激素对亚洲玉米螟幼虫滞育的影响

激素对亚洲玉米螟幼虫滞育的影响＊赵章武＊＊曹梅讯（中国科学院上海昆虫研究所上海２０００２５）亚洲玉米螟Ｏｓｔｒｉｎｉａｆｕｒｎａｃａｌｉｓ是我国乃至亚洲地区的重要农业害虫之一。它具有兼性滞育的特点,年发生１～７代,以末龄老熟滞育幼虫越冬。来年春天终止...     

基于小RNA测序的风轮菜microRNA及其靶基因分析

本研究以风轮菜(Clinopodium chinense (Benth.) O. Kuntze)为材料,采用BGISEQ-500测序平台对风轮菜根、茎和叶的小RNA进行转录组测序,并对其黄酮类物质合成途径中参与调控的microRNA(miRNA)及其靶基因进行了分析。结果显示,鉴定出的保守miRNA有86个,属于26个家族,新发现miRNA 8个,筛选出风轮菜黄酮类物质合成途径中调控3个关键酶的候选miRNA(novel＿mir3、miR167d-5p、miR396h)。通过对靶基因编码的关键酶4-香豆酸辅酶A连接酶进行序列分析和同源建模,发现其具有高度保守的底物结合区域、催化结构域及两个保守的肽基序。     

生化网络中基序的适应性与敏感性

复杂生物系统的适应性和敏感性是许多生物网络中的两个基本特性,改善这两者有着十分重要的意义。然而,要同时改善两者往往有一定的困难。基于生物系统自适应调控的思想,一种能同时改善两者的方法被提出,并用40种典型的生化网络中的基序为例说明此方法的可行性。结果表明此方法对于所有40种基序均有效。此外,还从数值上论证了方法对参数的鲁棒性。     

Cellular Uptake and Antitumor Activity of DOX-hyd-PEG-FA Nanoparticles

A PEG-based, folate mediated, active tumor targeting drug delivery system using DOX-hyd-PEG-FA nanoparticles (NPs) were prepared. DOX-hyd-PEG-FA NPs showed a significantly faster DOX release in pH 5.0 medium than in pH 7.4 medium. Compared with DOX-hyd-PEG NPs, DOX-hyd-PEG-FA NPs increased the intracellular accumulation of DOX and showed a DOX translocation from lysosomes to nucleus. The cytotoxicity of DOX-hyd-PEG-FA NPs on KB cells was much higher than that of free DOX, DOX-ami-PEG-FA NPs and DOX-hyd-PEG NPs. The cytotoxicity of DOX-hyd-PEG-FA NPs on KB cells was attenuated in the presence of exogenous folic acid. The IC₅₀ of DOX-hyd-PEG-FA NPs and DOX-hyd-PEG NPs on A549 cells showed no significant difference. After DOX-hyd-PEG-FA NPs were intravenously administered, the amount of DOX distributed in tumor tissue was significantly increased, while the amount of DOX distributed in heart was greatly decreased as compared with free DOX. Compared with free DOX, NPs yielded improved survival rate, prolonged life span, delayed tumor growth and reduced the cardiotoxicity in tumor bearing mice model. These results indicated that the acid sensitivity, passive and active tumor targeting abilities were likely to act synergistically to enhance the drug delivery efficiency of DOX-hyd-PEG-FA NPs. Therefore, DOX-hyd-PEG-FA NPs are a promising drug delivery system for targeted cancer therapy.     

低氧对胚胎干细胞增殖的影响

目的:观察间歇性低氧和持续性低氧对体外培养的胚胎干细胞(ES细胞)增殖的影响.方法:利用细胞记数法和BrdU (5-溴脱氧尿苷)掺入的流式细胞分析检测细胞增殖,并用RT -PCR的方法检测低氧诱导因子(HIF-1a)的表达变化.结果:①将ES细胞分别放在低氧(3%～10% O2)和常氧(20% O2)的环境中培养24 h后,在低氧环境中培养的ES细胞数较常氧组明显减少;②将ES细胞分别给予间歇性低氧刺激(3%～10% O2),每天10 min,连续4 d后,发现3%低氧组较常氧对照组的细胞增殖明显升高.③用RT-PCR方法观察HIF-1a的表达与细胞增殖的关系,发现在常氧环境中培养的ES即有HIF-1a的表达,ES细胞在持续低氧24 h或间歇性低氧(3%～10% O2)刺激4 d后对HIF-1a的表达均无明显影响.结论:间歇性低氧(3% O2)可明显促进体外培养的ES细胞增殖,而持续性低氧抑制ES细胞增殖,间歇性低氧(3% O2)刺激促进ES细胞增殖的机制尚有待于进一步的研究.     

不同理化因子对雪莲培养细胞中黄酮类形成的影响

研究了不同理化因子对水母雪莲(Saussurea medusa Maxim)愈伤组织生长及黄酮类化合物生物合成的影响。结果表明,有利于细胞生长及黄酮形成的合适温度为25℃。白光对愈伤组织生长无促进作用,但有利于黄酮的形成。培养基中添加1mg／L NAA和O．2mg／L的KT组合对细胞的生长较有促进作用。5％蔗糖和1％葡萄糖的组合有利于细胞的生长和黄酮的形成。用⁶⁰C0-γ射线辐照愈伤组织,在剂量为4000Gy的条件下,获得一个合成黄酮能力高于原愈伤组织70％的细胞系。用高效液相和紫外分光光度法,测定离体培养光照条件下干细胞总黄酮的含量为3．2％,是暗培养的4．4倍。培养温度25℃时干细胞黄酮的含量为2．02％,分别为20℃,35℃时的5倍和3．2倍。     

