Bt rice expressing Cry1Ab does not stimulate an outbreak of its non-target herbivore, Nilaparvata lugens

In this study, the non-target effects of Bt rice “KMD2” expressing a Cry1Ab protein on the performance of the brown planthopper (BPH), Nilaparvata lugens, over multiple generations were evaluated under laboratory and field conditions. In the laboratory, BPH was reared to observe the impact of the Bt rice as compared to its parental non-Bt cultivar Xiushui 11, while the population dynamics and oviposition performance of BPH were investigated in the field. The survival of BPH nymphs fed Bt and non-Bt rice did not differ significantly. The nymph developmental duration of BPH was significantly delayed by the Bt rice by comparison with the non-Bt rice for the 1st and 2nd but not the 4th generation. Most importantly, the fecundity of BPH on the Bt rice was significantly decreased in every generation when compared with the non-Bt rice. In the field investigations, the population density of BPH nymphs was significantly lower in the Bt rice field. However, the temporal pattern of population dynamics of BPH adults was similar between the Bt and non-Bt rice, presumably due to migratory interference of the adults. In the Bt rice field, the percentage of tillers with eggs and the number of eggs per tiller were also significantly lower from tillering to mature stage. Additionally, Cry1Ab protein could not be detected in guts from single BPH adults. In general, our results suggest that the Bt rice “KMD2” could not stimulate an outbreak of BPH.     

毕氏海蓬子SbDREB基因的克隆与表达分析研究

以毕氏海蓬子的基因组为模板,通过PCR技术扩增到一个编码DREB蛋白AP2保守结构域的基因片段;根据该片段序列设计引物,以毕氏海蓬子经NaCl处理的植株肉质茎cDNA为模板,应用RACE技术获得该基因的cDNA全长,命名为SbDREB(GenBank登录号:JF894301)。SbDREB基因cDNA全长1206bp,包含一个编码284个氨基酸的完整开放阅读框。对氨基酸序列比对分析表明,该蛋白在靠近N端具有典型的AP2/EREBP保守结构域,且该结构域与一些高等植物DREB类转录因子的AP2区域具有高度同源性。进化树分析表明SbDREB属于DREB亚家族中的A-6亚族。实时荧光定量PCR结果显示:干旱、高盐和ABA能够诱导其表达,而低温则使其表达下调,表明该基因在毕氏海蓬子植株对干旱、盐和低温等非生物胁迫的应答中起作用。     

杂交试验中的最佳样本含量

杂交试验是一项费时费钱的工作,因此在进行试验之前如能进行严密的设计,给出试验所需的样本大小是十分必要的,统计学中常见的估计样本容理的公式不宜应用于杂交试验,本文分两种情况给出了杂交试验中样本容量的估计公式,据此估计出的样本容量安排杂交试验,可在满足试验者要求的条件下,使试验的总成本最低或使试畜的总头数最少。     

Immunogenicity of the Spike Glycoprotein of Bat SARS-like Coronavirus

A group of SARS-like coronaviruses(SL-CoV)have been identified in horseshoe bats.Despite SL-CoVs and SARS-CoV share identical genome structure and high-level sequence similarity,SL-CoV does not bind to the same cellular receptor as for SARS-CoV and the N-terminus of the S proteins only share 64%amino acid identity,suggesting there are fundamental differences between these two groups of coronaviruses.To gain insight into the basis of this difference,we established a recombinant adenovirus system expressing t...     

Synthesis and evaluation of nitric oxide-releasing derivatives of farnesylthiosalicylic acid as anti-tumor agents

Novel furoxan-based nitric oxide (NO)-releasing derivatives (11a–p) of farnesylthiosalicylic acid (FTA) were synthesized. Compounds 11d, 11f, 11k, and 11m–o displayed anti-tumor activities superior to FTA and sorafenib in most cancer cells tested. Analysis of six compounds revealed that 11d, 11f, 11n, 11o, and 11p, but not 11a that had low anti-tumor activity, produced high levels of NO, associated with their strong anti-tumor activity. Furthermore, the anti-tumor activity of 11f was partially mimicked by the furoxan moiety, but reduced by pre-treatment with hemoglobin. Importantly, treatment with 11f inhibited Ras-related signaling in cancer cells. Apparently, the high anti-tumor activity of 11f was attributed to the synergic effect of high levels of NO production and inhibition of Ras-related signaling in cancer cells. Our findings suggest that the furoxan/FTA hybrids may hold greater promise as therapeutic agents for the intervention of human cancers.     

