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.     

白羊草茎段愈伤组织诱导和植株再生

首次采用白羊草拔节期茎段为外植体,通过对其组织培养中愈伤组织诱导和植株再生情况进行研究,从而筛选出其在组织培养过程中较合适的激素组合。结果表明,茎段作为外植体时,愈伤诱导在仅附加2,4-D 2.0 mg/L诱导培养基中的诱导率高于2,4-D和6-BA的激素组合;诱导出的愈伤组织转入MSB+6-BA 0.07 mg/L+NAA 0.05 mg/L分化培养基中,分化率显著高于其他激素组合。     

异种动物细胞核移植研究现状及相关问题的探讨

随着体细胞核移植相继在多种动物中取得成功 ,异种细胞核移植技术在拯救濒危野生动物、人类干细胞克隆和细胞核质互作研究等方面具有特殊意义 ,受到广泛重视并取得了很大进展。文章对异种细胞核移植技术研究现状进行了综述 ,并对其应用前景和存在的问题进行了探讨。     

烟梗组织结构与吸水性关系的研究

[目的]研究烟梗组织结构与吸水性的关系,为烟梗利用率的提高提供理论依据。[方法]采用石蜡切片法制作烟梗组织切片,称重法测定烟梗吸水率,分析了不同产地、不同年份的烟梗组织结构及其吸水性。[结果]同一年份不同产地的烟梗吸水性可能与髓腔、导管等组织结构有关,而与产地关系不大;同一产地不同年份的烟梗吸水性与年份呈负相关。[结论]烟梗的吸水性与其组织结构、生长年份关系密切,该研究为烟梗资源的充分合理利用提供了科学依据。     

冷季型草坪草根茎比与草坪品质的关系

该研究通过对冷季型混播草坪 (高羊茅 +草地早熟禾 )地上、地下生物量的测定 ,结合草坪综合品质的观测 ,揭示出了冷季型草坪合理的根茎比值 .在环境胁迫严重的 8,9月份 ,发现以高羊茅和草地早熟禾占优势的混播草坪最适根茎比值为 1 0 ,而在生长条件适宜的秋季 ,根茎比与草坪品质没有对应关系     

大蒜茎粉和牛至草粉对镜鲤生长性能、消化酶活性以及血清生化指标的影响

试验研究了大蒜茎粉和牛至草粉对镜鲤(Cyprinus carpio L.minor)生长性能、消化酶活性及血清生化指标的影响,为进一步开发利用天然植物添加剂提供理论参考。试验共设7个处理组:G1空白对照组,G2添加10 mg/kg黄霉素,G3、G4分别添加0.5%和2.5%大蒜茎粉,G5、G6分别添加0.1%和0.5%牛至草粉,G7添加0.5%大蒜茎粉和0.5%牛至草粉。每个处理设3个重复,每个重复10尾鱼,初始体重为(201.45±16.25) g,试验共进行8周。结果表明:与G1和G2相比,G3显著提高了特定生长率和增重率,显著降低了饵料系数(P<0.05),G3、G4和G5、G6显著提高了蛋白质效率(P<0.05)。与G1对比,G3显著提高了肝胰脏、前肠和中肠蛋白酶活性(P<0.05),肝胰脏和中肠脂肪酶活性(P<0.05)。G4显著提高了肝胰脏蛋白酶活性(P<0.05)。G5、G6、G7比G1和G2显著提高了前肠淀粉酶和脂肪酶活性(P<0.05)。与G1相比,G3、G6和G7血总蛋白、白蛋白、球蛋白浓度显著提高(P<0.05),G2血清总胆固醇、谷草转氨酶和谷丙转氨酶显著降低(P<0.05),各试验组肌酐均无显著差异(P>0.05)。结论:饲料中添加0.5%大蒜茎粉可以有效提高镜鲤生长性能,但是添加牛至草粉促生长作用不明显。     

Decomposition of leguminous crop residues in a ‘jhum’ cultivation system in Arunachal Pradesh,India

Decomposition of leaves, stems, and roots of two leguminous plants, french bean and pea, was studied in a ‘jhum’ cultivation (shifting agriculture) system in north‐eastern India in litter bag experiments. The dynamics of decomposition varied between the crop residues and species studied. All the three studied types of residues of french bean and the leaves and roots of pea showed polynomial decomposition model with three distinct phases: an initial slow decomposition phase (1), followed by a faster decomposition rate (2) and again by a slow decomposition phase (3). However, the stems of pea plants showed an exponential increase in the decomposition rate during field incubation. Initial N, lignin, and lignin : N ratio were determined in crop residues. In general, roots decomposed slowly as compared to the leaves and stems due to greater lignin content. Soil microbial activity as determined by CO₂ evolution was significantly correlated with the decomposition rates. Over all, the decay constants reveal that these fast decomposing leguminous crop residues can be properly managed for soil nutrient management in the low input shifting agricultural fields in the hills.     

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。     

大三叶升麻嫩茎无性系的建立

为保护野生资源,实现人工栽培,以大三叶升麻茎为试验材料,进行愈伤组织的培养,以及试管苗的生根、生根继代培养和试管苗的移栽、定植的研究,建立起野生大三叶升麻无性系。结果表明:MS+BA 0.2 mg/L+2,4-D 2.0～2.5 mg/L是嫩茎愈伤组织诱导培养的理想培养基;MS+AgNO31.0 mg/L+GA30.5 mg/L+ZT 0.8 mg/L+NAA 0.1 mg/L是嫩茎愈伤组织分化培养的理想培养基;把不定芽的基部在NAA 4.0mg/L的溶液中处理约5 min,接种到1/3MS为基本培养基,附加IBA 0.6 mg/L的培养基上,进行生根培养的方法是生根培养的理想培养方法;1/3MS+IBA 0.6 mg/L+NAA 0.1 mg/L也是增殖培养的理想培养基;试管苗移栽、定植易成活。定植成活的试管苗保持了野生大三叶升麻的所有植物学性状。     

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。