Significant genetic admixture after reintroduction of peregrine falcon (<Emphasis Type="Italic">Falco peregrinus</Emphasis>) in Southern Scandinavia

The peregrine falcon (Falco peregrinus) population in southern Scandinavia was almost extinct in the 1970’s. A successful reintroduction project was launched in 1974, using captive breeding birds of northern and southern Scandinavian, Finnish and Scottish origin. We examined the genetic structure in the pre-bottleneck population using eleven microsatellite markers and compared the data with the previously genotyped captive breeding population and contemporary wild population. Museum specimens between 53 and 130 years old were analyzed. Despite an apparent loss of historical genetic diversity, the contemporary population shows a relatively high level of genetic variation. Considerable gene introgression from captive breeding stock used to repopulate the former range of southern Scandinavian peregrines may have altered the genetic composition of this population. Both the historical and contemporary northern and southern Scandinavian populations are genetically differentiated. The reintroduction project implemented in the region and the use of non-native genetic stock likely prevented the southern Scandinavian population from extinction and thus helped maintain the level of genetic diversity and prevent inbreeding depression. The population is rapidly increasing in numbers and range and shows no indication of reduced fitness or adaptive capabilities in the wake of the severe bottleneck and the reintroduction.     

Genome Size: A Novel Genomic Signature in Support of Afrotheria

Molecular phylogenetic analyses suggest an emerging phylogeny for the extant Placentalia (eutherian) that radically departs from morphologically based constructions of the past. Placental mammals are partitioned into four supraordinal clades: Afrotheria, Xenarthra, Laurasiatheria, and Euarchontoglires. Afrotheria form an endemic African clade that includes elephant shrews, golden moles, tenrecs, aardvarks, hyraxes, elephants, dugongs, and manatees. Datamining databases of genome size (GS) shows that till today just one afrotherian GS has been evaluated, that of the aardvark Orycteropus afer. We show that the GSs of six selected representatives across the Afrotheria supraordinal group are among the highest for the extant Placentalia, providing a novel genomic signature of this enigmatic group. The mean GS value of Afrotheria, 5.3 ± 0.7 pg, is the highest reported for the extant Placentalia. This should assist in planning new genome sequencing initiatives. [Reviewing Editor: Dmitri Petrov]     

Winter spatial distribution of fish larvae assemblages relative to the hydrography of the waters surrounding Taiwan

The aim of this study was to investigate the species composition and distribution of fish larvae in relation to hydrographic conditions in the waters surrounding Taiwan Island (TI) in February 2003. In total, 242 kinds of fish larvae belonging to 127 genera and 75 families were recognized. Among these, 109 taxa were identified to the family or genus level, others to the species level. The 12 predominant types, which constituted 71% of the total fish larvae, were Engraulis japonica, Scomber sp., Diaphus spp., Benthosema pterotum, Carangoides ferdau, Embolichthys mitsukurii, Maurolicus sp., unidentified Myctophidae, Gonostoma gracile, Trichiurus lepturus, unidentified Gobiidae, and Myctophum asperum. The distribution of fish larvae showed a clear association with water masses around TI, with higher abundances and lower species richness northwest of TI where the China Coastal Current prevails, and lower abundances and higher species diversity east of TI where the Kuroshio Current dominates. Cluster analysis distinguished three station groups and four species groups, and the distribution patterns of fish larvae also corresponded to hydrographic conditions. The total abundances of fish larvae and eight of the 12 predominant taxa showed significant and positive correlations with zooplankton abundance, which suggests that food source might be a key factor determining the abundance and distribution of fish larvae during the winter.     

