犬造血干细胞移植的作用机制及应用研究进展

造血干细胞(hematopoietic stem cell, HSC)位于造血系统的顶端, 是造血系统中唯一具有多能性和自我更新能力的细胞, 可以分化为各种功能的血细胞, 维持血液系统的建立和动态平衡, 是目前研究最为透彻、临床应用最为成熟的成体干细胞。造血干细胞的这些重要特性, 使得基于造血干细胞在治病机制研究和临床应用中的研究取得了很大进展。以造血干细胞为基础的再生医学治疗是目前治疗恶性血液病和遗传病的首选方法, 如造血干细胞治疗犬白细胞黏附缺陷综合征、犬遗传性贫血、犬淋巴瘤、犬白细胞减少症、犬X连锁严重联合免疫缺陷病等, 但由于白细胞抗原匹配的供体稀缺、可获得的造血干细胞数量有限等原因, 无法满足临床需求, 因此, 如何通过体外培养获得满足临床需要的造血干细胞成为近年来学者们研究的热点问题。作者参照现有研究成果对造血干细胞的来源和体外分离培养、治病机制进行系统的描述, 并对造血干细胞移植治疗遗传性溶血性贫血、白细胞黏附缺陷综合征、淋巴瘤、白细胞减少症、X连锁严重联合免疫缺陷病的临床研究进行综述, 以期为今后将造血干细胞广泛应用于临床治疗提供参考依据。     

Characterisation and origin of rust and powdery mildew resistance genes in VPM1 wheat

Summary The expression of rust resistances conferred by closely linked genes derived from VPM1 varied with environmental conditions and with genetic backgrounds. Under low light and low temperature conditions seedlings carrying Yr17 showed susceptible responses. Stem rust and leaf rust resistance genes Sr38 and Lr37 tended to confer more resistance at 17±2° C than at normal temperatures above > 20° C. These studies supported the hypothesis that Yr17, Lr37 and Sr38 were derived from Aegilops ventricosa, whereas Pm4b was probably derived from T. persicum. Studies on certain addition lines and parental stocks indicated that wheat cytoplasm may enhance the expression of Sr38.     

A test of supposed mutants for stem rust resistance in wheat

Summary Eight stem rust (Puccinia graminis tritici Eriks. and Henn.) resistant lines (designated TICENA lines) that had been selected by Veiga et al. (1981) following gamma radiation of BH-1146 wheat (Triticum aestivum L.) were studied. Six of the lines were resistant to race 15B-1 of stem rust and susceptible to race 56, and proved to carry the gene Sr7a. TICENA 4 carries two unidentified genes, each giving resistance to one of the two races. TICENA 10 carries Sr6, Sr7a and an unidentified gene giving resistance to race 56 but not 15B-1. The results raise doubts about the supposed origin of the lines as mutants.     

驱蚊草组培快繁技术研究初报

以驱蚊草茎段为试材，正交设计法考察3种激素对其增殖率的影响，结果表明，MS+6-BA1.0 mg/L +IBA0.1 mg/L +GA3 1.1 mg/L为增殖培养的适宜培养基。1/2MS+ IBA0.1mg/L为生根培养的适宜培养基。     

