倭竹属地理分布的研究

倭竹属Shibataea Makino隶于禾本科之竹亚科,现已知有8种,分布于我国东南部的浙江、福建、江苏、安徽、江西等省,广东、台湾两省有少量栽培,日本产1种。苏联、西德、印尼等国所栽培的倭竹均系自我国或日本引入。我国浙-闽地区产8种,且都有野生发现,是本属的现代分布中心。倭竹属植物体型矮小,常植于庭院或公园中供观赏。近年来盆景艺术迅速发展,微型园林日益兴起,倭竹属植物体态优美,常绿,耐寒且易于栽培,为广大园林工作者所垂青。     

乙型肝炎病毒前S2抗原决定簇（HBVPreS2epitope）与乙型肝炎病毒核心抗原（HBcAg）的基因融合与表达

乙肝前Ｓ２（ＨＢＶＰｒｅＳ２）肽段由５５个氨基酸组成,其Ｎ端肽段含Ｔｈ和Ｂ细胞抗原决定簇。我们将化学合成的ＰｒｅＳ２ｅｐｉｔｏｐｅ（１２０－１４５）基因与ＨＢｃＡｇ基因不同位点进行融合,融合基因在大肠杆菌中获得表达,并对融合蛋白进行了纯化。经ＥＬＩＳＡ和Ｗｅｓｔｅｒｎ－ｂｌｏｔ实验表明,融合蛋白具有ＰｒｅＳ２和ＨＢｃＡｇ两者的抗原性。此外,研究还表明,强启动子能使表达水平有一定提高。     

倭竹族花序演化的探讨

倭竹族隶于禾本科之竹亚科。本族计有10属约150余种。分布于东南亚季风带的印度、越南、中国及日本等国,我国产8属约120种,占该族全部属种的80％。其中唐竹属、短穗竹属、筇竹属、八月竹属等均为我国所特产,唐竹属1种早期引入日本栽培,倭竹属、大节竹属、方竹属、刚竹属等也主要分布于我国,只有少数种分布于其它国家,业平竹属和阴阳竹属为日本特产。 刚竹属计有70种之多,我国产50种以上,是本族中种类最多的属,其中有许多种类分布广、适应能力强,用途多、产量大。是重要的植物资源.尤其是毛竹,是我国亚热带地区的主要栽培竹种。 倭竹族花序演化的研究对于进一步认识和鉴别竹类植物.了解竹类植物的演化关系。使竹类植物的系统安排更加合理都是有益的。倭竹族的花序属于假花序.与真花序相比较属于原始类型。本族中花序轴反复分枝.具有极多小穗的短穗竹属,业平竹属等是比较原始的,大节竹属、唐竹属的花序简化、花序轴不分枝或仅有少数分枝,含小穗数很少是进化类型。     

长期培肥黑土微生物量磷动态变化及影响因素

长期采用两种不同量有机肥(M2、M4)、化肥(NPK)方式培肥黑土,研究微生物量P在作物生长季动态变化．结果表明。施用有机肥微生物量P显著高于施用化肥(NPK)和不施肥(CK),微生物量P分别为M48．75～47．68mg·kg^-1,M2 3．02～37．16mg·kg^-1,NPK1．59～10．62mg·kg^-1,CK0．76～6．74mg·kg^-1之间,波动性较大．M4、M2处理微生物量P最大值出现在抽雄吐丝期,NPK、CK处理最大值出现在大喇叭口期;施肥数量和种类不同所引起的黑土微生物量P的差异并未因季节变化及玉米生育时期影响而明显改变．微生物量P的动态变化与绝大多数黑土生物、理化特性指标的动态变化没有显著的相关性;微生物量P与黑土生物、理化特性(除全钾外),植物氮、磷、钾含量有极显著的正相关关系,与黑土含水量呈显著正相关关系．     

Comparative genomics of duplicate γ-glutamyl transferase genes in teleosts: medaka (Oryzias latipes), stickleback (Gasterosteus aculeatus), green spotted pufferfish (Tetraodon nigroviridis), fugu (Takifugu rubripes), and zebrafish (Danio rerio)

