人血小板生成素全长分子在酵母系统中的分泌表达及活性分析

外源基因可通过整合型载体被整合到毕赤酵母（Ｐｉｃｈｉａｐａｓｔｏｒｉｓ）染色体上,获得遗传性稳定分泌表达株．利用酵母信号肽ＭＦα,对该信号肽蛋白酶识别位点的相关序列进行重新设计,使天然人ＴＰＯ成熟肽在毕赤酵母系统中分泌表达成功．表达产物经Ｗｅｓｔｅｒｎ－ｂｌｏｔ进行分析,分子量约为６６ｋＤ处蛋白条带可被ＴＰＯ抗体识别;表达量约为０．１ｇ／Ｌ;Ｎ端氨基酸序列分析结果与设计的一致;表达产物对小鼠骨髓细胞形成巨核细胞集落形成单位（ｍｅｇａｋａｒｙ－ｏｃｙｔｅｃｏｌｏｎｙｆｏｒｍｉｎｇｕｎｉｔ,ＣＦＵ－Ｍｅｇ）具有明显的刺激作用．     

人肝金属硫蛋白-I_A基因在鱼腥藻中的克隆与表达

将人工合成的人肝金属硫蛋白（ｍｅｔａｌｏｔｈｉｏｎｅｉｎ,简称ＭＴ）－ＩＡ基因插入至中间载体ｐＲＬ－４３９上强启动子ｐｓｂＡ后,再将其与穿梭载体ｐＫＴ－２１０相连,得到大肠杆菌－蓝藻穿梭表达载体ｐＫＴ－ＭＴ,用三亲接合转移法将ｐＫＴ－ＭＴ转入丝状体蓝藻－鱼腥藻７１２０,经链霉素筛选,得到了稳定的转人肝ＭＴ－ＩＡ基因鱼腥藻．纯化单藻落,液体扩大培养．从鱼腥藻中提取的质粒经Ｓｏｕｔｈｅｒｎ印迹分析,确定人肝ＭＴ－ＩＡ基因已转入鱼腥藻７１２０中,Ｗｅｓｔｅｒｎ印迹分析表明,金属硫蛋白在转人肝ＭＴ－ＩＡ基因鱼腥藻中得到了表达．经原子吸收光谱法测定表达量约为７００μｇＭＴ／ｇ鲜藻,重金属耐受性实验表明,得到了能耐受重金属－镉的转人肝ＭＴ－ＩＡ基因鱼腥藻,它将在清除水域中重金属污染和医药研究方面发挥重要作用．     

铁线莲属研究随记(Ⅰ)

