臭蛙群三种蛙类核型及染色体带型的比较(英文)

本文比较了3种臭蛙,即云南臭蛙（R. andersonii）、无指盘臭蛙（R.grahami）和滇南臭蛙（R.tiennanensis）的核型、C-带和银染核仁组织者区（Ag-NORs）。结果表明,3种臭蛙的核型均为2n=26（NF=52）,由5对大型染色体和8对小型染色体组成,与蛙科大多数种类的核型相似,但是染色体形态和次缢痕的位置和数目有差异。其中,云南臭蛙和无指盘臭蛙的核型相似程度比较大,与其他已报道的臭蛙类的核型相差不大,而滇南臭蛙的核型比较特殊,与其他臭蛙类的核型存在显著差异。 C-带技术显示的结果表明,3种臭蛙所有染色体的着丝点都有比较显著的C-带,而居间区C-带和端点C-带却存在明显的差异。3种中,滇南臭蛙的C-带带型比较特殊。有趣的是在研究中还发现,云南臭蛙的早中期细胞（染色体很长）染色体上发现了很多结构异染色质区,除着丝点C-带外,几乎所有的染色体上都有居间区或端点C-带,而在晚中期细胞中所观察到的C-带数目却较少,除着丝点外,只在少数染色体上发现了C-带。 云南臭蛙和无指盘臭蛙的Ag-NORs位于第10对染色体的长臂上,与该染色体上的次缢痕位置相对应,而滇南臭蛙的Ag-NORs位于第6...

云南澜沧江流域传粉昆虫--熊蜂多样性现状与保护对策

中国科学院基金;其它部委、高等院校基金

大肠杆菌基因中密码子前后碱基的使用与蛋白质结构

对一组E. coli基因中编码蛋白质各类二级结构(#alpha#-螺旋、#beta#-折叠片、无规卷曲和回折)的密码子前后碱基的使用情况进行统计分析和比较,发现一些密码子前后碱基的使用有偏向,而且这些偏向与蛋白质的二级结构有关联。这同时亦表明,E. coli基因中同义密码子的选用与蛋白质的二级结构有一些关联。模型对于蛋白质结构预测算法的改进以及基因工程的研究有辅助作用。

In vitro activities of small peptides from snake venom against clinical isolates of drug-resistant Mycobacterium tuberculosis

The recent re-emergence of tuberculosis, especially the multidrug-resistant cases, has highlighted the importance of screening effective novel drugs against Mycobacterium tuberculosis. In this study, the in vitro activities of small peptides isolated from snake venom were investigated against multidrug-resistant M. tuberculosis. Minimum inhibitory concentrations (MICs) were determined by the Bactec TB-460 radiometric method. A small peptide with the amino acid sequence ECYRKSDIVTCEPWQKFCYREVTFFPNHPVYLSGCASECTETNSKWCCTTDKCNRARGG (designated as vgf-1) from Naja atra (isolated from Yunnan province of China) venom had in vitro activity against clinically isolated multidrug-resistant strains of M. tuberculosis. The MIC was 8.5 mg/l. The antimycobacterial domain of this 60aa peptide is under investigation. (C) 2003 Elsevier Science B.V. and the International Society of Chemotherapy. All rights reserved.

Social organization of black-and-white snub-nosed monkeys (Rhinopithecus bieti) at Deqin, China

Data on social organization of two bands of black-and-white snub-nosed monkeys (Rhinopithecus bieti) 14 were collected when the monkeys were crossing an open spot at Nanren and Bamei (northwest of Yunnan, China) using a sampling rule where individuals wit

The use of energy in China: Tracing the flow of energy from primary source to demand drivers

We present a map of the transformation of energy in China as a Sankey diagram. After a review of previous work, and a statement of methodology, our main work has been the identification, evaluation, and treatment of appropriate data sources. This data is used to construct the Sankey diagram, in which flows of energy are traced from energy sources through end-use conversion devices, passive systems and final services to demand drivers. The resulting diagram provides a convenient and clear snapshot of existing energy transformations in China which can usefully be compared with a similar global analysis and which emphasises the potential for improvements in energy efficiency in 'passive systems'. More broadly, it gives a basis for examining and communicating future energy scenarios, including changes to demand, changes to the supply mix, changes in efficiency and alternative provision of existing services. © 2012 Elsevier Ltd.