miR-204 inhibits proliferation of Hodgkin lymphoma cells by targeting Sirt1/p53 signaling pathway

AIM: To investigate the effect of microRNA-204 (miR-204) on the proliferation of Hodgkin lymphoma cells and the underlying mechanism. METHODS: The expression of miR-204 and Sirt1 mRNA in Hodgkin lymphoma tissues was detected by RT-qPCR. After transfection with miR-204 mimic, Sirt1 siRNA and miR-204 mimic+pcDNA3.1-Sirt1 into the L428 cells, the cell viability and BrdU incorporation were measured by CCK-8 assay and BrdU assay, respectively. The protein levels of Sirt1 and acetylated p53 (ac-p53) were determined by Western blot.The targeting relationship between miR-204 and Sirt1 was verified by double luciferase reporter assay. RESULTS: The low expression of miR-204 and the high mRNA expression of Sirt1 were found in the Hodgkin lymphoma tissues. Compared with control group, the cell viability, BrdU incorporation and the protein levels of Sirt1 and ac-p53 were significantly decreased after L428 cells were transfected with miR-204 mimic or Sirt1 siRNA (P<0.05). Compared with miR-204 mimic alone group, the cell viability, BrdU incorporation and the protein levels of Sirt1 and ac-p53 were increased after L428 cells were co-transfected with miR-204 mimic and pcDNA3.1-Sirt1 (P<0.05). The results of double luciferase reporter assay confiermed that Sirt1 was the target gene of miR-204. CONCLUSION: The inhibitory effect of miR-204 on the proliferation of L428 cells may be achieved by inhibiting the expression of Sirt1 and promoting the up-regulation of ac-p53.     

羊痘研究概况

羊痘病毒基因组庞大,约有150 kb,包括中间编码区和两端相同的反向末端重复序列;绵羊痘病毒和山羊痘病毒基因组彼此十分相似,约有96%的核苷酸完全相同.p32蛋白是目前世界各地分离鉴定的所有羊痘病毒株共有的且特异性很强的结构蛋白,在诊断和预防方面具有重要的应用价值.虽然羊疸从临床症状和宿主特异性上很客易做出诊断,但进一步的实验室确诊还是必要的,现已有多种检测方法和诊断试剂.控制该病最有效的方法是使用疫苗对易感动物进行免疫接种.文章从病原学、诊断和预防控制等方面对羊痘进行综述.     

基于ATmega16和SHT71的鸡舍温湿度测控系统

鸡舍温度对鸡的产蛋量、蛋的大小和蛋壳厚度都有不良的影响。鸡舍的空气湿度对鸡体蒸发散热和非蒸发散热都有影响。为此,提出了基于ATmega16、计算机及SHT71组成的鸡舍温湿度检测控制系统。它可以利用SHT71完成对鸡舍环境温度和湿度的自动检测,把数据通过RS485传输到计算机,通过计算机进行相应的数据处理,并控制风扇和水帘,来对鸡舍的温湿度进行自动调节。最后,利用PROTEUS对整个系统进行仿真调试。     

沙田柚黄龙病病原16S rDNA片段的克隆与序列分析

采集田间表现斑驳症状的沙田柚叶脉,用CTAB法提取总DNA。根据柑橘黄龙病病原16S rDNA的核苷酸序列设计引物P1/P2,进行PCR扩增,获得1条大小为1 167 bp的片段。酶切分析显示,该片段可被切成大小分别约为640 bp和520 bp的2个片段。扩增产物经纯化,与pM D 18-T V ector连接,转化大肠杆菌(E scherich ia coli)DH 5α,筛选克隆重组子。对PCR产物进行测序及序列分析,结果表明,与柑橘黄龙病病原亚洲种16S rDNA的同源性为99%,与非洲种的同源性为97%,与美洲种的同源性为96%。认为,沙田柚的斑驳症状是由黄龙病病原引致的,称之为沙田柚黄龙病。该沙田柚黄龙病病原属于柑橘黄龙病病原亚洲种(L iberobacter as iaticus)中的一个成员。系统进化树分析显示,沙田柚黄龙病病原与中国柑橘黄龙病病原亲缘关系最近,推测是直接来自中国柑橘黄龙病病原。     

胨冻样芽孢杆菌(Bacillus mucilaginosus YNUCC0001)絮凝剂生产、絮凝特性及其系统发育学分析

对BacillusmucilaginosusYNUCC000116SrDNA的1481bp片段与GenBank中最相似的16个分类单位进行了比较。UPGMA,NJ,ME和MP方法构建的系统发育树显示B.mucilaginosusYNUCC0001与B.mucilaginosusHSCC1605T、B.mucilaginosus1480D及Paenibacillussp.NBT形成一个单系群分支。在50L全自动发酵罐中30℃发酵52h后,菌株YNUCC0001产生的胞外生物多聚絮凝剂(EBF)达到最大产率(粘度:3420C.P.)。在pH4.0、用量为0.25mlL-1的条件下,这种EBF对高岭土悬浊液的絮凝活性最大(99.8%);121℃高压灭菌60min后絮凝活性维持在98.6%。Hg2+,Ca2+,Mg2+,K+,Zn2+对其絮凝活性有促进作用,而Fe3+、Al3+、EDTA和Cu2+则有强烈抑制。     

