陆地与海洋来源放线菌次级代谢能力的核糖体工程改造

以3株抗肿瘤活性新化合物产生菌放线菌野生株YN17707(陆地)、18522(陆地)和007(海洋)为出发菌,用核糖体工程抗生素抗性筛选技术,改造次级产物代谢生产能力。通过链霉素抗性筛选,得到突变株212株,经发酵产物的TLC和HPLC分析,高产原始菌所产化合物的突变株87株(41%),可产新产物的突变株22株(10%)。在18522的108株突变株中,高产突变株达53.7%(58株),产新产物突变株达11.1%(12株),链霉素抗性筛选对18522的效果较为理想。     

2株无抗肿瘤活性放线菌野生株的抗生素抗性突变株及其抗肿瘤活性筛选

以2株放线菌无活性野生株M15(海洋)和M13(陆地)为原始菌,利用核糖体工程抗性筛选技术,通过对M15的链霉素、新霉素、利福平、庆大霉素抗性筛选,得到抗性突变株共63株,经对M13的链霉素抗性筛选,得到链霉素抗性突变株18株。其中,6株M15突变株在活性测试中示有抗肿瘤活性,100μg/mL样品对K562细胞的抑制率大于30%,活性最强的1株新霉素8μg/mL抗性突变株CTM154-8N抑制率高达93.3%,而从M13突变株中没有发现活性突变株。     

关于确保甘肃省祁连山生态保护红线落地并严守的科技支撑建议

祁连山是中国西部重要生态安全屏障,是国家重点生态功能区,其生态保护与治理一直受到国家、地方政府和当地居民高度关注。目前,在祁连山的生态保护工作中,缺乏对现状基础数据的全面掌握,区域经济发展与生态环境保护矛盾突出,生态环境综合监测系统不完备,生态补偿机制推进实施缺乏创新。在全面梳理祁连山目前存在的重大生态问题的基础上,提出了祁连山生态保护红线落地并严守的建议,包括加快开展祁连山综合科学考察、完善并落实开展生态补偿机制、探索以正面清单为导向的协调发展模式、促进生态安全与地方经济社会可持续发展相协调、进一步实施重大配套政策、完善保障支撑体系等。     

小叶锦鸡儿(Caragana microphylla)群落蒸散发模拟

基于2016、2017年生长季原位气象监测数据,利用Shuttleworth-Wallace(S-W)模型模拟了科尔沁沙地主要固沙植物小叶锦鸡儿(Caragana microphylla)群落的蒸散发,对蒸散组分进行了拆分,并利用涡度相关系统对模拟蒸散发值进行了验证。结果表明:2016、2017年生长季小叶锦鸡儿群落蒸散发量分别为345.4、325.2 mm,土壤蒸发量分别为93.8、83.8 mm,植被蒸腾量分别为251.6、241.4 mm,土壤蒸发占总蒸散发分别为27.2%、25.8%。30 min尺度上模拟值与实测值一致性较高,模拟精度大体表现为晴天>阴天>雨天。持续干旱和降水后,小叶锦鸡儿蒸腾耗水规律明显不同,持续干旱时期小叶锦鸡儿保持较低的蒸腾耗水,且具有明显的"午休"现象,连续降水后小叶锦鸡儿"午休"消失,蒸腾耗水增强。饱和水汽压差是影响小叶锦鸡儿蒸散发的主要因子。     

Methods Comparison for Microsatellite Marker Development： Different Isolation Methods, Different Yield Efficiency

Microsatellite markers have become one kind of the most important molecular tools used in various researches. A large number of microsatellite markers are required for the whole genome survey in the fields of molecular ecology, quantitative genetics and genomics. Therefore, it is extremely necessary to select several versatile, low-cost, efficient and time- and labor-saving methods to develop a large panel of microsatellite markers. In this study, we used Zhikong scallop (Chlamys farreri) as the target species to compare the efficiency of the five methods derived from three strategies for microsatellite marker development. The results showed that the strategy of constructing small insert genomic DNA library resulted in poor efficiency, while the microsatellite-enriched strategy highly improved the isolation efficiency. Although the mining public database strategy is time- and cost-saving, it is difficult to obtain a large number of microsatellite markers, mainly due to the limited sequence data of non-model species deposited in public databases. Based on the results in this study, we recommend two methods, microsatellite-enriched library construction method and FIASCO-colony hybridization method, for large-scale microsatellite marker development. Both methods were derived from the mi-crosatellite-enriched strategy. The experimental results obtained from Zhikong scallop also provide the reference for microsatellite marker development in other species with large genomes.     

