Phylogenetic position of Schnabelia, a genus endemic to China： Evidence from sequences of cpDNA matK gene and nrDNA ITS regions

The chloroplast gene matK and the internal transcribed spacers (ITS) of the nuclear ribosomal DNA from Schnabelia, a genus endemic to China, and 6 genera of Verbenaceae and 13 genera of Lamiaceae were sequenced. The phylogenetic signal and validity outgroups were measured and evaluated by means of the relatively apparent synapomorphy analysis (RASA). Independent and combined phylogenetic analyses for the matK and ITS sequences were performed using the maximum parsimony (MP), neighbor-joining (NJ) and maximum likelihood (ML) methods, indicating that Schnabelia oligophylla and Caryopteris terniflora form a sister-group relationship. The Caryopteris complex is not shown to be a monophyly because Trichostema, C. paniculata and C. forrestii are paraphyletic to the clade containing the remaining members of the complex. A monophyly of Ajugoideae proposed by Cantino et al., including 8 genera in this study, is strongly supported and the closest relatives of Schnabelia are in the Ajugoideae (Lamiaceae), especially near Caryopteris terniflora. The polygenetic analyses also showed that the genera of Lamiaceae and Verbenaceae sampled in this tudy are phylogenetically mixed and the genus Avicennia is distant to other genera of Verbenaceae. RASA and combined analysis can be used as effective approaches to determining the relationships among phylogenetically complex groups.     

Recombinant PsbF from Synechococcus sp. PCC 7002 forms β:β homodimeric cytochrome b559

All organisms with oxygenic photosynthesis contain two photosystems:photosystem Ⅰ(PSⅠ)and photo-systemⅡ(PSⅡ),The minimal photosystem Ⅱ particles which are photochemically active contain three subunits:D1,D2 and cytochrome b559 (Cyt b559),The function of Cyt b559 remains unclear,We have successfully overxpressed the psbF gene,encoding the β subunit of Cyt b559,from a marine cyanobacterium Synechoccous sp.PCC 7002 as a fusion gene and obtained a redox-active from of Cyt b559,When the N-terminal GST protein of the fusion gene product was removed with thrombin ,the PsbF protein was still redox-active,suggesting that the recombinant PsbF can form dimer in Escherichia coli.The absorption spectra of either the oxidized from or the reduced form of both GST fusion protein and the purified PsbF dimer and the difference Spectra between the two forms are the same as that of the Cyt b559 isolated from the higher plants .Redox titration analysis of recombinant PsbF showed that the mid-point redox potential of the recombinant Cyt b559 was approximately 50 mV, which is close to the low potential of Cyt b559 ,The results are helpful to the understanding of locatlization and function of Cyt b559 on thylakoid membranes.Ⅰ     

简便实用的转抗除草剂基因后代植株鉴定方法--种子萌发测定法

种子萌发法是检测外源抗性基因在转基因植物中的表达和分析外源抗性基因在转基因植物中遗传行为的简单而直接的方法,以转ｂａｒ基因燕麦后代Ｒ２种子为材料,用不同体积分数的除草剂Ｃｈａｌｌｅｎｇｅ处理种子,萌发的幼苗经ＰＣＲ和Ｓｏｕｔｈｅｒｎ ｄｏｔ ｂｌｏｔ鉴定,发现在０．０３％的除草剂上萌发的幼苗,部分不含ｂａｒ基因,而在０．０７％和０．０９％的除草剂上萌发的幼苗,均含ｂａｒ基因。用０．０７％的除草剂测     

企业文化基因及其识别实证研究

企业文化评价与识别研究是管理学科的热点和难点问题.在回顾企业DNA研究应用的基础上,提出并界定了企业文化基因概念,对企业文化基因识别进行了实证研究.     

