马氏珠母贝Rab7基因序列特征及其与耐低温性状的关系

Rab蛋白是膜泡运输过程中的重要调节因子,在囊泡运输和水产动物的免疫应答中行使重要功能。本研究鉴定了马氏珠母贝(Pinctada fucata martensii)的Rab7基因(Pm-Rab7),分析了Pm-Rab7在6个组织中及在温度胁迫(低温组17 ℃、对照组22 ℃、高温组32 ℃)下的表达模式,筛选和比较分析了马氏珠母贝耐低温选育系(low temperature resistant line, R) F3和北部湾野生群体(Beibu Gulf wild population, W)的Pm-Rab7外显子区的SNP位点。结果显示,Pm-Rab7序列全长为1 153 bp,5′端、3′端和开放阅读框(ORF)序列长度分别为30、505和618 bp,共编码205个氨基酸;Pm-Rab7具有一个RAB保守结构域,并与太平洋牡蛎(Crassostrea gigas)相似度最高(92.79%)。系统进化树结果显示,Pm-Rab7与太平洋牡蛎等软体动物聚为一支。Pm-Rab7在所检测的组织都有表达,其中在性腺和鳃中的表达显著高于外套膜和肝胰腺等组织(P<0.05)。Pm-Rab7温度胁迫后时序表达分析发现,在17 ℃低温组,Pm-Rab7的表达量呈先上升再下降的趋势,在6 h~3 d内均显著高于22 ℃对照组(P<0.05),在1 d时达到峰值;在32 ℃高温组,Pm-Rab7表达量总体稳定,仅12 h时显著高于对照组(P<0.05),其他时间点与对照组无显著差异(P>0.05);说明该基因的表达与马氏珠母贝对低温胁迫的响应密切相关。Pm-Rab7基因的外显子区域在马氏珠母贝耐低温选育系和北部湾野生群体中共检测到7个SNP位点,其中3个位点的基因型频率在2个群体间具有显著性差异,说明这些位点可能与其耐低温性状相关。结果表明,Pm-Rab7可能在马氏珠母贝耐低温适应过程中发挥重要作用,研究结果可为深入探讨马氏珠母贝对温度变化的环境适应性研究提供参考资料。     

高含量原粉生产菌株苏云金芽孢杆菌LX-7的研究

从土壤中分离的苏云金芽孢杆菌LX-7高毒力菌株,利用单因子筛选和正交试验,得到其最佳培养基配方(g/L)为:玉米淀粉30,氮源A 30,氮源D 15,氮源E 15,并对其发酵工艺和后处理工艺进行了优化,40 000 L发酵罐发酵制得原粉效价达到80 000 IU/mg以上,晶体蛋白含量达到13.2%.     

橡胶树优良品种热研7-33-97在海南中部山区适应性研究

以PR107为对照,对试种在海南中部山区乌石分公司橡胶优良品种热研7—33—97的生产系比的生长、产量及抗性等性状进行鉴定研究,结果表明：热研7—33—97生长较快,开割前、后茎围年均增长6．1和2．8cm;产量较高,开割第1和第4年干含平均为31％,开割当年年均株产和亩产分别为2．5kg／株和694．5kg／hm^2,抗寒性、死皮率及经济效益表现等均优于对照PR107,是对海南中部山区有良好适应性的优良品种,可在该区域逐步扩大种植面积。     

CP7菌株抗菌蛋白粗提物对家蚕黑胸败血菌的抑杀作用

利用分子生物学方法和电镜技术,从多粘类芽孢杆菌(Paenibacillus polymyxa)的一个新菌株CP7的发酵培养液中提取出抗菌蛋白,研究其抑制家蚕黑胸败血菌(Bacillussp.)的活性作用和杀菌机制。抗菌蛋白粗提液作用于黑胸败血菌后,引起菌体和芽孢变形、凹陷、空瘪等形态上的异常;对菌体细胞组织产生损伤作用,出现细胞壁皱缩、细胞膜受损、细胞器消溶、胞内物质(磷和DNA)外泄等现象;对菌体和芽孢的呼吸代谢产生影响,耗氧量在短时间内急剧增加,氧呼吸作用的持续时间缩短,最终耗氧量减小。分析认为:CP7抗菌蛋白对黑胸败血菌菌体和芽孢会产生直接的损伤作用,细胞壁和细胞膜的结构遭到破坏,严重时会导致细胞质消溶与外泄,并通过影响呼吸代谢的途径而协同起到抑菌、杀菌的作用。     

A vaccine formulation combining rhoptry proteins NcROP40 and NcROP2 improves pup survival in a pregnant mouse model of neosporosis

Currently there are no effective vaccines for the control of bovine neosporosis. During the last years several subunit vaccines based on immunodominant antigens and other proteins involved in adhesion, invasion and intracellular proliferation of Neospora caninum have been evaluated as targets for vaccine development in experimental mouse infection models. Among them, the rhoptry antigen NcROP2 and the immunodominant NcGRA7 protein have been assessed with varying results. Recent studies have shown that another rhoptry component, NcROP40, and NcNTPase, a putative dense granule antigen, exhibit higher expression levels in tachyzoites of virulent N. caninum isolates, suggesting that these could be potential vaccine candidates to limit the effects of infection. In the present work, the safety and efficacy of these recombinant antigens formulated in Quil-A adjuvant as monovalent vaccines or pair-wise combinations (rNcROP40 + rNcROP2 and rNcGRA7 + rNcNTPase) were evaluated in a pregnant mouse model of neosporosis. All the vaccine formulations elicited a specific immune response against their respective native proteins after immunization. Mice vaccinated with rNcROP40 and rNcROP2 alone or in combination produced the highest levels of IFN-γ and exhibited low parasite burdens and low IgG antibody levels after the challenge. In addition, most of the vaccine formulations were able to increase the median survival time in the offspring. However, pup survival only ensued in the groups vaccinated with rNcROP40 + rNcROP2 (16.2%) and rNcROP2 (6.3%). Interestingly, vertical transmission was not observed in those survivor pups immunized with rNcROP40 + rNcROP2, as shown by PCR analyses. These results show a partial protection against N. caninum infection after vaccination with rNcROP40 + rNcROP2, suggesting a synergistic effect of the two recombinant rhoptry antigens.     

