南方杂色鲍苗大规模死亡病原菌的分离鉴定及其回归感染试验

自2002年下半年开始,南方杂色鲍苗出现大规模死亡的问题,严重影响到南方鲍鱼产业的发展。从汕尾鲍鱼场发病杂色鲍苗中分离到一批菌株,本研究对16号优势菌株进行了比较深入的工作,回归感染试验证明其为病原菌,API 20E条带分析表明其为溶藻弧菌(Vib-rio alginolyticus),药敏试验揭示其对卡那霉素、氯霉素、氨苄西林、链霉素、四环素有抗药性,但对青霉素、复方新诺明、庆大霉素、多粘霉素敏感。本研究结果为我国南方杂色鲍苗掉板症的防治提供科学依据。     

饲料中维生素B6对皱纹盘鲍幼鲍蛋白质代谢的影响

以皱纹盘鲍(Haliotis discus hannaiIno)幼鲍为研究对象,探讨维生素B6对其蛋白质代谢的影响。设计了3种维生素B6不同含量(0,40,4 000 mg/kg)的半精制饲料,在循环水养殖系统中养殖幼鲍240 d。结果表明,皱纹盘鲍内脏团和肌肉中磷酸吡哆醛(PLP)的含量随饲料中维生素B6的添加而显著升高(P<0.05)。饲料中不同维生素B6水平对肌肉组织中蛋白含量没有显著影响(P>0.05),而显著升高内脏团中蛋白质的含量(P<0.05)。内脏团和肌肉中的谷丙转氨酶(ALT)和谷草转氨酶(AST)活力随着饲料中维生素B6添加量的升高而显著增强,分别在维生素B6的添加量为4 000 mg/kg时取得最大值(P<0.05)。内脏团中所检测的各种氨基酸的含量与饲料中维生素B6添加量没有显著影响(P>0.05)。然而,肌肉中的天冬氨酸(Asp)、苏氨酸(Thr)、丝氨酸(Ser)、牛磺酸(Tau)的含量随着饲料中维生素B6添加量的升高而显著增加,并且分别在维生素B6添加量为4 000 mg/kg时取得最大值(P<0.05)。肌肉中甘氨酸(Gly)、丙氨酸(Ala)、缬氨酸(Val)、蛋氨酸(Met)的含量在两个维生素B6添加组(40 mg/kg和4 000 mg/kg)之间没有显著差异(P>0.05),但均显著高于维生素B6缺乏组(0 mg/kg)的值(P<0.05)。     

杂色鲍裂壳病球状病毒的初步观察

1999年以来 ,广东汕尾地区养殖杂色鲍Haliotisdiversicolor出现了“裂壳病” ,经电镜观察 ,发现感染了一种球状病毒 ,大小为 1 5 0— 2 2 0nm ,皆存在于细胞的细胞质中 ,细胞核内没有发现病毒。主要侵染鲍的腹足、外套膜、性腺、肝、鳃等部位。病鲍表现为头端壳缘外翻 ,呼吸孔融合成一条线 ,活力减弱 ,身体消瘦 ,逐渐死亡。     

九孔鲍(Haliotis diversicolor supertexta)耐低盐与生长性状的遗传参数评估

采用不平衡巢式设计方法和人工授精技术,1个雄九孔鲍(Haliotis diversicolor supertexta)配3个雌九孔鲍,建立12个半同胞家系和36个全同胞家系,各家系养殖240d后统计每个家系生长性状,并分别从所建立36家系中随机选取40个稚鲍,在盐度16下进行耐盐实验,48h后统计各个家系的存活率,应用约束最大似然法(Restricted Maximum Likelihood Method,REML)估算九孔鲍体重,壳宽,壳长与耐低盐性状的遗传参数。结果表明,九孔鲍稚鲍在240日龄时,壳长、壳宽和体重遗传力为中等遗传力,估计值分别为0.18±0.04,0.13±0.06,0.18±0.15;耐低盐性状遗传力较低,估计值为0.056±0.022,48h家系的平均存活率为0.44±0.23。壳长,壳宽,体重与耐低盐性状的表型相关与遗传相关系数分别为?0.04—?0.156和?0.03—0.14,呈负相关关系,检验不显著。结果证明,对九孔鲍生长性状与耐低盐性状进行改良时,可采用复合育种技术,以加快育种进程。     

Identification of genes expressed in juvenile Haliotis rufescens in response to different copper concentrations in the north of Chile under controlled conditions

This study reports molecular markers potentially associated with resistance or sensitivity to the impact of copper in juvenile red abalone, Haliotis rufescens, in the north of Chile under experimental conditions. Genomic analysis was made applying subtractive hybridization libraries (SSH) to identify genes up-and down regulated during cooper exposure in abalone over periods of 12 and 168 h exposed to 2.5 and 10 μg/L of Cu⁺². Results obtained from the SSH library revealed 368 different sequences regulated by copper, that correspond to eight major physiological functions. The validation of these sequences obtained by SSH as well as their expression kinetics were made by PCR in real time on 14 potential genes regulated by metal stress. This study provides information for the characterization of potential genomic markers that may be used in future environmental monitoring and to investigate new mechanisms of stress to copper in this commercially important marine species.     

