山西忻州中新世鼠兔科化石

本文记述了山西忻州发现的跑兔属—新种.该种以个体较小, P~2 较简单,无前沟, M~2 后叶无后突, P_3 小,无前内沟与前外沟等特征与属型种 B. forsythmajori 相区别,命名为杨胡跑兔 B. yanghuensis sp. nov..新种在进化水平上较属型种稍原始,但两者显示出较近的系统关系.根据 B. yanghuensis sp. nov. 的进化水平,推断其地质时代可能为中中新世早期,约相当于欧洲 Orleanian 期.     

中国壳斗科植物属的空间多样性及差异

该文采用地理信息系统技术,以县为空间数据的基本单元,以壳斗科植物为研究对象,制作属的空间分布图,计算空间相似性系数,分析壳斗科各属的空间多样性及其差异。结果表明,三棱栎属为连续分布,与其他属的空间分布最不相似,其他属均为间断分布,其中锥属、青冈属、柯属空间分布最相似,这3个属的多样化中心均有云南南部,水青冈的多样化中心比前3个属偏北,栎属多样化中心是四川西南部和云南西北部,西北地区东南部是联系南方与北方栎属植物的重要通道。     

植物谷氨酸受体的研究进展

离子型谷氨酸受体(iGLuR)是哺乳动物中一类由L-氨基酸(如谷氨酸、甘氨酸)等配体门控的阳离子通道, 具有调节兴奋性神经信号传递和引导神经元发育等分子功能。1998年研究者在拟南芥(Arabidopsis thaliana)中发现了20个与iGLuRs同源的序列(即AtGLRs), 它们的功能涉及植物光信号传递、根尖分生细胞活性、花粉管生长、胞质Ca²⁺流以及应答多种生物和非生物环境胁迫等。该文从谷氨酸受体(GLR)的结构特征、离子通道激活与配体的关系、表达模式及可能的生物学功能等方面, 综述了近十几年来关于植物GLR和氨基酸信号的研究成果, 旨在为相关领域的同行提供有益的参考。     

A NEWLY ANTI-Streptococcus suis BACTERIOCIN PRODUCING STRAIN FROM UNWEANED PIGLETS FECAL MATTER: ISOLATION, PRELIMINARY IDENTIFICATION, AND OPTIMIZATION OF MEDIUM COMPOSITION FOR ENHANCED BACTERIOCIN PRODUCTION

A newly isolated anti-Streptococcus suis bacteriocin-producing strain LPL1-5 was obtained from healthy unweaned piglets' fecal matter, and was designated as Lactobacillus pentosus LPL1-5 based on morphology, biochemical properties, and 16S rDNA sequencing analysis. The medium composition for enhanced bacteriocin production by L. pentosus LPL1-5 was optimized by statistical methodology. Yeast extract, K(2)HPO(4)?·?3H(2)O, and MnSO(4)?·?H(2)O were identified as significant components influencing pentocin LPL1-5 production using the Plackett-Burman method. Response surface methodology was applied for further optimization. The concentrations of medium components for enhanced pentocin LPL1-5 production were as follows (g/L): lactose 20.00, tryptone 10.00, beef extract 10.00, yeast extract 14.00, MnSO(4)?·?H(2)O 0.84, K(2)HPO(4)?·?3H(2)O 4.92, triammonium citrate 2.00, Na-acetate 5.00, MgSO(4)?·?7H(2)O 0.58, Tween 80 1.00. Under the optimized condition, a value of 3154.65?±?27.93 IU/mL bacteriocin activity was achieved, which was 4.2-fold that of the original medium.     

