenesis and their father was 27.4%, and there were no bands only shared by gynogenesis and their father, the common carp. It revealed that the chromosome of their father, the common carp, did not penetrate into the construction of gynogenetic tench.

摘要:Probes are essential for study of gene expression and regulation. In this study, a method was established to prepare the biotin- labeled probe for 18S rRNA gene of freshwater prawn, Macrobrachium rosenbergii . And the labeled method was used to produce a lysozyme gene probe, then applied in analy sis of lysozyme gene expression. Primers were designed according to the nucleotide sequences of 18S rRNA of Decapoda in order to isolate the 18S rRNA gene sequences of M. rosenbergii. Total genomic DNA was isolated from hepatopancreas of the freshwater prawn. A specific DNA fragment with desired size was amplified by PCR using the total DNA as templates. The DNA fragment was inserted into pGEM- T Easy vector and sequenced. The result of BLAST and alignment analy sis confirmed that the DNA fragment iso lated was the 18S rRNA gene of M. r osenbergii, which was 418 nt in length. Biotin- labeled probe of the 18S rRNA was then produced by PCR using the recombinant plasmid as templates. The biotin-21- dTTP and the non- labeled dNTP were added to the PCR reaction system. Ratio of the biotin- 21-dTTP and the non- labeled dTTP was 3 to 1. The yield of the labeled probe is 300 ng#LL- 1. The detection limit of the probe is 60 pg. A biotin- labeled probe of ly so zyme gene was prepared by the same label method, and the yield of the lysozyme gene probe is 500 ng#LL- 1. These biotin- labeled probes were applied in Northern dot blotting analysis of tissue distribution of lysoyzme mRNA of M. rosenbergii. Signals were scanned and quantified by Analy sis System of Biolo gy Image. The signal intensity ratio of the lysozyme to 18S rRNA represents the relative expression level of lysozyme mRNA. The results showed that the lysozyme mRNA existed in all the tissues checked, including eye, muscle, gill, hepatopancreas, haemocytes and intestine. But lysoy zme mRNA levels varied among different tissues. The highest level was found in the intestine, and the second was in the hepatopancreas and the lowest was in the muscle. The signal intensities of 18S rRNA among tissues were consistent, which showed that the 18S rRNA gene expressed stably in different tissues and could be used as an internal standard for researches of specific gene expression in prawns.

摘要:Natural resistance associated macrophage protein ( Nramp) is an innate resistance protein to intracellular parasites, which is expressed plentifully in macrophage cells. Nramp has been studied in mouse, human, cattle, rainbow trout and channel catfish. However, little was known about the structure of Pagrus maj or Nramp. In order to get the complete sequence of Pagrus major Nramp, a pair of primer is designed according to a 200bp known sequence of Pagrus major Nramp cDNA. By the use of SMART RACE, the full Nramp of Pagrus maj or cDNA about 5 000 bp was obtained, including about 200 bp 5c terminal region ( UTR) , complete encoding region and 3c terminal region. There were 3 ployA signals, which showed many possibilities of cutting at 3c terminal region. The character of Pagrus major Nramp nucleotide sequence and deduced amino acid sequence are analyzed. 12 putative transmembrane( TM) regions, a consensus transport motif ( CTM) , a predicted protein kinase C phosphroylation site and three predicted N- link glycosylation sites are indicated in its deduced amino acid sequence. The . consense transport motif. CTM is located between TM8 and TM9. Furthermore, a protein kinase C phosphroylation site and three N- link glycosylation sites were predicted. The alignment of amino acid sequences between Pagr us major Nramp cDNA and several animals is analyzed and the deduced amino acid sequence of Pagrus major Nramp had 77. 8%, 83. 0%, 82. 3%, 80. 0%, 81. 1%, 60. 4%, 70. 3%, 58. 5%, 69. 5% identity w ith rainbow trout A( AAD20721) , rainbow trout B ( AAD20722) , channel catfish ( AF400108) , fathead minnow ( AAF01778) , common carp ( CAB60196) , mouse 1 ( AAA39838) , mouse 2 ( AAC42051) , human 1 ( D50403) , human 2 ( NP - 000608) , respectively . The alignment reveals high conservation in TM and CTM regions. Analysis result makes us get familiar with the structure and character of fish Nramp, furthermore, offer s some information for the enhancement of immunity of fish and genetic amelioration on fish breeding.

摘要:The variations of muscle tissus , peroxidase and Ca2 2ATPase activities and Vp (pasteurization value) were investigated with the fresh samples of grass carp ( Ctenopharyngodon idellus ) heated at different temperatures , thus revealing the mechanism of denaturation of muscle protein by heating. The experimental results showed the great difference in muscle tissue structure before and after the samples heated. In the initial stage of heating the water loss accounted for 50 % of the total. When the samples were separately heated at 75 , 85 , and 95 ℃, fh values (dehydration curve slope) were 5 , 4. 1 and 1. 7 , respectively , while Vp reaching 40 minutes were 22 , 8 and 5 min , respectively. As to the time for deactivation of peroxidase in the heated samples at the various temperatures , it varied from 38 , 10 and to less than 6 min , respectively and the deactivation rates of Ca2 2ATPase in 1 min were 50 % , 88 % and 100 % , respectively. Consequently , the higher temperature the sample was heated , the faster rate of thermocon ductivity , the lower rate of water loss , and the faster rate of peroxidase deactivation it was. Also , the Vp for the least requirement of pasteurization ( Vp ≥40min) was obtained.

摘要:This present paper studied the technological characteristics of seawater treated by sand filtering , net filtering and reserve2water disinfection. The results showed that after treatment the average filtering ratio of phytoplankton was 89. 98 % , and that of zooplanktonwas89.5%; thatitcanisolatetheotherspeciesofshrimpandcrabbythefilteringnetof morethan40mesh,anditwas difficult for Copepoda to pass through the filtering net of more than 60 mesh ,so it can block the horizontal disseminate pathway of WSSV ; and that 6 ?10 6 of the efficient chlorine can kill Copepoda but most aquatic creatures were dead in the water treated by 10 ?10 6 of the efficient chlorine , and it can transfer algae after killing the harmful creatures by using bleaching powder when there was reserve water. The result of water culture for 4 days , in out2seawater and the water treated with sand filtering or net filtering of 60 mesh or 6 ?10 -6of efficient chlorine , showed that the species and quantity of plankton were the most by out2sea2water culture , and it reduced respectively in the water treated by filtering with 6 mesh ,sand filtering and 6 ?10 -6 of efficient chlorine.