CP7菌株的抗菌活性及菌种鉴定

经分离、筛选获得一株高效分泌抗菌物质的CP7菌株,从该菌株中提取的抗菌产物,对大肠杆菌标准株、金黄色葡萄球菌标准株、苏云金杆菌等细菌;瓜类炭疽病菌、水稻纹枯病菌等真菌有较好的抑菌作用。用16S rDNA序列分析法进行生物分子的分类,该菌株16S rDNA序列与类芽孢杆菌属的34个细菌的同源性为96%~99%,与多粘类芽孢杆菌的同源性为99%。用传统细菌学的方法对CP7菌株进行鉴定,其形态特征、生理生化特性与多粘类芽孢杆菌的特征特性相一致。表明CP7菌株属于多粘类芽孢杆菌。     

Assessing the Value of Using a Remote Sensing-Based Evapotranspiration Map in Site-Specific Management

ABSTRACT

In the glaciated regions of the northern Great Plains, water - either too much or too little - influences soil development, carbon storage, and plant productivity. Integrating site-specific water variability information directly into management is difficult. Simulation models that employ remotely sensed data can generate hard to measure values such as evapotranspiration (ET). This information can be used to identify management zones. The objective of this study was to determine if the METRIC (Mapping Evapotranspiration at High Resolution and with Internalized Calibration) model, which uses weather station and remote sensing data can be used as a tool in site-specific management. This study was conducted on a 65 ha corn (Zea mays L.) field located in east central South Dakota. The METRIC model used Landsat 7 data collected on August 4, 2001 to calculate ET values with spatial resolution of 30 m. ET values were correlated with corn yield (r = 0.85??), apparent electrical conductivity (EC_a; r = 0.71??), soil organic carbon (SOC; r = 0.32?), and pH (r = 0.28?). In the footslope positions, high ET values were associated with high corn yields, SOC, EC _a , and pH values, while in the summit/shoulder areas low ET values were associated with low yields, SOC, EC_a, and pH values. The strong relationship between ET and productivity was attributed to landscape processes that influenced plant available water, which in turn influenced productivity. Cluster analysis of the ET and EC data showed that these data bases complimented each other. Remote sensing-based ET data was most successful in identifying areas where water stress reduced corn yields, while EC_a was most successful in identifying high yielding management zones. Findings from this study suggest that remote sensing-based ET estimates can be used to improve management zone delineation.     

RP—HPLC法测定泽兰中木犀草素-7-0-β-D-葡萄糖苷的含量

目的建立反相高效液相色潜法测定泽兰中木犀草素-7-0-β-D-葡萄糖苷的含量。方法采用AlltimaTM—C18（250minx4．6mm,51．Lm）;以乙腈-0．2％磷酸水溶=20：80进行等度洗脱,流速为1．0ml／min,检测波长为350mm,柱温为35℃。结果木犀草素-7-0-β-D-葡萄糖苷的线性范围为0．412-10．30μg（r=0．9999）,平均回收率为100．25％。结论该方法结果准确、简便可行、重复性好,可为泽兰的质量控制提供依据。     

siat7e基因和st3gal I基因双表达载体的构建及其初步应用

应用聚合酶链式反应（PCR）技术,从人类基因组中扩增出全长为1011bp的唾液酸转移酶（siat7e基因）,并从鸡基因组中扩增出全长为1029bp的β-半乳糖苷α-2,3-唾液酸转移酶I（ST3GALI）基因。将它们分别克隆入pMDl8一T载体中。对扩增的全长siat7e基因序列采用BamHI和Pst I双酶切后连接入pReceiver真核表达载体,构建pRE—SIAT重组表达载体,进而,对扩增的全长st3galI基因采用SacI和劢0I双酶切,后连接入pRE—SIAT重组表达载体,构建pRE—SIAT—ST3重组真核表达载体。经限制性内切酶消化及DNA序列分析,证实构建的重组表达质粒是正确的。将构建的双基因表达载体转染MOCK细胞,利用荧光显微镜观察,可见细胞表达明显的绿色荧光,从而初步证实了外源基因在MDCK细胞中的正确表达。本研究为最终构建能够适应悬浮培养,并且对禽流感病毒更为易感的MDCK细胞系奠定了基础。     

Cloning,tissue expression and polymorphisms of chicken Krüppel‐like factor 7 gene

Krüppel‐like factor 7 (KLF7) has been extensively studied in mammalian species, but its role in birds is still unclear. In the current study, cloning and sequencing showed that the full‐length coding region of chicken KLF7 (Gallus gallus KLF7, gKLF7) was 891 bp long, encoding 296 amino acids. In addition, real‐time RT‐PCR analysis showed that gKLF7 was broadly expressed in all 15 chicken tissues selected, and its expression was significantly different in spleen, proventriculus, abdominal fat, brain, leg muscle, gizzard and heart between fat and lean broilers at 7 weeks of age. Additionally, one novel single nucleotide polymorphism (SNP), XM_426569.3: c. A141G, was identified in the second exon of gKLF7. Association analysis showed that this locus was significantly associated with fatness traits in Arbor Acres broiler random population and the eighth generation of Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) population (P < 0.05). These results suggest that gKLF7 might be a candidate gene for chicken fatness traits.