Recent progress in research on insect histone deacetylases (HDACs)

组蛋白乙酰化修饰是一种重要的蛋白质翻译后修饰方式,由组蛋白乙酰基转移酶HATs和组蛋白去乙酰化酶HDACs共同调节.昆虫HDACs蛋白家族根据其同源性和结构的不同共分为4类,各昆虫物种之间既具有较高的保守同源性,同时也表现出一定的物种特异性.HDACs主要参与昆虫的胚胎发育、体节形成、寿命和神经行为等方面的调节.本文从HDACs蛋白的种类、系统发育、生理功能等方面展开,介绍了近年来国内外昆虫HDACs领域的最新研究进展,以期对研究昆虫表型可塑性调节机制以及探索新的害虫防治方法提供借鉴.     

思茅松毛虫四龄幼虫肠道好氧细菌的ARDRA分析及鉴定

从思茅松毛虫Dendrolimu kikuchii Matsumura4龄幼虫肠道环境中分离、纯化、培养,获得11株好氧细菌菌株。以细菌基因组DNA为模板,用细菌通用引物(27f、1492r)对模板进行PCR扩增,并用4种限制性内切酶HaeⅢ、HindⅢ、HinfⅠ、TaqⅠ对PCR产物进行ARDRA(amplified rDNA restriction analysis)多态性分析,在84%的相似水平上可分成6大类群,多样性丰富。对6大类群的代表菌株进行16SrDNA序列测定,分析表明:分离到的11株好氧细菌中4N05、4N08和4N11归属克雷伯氏杆菌属(Klebsiellasp.),4N02归属Lysinibacillus属;4N03和4N09确定到种,分别是γ-变形杆菌(Gamma proteobacterium)和枯草芽孢杆菌(Bacillus subtilis strain);4N04、4N06、4N07和4N01、4N10也可以确定到种,其中前3株是短短芽孢杆菌(Brevibacillus brevisstrain),后2株是沼泽短芽孢杆菌(Brevibacillus limnophilusstrain),并且这5株菌都归属短芽孢杆菌属(Brevibacillus sp.)。通过研究,既可以为松毛虫的生物防治提供微生态理论依据,又丰富了微生物资源库。     

Extracellular membrane-proximal domain of HAb18G/CD147 binds to metal ion-dependent adhesion site (MIDAS) motif of integrin β1 to modulate malignant properties of hepatoma cells

Several lines of evidence suggest that HAb18G/CD147 interacts with the integrin variants α3β1 and α6β1. However, the mechanism of the interaction remains largely unknown. In this study, mammalian protein-protein interaction trap (MAPPIT), a mammalian two-hybrid method, was used to study the CD147-integrin β1 subunit interaction. CD147 in human hepatocellular carcinoma (HCC) cells was interfered with by small hairpin RNA. Nude mouse xenograft model and metastatic model of HCC were used to detect the role of CD147 in carcinogenesis and metastasis. We found that the extracellular membrane-proximal domain of HAb18G/CD147 (I-type domain) binds at the metal ion-dependent adhesion site in the βA domain of the integrin β1 subunit, and Asp(179) in the I-type domain of HAb18G/CD147 plays an important role in the interaction. The levels of the proteins that act downstream of integrin, including focal adhesion kinase (FAK) and phospho-FAK, were decreased, and the cytoskeletal structures of HCC cells were rearranged bearing the HAb18G/CD147 deletion. Simultaneously, the migration and invasion capacities, secretion of matrix metalloproteinases, colony formation rate in vitro, and tumor growth and metastatic potential in vivo were decreased. These results indicate that the interaction of HAb18G/CD147 extracellular I-type domain with the integrin β1 metal ion-dependent adhesion site motif activates the downstream FAK signaling pathway, subsequently enhancing the malignant properties of HCC cells.     

Non-linear response of stomata in Pinus koraiensis to tree age and elevation

Knowledge on variations in stomata is useful in reflecting leaf physiological characteristics of CO₂ uptake and water transpiration, and predicting the responses of plants to future climate change. Stomatal density and number of stomatal rows (current-year, 1- and 2-year-old needles) in relation to tree age (ranging from 25 to 320 years old), elevation (ranging from 738 to 1,380 m a.s.l.), and sun exposure (sun and shade exposure) were investigated in Pinus koraiensis trees. Stomatal density and number of stomatal rows in relation to tree age and elevation showed a humped curve with the maximum values at intermediate levels of tree age (210 years old) and elevation (1,050 m a.s.l.), respectively. Needle age but not sun exposure significantly affected the stomatal density across tree ages and elevations. Our results suggest that variations in stomatal density of Pinus koraiensis needles are related to ontogenetic growth and environmental factors.     