三角梅苞叶色彩参数和色素含量分析及蓝色转基因受体的筛选北大核心CSCD

三角梅作为重要的观赏植物颜色繁多,但缺乏稀有的蓝色。为筛选适合的蓝色转基因受体,明确不同品种三角梅苞片吸收利用DHM(二氢杨梅素)合成甜菜色素途径竞争产物(类黄酮色素)的潜在能力,该研究对红色、白色、黄色和紫色4大花色6个品种的三角梅苞片进行离体诱导培养,测定诱导培养后苞片色彩参数及色素含量变化,并进行相关性分析。结果显示:(1)三角梅苞片红绿色相值(a*)是决定苞片呈色的主要色彩参数,其色彩主要由甜菜色素和黄酮类色素决定,并以甜菜红素的影响最大。(2)除白色品种三角梅苞片中黄酮类色素含量大于甜菜色素含量外,其余品种苞片发育中甜菜色素含量均呈上升趋势,黄酮类色素呈下降趋势。(3)甜菜色苷含量与苞片a*值呈显著正相关关系,同时与苞片黄蓝色相值(b*)呈显著负相关关系;总黄酮含量与苞片b*值呈显著正相关关系,与苞片a*值呈极显著负相关关系。(4)经DHM体外诱导培养后,苞片总黄酮含量及占比在4个品种三角梅(‘新加坡大白’、‘宝老橙’、‘中国丽人’、‘黄蝶’)中明显升高,但各品种苞片总甜菜色素含量及占比均下降,并以‘新加坡大白’苞片中总黄酮含量上升幅度最大(65.77%),含量占比变化(增加26.91%)也为6个品种中最大。(5)灰色关联度综合分析显示,白色品种‘新加坡大白’与灰色关联度分析拟定的参考品种关联度最高(0.7444),表明三角梅品种中‘新加坡大白’可考虑作为蓝色转基因三角梅的受体品种。     

SorCS3 promotes the internalization of p75NTR to inhibit GBM progression

Glioblastoma (GBM) is a fatal malignancy caused by dysregulation of cellular signal transduction. Internalization plays a key role in maintaining signalling balance. Previous reports showed that Sortilin related VPS10 domain containing receptor 3 (SorCS3) has the ability to regulate internalization. However, the impacts of SorCS3 on the biological processes involved in GBM have not yet been reported. In this study, we investigated the bio-function of SorCS3 in GBM. We found that SorCS3 was significantly downregulated in GBM. In addition, low expression level of SorCS3 predicted poor prognoses in patients with GBM. Here, we proved that SorCS3 suppressed cell invasion and proliferation mainly via NGF/p75^NTR pathway in GBM. We found that SorCS3 co-localized with p75^NTR in GBM cells and regulated the p75^NTR protein level by promoting trafficking of the endosomal to the lysosome. Immunofluorescence (IF) and Co-Immunoprecipitation (Co-IP) detection confirmed that SorCS3 bound to p75^NTR, which subsequently increased the internalization of p75^NTR, and then transported p75^NTR to the lysosome for degradation, ultimately contributing to inhibit of glioma progression. Taken together, our work suggests that SorCS3 is a marker of promising prognosis in GBM patients and suggests that SorCS3 regulates internalization, which plays a pivotal role in inhibiting glioma progression.Subject terms: Tumour-suppressor proteins, Protein transport     

Characterization of small RNAs in early zebrafish PGCs

Small RNAs, including miRNAs, siRNAs, and PIWI-interacting RNAs (piRNAs), are small noncoding RNAs that are 21-30 nucleotides in length and play important roles...     

The effect of dolichol on the structure and phase behaviour of phospholipid model membranes

The effect of dolichol C(95) on the structure and thermotropic phase behaviour of dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylethanolamine and stearoyloleoylphosphatidylethanolamine has been examined by synchrotron X-ray diffraction and differential scanning calorimetry. The presence of dolichol C(95) had no detectable effects on the temperature of either the gel to ripple or the ripple to liquid-crystal phase transition of dipalmitoylphosphatidylcholine. A proportionate increase of a few degrees in the temperature of the gel to lamellar liquid-crystal phase transition is observed in dispersions of dipalmitoylphosphatidylethanolamine and significantly there is a decrease in the temperature of the lamellar to non-lamellar phase transition of stearoyloleoylphosphatidylethanolamine. There was no significant change in the bilayer repeat spacing of all three mixed dispersions in gel phase in the presence of up to 20 mol% dolichol C(95). Electron density calculations showed that there was no change of bilayer thickness of dipalmitoylphosphatidylcholine with incorporation of up to 7.5 mol% dolichol C(95). These data suggest that effect of dolichol on the phospholipid model membranes depend on both the head group and the hydrocarbon chains of the phospholipid molecules. The presence of dolichol in phosphatidylcholine bilayers conforms to a model in which the polyisoprene compound is phase separated into a central domain sandwiched between the two monolayers in gel phase. In bilayers of phosphatidylethanolamines dolichol tends to stabilize the bilayers in gel phase at low temperatures and destabilize the bilayers in lamellar disordered structure at high temperatures. Non-lamellar structures coexist with lamellar disordered phase over a wide temperature range suggesting that dolichol is enriched in domains of non-lamellar structure and depleted from lamellar phase. These findings are useful to understand the function of dolichol in cell membranes.