病原生物学专业研究生综合素质培养的探讨

病原生物学是基础医学中一门重要学科,高素质病原生物学人才培养,是适应社会发展、满足社会需求、促进创新型人才建设的关键.作者在实际工作中,注重引导学生学习态度和思维模式的转变,开展多种形式的教学,从学习态度、科研能力、协作能力等方面对病原生物学专业研究生综合素质的培养进行了初步的探讨,把研究生带到知识前沿、形成研究问题、引导批判和创新,使研究生掌握一定的科研思路与科研方法;注重动手能力的训练,严格施教,加强学术道德教育,探索高素质病原生物学研究生培养的新模式.     

结球甘蓝和青花菜小孢子胚植株再生

结球甘蓝（Brassica oleracea var.capitata）和青花菜（Brassica oleracea var.italica）小孢子胚再生植株频率低是目前影响游离小孢子培养技术有效应用的关键问题之一,研究其小孢子胚植株再生频率的影响因素,提高胚再生植株频率,对促进游离小孢子培养技术在甘蓝类蔬菜育种中更好地应用具有重要意义。该文以结球甘蓝中甘11和青花菜TI-111等基因型为试材,对影响游离小孢子胚再生成植株的固体培养基类型、琼脂浓度、胚的类型及胚在液体培养基中的滞留时间等因素进行了研究。结果表明：游离小孢子培养25天的子叶胚在琼脂浓度为1%–1.25%的B5培养基上植株再生频率最高。进一步通过8个不同基因型对上述实验结果进行了验证,结果显示,游离小孢子培养25天的子叶胚在1%琼脂浓度的B5培养基上植株再生频率达77.8%–97.2%。     

植物细胞程序性死亡研究进展

植物细胞死亡分为坏死和程序性死亡。细胞程序性死亡是具有信号或一系列分子参与,并且由细胞内在的死亡程序介导的有序过程。它在植物生长发育和抵御外界胁迫中具有重要作用。简要介绍了植物PCD的特征,对植物PCD中的信号分子和类caspase的作用等进行了综述,并对植物PCD存在的问题进行分析和展望,为深入研究植物PCD提供参考。     

一种展示SARS冠状病毒受体结合区的重组枯草杆菌芽孢的制备及免疫原性分析

目的：利用枯草杆菌芽孢呈递技术制备表达SARS冠状病毒S蛋白受体结合区（RBD）的重组芽孢。方法：将枯草杆菌 CotB 基因构建到基因组整合质粒pDG1664中,再将 RBD 基因连接到 CotB 基因的下游,构建成重组质粒pDG1664-CotB-RBD,通过同源重组整合到PY-79枯草杆菌基因组中;利用红霉素抗性筛选重组菌并进行PCR和DNA测序鉴定,Western印迹鉴定重组菌芽孢表面RBD蛋白的表达情况;用表达RBD的重组芽孢以口服方式免疫小鼠,通过ELISA和流式细胞术检测重组芽孢的免疫原性。结果：制备出枯草杆菌基因组整合了RBD抗原基因的重组菌株RS1931,形成的重组芽孢表达相对分子质量约62×103的CotB-RBD融合蛋白;重组芽孢免疫的小鼠血清RBD抗原特异性IgG抗体滴度在末次免疫后2周可达1∶10880,重组芽孢初免后18周的小鼠脾细胞中IFN-γ＋CD4^＋、IL-4＋CD4^＋和IFN-γ＋CD8^＋T细胞比例上调,表明重组芽孢经口服免疫产生良好的体液免疫和细胞免疫应答。结论：针对SARS冠状病毒S蛋白RBD建立了枯草杆菌芽孢呈递技术方法,制备出在枯草杆菌芽孢表面稳定表达外源RBD蛋白的重组株,获得的重组芽孢具有良好的免疫原性,为开发芽孢呈递型SARS疫苗奠定了基础。     

病毒功能性受体的筛选新策略及其应用

病毒通过与靶细胞表面的特异性受体结合,进而吸附、入侵靶细胞,劫持细胞的复制机器完成自身的复制周期。细胞受体作为病毒入侵宿主的门户,细胞受体的结构与功能及其介导病毒入侵的机制一直是病毒学研究的热点之一。对细胞受体的研究有助于了解病毒的致病机制并为病毒性疾病的防控提供科学依据。近年来,利用功能缺失性基因组学筛选病毒功能性受体的进展极大地拓展了人类对病毒入侵机制的认识和理解。目前,应用较为广泛的病毒功能性受体筛选策略包括RNA干扰技术、利用单倍体细胞系随机插入逆转录病毒致突变技术以及基于CRISPR/Cas9系统的新型编辑技术。本文系统介绍并比较了这三种病毒功能性受体筛选新策略,同时对其应用及优缺点进行了归纳总结,可为相关研究者提供一定的参考。     