皱纹盘鲍(Haliotis discus hannai)WNT4基因生物信息学分析及与性腺发育相关性的研究

WNT4作为WNT基因家族的重要成员,在动物的性腺发育过程中起重要调控作用。从皱纹盘鲍(Haliotis discus hannai)转录组文库中获得WNT4基因的cDNA序列,该序列长2002 bp,包括5′非编码区(5′UTR)342bp,3′非编码区(3′UTR)595bp,开放阅读框(ORF)长度为1071bp,可以编码356个氨基酸。该蛋白序列与福寿螺(Pomaceacanaliculata)、长牡蛎(Crassostreagigas)、栉孔扇贝(Azumapectenfarreri)和厚壳贻贝(Mytiluscoruscus)的同源性分别为71.86%、 70.92%、 67.51%和65.32%。通过qRT-PCR分析WNT4基因在雌雄皱纹盘鲍不同月份不同组织中的表达特点,其结果显示,除肝胰腺外,WNT4基因在其雌雄个体不同月份的鳃、外套膜、肌肉和性腺中均有表达;在雌性个体性腺中, WNT4基因的表达量以7月份为最高,显著高于其他月份;其次为5、8月,显著高于6、9月的表达量;5月与8月、6月与9月之间均差异不显著。在雄性个体性腺中,不同月份WNT4的表达量7月8月9月5月6月; 7、8月的表达量均显著高于其他月份, 9月显著高于6月的表达量,与5月差异不显著,5月表达量与6月差异不显著。此外,WNT4基因在精巢的表达量均高于卵巢。原位杂交(ISH)结果显示, WNT4在5—9月雌性皱纹盘鲍性腺的卵母细胞和雄性性腺的结缔组织均有明显的蓝紫色杂交信号。皱纹盘鲍WNT4基因在各个组织均有表达,表明其的表达特点是广泛性的,参与多种组织细胞的生命过程;在不同月份性腺中的表达特征,推测其可能在两性性腺发育过程中发挥作用。     

杂色鲍血蓝蛋白多克隆抗体的制备与血蓝蛋白35kDa片段鉴定

以杂色鲍(Haliotis diversicolor Reeve)为研究对象,通过密度梯度离心方法纯化得到高纯度血蓝蛋白,以其作为抗原皮下注射免疫新西兰大白兔,从而获得高效价的兔源多克隆抗血清。进一步通过Protein A抗原亲和纯化的方法对该抗血清纯化,最终获得效价更高、检测特异性更好的血蓝蛋白多克隆抗体。应用该抗体进行Western检测发现,鲍血淋巴中存在着多样的血蓝蛋白衍生产物;进一步结合质谱技术对其中35 kDa条带进行鉴定发现,其来源于血蓝蛋白I型亚基的H结构域。     

Acclimation-dependent expression of heat shock protein 70 in Pacific abalone (Haliotis discus hannai Ino) and its acute response to thermal exposure

Heat shock protein 70 (Hsp70) is one important member of heat shock protein (Hsp) family that is responsible for various stresses, especially thermal stress. Here we examined the response of Hsp70 gene to both chronic and acute thermal exposure in Pacific abalone (Haliotis discus hannai Ino). For the chronic exposure, abalones were maintained at 8, 12, 20, and 30°C for four months and their mRNA levels were measured. The highest mRNA level of Hsp70 gene relative to actin gene was detected in the 30°C-acclimated group, followed by the 8°C-acclimated group and then the 12°C- and 20°C-acclimated groups. After the long-term acclimation, gills from each of the above acclimation groups were dissected and exposed to different temperatures between 8°C and 38°C for 30 min. Hsp70 expression in gills acclimated to different temperatures responded differentially to the same temperature exposure. The incubation temperature that induced maximum Hsp70 mRNA expression was higher in the higher temperature acclimation groups than lower temperature groups. Pacific abalones could alter the expression pattern of Hsp70 gene according to environmental thermal conditions, through which they deal with the stress of thermal variations.     

皱纹盘鲍(Haliotis discus hannai)肠道潜在益生菌的筛选及对幼鲍生长的影响

采用体外实验筛选益生菌结合16SrDNA序列分析法,从124株不具有溶血作用的皱纹盘鲍(Haliotis discus hannai)肠道细菌中筛选得到5株潜在益生菌并进行了分子鉴定,进一步对5株潜在益生菌进行了安全性实验及体内饲喂实验。结果表明,2株具有拮抗哈维弧菌和灿烂弧菌能力的潜在益生菌分别被鉴定为Shewanella sp.(WA64)和Shewanella sp.(WA65),一株产海藻酸酶和淀粉酶的潜在益生菌被鉴定为Vibrio sp.(WA51),产蛋白酶潜在益生菌被鉴定为Bacillus sp.(FA12),产琼脂酶潜在益生菌被鉴定为Tamlana sp.(FA86);安全性实验表明5株潜在益生菌在107cfu/ml下对皱纹盘鲍没有明显的毒害作用;通过体内饲喂实验发现,潜在益生菌WA64、WA65的复合作用能够显著提高幼鲍增重率和存活率(P<0.05),并在生产条件下能够明显降低幼鲍的死亡量。经抗生素敏感性实验,WA64菌株对15种抗生素均敏感或中度敏感,WA65菌株仅对庆大霉素和链霉素2种抗生素产生耐药。     

Two‐dimensional model of diffusion processes around a river mouth

The steady state diffusion equation is solved for two‐dimensional flow around a point source along an infinite straight boundary. Solutions obtained are related to the observed distribution of temperature and salinity around the mouth of the Buller River, South Island, New Zealand.