表达β-1,3-葡聚糖酶及几丁质酶基因的转基因烟草及其抗真菌病的研究

利用烟草碱性β－１,３－葡聚糖酶及菜豆碱性几丁质酶基因构建了组成型表达的双价植物表达载体ｐＢＬＧＣ,利用农杆菌介导法转化了烟草,并得到了转基因植株。对其进行分子生物学分析的结果表明,部分转基因植株在所有检测中都显示较强的阳性反应,这说明外源基因已整合到烟草基因组中得到正确表达。活体接菌实验初步表明,转基因植株与对照相比,对赤星病的侵染具有较强的抵抗能力。     

间充质干细胞源性外泌体miRNAs参与损伤心血管细胞修复的研究进展

外泌体是由各种组织和细胞所释放的细胞外囊泡,在细胞之间充当各种分子(包括蛋白质,脂质和RNA)的载体,从而调节或干预特定的生理过程.MiRNAs是一类小的非编码RNA,能够靶向多个mRNA并诱导其降解或翻译抑制以调控相关基因表达.目前对外泌体内微小RNA(miR-NAs)的研究最为广泛.间充质干细胞(MSCs)是一种多...     

Phyto-availability and speciation change of heavy metals in soils amended with lignin as micro-fertilizer

Lignin is a primary byproduct from the black liquor treatment in paper making industries, its application as micro-fertilizer in agricultural land might provide a promising alternative to sewage discharge. However, application of such a micro-fertilizer might affect the soil properties and result in soil pollution. In this study, the effects of lignin application on phytoavailability and speciation change of heavy metals in soils were investigated. Greenhouse experiments showed that lignin application improved the growth of winter wheat (Triticum aestivum L.) in all three soils investigated. The increase of the biomass for wheat shoot was 59.7%, 39.8% and 12.3% for Beijing soil, Jiangxi soil and Dongbei soil, respectively. In contrast, lignin amendment decreased the concentrations of heavy metals in wheat shoots from 2.2% to 61.0%. Sequential extraction procedure of a three-step BCR was used to investigate the fraction distribution. The extractable fractions were specified as fraction B1: water soluble, exchangeable and carbonate bound or weakly specifically adsorbed; B2: Fe-Mn oxide bound; B3: organic matter and sulfide bound. The results showed that lignin application led to the redistribution of heavy metals in each fraction. Generally, heavy metals decreased in B1 and B2 fractions and increased in B3 fraction. Upon the results short-term application of lignin in agricultural land not only improves the growth of wheat but also reduces the phyto-abailability of heavy metal in wheat.     

羊毛硫肽SapB类多肽促进链霉菌形态分化作用的研究

【目的】链霉菌属于革兰氏阳性菌,以复杂的形态分化过程和强大的次级代谢产物合成能力为主要特征。链霉菌的形态分化与次级代谢产物的产生密切相关。Ⅲ型羊毛硫肽SapB能够促进天蓝色链霉菌气生菌丝体形成,暗示这类多肽可以作为靶标用于形态分化改造工程开发。本研究表征了SapB类多肽对多种链霉菌形态分化的影响,为该类多肽的工程化应用提供理论基础。【方法】生物信息学分析多个链霉菌基因组中SapB类多肽的生物合成基因簇,构建SapB类多肽的异源表达载体,利用接合转移方法导入不同链霉菌中进行异源表达,探究SapB类多肽对链霉菌形态分化的影响。【结果】SapB类多肽在不同程度上促进了多个链霉菌由营养菌丝向气生菌丝分化,表现为气生菌丝体数量的增多和分化速度的加快,缩短了链霉菌形态分化周期。【结论】SapB类多肽的过表达有助于缩短链霉菌形态分化周期,可用于针对链霉菌形态分化的工程改造。     

