哺乳动物克隆的研究进展

哺乳动物体细胞克隆是20世纪末生命科学领域最引人注目的高新技术,该技术在农业、生物学和医药等方面具有广泛的应用前景。近年来克隆技术发展迅速,多种哺乳动物相继克隆成功,但也存在着克隆效率太低、克隆动物表型正常而实质异常等问题。本文在近年来克隆技术研究的基础上,对克隆的概念、研究历史以及克隆的方法、过程进行了综述,展望了克隆的意义及克隆动物的应用前景,分析了目前克隆技术尚存在的问题,并提出了解决这些问题的关键。     

Taxonomy, age and environment status of the Yuanmou hominoids

When, where and from which hominoid the human originated has been one of the key subjects in the study of human natural history. It is therefore very important to learn the chronological, geographical and taxonomic distribution of all hominoids. Yunnan Pr…     

Effect of the calmodulin inhibitor R24571 (calmidazolium) on rat embryos cultured in vitro

Summary The possible effects of inhibition of the calcium-binding protein, calmodulin, on mammalian morphogenesis have been investigated by culturing rat embryos in vitro from 9 1/2 to 11 1/2 days of development in the presence of R24571 (calmidazolium), a specific inhibitor of calmoldulin. Embryos cultured in 10^–2 mM R24571 for 48 h show inhibited development and exhibit a range of morphogenetic abnormalities including assymetry and neural tube defects. Embryos exposed to R24571 for the first 24 h of a 48 h culture are more severely affected than embryos exposed to R24571 for the last 24 h.Acknowledgments. We wish to thank Mr C. Veltkamp and Mr B. lewis for their expert help with the scanning electron microscopy and photography.     

哺乳动物神经纤维的双向脉冲选择性刺激研究

为了研究神经纤维的双向脉冲选择性刺激方法,对神经纤维的各种物理模型进行了研究和比较,建立了哺乳动物有髓神经纤维的仿真系统,并利用该系统对以前工作中提出的３种双向脉冲的选择性刺激方法（单电极,双电极和三电极方法）进行了研究,发现也可以实现复合神经干中细神经纤维的选择性兴奋,证明这些方法同样适用于哺乳动物的神经纤维模型。     

五道峡自然保护区兽类资源生态评价

对五道峡自然保护区兽类资源进行了调查,共记录到兽类59种,隶属于8目25科,其中,古北种12种,东洋种38种,广布种9种;国家重点保护动物42种,湖北省重点保护动物18种,被列入《濒危野生动植物种国际贸易公约》的兽类20种（附录Ⅰ9种、附录Ⅰ4种、附录Ⅱ7种）,被列入《中国濒危动物红皮书》的兽类有18种（濒危物种3种、稀有种2种、易危物种13种）;分析其区系特征,表现为东洋种占优势,珍稀兽类较多,特有种4种;分析其多样性特征。有7种生活型。水栖种类最少,并与神农架国家级自然保护区、后河国家级自然保护区、壶瓶山国家级自然保护区的多样性进行了比较研究．对兽类资源进行了评价,并提出了保护建议。     

β-hCG重组基因在几种哺乳类细胞中的表达

为探讨用哺乳类细胞表达β-hCG基因。将重组β-hCG基因导入L－1和CNE－2细胞，在L－1细胞中得到10ng／mL的β-hCG，在CNE－2细胞中有7ng／mL的β-hCG，而且β-hCG还能在传代培养的L－1和CNE－2细胞中产生。再将重组β-hCG基因和dhfr基因其导入CHO细胞，在培养液中得到6．85mg／mL的表达量，说明β-hCG重组基因在哺乳类细胞中有表达功能，但尚未获得能稳定表达β-hCG的单克隆CHO细胞株。     

A preliminary report on the newly found Tianyuan Cave, a Late Pleistocene human fossil site near Zhoukoudian

The Tianyuan Cave is the only human fossil-bearing site containing rich mammalian fossils found in the last decades near Zhoukoudian. Up to now more than 34 specimens of the human body have been recovered, and the mammalian fossils can be put into 29 species. Cervids dominate the fauna, and carnivores are very rare. Based on the primary examination, the human fossils can be attributed to the species Homo sapiens. All the mammalian fossils, except one between tooth of Crocuta belong to the species that still exist today. But some of them are the first records in fossil form north of the Yellow River, such as Arctonyx and Capricornis. Based on the mammalian fauna study, it seems that the Tianyuan Cave can be correlated with the Upper Cave.Sixty-three percent of the species of the mammalian fauna from the Tianyuan Cave are also present in the Upper Cave.The characters of the deposits also share some similarities between the Tianyuan Cave and the Upper Cave; both of them are mainly composed of breccia without cement. The dating using the U-series method on deer tooth samples indicates that the geological age of the new site is around 25 thousand years B.P. This is the first discovery of human sites outside the core area of the Peking Man Site at Zhoukoudian,which throws new light onto this world famous site complex.