牛胎肺间充质干细胞体外培养及生物学特性研究

[目的]建立牛胎肺间充质干细胞（Mesenchymal stem cells,MSCs）体外培养体系并对其进行生物学特性研究。[方法]取3～5月龄牛胎儿肺脏,得到MSCs。通过控制胰酶消化时间,去除难消化的上皮样贴壁细胞,获得纯化的牛肺MSCs,研究其形态、增殖情况及体外诱导分化潜能。[结果]牛胎肺MSCs可在体外扩增培养,传至24代以上,表达CD29、CIM4和CDl66,不表达CDM、CIM5和BOL-DR,并具有向成骨细胞诱导分化的潜能。[结论]从牛胎肺中可以分离出MSCs,可以在体外培养,并可诱导分化为成骨细胞。     

诱导性多潜能干细胞的研究进展

对iPS细胞的制备方法、提高制备iPS细胞效率和安全性的方法与应用进行了综述。     

从水力结构比较3种共存木本植物的抗旱策略

通过盆栽控水方法测定了华北石质山区刺槐、栓皮栎和侧柏3个主要造林树种在干旱胁迫以及随后的复水条件下气体交换和水分关系的变化,分析了这3个树种抗旱特性的差异。结果表明：1）在供水充足时,刺槐光合作用强、气孔导度大、耗水速度快。2）刺槐对土壤水分变化最为敏感,当土壤水分含量降低时,其光合速率和气孔导度迅速下降。3）复水后,...     

Characterization and Differentiation into Adipocytes and Myocytes of Porcine Bone Marrow Mesenchymal Stem Cells

Bone marrow mesenchymal stem cells （BMSCs） could differentiate into various cell types including adipocytes and myocytes, which had important scientific significance not only in the field of tissue regeneration, but also in the field of agricultural science. In an attempt to exhibit the characterization and differentiation into adipocytes and myocytes of porcine BMSCs, we isolated and purified porcine BMSCs by red blood cell lysis method and percoll gradient centrifugation. The purified cells presented a stretched fibroblast-like phenotype when adhered to the culture plate. The results of flow cytometry analysis and immunofluorescence staining demonstrated that the isolated cells were positive for mesenchymal surface markers CD29, CD44 and negative for hematopoietic markers CD45 and the adhesion molecules CD31. Cells were induced to differentiate into adipocytes with adipogenic medium containing insulin, dexamethasone, oleate and octanoate. Oil Red O staining demonstrated that the porcine BMSCs successfully differentiated to adipocytes. Moreover, the findings of real-time PCR and Western blotting indicated that the induced cells expressed adipogenic marker genes （PPAR-y, C/EBP-c~, perilipin, aP2） mRNA or proteins （PPAR-3,, perilipin, aP2）. On the other hand, porcine BMSCs were induced into myoctyes with myogenic medium supplemented with 5-azacytidine, basic fibroblast growth factor, chick embryo extract and horse serum. Morphological observation by hochest 33342 staining showed that the induced cells presented as multi-nucleus muscular tube structure. And myogenic marker genes （Myf5, desmin） mRNA or proteins （MyfS, MyoD, myogenin, desmin） were found in the induced cells. In addition, the results of immunofluorescence staining revealed that myogenic marker （Myf5, MyoD, myogenin, desmin, S-MyHC） proteins was positive in the induced cells. Above all, these results suggested that the isolated porcine BMSCs were not only consistent with the characterization of mesenchymal stem cells, but also exhibited the multipotential capacity to form adipocytes and myocytes, which provided the basis to investigate the regulation mechanism involved in the selective differentiation of porcine BMSCs.     

收获期烟秆的拉拔力及影响因素

测定并分析烟秆拉拔力与拉拔位移、烟秆直径、土壤含水率、土壤紧实度之间的相互关系。结果表明：拉拔烟秆是一个拉拔力上升阶段和拉拔力下降阶段的综合作用过程,当土壤含水率较低(13.2%)、土壤紧实度较大(18.6 kg/cm2)时,烟秆拉拔位移为14 cm,拉拔力最大值为1 654 N;当土壤含水率较高(21.8%)、土壤紧实度较小(11.54 kg/cm2)时,烟秆拉拔位移为16 cm,拉拔力最大值为1 628 N。烟秆直径与起拔力之间呈正相关直线回归关系,相关系数为0.88,烟秆直径为26.1～38.3 mm时,起拔力为551～1 840 N;土壤含水率越大,起拔力越小;土壤紧实度越大,起拔力越大。     

A FIASCO-Based Approach for Detection and Diagnosis of Puccinia graminis f. sp. tritici in China