不同形式蛋氨酸对建鲤生长性能及血清游离氨基酸含量的影响

为考察不同形式蛋氨酸对建鲤生长的作用效果, 实验以豆粕、鱼粉、棉粕为蛋白源, 配制缺乏蛋氨酸的基础饲料(对照组, 蛋氨酸含量为0.48%), 在基础饲料中分别添加晶体蛋氨酸、微囊蛋氨酸、蛋氨酸羟基类似物(MHA)及蛋氨酸羟基类似物钙盐(MHA-Ca), 使蛋氨酸含量达到0.58%, 获得5个饲料处理组, 饲养平均体重为(8.61.0) g的建鲤(Cyprinus carpio var Jian)8周。结果显示: 各组鱼体增重率分别为343.51%、350.77%、382.80%、384.02%和385.59%; 饲料系数分别为1.58、1.55、1.42、1.42和1.41; 晶体蛋氨酸组鱼体增重率、饲料系数与对照组无显著差异(P0.05), 微囊蛋氨酸组、MHA组、MHA-Ca组增重率较对照组提高11.4%、11.8%、12.2% (P0.05), 饲料系数降低10.1%、10.1%、10.8% (P0.05)。各处理组在肌肉水分、脂肪含量间无显著差异(P0.05), MHA组肌肉粗蛋白含量较晶体蛋氨酸组显著下降, 其他各组间无显著差异(P0.05)。对摄食后不同时间的血清游离氨基酸浓度变化的分析表明, 对照组在摄食后2h或3h达到峰值, 晶体蛋氨酸组、MHA组在摄食后1h达到吸收峰值, 微囊蛋氨酸组在摄食后1h或2h达到峰值, 而MHA-Ca组则在摄食后3h达到峰值。上述结果表明, 在蛋氨酸缺乏的颗粒饲料中补充晶体蛋氨酸, 对建鲤生长性能无改善作用, 而添加微囊蛋氨酸、蛋氨酸羟基类似物、蛋氨酸羟基类似物钙盐则显著提高了鱼体生长性能, 降低饲料系数。       

线粒体DNA的异质性

哺乳动物线粒体DNA（mitochondrial DNA, mtDNA）位于线粒体.当细胞中mtDNA发生突变时,就会出现野生型与突变型mtDNA的共存.这种情况被称为mtDNA异质性.从mtDNA异质性的形成到在表型上引起相应的病变是一个复杂的过程.mtDNA异质性是如何形成和其在特异组织的增殖复制,mtDNA异质性的变化对个体的影响,如何提高mtDNA突变负荷检测的精度和灵敏度都是近些年的研究热点.本文对mtDNA异质性的检测、遗传、组织特异性以及其相关的疾病等方面进行了阐述.     

大窑遗址二道沟地点石制品研究的抽样方法设计

结合简单随机抽样、整群抽样和连续重复抽样的特点,基于中心极限定理,本文设计了适用于大批量石制品抽样调查的具体方案,通过边抽样、边评价的方式,利用有限的样本量推断总体特征,并将其实际应用到大窑遗址二道沟地点石制品的研究中,取得了良好的效果。此外,该抽样方案对于石制品的物源追溯、遗址区域调查等也有一定的实用价值。     

内蒙古大窑遗址27号洞石制品研究

大窑遗址27号洞于1986年被发掘,共有3个层位包含文化遗物,出土石制品总计520件。本文着重对石制品进行研究,发现27号洞的石制品主体为石片石器组合,存在少量细石核预制产品。石核以单台面为主,尤以将石片腹面作为台面进行剥片的石核最具特色;石器类型有边刮器、锯齿刃器、砍砸器、石球/石锤等。结合石制品类型与堆积性质初步推断,27号洞石制品的年代不早于旧石器时代晚期晚段。     

Evolution of the cyclin gene family in plants

Cyclins are key regulators of cell cycle progression. Previous studies have shown that cyclin genes in plants can be divided into 10 groups. However, because those studies only focused on genes from two well-known model plants (i.e., Arabidopsis thaliana (L.) Heynh. and Oryza sativa L.), it remains unclear whether the 10 groups are reasonably defined. In this study, by analyzing the genomes of 10 representative plants (Chlamydomonas reinhardtii P. A. Dang, Physcomitrella patens(Hedw.) Bruch & Schimp., Selaginella moellendorffii Hieron., Picea abies (L.) H. Karst., Amborella trichopoda Baill., A. thaliana, Populus trichocarpa Torr. & A. Gray ex Hook., Vitis vinifera L., O. sativa, and Sorghum bicolor (L.) Moench), we estimated the phylogenetic relationships of plant cyclins and investigated their evolutionary patterns. We confirmed that plant cyclins can be classified into 10 groups, although only eight ancestral genes may have existed in the most recent common ancestor of extant green plants. We also found that, due to the frequent occurrences of gene duplication events, several groups have expanded extensively in seed plants and, particularly, flowering plants, so that multiple genes belonging to different subgroups are present in a species. Reconciliation of the evolutionary histories of these groups and subgroups further led to the identification of evolutionarily highly conserved and rapidly duplicating gene lineages. These results will guide the classification and nomenclature of plant cyclins and help understand the conservativeness and variation in their functions.     

弃耕演替与恢复生态学

弃耕演替是一种重要的演替模式 ,可以为生态恢复规划提供指导。弃耕演替为进展演替 ,但要恢复为稳定的生态系统可能会经历很长一段时间。这是由演替本身的规律决定的。适当的人为干预可能会改变这种状况 ,并使演替进程大大缩短。对弃耕演替的研究是恢复生态学兴起的原始策动力 ,恢复生态学是在对弃耕演替的研究中形成并获得发展的。弃耕演替研究隶属于恢复生态学 ,是恢复生态学涵盖的一个重要领域。