球孢白僵菌Hog1 MAPK同源基因BbHog1的克隆及特征分析

根据几种丝状真菌Hog1 MAPK的保守氨基酸序列设计简并引物,从昆虫病原真菌球孢白僵菌中扩增出MAPK同源基因的部分片段,然后利用YADE法延伸该片段的上、下游邻接序列,获得MAPK编码基因的全长序列,命名为BbHog1。序列分析表明,该基因编码358个氨基酸的多肽,推测分子量为40.99kDa,等电点为5.49。BbHog1含有MAPK保守的蛋白激酶激活域(TGY),序列与粗糙脉孢霉os-2(AF297032)、烟曲霉OSM1(XM_747571)、隐球酵母HOG1(AF243531)和酿酒酵母Hog1(Z73285)等Hog1 MAPK高度同源,相似性分别为94%、89%、83%和80%。系统聚类结果表明,BbHog1与酵母Hog1 MAPK同源。Southern杂交表明,BbHog1在球孢白僵菌基因组中以单拷贝形式存在。Northern分析表明,BbHog1在高渗、亚高温和营养胁迫等条件下的表达明显升高。由此推测,BbHog1基因可能与球孢白僵菌对逆境胁迫的适应性调节密切相关。     

Integrating Culture-based Antibiotic Resistance Profiles with Whole-genome Sequencing Data for 11,087 Clinical Isolates

Emerging antibiotic resistance is a major global health threat. The analysis of nucleic acid sequences linked to susceptibility phenotypes facilitates the study of genetic antibiotic resistance determinants to inform molecular diagnostics and drug development. We collected genetic data(11,087 newly-sequenced whole genomes) and culture-based resistance profiles(10,991 out of the11,087 isolates comprehensively tested against 22 antibiotics in total) of clinical isolates including18 main species spanning a time period of 30 years. Species and drug specific resistance patterns were observed including increased resistance rates for Acinetobacter baumannii to carbapenems and for Escherichia coli to fluoroquinolones. Species-level pan-genomes were constructed to reflect the genetic repertoire of the respective species, including conserved essential genes and known resistance factors. Integrating phenotypes and genotypes through species-level pan-genomes allowed to infer gene–drug resistance associations using statistical testing. The isolate collection and the analysis results have been integrated into GEAR-base, a resource available for academic research use free of charge at https://gear-base.com.     

Thoughts of a Travelling Ecologist, 6 On monitoring

Monitoring. We, ecologists, hear the word nearly every day. From the most unexpected corners this word springs out, much used and abused. One one hand, it is often used by my peers to justify their work, their project or even their existence as scientists. They claim to do useful work, because they monitor some phenomenon or another. This, goes the argument, is essential for the continued survival of … generally, nothing less than humankind.     

A 10-miRNA risk score-based prediction model for pathological complete response to neoadjuvant chemotherapy in hormone receptor-positive breast cancer

Patients with hormone receptor(HR)-positive tumors breast cancer usually experience a relatively low pathological complete response(p CR) to neoadjuvant chemotherapy(NAC). Here, we derived a 10-micro RNA risk score(10-mi RNA RS)-based model with better performance in the prediction of p CR and validated its relation with the disease-free survival(DFS) in 755 HRpositive breast cancer patients(273, 265, and 217 in the training, internal, and external validation sets, respectively). This model,pres...     

麻蝇和丽蝇幼虫肠道主要蛋白酶活性鉴定

蛋白酶是昆虫肠道的重要消化酶类［１］。研究表明,蛋白酶抑制剂能够抑制昆虫肠道蛋白酶活性,使昆虫生长发育不良甚至死亡,在害虫防治中显示出应用潜力［２～４］。但是,要选择有效的蛋白酶抑制剂,最首要的工作是研究昆虫肠道蛋白酶的特性［５］。蝇类是重要的卫生害虫,确定其肠道蛋白酶的类型,了解其肠道蛋白酶的特性,对蝇类的防治有重要意义。本文以棕尾别麻蝇Ｂｏｅｔｔｃｈｅｒｉｓｃａｐｅｒｅｇｒｉｎａ和巨尾阿丽蝇Ａｌｄｒｉｃｈｉｎａｇｒａｈａｍｉ为材料,分析了其肠道蛋白酶同工酶,鉴定了其肠道主要蛋白酶活性类型,并…     

Iron transport in the genus Marinobacter

Marinobacter belong to the class of Gammaproteobacteria and these motile, halophilic or halotolerent bacteria are widely distributed throughout the world’s oceans having been isolated from a wide variety of marine environments. They have also been identified as members of the bacterial flora associated with other marine organisms. Here, using a combination of natural products chemistry and genomic analysis, we assess the nature of the siderophores produced by this genus and their potential relationship to phylogeny and lifestyle/ecological niche of this diverse group of organisms. Our analysis shows a wide level of diversity in siderophore based iron uptake systems among this genus with three general strategies: (1) production and utilization of native siderophores in addition to utilization of a variety of exogenous ones, (2) production and utilization of native siderophores only, (3) lack of siderophore production but utilization of exogenous ones. They all share the presence of at least one siderophore-independent iron uptake ABC transport systems of the FbpABC iron metal type and lack the ability for direct transport of ferrous iron. Siderophore production and utilization can be correlated with phylogeny and thus it forms a type of chemotaxonomic marker for this genus.     

