球囊菌胁迫中华蜜蜂幼虫肠道过程中病原的转录组学研究

【目的】本研究利用RNA-seq技术对球囊菌胁迫的中华蜜蜂(中蜂)幼虫肠道进行深度测序,经趋势分析得到差异表达基因(DEGs)的显著表达模式,进而对胁迫过程中的球囊菌进行转录组学分析。【方法】利用Illumina HiSeq 2500平台对球囊菌胁迫的中蜂幼虫肠道进行深度测序,并利用相关软件进行了深入分析。最后,通过RT-qPCR对RNA-seq数据进行了验证。【结果】本研究共得到球囊菌的41133932条高质量clean reads。22865个DEGs共聚类为8个基因表达模式,其中,16769个DEGs聚类为2个显著上调趋势与2个显著下调趋势。GO富集分析结果显示,显著上调与显著下调趋势中的DEGs分别富集于40与37个GO term,基因富集数最多的为细胞进程(2486 unigenes)。KEGG代谢通路(pathway)富集分析结果显示,显著上调与显著下调趋势中的DEGs分别富集于119和112个pathway,基因富集数最多的分别是氨基酸生物合成(127 unigenes)与核糖体(98 unigenes)。进一步分析表明球囊菌在胁迫中蜂幼虫肠道的过程中通过提高物质合成促进其增殖,而宿主通过抑制球囊菌的蛋白合成抵御病原入侵。富集在MAPK信号通路的11个DEGs的表达水平随着胁迫时间的延长而逐渐下降,推测中蜂幼虫通过抑制该通路而阻遏球囊菌增殖。【结论】本研究不仅为揭示白垩病过程中的球囊菌-中蜂幼虫互作提供了重要信息,也为阐明不同抗性蜂种的球囊菌抗性差异奠定了基础。     

The Ubiquitin Receptor DA1 Regulates Seed and Organ Size by Modulating the Stability of the Ubiquitin-Specific Protease UBP15/SOD2 in Arabidopsis

Although the control of organ size is a fundamental question in developmental biology, little is known about the genetic and molecular mechanisms that determine the final size of seeds in plants. We previously demonstrated that the ubiquitin receptor DA1 acts synergistically with the E3 ubiquitin ligases DA2 and ENHANCER1 OF DA1 (EOD1)/BIG BROTHER to restrict seed growth in Arabidopsis thaliana. Here, we describe UBIQUITIN-SPECIFIC PROTEASE15 (UBP15), encoded by SUPPRESSOR2 OF DA1 (SOD2), which acts maternally to regulate seed size by promoting cell proliferation in the integuments of ovules and developing seeds. The sod2/ubp15 mutants form small seeds, while overexpression of UBP15 increases seed size of wild-type plants. Genetic analyses indicate that UBP15 functions antagonistically in a common pathway with DA1 to influence seed size, but does so independently of DA2 and EOD1. Further results reveal that DA1 physically associates with UBP15 in vitro and in vivo and modulates the stability of UBP15. Therefore, our findings establish a genetic and molecular framework for the regulation of seed size by four ubiquitin-related proteins DA1, DA2, EOD1, and UBP15 and suggest that they are promising targets for increasing seed size in crops.     

Evaluation of injury thresholds for predicting severe head injuries in vulnerable road users resulting from ground impact via detailed accident reconstructions

Biomechanics and Modeling in Mechanobiology - The aim of this study was to evaluate the effectiveness of various head injury criteria and associated risk functions in prediction of vulnerable road...     

Aspirin inhibits osteoclast formation and wear-debris-induced bone destruction by suppressing mitogen-activated protein kinases

Excessive osteoclast recruitment and activation is the chief cause of periprosthetic osteolysis and subsequent aseptic loosening, so blocking osteolysis may be useful for protecting against osteoclastic bone resorption. We studied the effect of aspirin on titanium (Ti)-particle-induced osteolysis in vivo and in vitro using male C57BL/6J mice randomized to sham (sham surgery), Ti (Ti particles), low-dose aspirin (Ti/5 mg·kg⁻¹·d⁻¹ aspirin), and high-dose aspirin (Ti/30 mg·kg⁻¹·d⁻¹ aspirin). After 2 weeks, a three-dimensional reconstruction evaluation using micro-computed tomography and histomorphology assessment were performed on murine calvariae. Murine hematopoietic macrophages and RAW264.7 lineage cells were studied to investigate osteoclast formation and function. Aspirin attenuated Ti-particle-induced bone erosion and reduced osteoclasts. In vitro, aspirin suppressed osteoclast formation, osteoclastic-related gene expression, and osteoclastic bone erosion in a dose-dependent manner. Mechanically, aspirin reduced osteoclast formation by suppressing receptor activator of nuclear factor kappa-B ligand-induced activation of extracellular signal-related kinase, p-38 mitogen-activated protein kinase, and c-Jun N-terminal kinase. Thus, aspirin may be a promising option for preventing and curing osteoclastic bone destruction, including peri-implant osteolysis.     

Overexpression of MTA3 Correlates with Tumor Progression in Non-Small Cell Lung Cancer

The objective of the current study was to investigate the expression pattern and clinicopathological significance of MTA3 in patients with non-small cell lung cancer (NSCLC). The expression profile of MTA3 in NSCLC tissues and adjacent noncancerous lung tissues was detected by immunohistochemistry. MTA3 was overexpressed in 62 of 108 (57.4%) human lung cancer samples and correlated with p-TNM stage (p<0.0001), nodal metastasis (p = 0.0009) and poor prognosis (p<0.05). In addition, the depletion of MTA3 expression with small interfering RNAs inhibited cell growth and colony formation in the A549 and H157 lung cancer cell lines. Moreover, MTA3 depletion induced cell cycle arrest at the G1/S boundary. Western blotting analysis revealed that the knockdown of MTA3 decreased the protein levels of cyclin A, cyclin D1 and p-Rb. These results indicate that MTA3 plays an important role in NSCLC progression.     

