Ad-IL-24对SGC-7901胃癌细胞生长抑制的体外实验

旨在研究携带人IL-24基因的腺病毒表达载体(Ad-IL-24)对SGC-7901人胃癌细胞的生长抑制作用并分析其分子机制。以不同MOI(感染复数)的Ad空载体腺病毒感染SGC-7901人胃癌细胞,筛选出最佳感染剂量;Ad-IL-24以最佳感染剂量感染SGC-7901胃癌细胞,RT-PCR法和Western blotting法检测腺病毒介导的IL-24基因在SGC-7901胃癌细胞中的转录;MTT法检测Ad-IL-24对SGC-7901胃癌细胞的生长抑制作用,流式细胞仪检测其诱导SGC-7901人胃癌细胞凋亡和细胞周期改变的效应,Hoechst33258染色荧光显微镜检测其诱导胃癌细胞凋亡的核形态改变;RT-PCR半定量法进一步检测SGC-7901胃癌细胞中凋亡相关基因的转录。结果显示,100MOI为感染SGC-7901胃癌细胞的腺病毒最佳感染剂量;Ad-IL-24能成功介导IL-24基因在SGC-7901胃癌细胞中转录性表达;Ad-IL-24感染SGC-7901胃癌细胞后,能明显抑制胃癌细胞生长和诱导凋亡;Ad-IL-24能显著上调SGC-7901胃癌细胞中bax、caspase-3和p53的表达和下调bc...     

真菌中锌簇蛋白的结构和功能

锌簇家族蛋白即Zn₂Cys₆类锌指蛋白,是真菌中特有的一类蛋白,它们属于转录因子类,广泛参与真菌中初级和次级代谢、胁迫应答和细胞分裂等生命活动的调控。锌簇蛋白主要包括N端的DNA结合结构域、中间的调节结构域和C端的酸性区域,其中DNA结合结构域包含锌指基序并负责结合靶基因的启动子。目前已经解析了多个锌簇家族转录因子DNA结合结构域的三维结构,并发现该家族中一些蛋白能够参与调控多个基因的表达,但缺乏对其结构、动力学和功能关系的全面分析。本文综合分析了不同锌簇蛋白与DNA结合的结构特征,总结其结构域与功能的关系,指出锌簇蛋白研究的重要方向,旨在为锌簇家族蛋白的深入研究提供思路。     

Failed Stabilization for Long-Term Potentiation in the Auditory Cortex of Fmr1 Knockout Mice

Fragile X syndrome is a developmental disorder that affects sensory systems. A null mutation of the Fragile X Mental Retardation protein 1 (Fmr1) gene in mice has varied effects on developmental plasticity in different sensory systems, including normal barrel cortical plasticity, altered ocular dominance plasticity and grossly impaired auditory frequency map plasticity. The mutation also has different effects on long-term synaptic plasticity in somatosensory and visual cortical neurons, providing insights on how it may differentially affect the sensory systems. Here we present evidence that long-term potentiation (LTP) is impaired in the developing auditory cortex of the Fmr1 knockout (KO) mice. This impairment of synaptic plasticity is consistent with impaired frequency map plasticity in the Fmr1 KO mouse. Together, these results suggest a potential role of LTP in sensory map plasticity during early sensory development.     

Unidirectional Optical Transmission of a Dual Metallic Grating with Grooves

In this paper, a dual grating structure for unidirectional transmission is presented. The forward and backward transmission performances have been investigated by finite element method. To enhance the forward transmission and to suppress the backward transmission simultaneously, we suggested to cut grooves on the surfaces of one of the gratings, and the effects of the grooves on the optical transmission have been studied. The numerical simulation results reveal that the transmission contrast ratio and the optical unidirectional transmission of the structure can be improved markedly by properly arranging the size and the position of the grooves. The forward transmission can be more than 90%, while the backward transmission transmittance is less than 5%.

     

Tissue Culture-Induced Heritable Genomic Variation in Rice,and Their Phenotypic Implications

Background

Somaclonal variation generally occurs in plants regenerated from tissue culture. However, fundamental issues regarding molecular characteristics, mutation rates and mutation spectra of plant somatic variation as well as their phenotypic relevance have been addressed only recently. Moreover, these studies have reported highly discrepant results in different plant species and even in the same plant genotype.

Methodology/principal findings

We investigated heritable genomic variation induced by tissue culture in rice by whole genome re-sequencing of an extensively selfed somaclonal line (TC-reg-2008) and its wild type (WT) donor (cv. Hitomebore). We computed the overall mutation rate, single nucleotide polymorphisms (SNPs), small scale insertions/deletions (Indels) and mobilization of transposable elements (TEs). We assessed chromosomal distribution of the various types of genomic variations, tested correlations between SNPs and Indels, and examined concomitancy between TE activity and its cytosine methylation states. We also performed gene ontology (GO) analysis of genes containing nonsynonymous mutations and large-effect mutations, and assayed effects of the genomic variations on phenotypes under both normal growing condition and several abiotic stresses. We found that heritable somaclonal genomic variation occurred extensively in rice. The genomic variations distributed non-randomly across each of the 12 rice chromosomes, and affected a large number of functional genes. The phenotypic penetrance of the genomic variations was condition-dependent.

Conclusions/significance

Tissue culture is a potent means to generate heritable genetic variations in rice, which bear distinct difference at least in space (chromosomal distribution) from those occurred under natural settings. Our findings have provided new information regarding the mutation rate and spectrum as well as chromosomal distribution pattern of somaclonal variation in rice. Our data also suggest that rice possesses a strong capacity to canalize genetic variations under normal growing conditions to maintain phenotypic robustness, which however can be released by certain abiotic stresses to generate variable phenotypes.     