趋化因子CXCL2及其受体CXCR2在子宫颈鳞状细胞癌和子宫颈上皮内瘤变组织中的表达

目的 探讨子宫颈鳞状细胞癌(cervical squamous cell carcinoma,CSCC)组织和子宫颈上皮内瘤变(cervical intraepithelial neoplasia,CIN)组织中趋化因子(C-X-C基元)配体2[chemokine(C-X-C motif)ligand 2,CXCL2]...     

The porcine chloride channel calcium-activated family member pCLCA4a mirrors lung expression of the human hCLCA4

Pig models of cystic fibrosis (CF) have recently been established that are expected to mimic the human disease closer than mouse models do. The human CLCA (originally named chloride channels, calcium-activated) member hCLCA4 is considered a potential modifier of disease severity in CF, but its murine ortholog, mCLCA6, is not expressed in the mouse lung. Here, we have characterized the genomic structure, protein processing, and tissue expression patterns of the porcine ortholog to hCLCA4, pCLCA4a. The genomic structure and cellular protein processing of pCLCA4a were found to closely mirror those of hCLCA4 and mCLCA6. Similar to human lung, pCLCA4a mRNA was strongly expressed in porcine lungs, and the pCLCA4a protein was immunohistochemically detected on the apical membranes of tracheal and bronchial epithelial cells. This stands in sharp contrast to mouse mCLCA6, which has been detected exclusively in intestinal epithelia but not the murine lung. The results may add to the understanding of species-specific differences in the CF phenotype and support the notion that the CF pig model may be more suitable than murine models to study the role of hCLCA4.     

Binding of trastuzumab to ErbB2 is inhibited by a high pericellular density of hyaluronan

Although trastuzumab is an efficient drug, primary and acquired resistance is a challenging problem. The authors have previously shown in mouse xenograft experiments that masking ErbB2 by hyaluronan leads to diminished binding of the antibody and consequent resistance. In the current work, they correlated trastuzumab binding with the pericellular density of hyaluronan in ErbB2-overexpressing human breast cancer samples. A method for quantifying the relative binding of trastuzumab was developed involving constant and low-frequency background subtraction, segmenting the image to membrane and background pixels followed by evaluation of trastuzumab fluorescence, normalized with the expression level of ErbB2, only in the membrane. The normalized binding of trastuzumab showed a negative correlation with the pericellular density of hyaluronan (r = -0.52) with the effect being the most pronounced in the extreme cases (i.e., low and high hyaluronan densities predicted strong and weak binding of trastuzumab, respectively). Removal of hyaluronan by hyaluronidase digestion unmasked the trastuzumab binding epitope of ErbB2 demonstrated by a significantly increased normalized binding of the antibody. The results show that the accumulation of pericellular hyaluronan plays a crucial role in masking ErbB2.     

YKL-40 is differentially expressed in human embryonic stem cells and in cell progeny of the three germ layers

The secreted glycoprotein YKL-40 participates in cell differentiation, inflammation, and cancer progression. High YKL-40 expression is reported during early human development, but its functions are unknown. Six human embryonic stem cell (hESC) lines were cultured in an atmosphere of low or high oxygen tension, in culture medium with or without basic fibroblast growth factor, and on feeder layers comprising mouse embryonic fibroblasts or human foreskin fibroblasts to evaluate whether hESCs and their progeny produced YKL-40 and to characterize YKL-40 expression during differentiation. Secreted YKL-40 protein and YKL-40 mRNA expression were measured by enzyme-linked immunosorbent assay (ELISA) and quantitative RT-PCR. Serial-sectioned colonies were stained for YKL-40 protein and for pluripotent hESC (OCT4, NANOG) and germ layer (HNF-3β, PDX1, CD34, p63, nestin, PAX6) markers. Double-labeling showed YKL-40 expression in OCT4-positive hESCs, PAX6-positive neuroectodermal cells, and HNF-3β-positive endodermal cells. The differentiating progeny showed strong YKL-40 expression. Abrupt transition between YKL-40 and OCT4-positive hESCs and YKL-40-positive ecto- and neuroectodermal lineages was observed within the same epithelial-like layer. YKL-40-positive cells within deeper layers lacked contact with OCT4-positive cells. YKL-40 may be important in initial cell differentiation from hESCs toward ectoderm and neuroectoderm, with retained epithelial morphology, whereas later differentiation into endoderm and mesoderm involves a transition into the deeper layers of the colony.