Mutations in <Emphasis Type="Italic">CsPID</Emphasis> encoding a Ser/Thr protein kinase are responsible for round leaf shape in cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L.)

Key message

Two round-leaf mutants, rl-1 and rl-2, were identified from EMS-induced mutagenesis. High throughput sequencing and map-based cloning suggested CsPID encoding a Ser/Thr protein kinase as the most possible candidate for rl-1. Rl-2 was allelic to Rl-1.

Abstract

Leaf shape is an important plant architecture trait that is affected by plant hormones, especially auxin. In Arabidopsis, PINOID (PID), a regulator for the auxin polar transporter PIN (PIN-FORMED) affects leaf shape formation, but this function of PID in crop plants has not been well studied. From an EMS mutagenesis population, we identified two round-leaf (rl) mutants, C356 and C949. Segregation analysis suggested that both mutations were controlled by single recessive genes, rl-1 and rl-2, respectively. With map-based cloning, we show that CsPID as the candidate gene of rl-1; a non-synonymous SNP in the second exon of CsPID resulted in an amino acid substitution and the round leaf phenotype. As compared in the wild type plant, CsPID had significantly lower expression in the root, leaf and female flowers in C356, which may result in the less developed roots, round leaves and abnormal female flowers, respectively in the rl-1 mutant. Among the three copies of PID genes, CsPID, CsPID2 and CSPID2L (CsPID2-like) in the cucumber genome, CsPID was the only one with significantly differential expression in adult leaves between WT and C356 suggesting CsPID plays a main role in leaf shape formation. The rl-2 mutation in C949 was also cloned, which was due to another SNP in a nearby location of rl-1 in the same CsPID gene. The two round leaf mutants and the work presented herein provide a good foundation for understanding the molecular mechanisms of CsPID in cucumber leaf development.

     

Spatial and temporal variation of fish assemblages and their associations to habitat variables in a mountain stream of north Tiaoxi River,China

The spatial and temporal variations of the fish assemblages in mountain streams of China are poorly understood. The relationships between the fish assemblage and selected habitat features were examined in the North Tiaoxi River, one of headwaters of Taihu Lake. A total of 3,348 individuals belonging to 5 orders, 11 families, 25 genera and 34 species were collected including 33 native species and one invasive species. Among those, about 20 species were endemic to China. Non-metric Multidimensional Scaling (NMDS) was applied to compare fish assemblage structures from upstream to downstream during four seasons. Species assemblages differed along the stream continuum, but there was little apparent change associated with the seasons. Species richness and Shannon-Weaver index (H′) tended to increase along the stream continuum from the upstream to downstream and the proportion of invertivorous fish tended to significantly decrease along the continuum with a parallel significant increase in the percentage of omnivores. Fish assemblages were significantly related to both water quality and habitat structure variables. Canonical Correspondence Analysis ordinations (CCA) revealed that 6 of the 14 selected environmental variables had significant relationships with the fish assemblage such as distance to source, stream width, altitude, pH, water depth, and water velocity and different sampling sites were associated with different environmental variables in different seasons. The main differences in fish assemblage structure and diversity within the whole watercourse are probably related to large-scale factors such distance to source, altitude and stream width. Differences of instream characteristics are likely to be caused by natural variability of the ecosystems but also, in some case, by anthropogenic influence like human settlements, agriculture and river embankment and pollution from small factory.     

山西晋中小南庄墓地人骨的C、N稳定同位素:试析小麦在山西的推广

小麦何时何地对中国北方传统的粟黍农业产生影响是近些年学术界研究的焦点问题之一。相关研究表明,小麦对中国北方不同地区粟黍农业的影响存在时间上的差异。古文献及考古研究表明,小麦在龙山时期就开始在中国北方地区出现,但直到东周及其后才逐步对粟黍农业产生显著的影响。为了探索小麦在东周时期在山西地区推广的程度和其对先民食物结构和生业经济的影响程度及其背后的内在动因等,本文选取晋中小南庄墓地东周时期人骨进行了C、N稳定同位素分析,结果显示先民的δ~(13)C值和δ~(15)N值都比较集中(δ~(13)C值的范围为-9.0‰～-7.5‰,均值为-8.0‰±0.4‰,n=16;δ~(15)N值的范围为9.0‰-11.7‰,均值为10.5‰±0.9‰;n=16),说明他们以C_4类食物为主,也有少量C_3类食物,但动物蛋白消费有所区分。据他们对动物蛋白占有的不同,晋中小南庄墓地东周时期人至少可以划分为两个经济群体,第一个群体可能从事农耕经济,第二群体可能从事畜牧经济。从事农耕经济人群的食物中的C_3食物应该主要来源于小麦,这说明小麦在东周时期开始在晋中地区有所推广。小麦在山西地区的推广、种植和使用,对传统的粟黍农业产生了相应的影响,使得先民种植农作物的种类有所增加,这应该加快了秦汉时期农业高峰期的形成。然而,山西地区小麦的推广相对缓慢,这可能与当地根深蒂固的粟黍经济和饮食习惯密切相关。