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。     

携带blaNDM-1的质粒pNDM-BJ01在鲁氏不动杆菌中的适应度代价

[目的]了解编码新德里金属-β-内酰胺酶-1(blaNDM-1)的质粒pNDM-BJ01在鲁氏不动杆菌10621菌株中的适应度代价,进而评估该质粒在鲁氏不动杆菌群体中存续和扩散的潜能.[方法]通过不含亚胺培南的液体培养基连续传代培养,获得抗性质粒丢失的10621衍生菌株,利用生长曲线、生物被膜、无营养生存时间等体外适应度测量实验,分析10621NDM-1(+)及质粒缺失的10621NDM-1(-)之间的适应度差异.[结果]pNDM-BJ01在10621菌株中不稳定,连续传代11次即在群体中完全丢失.在26℃和37℃下,10621NDM-1( -)与10621NDM-1(+)菌株的生长曲线无显著性差异.在26℃条件下,10621NDM-1( -)菌株形成生物被膜的能力明显强于10621NDM-1(+),而在37℃条件下,10621 NDM-1(+)强于10621NDM-1(-).在无营养的PBS缓冲液中,10621NDM-1(-)菌株生存能力明显高于10621NDM-1(+).[结论]编码blaNDM-1的质粒pNDM-BJ01在鲁氏不动杆菌中具有较大的适应度代价,缺失这一质粒的菌株在外界环境中的生存能力强于抗性菌株,pNDM-BJ01在鲁氏不动杆菌存续与扩散的能力有限.     

Regional and Ontogenic Expression of the NMDA Receptor Subunit NR2D Protein in Rat Brain Using a Subunit-Specific Antibody

Abstract: A polyclonal antibody for the NMDA receptor subunit NR2D has been developed that identifies an ∼160-kDa band on immunoblots from NR2D transfected cells and CNS tissues. No cross-reactivity is seen with other NMDA receptor subunits. The NR2D receptor subunit is N -glycosylated in both brain and transfected cells. Transfected cells expressing NR2D are immunofluorescently labeled, whereas untransfected cells or cells transfected with other NMDA receptor subunit cDNAs are not. Similarly, the NR2D subunit is selectively and quantitatively immunoprecipitated, whereas the NR1, NR2A, or NR2B subunit is not. The relative densities of the NR2D subunit in nine areas of postnatal day 7 and adult rat brains have been determined by quantitative immunoblotting. NR2D was expressed at highest levels in the thalamus, midbrain, medulla, and spinal cord, whereas intermediate levels of this subunit were found in the cortex and hippocampus. Low or undetectable levels were seen in the olfactory bulb, striatum, and cerebellum. Following a peak after the first week of birth, NR2D protein levels decreased by about twofold in adulthood in all rat brain regions examined. More complete ontogenic profiles were determined for the diencephalon, telencephalon, and spinal cord where similar ontogenic patterns were seen. NR2D protein is present at high levels at embryonic stages of development, rises to a peak at postnatal day 7, and decreases but remains measurable during late postnatal life. This study demonstrates the generation and characterization of an antibody selective for the NR2D NMDA receptor subunit as well as a determination of the distribution and ontogenic profile of this subunit in rat brain. The results suggest that native NMDA receptors containing the NR2D subunit may have functional roles not only in the young brain but also in adult brain.     

肝脏发育相关信号通路

肝脏发育从肝芽的出现开始,到肝祖细胞的形成,接着肝祖细胞的增殖、分化和迁移,直至最后器官的形成,经历了复杂的细胞信号调控过程。本文综述了肝脏发育过程中常见的信号调控作用,包括成纤维生长因子(fibroblast growth factor,FGF)、骨形态发生蛋白(bone morphogenetic protein,BMP)、β-转化生长因子(transforming growth factor-β,TGF-β)、肝细胞生长因子(hepatocyte growth factor,HGF)和Wnt等信号通路,并重点讨论了在胚胎阶段调控肝脏发育的信号途径以及肝细胞和胆管细胞发育成熟过程中的信号因子作用,最后对肝脏再生相关的信号调控进行了简要介绍。     

