人巨细胞病毒的生物素DNA探针的制备和应用

本研究用克隆的HCMV AD169株DNA片段,制备了生物素标记的DNA探针,建立了检测临床脐带血、尿标本中HCMV DNA的核酸探针杂交方法。该探针可测出100pg同源DNA,不与人胚肺细胞、Hep-2细胞DNA以及其他疱疹病毒的DNA发生反应。用核酸杂交方法检测了30份脐带血标本,有11例阳性,阳性率为33％。10例孕妇尿标本中,3例阳性,阳性率为30％。检测结果表明：我们建立的生物素标记的HCMV DNA探针的点杂交法,具有高度的特异性、敏感性,比分离病毒法更迅速,可用于HCMV感染的临床标本的病毒核酸检测。     

益生元对口腔健康促进作用和机制研究进展

口腔微生物群落的动态平衡是维持口腔健康的关键因素。益生元是一类具有选择性、能够促进体内有益菌代谢增殖从而改善宿主健康的有机物质,主要通过调节口腔微生物生长代谢、抑制口腔菌斑生物膜形成、调节宿主免疫反应、参与硝酸盐-亚硝酸盐-一氧化氮代谢循环通路、调节氧化应激反应等途径调控口腔微生态,从而对口腔常见疾病,如龋齿、牙周病、口腔黏膜病的防治起到积极作用。本文主要就近年来益生元在口腔健康中的作用及相关机制的研究情况进行综述。     

青藏高原垫状点地梅叶际及内生可培养微生物多样性

【背景】垫状点地梅作为青藏高原最具代表性的垫状植物,其叶际和内生微生物对适应极端环境有重要意义,同时也是一种独特的资源。【目的】探究垫状点地梅叶际和叶内可培养微生物多样性,以及不同生存状态个体之间的微生物差异。【方法】采用纯培养方法分离和纯化3个不同地区垫状点地梅叶际和叶内的细菌、酵母菌和丝状真菌,并用16S rRNA基因和ITS区域序列进行分析鉴定。【结果】最终得到叶际微生物350株,鉴定为22属49种,优势种为Penicillium sajarovii;内生微生物274株,鉴定为19属45种,优势种为Bacillusmycoides;两者的优势属均为Penicillium。垫状点地梅叶际和叶内之间及不同生存状态个体之间微生物的α多样性大多无显著差异,各群落间的成员也有重叠,但物种组成存在显著的空间异质性。【结论】垫状点地梅叶际和叶内有着丰富的可培养微生物资源,来源于不同生存状态的个体或不同部位的微生物物种组成差别较大,微生物对不同环境的选择偏好形成了不同的群落模式。但这些不同来源的微生物群落之间同样存在高比例的共有菌株,这些共有菌株的异养方式和生态位并不固定,可兼共生和腐生生存,生...     

晋北典型针叶人工林叶功能性状特征及其与土壤因子的关系

为了解释植物叶片的资源分配特征及其与土壤因子间的适应策略,该研究以黄土高原东北缘山西省大同市新荣区油松、樟子松人工纯林及其柠条混交林为对象,采用样方法采集样木树冠中部生长良好的轮生枝中东西南北4个方向的枝条,并在每个枝条上选择里、中、外3处有代表性的当年生叶和多年生叶;采用 “S”形采样法在每个样方内选取9个取样点,用土钻采集各样点0～20 cm土壤样品;测定分析不同造林模式下油松、樟子松异龄叶功能性状特征、土壤理化性质以及二者的关系,为人工林培育及经营提供理论支撑。结果表明：(1)不同造林模式下油松及樟子松叶功能性状的差异集中在化学计量之间;随着叶龄增长,油松、樟子松均表现出干物质含量上升,氮磷含量下降的特征。(2)土壤全磷、全氮含量分别是油松当年及多年生叶的主要解释因子,土壤全磷与当年生叶碳氮比、有机碳、碳磷比均呈显著正相关关系,与全氮、叶面积及叶干物质含量呈显著负相关关系,土壤全氮与多年生叶全磷含量呈正相关关系,与叶有机碳、碳磷比、碳氮比则呈显著负相关关系。(3)樟子松当年生叶功能性状的关键土壤因子是土壤容重、全磷含量,其与叶碳氮磷的比值、干物质含量、碳含量呈正相关关系,而与氮磷含量呈负相关关系;多年生叶功能性状的关键土壤因子是土壤容重、含水量、pH,其与叶氮磷含量呈正相关关系,与碳含量、干物质含量、比叶面积等呈负相关关系。(4)油松及樟子松纯林的叶功能性状更易向关键土壤因子含量更高的方向偏移,说明与柠条混交可有效分异叶片生长对主要土壤因子的集中需求,但混交造林模式下林木长势有所衰弱;结合研究区资源匮乏现状,林木种植密度较大,竞争加剧了生存压力导致林木生长受限。     

Differences between migrasome,a ‘new organelle’, and exosome

The migrasome is a new organelle discovered by Professor Yu Li in 2015. When cells migrate, the membranous organelles that appear at the end of the retraction fibres are migrasomes. With the migration of cells, the retraction fibres which connect migrasomes and cells finally break. The migrasomes detach from the cell and are released into the extracellular space or directly absorbed by the recipient cell. The cytoplasmic contents are first transported to the migrasome and then released from the cell through the migrasome. This release mechanism, which depends on cell migration, is named ‘migracytosis’. The main components of the migrasome are extracellular vesicles after they leave the cell, which are easy to remind people of the current hot topic of exosomes. Exosomes are extracellular vesicles wrapped by the lipid bimolecular layer. With extensive research, exosomes have solved many disease problems. This review summarizes the differences between migrasomes and exosomes in size, composition, property and function, extraction method and regulation mechanism for generation and release. At the same time, it also prospects for the current hotspot of migrasomes, hoping to provide literature support for further research on the generation and release mechanism of migrasomes and their clinical application in the future.     