microRNAs与TP53基因调控网络研究进展

TP53基因(编码p53蛋白)作为一个重要的抑瘤基因,通过调控一系列信号转导通路广泛参与了多种恶性肿瘤的发生发展,一直是肿瘤分子生物学研究领域的热点.最近的研究发现,microRNAs(miRNAs)参与了TP53的信号通路,它们之间存在着复杂的调控网络.一方面,p53通过调控一些miRNAs的转录及转录后成熟,促进细胞周期阻滞、诱导细胞凋亡和衰老,抑制肿瘤发生.另一方面,许多miRNAs,如miR-25、miR-30d、miR-125b和miR-504等可直接调控p53的表达与活性,参与TP53信号通路的调节,还有一些miRNAs则通过调节p53上下游基因,发挥重要的生物学功能.其中,最具有代表性的是miR-34家族,它们受p53直接调控并参与TP53信号通路,通过靶向抑制多个TP53信号通路关键分子的表达,发挥抑瘤作用.此外,它们还可以通过抑制沉默信息调节子,增强p53的活性,反馈调节TP53信号通路.miRNAs与TP53之间调控网络的研究,是对TP53抑瘤机制的重要补充.     

慢加急性重型乙型病毒性肝炎患者血清干扰素γ水平的检测及临床意义

目的：探讨血清干扰素-γ（IFN-γ）在慢加急性重型乙型病毒性肝炎（acute．on．chronihepatitisBloverfailure,ACHBLF）发病中的作用,旨在为ACHBLF的诊治提供理论参考。方法：采用ELSIA法测定30例ACHBLF患者和30例CHB患者血清IFN-γ水平,采用全自动生化仪检测肝功能常规指标。结果：AcHBLF组IFN-γ水平显著高于CHB组,相比较有显著性差异（P〈0．05）;ACHBLF组TBIL、ALT水平显著高于CHB组,相比较有显著性差异（P〈0．05）;ACHBLF组PTA水平显著低于CHB组,相比较有显著性差异（P〈0．05）;ACHBLF患者的IFN．叮水平与TBIL呈显著正相关（r=0．818,P〈0．01）,与PTA呈显著负相关（r=0．529,P〈0．05）,而与ALT无明显相关性（r=0．172,P〉0．05）。结论：IFN-γ参与ACHBLF的发病,并且是ACHBLF病情严重程度的重要指标之一。     

3个彩色马蹄莲引进品种的核型分析

利用普通压片法对3个引进彩色马蹄莲(Zantedeschia hybrid)品种的染色体数与核型进行了分析。结果表明:所试验品种染色体数均为2n=32。染色体形态比较一致,多是由中部(m)以及近中部(sm)着丝粒染色体组成。其中,‘Allure’为2n=2x=32=14m(2SAT)+2sm,‘Cupdio’的核型公式为2n=2x=32=14m+2sm,Odessa的核型公式为2x=32=1M+15m(1SAT)。3个品种核型不对称系数分别为56.72%,56.25%和56.38%,核型分类显示其均为1A型。     

近红外光谱技术预测猪肉的pH、嫩度和蒸煮损失

以冷却猪肉为研究对象,评价近红外光谱（NIR）技术用于肉类物理特性预测的可行性以及不同的光谱处理方法和建模方法对预测准确性的影响。试样取自排酸24h的同一批猪胴体的小里脊肉,采集4000—10000cm-1的光谱。经外部验证的偏最小二乘（PLS）模型在预测pH时表现出良好的相关性（Rc^2=0．88,Rp^2=0．80,SEC=0．08,SEP=0．084）,嫩度与蒸煮损失模型的相关性分别是Rc^2=0．50和0．57,R;=0．34和0．50。在各种光谱预处理方法中,平滑处理结合多元散射校正（MSC）或标准正态变量变换（SNV）的效果最好。     

中国白条天牛属比较形态学研究(鞘翅目,天牛科,沟胫天牛亚科,白条天牛族)

比较研究了白条天牛属10种的外部形态特征.结果表明:颊、触角、前胸背板斑纹、鞘翅斑纹、鞘翅基部瘤突、中胸后侧片、前足第1跗节等外部形态特征在白条天牛属中具有种间分类学意义.上颚基部、腹部第7节腹板形状、触角长度可用于雌雄鉴别.通过比较云斑白条天牛Batocera lineolata Chevrolat,1852与多斑白条天牛Batocera horsfieldi(Hope,1839)的外部形态与雄性外生殖器特征,结果表明上述两种均为有效种.