“三生”空间视角下土地利用转型的生态环境效应及驱动力——以甘肃省为例

中国社会经济快速转型背景下土地利用变化所引发的环境问题被广泛关注。以土地利用现状遥感监测数据和统计资料为数据源,借助ArcGIS和SIMCA-P软件平台,基于"三生"空间视角,通过生态环境质量指数测度了1980—2018年甘肃省土地利用转型的生态环境效应,并运用偏最小二乘法揭示生态环境质量演变的驱动机制。研究发现:(1)"三生"空间结构演化和地域分异显著。生产、生活空间集中分布于河西走廊、陇中和陇东黄土高原并呈扩张态势;生态空间主要分布于陇南山地、甘南高原、祁连山地和河西走廊以北地带且整体呈缩减趋势;生产、生活空间的增长源于对生态空间的侵占。(2)生态环境质量改善和恶化趋势并存,整体上经历了先下降后上升的"U"形演化过程;空间上呈"东南高-西北低"的分布特征,空间格局演化具有明显的集聚性。(3)生态建设、科技进步等对生态环境改善具有明显的促进作用;而人口增加、社会消费水平提升在一定程度上加剧了生态环境压力;对外贸易对生态环境的影响具有双面性。     

基于功能性状的常绿阔叶植物防火性能评价

植物功能性状不仅便于评价植物的防火性能,也有利于筛选防火植物。本研究以宁波地区的29个常绿木本植物为对象,在测定植物比叶面积、叶干物质含量、叶片含水量、枝条干物质含量和树皮厚度5个功能性状,以及鲜叶的7个防火性能指标的基础上,通过因子分析将防火性能指标划分为抗燃性f_a(包含抗火性因子f₁和燃烧速度因子f₂2个公因子)与燃烧性f_b 2个防火因子,然后利用Pearson相关和偏相关建立了5个功能性状与各个防火因子的相关性,并对29物种的防火性能进行评价。结果表明：1)比叶面积和树皮厚度与抗火性因子f₁,枝条干物质含量、树皮厚度和当年生叶片含水量与燃烧速度因子f₂,比叶面积与抗燃性因子f_a,叶片干物质含量、比叶面积和当年生叶片含水量与燃烧性因子f_b间存在显著的相关关系;2)偏相关简化植物防火性状后,比叶面积和叶干物质含量分别对抗燃性因子f_a与燃烧性因子f_b的指示性最好;3)分别基于功能性状和燃烧试验的物种抗燃性排序相似度为0.80。本研究证明,基于简易观测的植物功能性状可较好地反映树种的抗火性和燃烧性,可作为植物防火性能有效的评价方法。     

用指纹图谱评价环境样本DNA的提取效果

研究了DNA指纹图谱技术在评价环境样本DNA提取效果方面的应用。采用 3种DNA提取方法提取垃圾渗滤水和活性污泥中的微生物DNA ,并用ARDRA和RISA图谱加以评价。实验结果表明 ,RISA图谱分析法可以作为评估DNA提取效果的有效手段。     

小鼠异常行为及其继代遗传特性

实验室条件下小鼠常表现多种异常行为,通过对跳跃爬行鼠和非跳跃爬行鼠的亲代及F1代的行为观察,研究小鼠异常行为在继代过程中的变化规律以及皮质醇浓度与异常行为的关系。结果表明:两代跳跃爬行鼠和非跳跃爬行鼠的异常行为差异显著(P<0.05),在正常行为中跳跃爬行鼠的平均睡眠时间和修饰行为的次数明显少于非跳跃爬行鼠(P<0.05),而探究行为的次数明显高于非跳跃爬行鼠(P<0.05)。F1代跳跃爬行鼠的异常行为类型基本和母体一致,异常行为的发生次数明显高于亲代,说明异常行为具有遗传基础。通过测定皮质醇浓度,发现跳跃爬行鼠的皮质醇平均浓度明显高于非跳跃爬行鼠(P<0.05),说明皮质醇的分泌量影响着异常行为的发生频率。     

Association between Telomere Length and Type 2 Diabetes Mellitus: A Meta-Analysis

Background

Several epidemiological studies have examined the association between shortened telomere length and type 2 diabetes mellitus (T2DM), while the results remained conflicting. We conducted a meta-analysis to derive a more precise estimation of the relationship between them.

Methods

We systematically reviewed the databases of PubMed, EMBASE, and Web of Science for all studies on the association between telomere length and T2DM. We conducted this study assessed by STATA 11.0. Data were summarized using random-effects or fixed-effects meta-analysis. The heterogeneity and publication bias among studies were examined by using χ²-based Q statistic test and Egger’s test, respectively.

Results

Nine cohorts consisting of 5759 cases and 6518 controls were selected into the meta-analysis. The results indicated that shortened telomere length was significantly associated with T2DM risk (OR: 1.291; 95% CI: 1.112, 1.498; P<0.001) with heterogeneity (I² = 71.6%). When three cohorts responsible for the heterogeneity were excluded, the pooled OR for the remaining cohorts indicated a significant association between shortened telomere length and T2DM (OR: 1.117; 95% CI: 1.002, 1.246; P = 0.045) without heterogeneity.

Conclusion

We found a statistically significant association between shortened telomere length and T2DM.