Impacts of soil fauna on litter decomposition at different succession stages of wetland in Sanjiang Plain, China

Litter decomposition is the key process in nutrient recycling and energy flow. The present study examined the impacts of soil fauna on decomposition rates and nutrient fluxes at three succession stages of wetland in the Sanjiang Plain, China using different mesh litterbags. The results show that in each succession stage of wetland, soil fauna can obviously increase litter decomposition rates. The average contribution of whole soil fauna to litter mass loss was 35.35%. The more complex the soil fauna group, the more significant the role of soil fauna. The average loss of three types of litter in the 4mm mesh litterbags was 0.3–4.1 times that in 0.058mm ones. The decomposition function of soil fauna to litter mass changed with the wetland succession. The average contribution of soil fauna to litter loss firstly decreased from 34.96% (Carex lasiocapa) to 32.94% (Carex meyeriana), then increased to 38.16% (Calamagrostics angustifolia). The contributions of soil fauna to litter decomposition rates vary according to the litter substrata, soil fauna communities and seasons. Significant effects were respectively found in August and July on C. angustifolia and C. lasiocapa, while in June and August on C. meyeriana. Total carbon (TC), total nitrogen (TN) and total phosphorus (TP) contents and the C/N and C/P ratios of decaying litter can be influenced by soil fauna. At different wetland succession stages, the effects of soil fauna on nutrient elements also differ greatly, which shows the significant difference of influencing element types and degrees. Soil fauna communities strongly influenced the TC and TP concentrations of C. meyeriana litter, and TP content of C. lasiocapa. Our results indicate that soil fauna have important effects on litter decomposition and this influence will vary with the wetland succession and seasonal variation. Foundation item: Under the auspices of State Key Development Program for Basic Research of China (No. 2009CB421103), Key Program of National Natural Science Foundation of China (No. 40830535/D0101), Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-BR-16, KSCX2-YW-N-46-06)     

The 1978 outburst of the recurrent nova WZ Sagittae

We give the results of photographic observations of the recurrent nova WZ Sge during its 1978 outburst, between December 5 and 25, using the double astrograph of Beijing Observatory. We discuss the observed properties and calculate the total energy released during the outburst to be about 1.07 (+40) erg. We estimate that the next outburst will occur around the year 2011.     

20世纪90年代中国东西部土地利用变化时空特征分析

在覆盖全国的1km栅格土地利用本底与动态成分数据时空信息平台支持下,应用土地利用动态度模型,分别计算了全国及东西部地区土地利用一级类型的单一和综合动态度,并分析了土地利用动态度的空间格局。通过分析东西部土地利用类型变化特征和土地利用类型转换特征,对20世纪90年代中国东西部土地利用变化过程的时空特征进行了全面分析,揭示了东西部地区土地利用变化的时空规律。并对主要土地利用类型变化的原因进行了分析。     

雄性半滑舌鳎雄激素受体基因的克隆与表达分析

利用RT-PCR方法从半滑舌鳎(Cynoglossus semilaevis)中克隆了雄激素受体(Androgen receptor,AR)基因cDNA的部分序列(434 bp),经BLAST比对与狼鲈(Dicentrarchus labrax)、花溪(Kryptolebias marmoratus)、三斑海猪鱼(Halichoeres trimaculatus)和三刺鱼(Gasterosteus aculeatus)的雄激素受体同源性分别为84%,82%,82%和81%.组织表达分析表明,AR基因在半滑舌鳎的性腺、肝、胃、脾、肾、头肾、肠、鳃、心、脑和肌肉这11种组织中均有表达,表达量有所差异.肾中表达量最丰富,鳃中最少.根据其他硬骨鱼类表达模式,推测半滑舌鳎可能只含有1种AR.     

北黄海温盐分布季节变化特征分析

利用2006～2007年夏冬春秋4个季节北黄海的大面调查资料,分析了4个季节北黄海温度和盐度大面以及典型断面分布特征,得出以下结论:2007年冷水团势力范围强于2006年,北黄海冷水团的形成受地形影响.黄海暖流冬春季较强,冬季最强,夏季最弱,秋季开始形成.鲁北沿岸流冬季最强,春季减弱,夏秋季消失,但夏季鲁北沿岸存在冬季鲁北沿岸流水的残余体,即鲁北沿岸水.辽南沿岸水4个季节都以低盐为特征,除夏季低盐中心位于庄河口外,其它3个季节低盐中心均位于调查区域的东北角.渤海与北黄海之间的水交换4个季节都存在.春季,断面盐跃层形成滞后于温跃层;秋季,断面盐跃层消失滞后于温跃层.