城市小型景观水体CO2与CH4排放特征及影响因素

淡水生态系统被认为是大气温室气体排放的重要来源,尤其在人类活动影响下,其排放强度可能进一步增强。城市小型景观水体是城市生态系统的重要组成,具有面积小、数量大以及人类干扰强的特征,其温室气体排放特征及影响因素尚不清楚。选择重庆市大学城8个景观水体和周边2个自然水体为对象,于2019年1、4、7、10月,利用漂浮箱和顶空法分析了水体CO₂与CH₄的溶存浓度及排放通量,旨在揭示城市小型景观水体CO₂与CH₄排放强度、时空变异特征以及影响因素。结果表明,10个小型水体CO₂、CH₄的溶存浓度范围分别为10.75-116.25 μmol/L和0.09-3.61 μmol/L（均值分别为（47.6±29.3）μmol/L、（1.13±0.56）μmol/L）,均为过饱和状态;漂浮箱法实测的8个景观水体CO₂和CH₄排放通量均值分别为（72.7±65.9）mmol m^-2 d^-1和（2.31±3.48）mmol m^-2 d^-1（顶空法估算值为（69.7±82.0）mmol m^-2 d^-1和（3.69±2.92）mmol m^-2 d^-1）,是2个自然水体的3.5-6.1和2.0-4.5倍,呈较强的CO₂、CH₄排放源;居民区景观水体CO₂和CH₄排放略高于校园区,均显著高于对照的自然水体;CO₂排放夏季最高,秋季次之,冬、春季最低,CH₄呈夏季>秋季≈春季>冬季的季节模式,温度和水体初级生产共同影响CO₂和CH₄排放的季节模式;水生植物分布对景观水体CO₂、CH₄排放有显著影响,有植物分布的水域比无植物水域平均高1.97和2.94倍;漂浮箱法和顶空法测得气体通量线性关系较好,但顶空法测得CO₂通量在春季明显偏低,而CH₄则普遍偏高。相关分析表明,景观水体碳、氮浓度、pH值以及DO等对CO₂排放具有较好的指示性,CH₄排放通量主要与水体中碳、磷浓度有关。城市小型景观水体CO₂、CH₄排放通量远高于大部分已有自然水体的研究结果,呈一种较强的大气温室气体排放源,在区域淡水系统温室气体排放清单中具有重要贡献,未来研究中应给以更多关注。     

ALPK2 acts as tumor promotor in development of bladder cancer through targeting DEPDC1A

Bladder cancer is one of the most common malignant tumors in the urinary system. The development and improvement of treatment efficiency require the deepening of the understanding of its molecular mechanism. This study investigated the role of ALPK2, which is rarely studied in malignant tumors, in the development of bladder cancer. Our results showed the upregulation of ALPK2 in bladder cancer, and data mining of TCGA database showed the association between ALPK2 and pathological parameters of patients with bladder cancer. In vitro and in vivo experiments demonstrated that knockdown of ALPK2 could inhibit bladder cancer development through regulating cell proliferation, cell apoptosis, and cell migration. Additionally, DEPDC1A is identified as a potential downstream of ALPK2 with direct interaction, whose overexpression/downregulation can inhibit/promote the malignant behavioral of bladder cancer cells. Moreover, the overexpression of DEPDC1A can rescue the inhibitory effects of ALPK2 knockdown on bladder cancer. In conclusion, ALPK2 exerts a cancer-promoting role in the development of bladder cancer by regulating DEPDC1A, which may become a promising target to improve the treatment strategy of bladder cancer.Subject terms: Cancer models, Bladder cancer     

坛紫菜原生质体的发育研究

用2％的海螺酶和1％的纤维素酶混合,将坛紫菜叶状体的4种不同细胞类型即:营养细胞、根丝细胞、精子囊和果孢子囊,分别解离成原生质体,并研究了这些不同部位和不同生长时期。细胞的生长、发育途径。由根丝细胞分离的原生质体能长成新的叶状体;由早期中部营养细胞分离的原生质体,有70％长成新的叶状体,其余的发育成精子囊和果孢子囊。再生叶状体在室内培养,能正常成熟。由精子囊和果孢子囊分离的原生质体,即精子细胞和果孢子细胞不能再生叶状体。前者形成新的精子囊放散精子,后者形成新的果孢子囊,放散果孢子发育成丝状体。晚期紫菜与早期紫菜比较,再生叶状体的数量显著减少,而发育成精子囊和果孢子囊的数量则大大增多。     

大雾岭保护区穿山甲冬季生境选择

1999年12月至2001年2月,对大雾岭自然保护区穿山甲冬季栖息地的选择进行了研究,结果表明对林型选择的先后次序为针阔混交林、灌木丛、常绿阔叶林、针叶林;最偏爱针阔混交林,最不喜爱针叶林.多选择陡坡(30～ 60°);干扰源距离较远(>1 000 m),干扰程度小;林下草灌层盖度高(81% ～ 100%),隐蔽程度好; 阳坡或半阴半阳坡;中低海拔(760 ～ 1 500 m);中下坡位;水源距离较近(<500 m);乔木郁闭度适中(31% ～ 70%)的生境.较少选择上坡位,林下草灌层中低(0 ～ 50%),乔木郁闭度偏高(71%～ 100%)或偏低(0～ 30%),阴坡的生境.对洞口设置的要求是多朝南,而且要求隐蔽条件好,多数为全隐蔽或半隐蔽;最不喜爱将洞口设置在裸露、隐蔽程度差的生境,强力避免洞口向北.坡度、干扰源距离和林下草灌层盖度是影响穿山甲冬季栖息地选择的关键环境因子.