A novel and highly efficient production system for recombinant adeno-associated virus vector

Recombinant adeno-associated virus(rAAV) has proven to be a promising gene delivery vector for human gene therapy. However, its application has been limited by difficulty in obtaining enough quantities of high-titer vector stocks. In this paper, a novel and highly efficient production system for rAAV is described. A recombinant herpes simplex virus type 1(rHSV-1) designated HSV1-rc/△UL2, which expressed adeno-associated virus type2(AAV-2) Rep and Cap proteins, was constructed previously. The data confirmed that its functions were to support rAAV replication and packaging, and the generated rAAV was infectious. Meanwhile, an rAAV proviral cell line designated BHK/SG2, which carried the green fluorescent protein(GFP) gene expression cassette, was established by transfecting BHK-21 cells with rAAV vector plasmid pSNAV-2-GFP. Infecting BHK/SG2 with HSV1-rc/△UL2 at an MOI of 0.1 resulted in the optimal yields of rAAV, reaching 250 transducing unit(TU) or 4.28×104 particles per cell. Therefore, compared with the conventional transfection method, the yield of rAAV using this "one proviral cell line, one helper virus" strategy was increased by two orders of magnitude. Large-scale production of rAAV can be easily achieved using this strategy and might meet the demands for clinical trials of rAAV-mediated gene therapy.     

<Emphasis Type="Italic">Phellinus</Emphasis> extracts inhibit migration and matrix metalloproteinase secretion in porcine coronary artery endothelial cells

Phellinus linteus is a fungus which is found primarily in tropical regions of the Americas, Africa, and Asia.P. linteus has been used in traditional medical practice for the treatment of arthritis, liver damage and cancer. Angiogenesis is a process that involves migration, proliferation and cell differentiation, as well as the formation of new capillary structures. The anti-angiogenic activities evidenced by natural compounds may actually be a critical effect for the inhibition of angiogenesis-dependent disease by these agents via the blockage of vascular development. This study assessed the effects of water extracts fromP. linteus (Phellinus extracts) on primary cultured porcine coronary artery endothelial cells (PCAECs).Phellinus extracts induced no changes in DNA synthesis or cell numbers, but inhibited the migration of PCAECs.Phellinus extracts also induced a reduction in the secretion of matrix metalloproteinase-2 (MMP-2) and MMP-9. Our results show that, in endothelial cells,Phellinus extracts may inhibit angiogenesis by reducing levels of MMP-2 and MMP-9 secretion.     

利用根癌农杆菌和基因枪法转化获得转抗虫融合蛋白基因(Bt-CpTI)甘蓝植株

以下胚轴、带柄子叶和茎尖为外植体,利用根癌农杆菌和基因枪法将抗虫融合蛋白基因(Bt-CpTI)导人甘蓝品种“中甘8号”,得到了13株卡那霉素抗性植株。经PCR扩增反应和Southern blot分子验证表明:农杆菌介导转化下胚轴和带柄子叶来源的Ⅰ型抗性植株均为转基因植株,而农杆菌介导转化茎尖外植体得到的Ⅱ型抗性植株属“假阳性”植株,基因枪介导转化茎尖的2株Ⅲ型植株中,有1株是非转基因植株。经胰蛋白酶抑制剂活性分析和抗虫测试证明,部分转基因植株有较高的胰蛋白酶抑制剂活性和抗菜青虫能力。     

α2—肾上腺素体介导大鼠主动脉收缩的特性

为阐明功能性α2－肾上腺素受体（α2－AR）的特性及其与α1－AR的相互关系,以离体大鼠主动脉为模型,进行收缩功能实验,发现在大鼠主动脉中,α1－AR和α2－AR产可介导其收缩效应并以α1－AR折作用为主,α1－AR可增强α2－AR介导的收缩效应,而α2－AR则对α1－AR介导的收缩效应无影响,在不可逆阻断α1－AR而保留α2－AR的条件下,α2－AR介导的缩血管效应消失,仅在阈值浓度的KCl存在下才能显示,且收缩幅度较对照组显著降低,结果表明,在离体大鼠主体动脉中存在功能性α2－AR,α2－AR的缩血管作用依赖于α1－AR的激动,其最大收缩反应远远小于α1－AR。     

Recovery of transgenic plants by pollen-mediated transformation in <Emphasis Type="Italic">Brassica juncea</Emphasis>