High-resolution crystal structure reveals a HEPN domain at the C-terminal region of S. cerevisiae RNA endonuclease Swt1

Swt1 is an RNA endonuclease that plays an important role in quality control of nuclear messenger ribonucleoprotein particles (mRNPs) in eukaryotes; however, its structural details remain to be elucidated. Here, we report the crystal structure of the C-terminal (CT) domain of Swt1 from Saccharomyces cerevisiae, which shares common characteristics of higher eukaryotes and prokaryotes nucleotide binding (HEPN) domain superfamily. To study in detail the full-length protein structure, we analyzed the low-resolution architecture of Swt1 in solution using small angle X-ray scattering (SAXS) method. Both the CT domain and middle domain exhibited a good fit upon superimposing onto the molecular envelope of Swt1. Our study provides the necessary structural information for detailed analysis of the functional role of Swt1, and its importance in the process of nuclear mRNP surveillance.     

Non-contiguous finished genome sequence of Anoxybacillus flavithermus subsp. yunnanensis type strain (E13T), a strictly thermophilic and organic solvent-tolerant bacterium

Anoxybacillus flavithermus subsp. yunnanensis is the only strictly thermophilic bacterium that is able to tolerate a broad range of toxic solvents at its optimal temperature of 55-60°C. The type strain E13^T was isolated from water-sediment slurries collected from a hot spring. This study presents the draft genome sequence of A. flavithermus subsp. yunnanensis E13^T and its annotation. The 2,838,393bp long genome (67 contigs) contains 3,035 protein-coding genes and 85 RNA genes, including 10 rRNA genes, and no plasmids. The genome information has been used to compare with the genomes from A. flavithermus subsp. flavithermus strains.     

Comparison of the Accuracy of Two Conventional Phenotypic Methods and Two MALDI-TOF MS Systems with That of DNA Sequencing Analysis for Correctly Identifying Clinically Encountered Yeasts

We assessed the accuracy of species-level identification of two commercially available matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems (Bruker Biotyper and Vitek MS) and two conventional phenotypic methods (Phoenix 100 YBC and Vitek 2 Yeast ID) with that of rDNA gene sequencing analysis among 200 clinical isolates of commonly encountered yeasts. The correct identification rates of the 200 yeast isolates to species or complex (Candida parapsilosis complex, C. guilliermondii complex and C. rugosa complex) levels by the Bruker Biotyper, Vitek MS (using in vitro devices [IVD] database), Phoenix 100 YBC and Vitek 2 Yeast ID (Sabouraud''s dextrose agar) systems were 92.5%, 79.5%, 89%, and 74%, respectively. An additional 72 isolates of C. parapsilosis complex and 18 from the above 200 isolates (30 in each of C. parapsilosis, C. metapsilosis, and C. orthopsilosis) were also evaluated separately. Bruker Biotyper system could accurately identify all C. parapsilosis complex to species level. Using Vitek 2 MS (IVD) system, all C. parapsilosis but none of C. metapsilosis, or C. orthopsilosis could be accurately identified. Among the 89 yeasts misidentified by the Vitek 2 MS (IVD) system, 39 (43.8%), including 27 C. orthopsilosis isolates, could be correctly identified Using the Vitek MS Plus SARAMIS database for research use only. This resulted in an increase in the rate of correct identification of all yeast isolates (87.5%) by Vitek 2 MS. The two species in C. guilliermondii complex (C. guilliermondii and C. fermentati) isolates were correctly identified by cluster analysis of spectra generated by the Bruker Biotyper system. Based on the results obtained in the current study, MALDI-TOF MS systems present a promising alternative for the routine identification of yeast species, including clinically commonly and rarely encountered yeast species and several species belonging to C. parapsilosis complex, C. guilliermondii complex, and C. rugosa complex.