于1999年5月至9月,作者先后访问了K、BM、P和S四个植物标本馆,在查阅他们收藏的铁线莲属植物标本的过程中,发现该属的一些分类学问题：(1)发现过去一些学者分别错误地将Clematis montana var．brevifoliola Kuntze,C．apiifolia var．biternata Makino,C．subumbellata Kurz,C．goudotiana Planch．&; Triana,C．insidiosa Baill.,C．kockiana Schneid．和C．longicauda A．Rich．等加以归并,这些均应予以恢复。(2)发现过去发表的subsect．Africanae M．Johnson,C．umbellifera Gagnep.,C．pubescens Benth.,C．rhodocarpa Rose,C．edentata Baker,C．djalonensis Cheval.,C．oliveri Kuntze,C．tibetana ssp．vernavi var．dentata Grey-Wilson,C．yunuanensis var．brevipedunculata W．T .Wang,C．clarkeana var．stenophylla Hand．-Mazz,C．subfalcata Pei ex M．Y．Fang,C．angustifoliola W．T .Wang,C．dasyandra var．polyantha Finet &; Gagnep.等学名不能成立,应加以归并。(3)对构成黄花铁线莲组sect．Meclatis的二亚组给出新的特征集要;根据C．sericea B．H．K．ex DC．与C．grossa Benth．的形态区别不大,有时甚至难以区分以及二者的分布区一南一北互相邻接的分布格局,认为二者可能为一对姊妹群,并将其等作为一个种的两个地理变种处理;认为在非洲大陆广布并分布到阿拉伯半岛的C．hirsuta Perr．&; Guill．包含4变种;将过去置于C．oweniae Harv．的变种var．jonodii移到此种中,并根据C．inciso-dentata A．Rich．特殊的绵毛毛被和内面无毛的萼片等特征,否定过去一些学者将其归并于C．hirsuta的意见,也将其作为C．hirsuta的一个变种处理。(4)描述了单性铁线莲组sect．Aspidanthera的一个特产马达加斯加岛的新亚组subsect．Insid iosae W．T．Wang和尾叶铁线莲亚组subsect．Connatae的一个特产非洲大陆的新系ser．Grandiflorae W．T． Wang以及8新种、1新变种。(5)发现杨宗愈等(1991)报道的秀丽铁线莲C．grata Wall．在我国7省区 (西藏东部、云南、四川、贵州、湖北、湖南、江西)有分布所依据的8号标本均非C．grata,而分别是与此 种相近缘的5个种或变种。(6)发现了伏毛绣球藤C．montana var．brevifoliola Kuntze(原知分布于锡金和印度西北部)在我国西藏、尼泊尔、不丹和缅甸北部,缅甸铁线莲C．burmanica Lace(原知分布于缅甸和 泰国)在我国云南西南部,小木通C．armandii Franch．(原知分布于我国长江流域、越南)在缅甸北部和印 度东北部,以及俞氏铁线莲C．yui W．T．Wang(原知分布于我国云南西北部和西藏东南部)在缅甸北部 的新分布。     

Ultrastructural Study of Secondary Wall Formation in the Stem Fiber of Phyllostachys pubescens

Ultrastructural changes in secondary wall formation of Phyllostachys pubescens Mazel fiber were investigated with transmission electron microscopy. Fiber developed initially with the elongation of cells containing ribosomes, mitochondria and Golgi bodies in the dense cytoplasm. During the wall thickening, the number of rough endoplasmic reticulum and Golgi bodies increased apparently. There were two kinds of Golgi vesicles, together with the ones from endoplasmic reticulum formed transport vesicles. Many microtubules were arranged parallel to the long axis of the cell adjacent to the plasmalemma. Along with the further development of fiber, polylamellate structure of the secondary wall appeared, with concurrent agglutination of chromatin in the nucleus, swelling and disintegration of organelles, while cortical microtubules were still arranged neatly against the inner side of plasmalemma. Lomasomes could be observed between the wall and plasmalemma. The results indicated that the organelles, such as Golgi bodies together with small vesicles, rough endoplasmic reticulum and lomasomes, played the key role in the thickening and lignification of the secondary wall of bamboo fiber, though cortical microtubules were correlative with the process as well.     

A revision of Clematis sect. Clematis(Ranunculaceae)

Clematis sect. Clematis is revised in this paper. Seventy-three species and 45 varieties are recognized. They are keyed, described, and illustrated in some cases, and are classified into five subsections. Brief taxonomic history and geographical distribution of the section are given, and the relationships of its subsections and with its close allies of the C. vitalba evolutionary stock of the subgenus Clematis are discussed. Main taxonomic changes are made as follows: (1) C. lancifolia Bur. & Franch., C. songarica Bunge, C. ispahanica Boiss., C. delavayi Franch. and C. phlebantha Williams, which have been previously regarded to be close to C. fruticosa Turcz. and its allies, and placed in sect. Fruticella Tamura by Tamura and some other authors, are here transferred to subsect. Angustifoliae Tamura according to the floral structure. (2) The existence of intermediate forms between the C. vitalba group and the C. flammula group indicates that these two groups are closely related to each other and should not be treated as two sections or even two subgenera. They are treated as two subsections within sect. Clematis . Two series, six species, and one variety are described as new, and five new ranks are made. 