7株解有机磷细菌的分离和鉴定

从土壤中分离筛选出7株解有机磷的微生物。对这7株解磷细菌进行了形态、生理生化性状测定及16SrDNA序列分析(GenBankaccessionNo:S2,AY651922;S3,AY661923;X1,AY651925;Y1,AY651924;H1,AY663435;H2,AY663436andHe,AY663436)。其中S2、S3、X1和He属于假单胞菌属(Pseudomonas),Y1属于芽孢杆菌属(Bacillus),H1属于不动杆菌属(Acinetobacter),H2属于寡养单胞菌属(Stenotrophomonas)。进一步通过G C含量和DNA-DNA杂交研究,结果表明,S2、S3和X1为产碱假单胞菌(Pseudomonasalcaligenes),Y1为蜡状芽孢杆菌(Bacilluscereus)。     

Survival of bacterial DNA and culturable bacteria in archived soils from the Rothamsted Broadbalk experiment

Dried soil samples from many sources have been stored in archives world-wide over the years, but there has been little research on their value for studying microbial populations. Samples collected since 1843 from the Broadbalk field experiment on crop nutrition at Rothamsted have been used to document changes in the structure and composition of soils as agricultural practices evolve, also offering an invaluable record of environmental changes from the pre- to post-industrial era in the UK. To date, the microbial communities of these soils have not been studied, in part due to the well-documented drop in bacterial culturability in dried soils. However, modern molecular methods based on PCR amplification of DNA extracted directly from soil do not require bacterial cells to be viable or intact and may allow investigations into the legacy of bacteria that were present at the time of sample collection.

In a preliminary study, to establish if dried soils can provide a historical record of bacterial communities, samples from the Broadbalk soil archive dating back to 1868 were investigated and plots treated with either farmyard manure (FYM) or inorganic fertilizer (NPK) were compared. As anticipated, the processes of air-drying and milling greatly reduced bacterial viability whilst DNA yields declined less and may be preserved by desiccation. A higher proportion of culturable bacteria survived the archiving process in the FYM soil, possibly protected by the increased soil organic matter. The majority of surviving bacteria were firmicutes, whether collected in 2003 or in 1914, but a wide range of genera was detected in DNA extracted from the samples using PCR and DGGE of 16S rRNA genes. Analysis of DGGE band profiles indicated that the two plots maintained divergent populations. Sequence analysis of bands excised from DGGE gels, from a sample collected in 1914, revealed DNA from - and β-proteobacteria as well as firmicutes. PCR using primers specific for ammonia oxidizing bacteria showed similar band profiles across the two treatments in recently collected samples, however older samples from the NPK plot showed greater divergence. Primers specific for the genus Pseudomonas were designed and used in real-time quantitative PCR to indicate that archived soil collected in 1868 contained 10-fold less pseudomonad DNA than fresh soil, representing around 10⁵ genomes g⁻¹ soil. Prior to milling, dramatically less pseudomonad DNA was extracted from recently collected air-dried soil from the NPK compared to the FYM plot; otherwise, the two plots followed similar trends. Overall bacterial abundance, diversity and survival during the archiving process differed in the two soils, possibly due to differences in clay and soil organic matter content. Nevertheless, the results demonstrate that air-dried soils can protect microbial DNA for more than 150 years and offer an invaluable resource for future research.     

高产水稻土细菌多样性的培养法与非培养法比较研究

利用细菌的通用引物扩增江西余江县高产水稻土红壤细菌总DNA和平板培养细菌混合总DNA的16S rDNA基因片段,在此基础上分别建立两种16S rDNA文库(文库a和文库b)。从两个文库中各随机挑选100个克隆,扩增出阳性克隆中的插入片段后选用HhaⅠ和RsaⅠ两种四碱基酶进行ARDRA(amplified rDNA restriction analysis)分析。统计比较分析发现,文库a的Shannon-Wienner指数、Simpson指数、丰富度、均一度分别为4.432、0.987、18.885和0.973,均高于文库b中相应的多样性参数(分别为2.271、0.758、5.736和0.501),即平板培养方法所展现的细菌群落结构多样性低于土壤中原始的多样性。结果表明,传统培养方法存在着很大的局限性,必须结合新的分子生物学技术手段才能更全面完善地认识土壤微生物群落结构多样性,以期充分利用其中丰富的微生物资源。     

p5CS基因在蒙农杂种冰草植株中的表达及耐盐性研究

为尽快培育出适宜我国干旱荒漠地区大面积推广的耐盐冰草新品种,试验以经PCR和Southern blot杂交检测的含有p5CS基因的蒙农杂种冰草植株为材料,用Northern blot检测目的基因在转化植株中的表达;并用1.5%NaCl盐溶液进行胁迫处理确定转化植株的耐盐性。结果表明:转基因冰草植株与DIG标记探针杂交呈现明显的杂交带;盐胁迫下,游离脯氨酸含量增加较快,质膜透性、丙二醛含量增加较小,SOD活性较高。说明p5CS基因能够在冰草基因组的转录水平上表达,表达植株的耐盐性明显增加。