Diversity of endophytic bacteria within nodules of the Sphaerophysa salsula in different regions of Loess Plateau in China

A total of 115 endophytic bacteria were isolated from root nodules of the wild legume Sphaerophysa salsula grown in two ecological regions of Loess Plateau in China. The genetic diversity and phylogeny of the strains were revealed by restriction fragment length polymorphism and sequencing of 16S rRNA gene and enterobacterial repetitive intergenic consensus-PCR. Their symbiotic capacity was checked by nodulation tests and analysis of nifH gene sequence. This is the first systematic study on endophytic bacteria associated with S. salsula root nodules. Fifty of the strains found were symbiotic bacteria belonging to eight putative species in the genera Mesorhizobium, Rhizobium and Sinorhizobium, harboring similar nifH genes; Mesorhizobium gobiense was the main group and 65 strains were nonsymbiotic bacteria related to 17 species in the genera Paracoccus, Sphingomonas, Inquilinus, Pseudomonas, Serratia, Mycobacterium, Nocardia, Streptomyces, Paenibacillus, Brevibacillus, Staphylococcus, Lysinibacillus and Bacillus, which were universally coexistent with symbiotic bacteria in the nodules. Differing from other similar studies, the present study is the first time that symbiotic and nonsymbiotic bacteria have been simultaneously isolated from the same root nodules, offering the possibility to accurately reveal the correlation between these two kinds of bacteria. These results provide valuable information about the interactions among the symbiotic bacteria, nonsymbiotic bacteria and their habitats.     

STAT6 ASODN对哮喘小鼠脾淋巴细胞影响的实验研究

目的研究STAT6反义寡核苷酸对哮喘小鼠脾淋巴细胞的影响作用。方法实验细胞分组:正常鼠空白组(A组)、正常鼠OVA组(B组)、哮喘空白组(C组)、哮喘OVA组(D组)、哮喘治疗组(E组)。正常设计并人工合成一段互补于小鼠STAT6 mRNA翻译起始区271-290的反义寡核苷酸片段,全链硫代修饰。用卵白蛋白和氢氧化铝复制哮喘模型,用淋巴细胞分离液分离脾淋巴细胞,进行体外培养并导入由阳离子脂质体转染剂Geneshuttle携带的反义寡核苷酸,观察反义寡核苷酸的转染对脾淋巴细胞STAT6蛋白表达水平及细胞培养上清中IL-4分泌水平的影响。免疫细胞化学观察脾淋巴细胞中STAT6蛋白的表达水平,同时采用酶联免疫吸附(ELISA)法测定脾细胞培养上清液中IL-4的浓度。结果D组细胞STAT6蛋白表达明显高于其余各组,均具有显著性差异(P均<0.01),STAT6 ASODN转染后,E组细胞该蛋白的表达量明显下降(P<0.01);D组脾淋巴细胞培养上清中IL-4分泌水平明显高于其余各组,均具有显著性差异(P均<0.01);STAT6 ASODN转染后,E组培养上清中IL-4分泌水平显著低于D组(P<0.01)。结论STAT6 ASODN可特异性抑制哮喘鼠脾淋巴细胞中STAT6蛋白的表达,并可特异性抑制脾淋巴细胞中IL-4的分泌,为反义基因技术治疗哮喘提供了依据。     

Detection of selection signatures in dairy and beef cattle using high-density genomic information

Background

Artificial selection for economically important traits in cattle is expected to have left distinctive selection signatures on the genome. Access to high-density genotypes facilitates the accurate identification of genomic regions that have undergone positive selection. These findings help to better elucidate the mechanisms of selection and to identify candidate genes of interest to breeding programs.

Results

Information on 705 243 autosomal single nucleotide polymorphisms (SNPs) in 3122 dairy and beef male animals from seven cattle breeds (Angus, Belgian Blue, Charolais, Hereford, Holstein-Friesian, Limousin and Simmental) were used to detect selection signatures by applying two complementary methods, integrated haplotype score (iHS) and global fixation index (F_ST). To control for false positive results, we used false discovery rate (FDR) adjustment to calculate adjusted iHS within each breed and the genome-wide significance level was about 0.003. Using the iHS method, 83, 92, 91, 101, 85, 101 and 86 significant genomic regions were detected for Angus, Belgian Blue, Charolais, Hereford, Holstein-Friesian, Limousin and Simmental cattle, respectively. None of these regions was common to all seven breeds. Using the F_ST approach, 704 individual SNPs were detected across breeds. Annotation of the regions of the genome that showed selection signatures revealed several interesting candidate genes i.e. DGAT1, ABCG2, MSTN, CAPN3, FABP3, CHCHD7, PLAG1, JAZF1, PRKG2, ACTC1, TBC1D1, GHR, BMP2, TSG1, LYN, KIT and MC1R that play a role in milk production, reproduction, body size, muscle formation or coat color. Fifty-seven common candidate genes were found by both the iHS and global F_ST methods across the seven breeds. Moreover, many novel genomic regions and genes were detected within the regions that showed selection signatures; for some candidate genes, signatures of positive selection exist in the human genome. Multilevel bioinformatic analyses of the detected candidate genes suggested that the PPAR pathway may have been subjected to positive selection.

Conclusions

This study provides a high-resolution bovine genomic map of positive selection signatures that are either specific to one breed or common to a subset of the seven breeds analyzed. Our results will contribute to the detection of functional candidate genes that have undergone positive selection in future studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12711-015-0127-3) contains supplementary material, which is available to authorized users.