Ca2+‐regulated and diurnal rhythm‐regulated Na+/Ca2+ exchanger AtNCL affects flowering time and auxin signalling in Arabidopsis

Calcium (Ca²⁺) is vital for plant growth, development, hormone response and adaptation to environmental stresses, yet the mechanisms regulating plant cytosolic Ca²⁺ homeostasis are not fully understood. Here, we characterize an Arabidopsis Ca²⁺‐regulated Na⁺/Ca²⁺ exchanger AtNCL that regulates Ca²⁺ and multiple physiological processes. AtNCL was localized to the tonoplast in yeast and plant cells. AtNCL appeared to mediate sodium (Na⁺) vacuolar sequestration and meanwhile Ca²⁺ release. The EF‐hand domains within AtNCL regulated Ca²⁺ binding and transport of Ca²⁺ and Na⁺. Plants with diminished AtNCL expression were more tolerant to high CaCl₂ but more sensitive to both NaCl and auxin; heightened expression of AtNCL rendered plants more sensitive to CaCl₂ but tolerant to NaCl. AtNCL expression appeared to be regulated by the diurnal rhythm and suppressed by auxin. DR5::GUS expression and root responses to auxin were altered in AtNCL mutants. The auxin‐induced suppression of AtNCL was attenuated in SLR/IAA14 and ARF6/8 mutants. The mutants with altered AtNCL expression also altered flowering time and FT and CO expression; FT may mediate AtNCL‐regulated flowering time change. Therefore, AtNCL is a vacuolar Ca²⁺‐regulated Na⁺/Ca²⁺ exchanger that regulates auxin responses and flowering time.     

产前胎儿磁共振成像的临床应用及研究进展

出生缺陷已经成为影响我国人口素质的重要卫生问题,产前诊断是减少患儿出生缺陷的有效预防手段和措施。作为产前超声诊断重要补充的手段,胎儿MRI检查具有多方位、多参数、高质量、大视野成像的特点。尤其在中枢神经系统方面具有US无法比拟的优势,随着宫内治疗技术的开展和提高,其潜在的价值和应用前景越来越明显。近年来,随着各种快速MR成像方法的应用,胎儿MRI研究有了很大进步,不仅能有效地评估胎儿的正常解剖、发育变异及病理改变,而且功能MRI也正积极尝试用于胎儿正常发育及疾病的研究中。正硝地解释胎儿MRI的影像学表现仍是今后一段时间内胎儿MRI研究的方向。客观地认识MRI在产前检查中的优势与劣势、合理地应用不同的成像序列,有利于更准确地检出病变。     

Allele-specific targeting of hsa-miR-657 to human IGF2R creates a potential mechanism underlying the association of ACAA-insertion/deletion polymorphism with type 2 diabetes

The biological mechanism of a recent discovered association of type 2 diabetes with the ACAA-insertion/deletion polymorphism at the 3′UTR of the IGF2R gene has remained unclear. A very recently emerging novel polymorphic control layer by microRNAs (miRNAs) makes it possible to elucidate this issue. In this study, a prediction by web tools MicroInspector and miRanda demonstrated that DNA sequence polymorphism (DSPs) ACAA-insertion/deletion in IGF2R 3′UTR is located within the hsa-miR-657 and hsa-miR-453 binding sites. And luciferase reporter assay revealed that hsa-miR-657 acts directly at the 3′UTR of the IGF2R. Furthermore, ACAA-deletion exerted a further repression compared with ACAA-insertion, indicating that hsa-miR-657 regulates IGF2R gene expression in a polymorphic control manner. Importantly, we also demonstrated that hsa-miR-657 can translationally regulate the IGF2R expression levels in Hep G2 cells. Thus, our findings testify the possibility that the ACAA-insertion/deletion polymorphism may result in the change of IGF2R expression levels at least in part by hsa-miR-657-mediated regulation, contributing to the elucidation for the pathogenesis of type 2 diabetes and raise the possibility that miRNAs or in combination with functional DNA sequence polymorphism may be valuable in the treatment of human type 2 diabetes.