The aroA-M1 encoding the mutant of 5-enolpyruvyl-shikimate-3-phosphate synthase (EPSPS) was introduced into the Brassica juncea genome by sonication-assisted, pollen-mediated transformation. The plasmid DNA and collected pollen grains were mixed in 0.3 mol/L sucrose solution and treated with mild ultrasonication. The treated pollen was then pollinated onto the oilseed stigmas after the stamens were removed artificially. Putative transgenic plants were obtained by screening germinating seeds on a medium containing glyphosate. Southern blot analysis of glyphosate-resistant plants indicated that the aroA-M1 gene had been integrated into the oilseed genome. Western blot analysis further confirmed that the EPSPS coded by aroA-M1 gene was expressed in transgenic plants. The transgenic plants exhibited increased resistance to glyphosate compared to untransformed plants. Some of those transgenic plants had considerably high resistance to glyphosate. The genetic analysis of T₁ progeny further confirmed that the inheritance of the introduced genes followed the Mendelian rules. The results indicated that foreign genes can be transferred by pollen-mediated transformation combined with mild ultrasonication.     

同型半胱氨酸对血管内皮功能的影响及通心络超微粉的干预作用

目的：观察同型半胱氨酸对血管内皮功能的影响,并探讨通心络超微粉的干预作用。方法：健康雄性Wis-tar大鼠,随机分为对照组、模型组、通心络组。离体主动脉环技术检测血管内皮依赖性舒缩功能,微循环仪观察肠系膜微循环变化,放免方法检测血浆内皮素（ET）、血管紧张素Ⅱ（AngⅡ）、血栓素（TXA2）、前列环素（PGI2）的含量及血清超氧化物歧化酶（SOD）与谷胱苷肽过氧化物酶（GSH-Px）的活性、一氧化氮（NO）及丙二醛（MDA）的含量。结果：与对照组比较,模型组血管内皮依赖性舒张反应明显减弱（p〈0.01）,肠系膜毛细血管对乙酰胆碱的扩张幅度与扩张率显著下降（P〈0.05）。与模型组比较,通心络组血管舒张反应明显改善（P〈0.01）,肠系膜毛细血管对乙酰胆碱反应性升高;与对照组比较,模型组AngⅡ、ET、TXA2含量明显升高（P〈0.05,p〈0.01）,而PGI2含量明显降低（P〈0.05）,同时血清中SOD与GSH-Px活力、NO含量明显降低（P〈0.001,P〈0.05）。与模型组比较,通心络组血浆AngⅡ、ET、TXA2的含量显著降低（P〈0.01）,而PGI2的含量明显升高（P〈0.01）,同时血清中SOD活力与NO含量显著升高（P〈0.01,P〈0.05）。结论：①高同型半胱氨酸血症可使内皮依赖性血管舒缩功能减退,其机制可能与高同型半胱氨酸血症引发血管舒缩因子平衡紊乱及大量自由基的产生有关。②通心络超微粉可使同型半胱氨酸所致血管内皮依赖性舒张功能的异常明显改善,可能与其抑制自由基的过量生成及调节内皮舒缩因子的平衡有关。     

小麦TaMlo基因的原核表达、抗体制备及细胞化学分析(简报)

白粉病菌(Blumeria graminis)是一类高度专化性的寄生真菌,可侵染650多种单子叶植物和 9000多种双子叶植物,能够引起多种麦类作物的白粉病,给农业生产带来巨大的损失。由于白粉病菌生理小种多、变异快,所以利用专化性抗病基因难以解决植物的持久抗病性问题。人们在研究大麦白粉病时．发现大麦Mlo基因的隐性突变可导致大麦对绝大多数白粉病菌生理小种的高效持久的广谱抗病性。Schulze-Lefert等多家实验室合作于1997年成功克隆了野生的 Mlo基因。进一步研究表明．该基因编码一种植物特有的具有7个跨膜区和羧基端长尾的膜蛋白(Mlo),它可能对植物细胞的坏死起负调控作用。但Mlo基因如何表达及其在白粉病菌发育中的作用机制尚不清楚。