The availability of multiple teleost (bony fish) genomes is providing unprecedented opportunities to understand the diversity and function of gene duplication events using comparative genomics. Here we examine multiple paralogous genes of γ-glutamyl transferase (GGT) in several distantly related teleost species including medaka, stickleback, green spotted pufferfish, fugu, and zebrafish. Through mining genome databases, we have identified multiple GGT orthologs. Duplicate (paralogous) GGT sequences for GGT1 (GGT1 a and b), GGTL1 (GGTL1 a and b), and GGTL3 (GGTL3 a and b) were identified for each species. Phylogenetic analysis suggests that GGTs are ancient proteins conserved across most metazoan phyla and those paralogous GGTs in teleosts likely arose from the serial 3R genome duplication events. A third GGTL1 gene (GGTL1c) was found in green spotted pufferfish; however, this gene is not present in medaka, stickleback, or fugu. Similarly, one or both paralogs of GGTL3 appear to have been lost in green spotted pufferfish, fugu, and zebrafish. Syntenic relationships were highly maintained between duplicated teleost chromosomes, among teleosts and across ray-finned (Actinopterygii) and lobe-finned (Sarcopterygii) species. To assess subfunction partitioning, six medaka GGT genes were cloned and assessed for developmental and tissue-specific expression. On the basis of these data, we propose a modification of the "duplication-degeneration-complementation" model of subfunction partitioning where quantitative differences rather than absolute differences in gene expression are observed between gene paralogs. Our results demonstrate that multiple GGT genes have been retained within teleost genomes. Questions remain, however, regarding the functional roles of multiple GGTs in these species.     

Temporal relationship of autophagy and apoptosis in neurons challenged by low molecular weight β‐amyloid peptide

Alzheimer's disease (AD) is an aging‐related progressive neurodegenerative disorder. Previous studies suggested that various soluble Aβ species are neurotoxic and able to activate apoptosis and autophagy, the type I and type II programmed cell death, respectively. However, the sequential and functional relationships between these two cellular events remain elusive. Here we report that low molecular weight Aβ triggered cleavage of caspase 3 and poly (ADP‐ribose) polymerase to cause neuronal apoptosis in rat cortical neurons. On the other hand, Aβ activated autophagy by inducing autophagic vesicle formation and autophagy related gene 12 (ATG12), and up‐regulated the lysoso‐mal machinery for the degradation of autophagosomes. Moreover, we demonstrated that activation of autophagy by Aβ preceded that of apoptosis, with death associated protein kinase phosphorylation as the potential molecular link. More importantly, under Aβ toxicity, neurons exhibiting high level of autophagosome formation were absent of apoptotic features, and inhibition of autophagy by 3‐methylade‐nine advanced neuronal apoptosis, suggesting that autophagy can protect neurons from Aβ‐induced apoptosis.     

应用CTB基因启动子及信号肽序列构建分泌性表达系统

利用霍乱毒素B亚基基因的启动子、信号肽序列及ctx操纵子的转录终止信号构建了分泌性表达的质粒载体pMCOSS。Β－半乳糖苷酶基因克隆至霍乱毒素B亚基基因的信号肽序列下游后能得到高效分泌性表达。不同的宿主菌和培养基成分中对β-半乳糖苷酶的表达产量有较大的影响,以MM2为宿主菌、在玉米浆培养基中β－半乳糖苷酶的表达产量达4 lOOu／ml,产物的大部分分泌至细胞的周质,活力测定的结果与SDS—PAGE电泳测定结果基本一致,说明表达的β－半乳糖苷酶绝大部分都具有酶活性。构建的蛋白质分泌性表达的载体－宿主系统及合适的培养条件为易形成包含体的蛋白质的高效表达提供了一条新的途径。     

原油微生物群落构成及降解菌降解特性的研究

为分离得到高效原油降解菌,直接向原油中加入营养物刺激,培养一段时间后原油乳化降解。气相色谱法、红外光谱法和紫外吸收均表明降解菌体系具有较强的降解原油烃的能力。采用细菌16S rDNA通用引物和PCR扩增等方法,构建原油降解菌体系16S rDNA克隆文库,并对所构建的文库进行分析。同时,从降解菌体系中分离得到一株降解菌,鉴定结果表明所分离的细菌为短小芽孢杆菌(Bacillus pumilus)。采用气相色谱技术对降解过程中的原油烃的变化进行分析,结果显示原油烃类组分会随着降解时间的变化而发生变化,降解菌表现出其对烷烃类物质的降解能力。