Stem or black rust of wheat, caused by the fungus Puccinia graminis Pers. f. sp. tritici Eriks.＆E. Henn. （Pgt）, has historically caused severe losses to wheat （Triticum aestivum L.） production worldwide. In the Fujian and Guangdong provinces of China, six moderate-to-severe epidemics of wheat stem rust have occurred, which caused destructive losses of wheat between 1949 and 1966, although these were brought under control by integrated management. A rapid and reliable detection of the pathogen will contribute to the accurate forecast and seasonal control of this disease. The objective of this study was to develop a diagnostic molecular marker generated from simple sequence repeats （SSR） for the early rapid identiifcation of P. graminis. The genomic DNA of P. graminis, Puccinia striiformis, Puccinia triticina and seven other species was ampliifed by a pair of SSR primers generated by the FIASCO （fast isolation by AFLP sequences containing repeats） enrichment protocol. The primer set Pgtw （f）/Pgtw （r） generated a polymorphic pattern displaying a 330-bp DNA fragment speciifc for P. graminis whereas no DNA fragment was obtained from other non-target wheat fungal pathogens. The detection limit of the primer was 1 ng DNA in a 25-mL PCR reaction. The SSR markers of P. graminis can also be used to detect the presence of latent hyphae in Pgt-infected wheat leaves as early as 30 h post-inoculation. A rapid approach to distinguish P. graminis from similar pathogenic fungi would be anticipated in further study.     

阶段性养分亏缺对大豆茎部性状及产量的影响

以垦农4号大豆为试验材料,在桶栽砂培条件下,研究了9个不同生育阶段养分亏缺对大豆茎部性状及产量的影响。结果表明,大豆不同生育时期的阶段性养分亏缺,均可对大豆的茎部性状及产量产生一定影响。VE—V3期养分亏缺可显著降低株高及产量,是株型及产量调控的关键时期,其他各阶段的养分亏缺均可通过前期或后期的养分供应得到恢复。R5阶段充足的水分供应比养分对产量的影响更大,是水分需求的关键时期。     

红细胞裂解法及不同培养条件对兔骨髓间充质干细胞体外增殖的影响

研究采用红细胞裂解液法从兔骨髓中分离BMSCs,相差显微镜观察其形态,四甲基偶氮唑盐法(MTT法)筛选基础培养液和血清浓度,绘制生长曲线,用流式细胞仪检测细胞周期,免疫细胞化学鉴定表面抗原。分离的细胞在形态学观察与生长动力学上均符合BMSCs特征;在实验范围内DMEM/F12+20%FBS是体外培养兔BMSCs的最佳体系;细胞周期结果显示,BMSCs平均82%处于G0/G1期,18%处于S+G2期;免疫细胞化学结果显示所分离的BMSCsCD90、CD44阳性表达,CD34阴性表达。本研究结果表明,通过红细胞裂解液法分离的兔BMSCs,其具有体外增殖和多向分化的潜能,可以作为组织工程的种子细胞。     

凹叶厚朴茎和叶的解剖学研究

采用石蜡切片法对凹叶厚朴的茎和叶的显微结构进行解剖观察,结果表明,凹叶厚朴在茎、叶轴、小叶柄的内皮层和髓中以及主脉下方的薄壁组织中都有分泌腔分布,部分细胞壁出现网状结构.凹叶厚朴的叶为异面叶,气孔仅分布于下表皮,为无规则型,栅栏组织发达.茎的初生构造中,皮层和髓的生活薄壁细胞丰富.茎的次生木质部为散孔材,导管端壁倾斜,具梯状复穿孔,木薄壁细胞稀少,呈星散分布.表明凹叶厚朴在进化中是较为原始的树种.     

白腐菌发酵玉米秸秆最佳条件研究

【目的】以玉米秸秆为材料,研究白腐菌对其发酵的最佳条件。【方法】采用L₉（3⁴）正交试验设计,以发酵后玉米秸秆中的粗蛋白和粗纤维含量为指标,以白腐菌发酵玉米秸秆时的秸秆含水率、温度、接种量、起始pH为主要影响因素,筛选白腐菌发酵玉米秸秆的最佳条件。【结果】白腐菌发酵玉米秸秆的最优条件为：秸秆含水率为70%,温度为30 ℃,接种量为0.25 g/kg,起始pH为4,在此条件下发酵7 d,秸秆粗纤维含量由348.7 g/kg下降为299.4 g/kg,粗蛋白含量由58.3 g/kg升高为116.6 g/kg。【结论】筛选出了白腐菌发酵玉米秸秆的最佳条件,为玉米秸秆资源化利用提供了参考。