Construction of mouse ESC line stably expressing Pdx1 by Tet-On system

AIM To construct the mouse embryonic stem cell （ESC） line with stable pancreatic and duodenal homeobox 1 （Pdx1） expression by Tet-On system, which may lay a foundation for further research on the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells. METHODS The Pdx1-overexpressing lentiviral vector with green fluorescent protein marker and puromycin resistance was constructed by Tet-On system and was used to infect the mouse ESC. The cells were divided into 3 groups： blank control group （ESC group）, empty lentivirus control group （PDX1^- ESC group） and Pdx1 lentivirus transfection group （PDX1⁺ ESC group）. Flow cytometry was used to detect the transfected cells after screening by doxycycline （DOX）. The function of Tet-On system and the expression of Pdx1 gene were detected. The transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were sorted by flow cytometry, and constructed ESC line with stable expression of Pdx1 and negative control ESC line were verified. RESULTS （1） The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were 90.72% and 94.01% after screening by DOX, respectively. The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group was 97.84% and 98.13% after sorting by flow cytometry, respectively. （2） With DOX, green fluorescence was observed in PDX1^- ESC group and PDX1⁺ ESC group. The mRNA and protein expression of Pdx1 was significantly increased in PDX1⁺ ESC group （P<0.05）. Without DOX, no green fluorescence was observed in the cells of the 3 groups, and no significant difference in the mRNA and protein expression of Pdx1 was observed （P>0.05）. （3） After 3 months of cryopreservation, the cell lines still survived in resuscitation culture and were regulated by DOX. CONCLUSION Using Tet-On system, the mouse ESC line with inducible Pdx1 expression were successfully established and could be used as an effective cell model to research the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells.     

鸡ES细胞体外定向诱导分化特性的研究

旨在探索鸡胚胎干细胞(ES细胞)体外定向诱导的多向分化潜能.分离鸡X期胚盘细胞,体外培养传代,经鉴定后,采用地塞米松(DEX)、β-甘油磷酸钠(β-GP)和维生素C(VitC)诱导ES细胞向成骨细胞分化;采用维甲酸(RA)、3-异丁基-1-甲基黄嘌呤(IBMX)诱导ES细胞向神经元样细胞分化;采用DEX、胰岛素、IBMX诱导ES细胞向脂肪细胞分化,比较不同浓度组合诱导剂的诱导效果,分别用Von Kossa's染色法、甲苯胺蓝染色法、免疫组化法、油红O染色法和RT-PCR鉴定诱导产生的细胞.结果显示,ES细胞被诱导3～21 d后,分化为成骨细胞,诱导率为40％～72％;被诱导4～7 d后,分化为神经元样细胞,诱导率为71％～84％;被诱导2～21 d后,分化为脂肪细胞,油红O染色阳性,并表达PPARγ基因.结果表明,在体外条件下,ES细胞可被特异的化学物质定向诱导分化为成骨细胞、神经元样细胞和脂肪细胞,具有多向分化潜能.     

贵州高羊茅新品种(系)比较试验

2007-2010年对选育鉴定的高羊茅(Festuca arundinacea)新品系,按照完全随机区组排列设计方法,进行品种比较试验.结果表明,在株高30～40 cm时刈割测产,大方高羊茅每年的鲜草产量和干物质产量都比对照Fawn高许多,其中第2年的鲜草产量和干物质产量分别为87 825和15 360 kg/hm2,...     

甘肃省农户经营主体演变分析及问题探讨

农户作为农业经营主体的主要组成部分,只有对其进行正确的分析和评价,把握其特点,才能为甘肃省各级政府农业发展、区域经济发展以及农业经营主体发展政策的制定提供参考。本研究从甘肃省农业经营主体这一视角介绍了农户经营主体的历史变迁,探讨了农户经营主体演变的特点,对农户经营主体变迁中存在的问题进行了较为详细地分析,并给出了相应建议。     

固态发酵芦笋老茎生产高蛋白反刍动物饲料的研究

通过单菌种固态发酵、复合菌种固态发酵以及不同配比的复合菌种固态发酵试验,对能够将芦笋老茎转化为反刍动物饲料的微生物菌种进行了筛选。结果表明,由青霉(Penicillium sp.)F-5、暗孢毛壳(Chaetomium atrosporum)F-21、曲霉(Aspergillus sp.)F-25菌株组成的配比为2:2:3的复合菌种是效果最好的菌种组合。芦笋老茎生料培养基经该复合菌种5 d固态发酵后,发酵产物中可溶性蛋白含量达到4.80 mg/g,与对照组相比增加了39.94%;粗蛋白含量达到11.18%,与对照组相比增加了38.54%;纤维素由22.74%降低到22.32%,降低了1.85%;木质素由12.90%降低到10.53%,降低了18.37%。这些结果证明芦笋老茎经微生物发酵后能转化为良好的高蛋白反刍动物饲料。