RNA干扰对大鲵蛙病毒主要功能基因表达及其增殖的影响

采用q PCR与病毒滴度测定观察RNA干扰(RNA interference,RNAi)对大鲵蛙病毒(Chinese giant salamander ranavirus,CGSRV)主要衣壳蛋白(major capsid protein,MCP)、甲基转移酶(methyltransferases,MTases)、DNA多聚酶(DNA polymerase)基因表达与病毒增殖的影响。结果表明,小干扰RNA(small interfering RNA,siRNA)能推迟鲤鱼上皮瘤细胞(epithelioma papillosum cyprini,EPC)出现病变,且病变程度也较对照组轻。在各功能基因表达量上,NC-FAM对照组与阴性对照组差异不显著(P0.05);而干扰组的干扰率极显著高于阴性对照组,其中siR-DP-1组siRNA对MCP基因的干扰率为79%,极显著高于其余组(P0.01);siR-MT-1、siR-MT-2组siRNA对MTases基因的干扰率为77%,极显著高于其余组(P0.01);siR-DP-1组siRNA对DNA polymerase基因的干扰率为79%,极显著高于其余组(P0.01)。干扰实验组病毒滴度与NC-FAM对照组和阴性对照组相比也有不同程度的降低。阴性对照组lg TCID50为8.362,NC-FAM对照组lg TCID50为7.848,siR-MCP、siR-MT、siR-DP实验组最低lg TCID50分别为5.764、5.317、5.362。证实RNAi能够抑制CGSRV主要功能基因的表达并影响病毒的复制。     

Putting the pieces together: Recent growth,nutritional condition,and mortality of Engraulis anchoita larvae in the Southwest Atlantic

Dynamics of clupeiform fish populations such as anchovy are frequently impacted by environmental variations which can affect the success of the species recruitment. Herein, we have analyzed recent otolith growth rate, RNA/DNA nutritional condition index (sRD), and mortality rate of argentine anchovy larvae Engraulis anchoita from three different nursery areas in the Southwest Atlantic. We have evaluated the relationship between the environmental variables (abundance of copepod nauplii, temperature, chlorophyll‐a concentration, and abundance of E. anchoita larvae) and larval endogenous variables (size, weight, age, and otolith radius) to sRD and recent growth rate. Fast larval growth rates were observed toward the northern sector of the studied area, characterized by higher temperature. High values of sRD were associated with higher nauplii abundance in the proximity of coastal fronts. The larvae with the lowest growths and lowest minimum values of nutritional condition coincided with the area where there was less abundance of nauplii and higher larval mortality. Larval size and nauplii abundance were positive explanatory factors for both recent growth rate and sRD index. Temperature had a positive effect on recent growth rate and a negative effect on sRD index. This condition index was poorly explained in terms of model fit in comparison with the growth model. The results herein provided could be significant to better understand the recruitment of the species, as to determining favorable areas for the growth and survival of anchovy larvae.     

基于碳、氮稳定同位素研究黄海及东海北部主要鱼类的营养级和食性

本研究通过对2011~2014年间在黄海及东海北部采集的36种海洋鱼类进行碳、氮稳定同位素测定,利用碳稳定同位素比值(δ¹³C)计算底层饵料贡献比(Bp)来确定鱼类的食性,利用氮稳定同位素比值(δ¹⁵N)计算其营养级(TL)。结果显示,这36种鱼类的营养级范围为2.75~4.34,平均值为3.47。其中,4种为完全浮游生物食性,8种为底栖生物食性,完全底栖生物食性为12种,混合食性为12种。中(TL=3.5~4)、低(TL<3.5)营养级的种类占大多数(91.67%),而高营养级(TL>4)种类较少,仅为3种,且全部为混合食性。营养级的研究结果与1986、1992和2004年的研究对比发现,个别种类发生了改变。如蓝点马鲛(Sconberonorus niphonius)营养级有不同程度的下降;而黄鲫(Setipinna t)aty却有不同程度的上升。食性的研究结果与2004、2009和2011年的研究对比发现,有些种类食性发生了较大变化,如白姑鱼(Argyrosomus argentatus);有些种类食性几乎没有变化,如小黄鱼(Larimichthys polyactis)。     