黑麦KingⅡ中白粉病抗性基因的染色体定位

寻找新的白粉病抗源对促进小麦白粉病抗性育种有重要意义.黑麦是重要的白粉病抗源之一,加强对黑麦白粉病抗性调查的研究也将有利于小麦育种.本实验调查了黑麦KingⅡ及衍生自中国春×黑麦KingⅡ的一套小麦一黑麦附加系的白粉病抗性.结果表明,黑麦KingⅡ对白粉病免疫,附加系中除3R和6R附加系对白粉病表现免疫外,其余5个附加系都高感白粉病.该结果表明3R和6R染色体上的白粉病抗性基因可以在小麦背景中得到表达.这为将黑麦白粉病抗性基因导入小麦提供了直接的桥梁材料.     

低氢、运动及低氢训练对肝细胞凋亡影响的研究进展

低氧与健康的研究是近年来临床医学、环境医学、航空航天医学和运动医学的研究重点问题之一。从肝细胞凋亡的角度研究运动对肝细胞的影响及其与运动性疲劳之间的关系,对科学制定训练计划等具有重要的意义。低氧训练使机体处于更加缺血和缺氧状态,血液的重新分配,使肝脏出现暂时的缺血,运动强度降低后血液重新回流形成血液再灌注,导致肝损伤,诱导细胞凋亡。细胞凋亡的过低或过高都导致疾病的发生。肝细胞凋亡的异常在急、慢性肝损伤的发病机制中起着重要的作用。就有关低氧、运动及低氧训练对肝细胞凋亡的影响,引起凋亡发生的基因调控及机制进行相关综述。     

五指山猪生长激素基因全序列克隆及序列分析

通过筛选一对引物，PCR扩增五指山小型猪GH基因全序列，并进行克隆测序分析、序列分析及氨基酸分析．结果表明，有98个位点不同，同源性为95．026％，外显子有2个碱基发生了突变，其中外显子2有1个位点的碱基突变导致了氨基酸异义取代。     

转植酸酶基因海水小球藻生理生化的初步研究

从42个转植酸酶基因小球藻单克隆藻株中筛选出植酸酶产量较高的8个株藻,经过7次传代,各藻株的植酸酶活保持在稳定的状态,证实植酸酶基因在小球藻中获得了稳定表达.对转基因小球藻所产生植酸酶的性质进行了初步研究,结果表明此酶最适作用pH值为3.8和6.0,最适作用温度为65℃.在相同培养条件下,转基因藻与未转基因藻生理指标并无明显差异,说明外源植酸酶基因的转入对小球藻的生长及生理指标无明显影响.     

2,3-Dihydroxybiphenyl dioxygenase gene was first discovered in Arthrobacter sp. strain PJ3

Bacterium strain PJ3,isolated from wastewater and identified as Arthrobacter sp. bacterium based on its 16S rDNA gene,could use carbazole as the sole carbon,nitrogen and energy source. The genomic library of strain PJ3 was constructed and a positive clone JM109(pUCW402) was screened out for the expression of dioxygenase by the ability to form yellow ring-fission product. A 2,3-dihydroxybiphenyl dioxygenase(23DHBD) gene of 933 bp was found in the 3360 bp exogenous fragment of pUCW402 by GenSCAN software and BLAST analysis. The phylogenetic analysis showed that 23DHBD from strain PJ3 formed a deep branch separate from a cluster containing most known 23DHBD in GenBank. Southern hybridization confirmed for the first time that the 23DHBD gene was from the genomic DNA of Arthrobacter sp. PJ3. In order to test the gene function,recombinant bacterium BL21(pETW-8) was constructed to express 23DHBD. The expression level in BL21(pETW-8) was highest compared with the recombinant bacteria JM109(pUCW402) and strain PJ3. We observed that 23DHBD was not absolute specific. The enzyme activity was higher with 2,3-dihydroxybiphenyl as a substrate than with catechol. The substrate specificity assay suggested that 23DHBD was essential for cleavage of bi-cyclic aromatic compounds during the course of aromatic compound biodegradation in Arthrobacter sp. strain PJ3.