Highly efficient regeneration and medicinal component determination of Phellodendron chinense Schneid

Phellodendron chinense Schneid is an important Chinese herb with berberine and phellodendrine in stems and leaves, but with little information available on in vitro culture of this species. Disinfection of explants in 75% alcohol for 45 s, sterilization in 0.1% HgCl₂ for 20 min, and submersion in 1.0 mol L⁻¹ gibberellin3 (GA₃) solution for 24 h was the optimal condition for seed germination. Murashige and Skoog’s (MS) medium supplemented with 2.0 mg L⁻¹ 6-benzylaminopurine (6-BA) in combination with 1.5 mg L⁻¹ 1-naphthylacetic acid (NAA) was optimal for callus induction. MS medium supplemented with 2.0 mg L⁻¹ 6-BA was the appropriate medium for induction of adventitious shoots, and 1/2MS medium supplemented with 2.0 mg L⁻¹ indole-3-butytric acid (IBA) and 0.5% active carbon was the optimal medium for root induction. The 15-d survival rate of regenerated plantlets after transplanting to basins containing perlite and peat moss (1:4) was greater than 80%, and the berberine and phellodendrine accumulation was lower in callus compared with regenerated plantlets. The establishment of highly efficient regeneration system provides technical support for genetic breeding of Phellodendron chinense Schneid.

     

Flexible chromosome painting based on multiplex PCR of oligonucleotides and its application for comparative chromosome analyses in Cucumis

Chromosome painting is a powerful technique for chromosome and genome studies. We developed a flexible chromosome painting technique based on multiplex PCR of a synthetic oligonucleotide (oligo) library in cucumber (Cucumis sativus L., 2n = 14). Each oligo in the library was associated with a universal as well as nested specific primers for amplification, which allow the generation of different probes from the same oligo library. We were also able to generate double‐stranded labelled oligos, which produced much stronger signals than single‐stranded labelled oligos, by amplification using fluorophore‐conjugated primer pairs. Oligos covering cucumber chromosome 1 (Chr1) and chromosome 4 (Chr4) consisting of eight segments were synthesized in one library. Different oligo probes generated from the library painted the corresponding chromosomes/segments unambiguously, especially on pachytene chromosomes. This technique was then applied to study the homoeologous relationships among cucumber, C. hystrix and C. melo chromosomes based on cross‐species chromosome painting using Chr4 probes. We demonstrated that the probe was feasible to detect interspecies chromosome homoeologous relationships and chromosomal rearrangement events. Based on its advantages and great convenience, we anticipate that this flexible oligo‐painting technique has great potential for the studies of the structure, organization, and evolution of chromosomes in any species with a sequenced genome.     

Correlations between glycolysis with clinical traits and immune function in bladder urothelial carcinoma

Background: Glycolysis was a representative hallmark in the tumor microenvironment (TME), and we aimed to explore the correlations between glycolysis with immune activity and clinical traits in bladder urothelial carcinoma (BLCA).Methods: Our study obtained glycolysis scores for each BLCA samples from TCGA by a single-sample gene set enrichment analysis (ssGSEA) algorithm, based on a glycolytic gene set. The relationship between glycolysis with prognosis, clinical characteristics, and immune function were investigated subsequently.Results: We found that enhanced glycolysis was associated with poor prognosis and metastasis in BLCA. Moreover, glycolysis had a close correlation with immune function, and enhanced glycolysis increased immune activities. In other words, glycolysis had a positive correlation with immune activities. Immune checkpoints such as IDO1, CD274, were up-regulated in high-glycolysis group as well.Conclusion: We speculated that in BLCA, elevated glycolysis enhanced immune function, which caused tumor cells to overexpress immune checkpoints to evade immune surveillance. Inhibition of glycolysis might be a promising assistant for immunotherapy in bladder cancer.     

Identification and Characterization of MicroRNAs by High Through-Put Sequencing in Mesenchymal Stem Cells and Bone Tissue from Mice of Age-Related Osteoporosis

The functional deficiencies of bone marrow-derived mesenchymal stem cells (MSCs) may contribute to the aging process and age-related diseases, such as osteoporosis. Although it has been reported that microRNAs (miRNAs) played an important role in mechanisms of gene regulation of aging, and their expression profiles in MSCs osteogenic differentiation were established in recent years, but it is still elusive for the dynamic patterns of miRNAs in aging process. Importantly, the miRNAs in aged bone tissue had not been yet reported so far. Here, we combined high through-put sequencing with computational techniques to detect miRNAs dynamics in MSCs and bone tissue of age-related osteoporosis. Among the detected miRNAs, 59 identified miRNAs in MSCs and 159 in bone showed significantly differential expressions. And more importantly, there existed 8 up-regulated and 30 down-regulated miRNAs in both MSCs and bone during the aging process, with the majority having a trend of down-regulation. Furthermore, after target prediction and KEGG pathway analysis, we found that their targeted genes were significantly enriched in pathways in cancer, which are complex genetic networks, comprise of a number of age-related pathways. These results strongly suggest that these analyzed miRNAs may be negatively involved in age-related osteoporosis, given that most of them showed a decreased expression, which could lay a good foundation for further functional analysis of these miRNAs in age-related osteoporosis.