The effect of feeding three anabolic steroids in different combinations on the growth,food conversion efficiency and protein and nucleic acid levels of liver,kidney, brain and muscle of mirror carp (Cyprinus carpio)

A study on the effect of three different anabolic-androgenic steroids on the growth, food conversion efficiency and nucleic acid contents of liver, kidney, brain and muscle of carp,Cyprinus carpio was undertaken. The three steroids, methyltestosterone (MT), ethylestrenol (EE) and oxandrolone (ON), were fed in different combinations at final concentrations of 5 or 6 mg/kg diet for 60 days. No effect on the growth was observed in any of the experimental groups. A decrease in the specific growth rate (11–21%) and food conversion efficiency (20–29%) was noted. Feeding of drugs increased the cranio-somatic and reno-somatic index in all except one group. Hepatosomatic (ON+MT) and viscero-somatic (ON+MT; EE+MT+ON) indices decreased. Protein increased and RNA/DNA decreased in only one group while a decrease in protein/DNA was observed in the liver of all experimental groups. RNA/DNA increased and protein/RNA decreased only in one group while no effect was seen in protein and protein/DNA contents in any of the treated kidneys. Proteins, protein/RNA and protein/DNA decreased in certain groups in brain tissue. In muscle, no effect was seen in proteins or protein/DNA. Protein/RNA decreased in all but one group while RNA/DNA was higher only in the group fed all the three steroids together.     

Carbon source and trophic position of pelagic fish in coastal waters of south-eastern Izu Peninsula,Japan, identified by stable isotope analysis

ABSTRACT:   It is important to clarify trophic dynamics in marine ecosystems for management of the fishing ground. Organic carbon sources and trophic position of pelagic fishes in the coastal waters of the south-eastern Izu Peninsula, Japan, were examined on the basis of carbon and nitrogen stable isotope distributions. The δ¹³C of the fishes was mostly distributed from −19 to −16‰ for nektonic fishes (13 species of adults and immatures) and planktonic fishes (10 species of larvae and juveniles), close to the δ¹³C values of particulate organic matter and planktonic decapods. These δ¹³C signatures for the inhabitants of the water column were in contrast with the high δ¹³C values (mainly −16 to −13‰) for demersal fishes of Scorpaeniformes and benthic polychaetes collected in the surf zone. These results indicate that nektonic and planktonic fishes depend on phytoplankton for carbon supply. The δ¹⁵N signatures suggest that the trophic position ranged 3.1–4.5 for the nektonic fishes and 2.9–3.7 for the planktonic fishes, premised on trophic level 3 for larval Japanese anchovy Engraulis japonicus . Thus, planktivorous fishes should be mainly assigned to trophic levels 3 and 4 in this area.     

应用氮稳定同位素技术研究辽东湾海域主要渔业生物的营养级

应用氮稳定同位素技术分析了2010年6月和8月辽东湾海域主要渔业生物的氮稳定同位素比值,研究了28种鱼类和26种无脊椎动物的营养位置。结果表明,辽东湾海域主要渔业生物的营养级处于2.98～4.84,集中在3.70～4.56;相比6月δ15N值的分析结果,8月有50%的鱼类δ15N值增加,孔鳐(Raja porosa)增幅最大,增加了1.06‰;9种鱼类δ15N值减少,鯒(Platycephalus indicus)减幅最大,减少了1.84‰,可见鱼类样品的δ15N值随季节的变化因种类而各异;8月有87.5%的无脊椎动物δ15N值减少,其中,减少幅度大于1‰的有6种,占37.5%,可见无脊椎动物的δ15N值随季节的变化较明显。通过对不同采样点同种生物δ15N值的比较发现,辽东湾近岸海域的10种无脊椎动物的δ15N值均高于远岸海域,差值范围为0.05‰～1.49‰,差异极显著(P<0.01),说明人类活动引起的陆源污水排放使近岸海洋生物的δ15N值升高。     

大鲵幼体蛋白质的需求量

为评定大鲵幼体对饲料蛋白质的需求量,以鱼粉为主要蛋白源配制6种蛋白质水平(干样基础)的实验饲料:D1(43.7%)、D2(47.1%)、D3(51.3%)、D4(55.7%)、D5(59.9%)和D6(64.4%),饲喂初始体质量为(20.99±0.15) g的大鲵幼体92 d。结果显示,①饲料蛋白质水平对大鲵增重率有显著影响,在D4组达到最大值,较D1组增加了276.4%,且全鲵蛋白质沉积率和肌肉RNA、RNA/DNA值、胃蛋白酶、H⁺-K⁺-ATPase、胰蛋白酶、脂肪酶和Na⁺-K⁺-ATPase、肝脏超氧化物歧化酶(SOD)均在D4组达到最佳,而肝脏和肠道丙二醛(MDA)在该组均达到最低;②随饲料蛋白质水平增加,肌肉粗蛋白线性增加,全鲵脂肪线性下降,全鲵水分和粗灰分在各组间差异不显著,全鲵粗蛋白先增加后趋于稳定,在D4组达到最大;③大鲵皮肤胶原蛋白含量在D4组达到最高,较D1组增加了27.83%。研究表明,以增重率、肌肉RNA/DNA值、蛋白质沉积率和皮肤胶原蛋白含量为评价指标,通过二次回归...     

单股正链RNA病毒基因组3＇非编码区功能

单股正链RNA病毒数量众多,对人、动物和植物造成很大的危害。病毒基因组3＇末端都具有一段非编码区,基因组3＇非编码区在病毒的复制过程中发挥着重要的作用。本文简单介绍了单股正链RNA病毒基因组3＇非编码区结构的预测、测定和功能的研究方法,并重点概括了不同单股正链RNA病毒3＇非编码区一级序列、茎-环结构、假结体、TLS等结构在病毒基因组的复制、转录和翻译中的调控作用以及目前存在的问题。     

Role of ILK siRNA on expression of GSK-3β and β-catenin in human tubular epithelial cells stimulated by high glucose

AIM：To investigate the effects of siRNA targeting integrin-linked kinase (ILK) on the expression of glycogen synthase kinase 3β (GSK-3β) and β-catenin during epithelial-mesenchymal transition (EMT) in human kidney proximal tubular epithelial cell line HKC induced by high glucose. METHODS：HKC cells were divided into 4 groups:normal glucose (NG) group, high glucose (HG) group, HG+HK (a vector containing the non-specific siRNA designed as negative control) group and HG＋ILK siRNA group. The inverted fluorescence microscope was used to examine the expression of green fluorescent protein (GFP). The expression of ILK at mRNA and protein levels was detected by RT-PCR and Western blotting. The expression of p-GSK-3β and β-catenin was observed by immunocytochemical staining. The protein expression of total GSK-3β, p-GSK-3β, nuclear β-catenin, total β-catenin, E-cadherin and α-smooth muscle actin (α-SMA) was measured by Western blotting. RESULTS：GFP was observed in HKC cells, indicating that the transfection was successful. Both the protein and mRNA of ILK were down-regulated in HG＋ILK siRNA group compared with HG group and HG+HK group, but still higher than those in NG group. Silencing of ILK down-regulated the expression of p-GSK-3β and nuclear β-catenin. No difference of total GSK-3β or total β-catenin was observed among the 4 groups. CONCLUSION:These data support a functional role of ILK, GSK-3β and β-catenin in tubular EMT induced by high glucose. ILK may promote tubular EMT by regulating the activity of GSK-3β and β-catenin, the downstream effectors of the Wnt/β-catenin pathway.