入侵昆虫基因组研究进展

随着全球贸易的加速发展,入侵物种对农林业、生态环境及人类健康的威胁日益严重。基因组学研究为阐明外来有害生物入侵的分子机制与生态适应性过程以及研发新型防控技术提供了新手段、新平台与大数据。本文综述了入侵昆虫基因组学研究的发展现状,系统总结了基因/基因家族、转座子/重复序列等基因组信息在决定昆虫入侵性中的重要作用,着力探讨了基因组学研究在助力害虫RNAi、昆虫不育技术(SIT)、化学生态防治和物理防治等防控新技术/新产品开发方面的潜力,并展望了基因组学研究应用于入侵昆虫综合防控的前景。     

棉铃虫膨胀线粒体基因组的鉴定与分析

以已公布的棉铃虫线粒体DNA序列对来自4头棉铃虫雄蛹的DNA的三代测序数据进行筛选,获得了11条与线粒体DNA有同源性的三代read序列,并根据其中的read 66003鉴定出了一种膨胀的线粒体基因组。该线粒体基因组大小为27 113 bp,其保守区域包含13个蛋白编码基因、2个rRNA基因、22个tRNA基因以及1个AT富集区,与已公布的棉铃虫线粒体基因组的结构相似。膨胀区域位于cox1基因编码区内部,大小为11 467 bp,经预测含有一个完整的真核基因(依赖ATP的RNA解旋酶)以及多种转座元件的片段,但与线粒体DNA无同源性,也无I类或Ⅱ类内含子存在的证据。对田间和室内棉铃虫DNA样品的PCR扩增未能检测到膨胀线粒体基因组的存在。以上结果表明膨胀片段可能是细胞核DNA序列通过偶然的水平转移事件而整合到线粒体基因组中的,且该种膨胀方式的发生概率极低。本文报道的膨胀线粒体基因组为日后动物线粒体基因组学的研究提示了一种独特的变异方式。     

利用CRISPR/Ca9技术靶向编辑芥蓝BoaZDS

以芥蓝(Brassicaoleraceavar.alboglabra)为材料,以ζ–胡萝卜素脱氢酶(ζ-Carotene desaturase,ZDS)基因为目标基因,建立其CRISPR/Cas9基因组编辑体系。在BoaZDS的编码区近5′端选择靶位点,构建了CRISPR/Cas9表达载体,通过农杆菌介导的遗传转化方法获得了19个芥蓝转基因阳性植株,Sanger测序分析发现其中13株成功突变,CRISPR/Cas9载体在芥蓝上的突变效率为68.42%,且所有突变植株均表现出明显的白化表型。     

香蕉与B基因组相关的SCAR标记研究

香蕉(Musa L.)是由2个二倍体野生种Musa acuminata Colla(AA基因型)和Musa balbisiana Colla(BB基因型)种内或种间杂交进化而来,其B基因组中带有重要的优良基因。利用与香蕉B基因组相关的gypsy-IRAP分子标记,成功开发了一对SCAR引物,适用于鉴定尖叶蕉(AAw)、长梗蕉(BB)、香牙蕉(AAA)、贡蕉(AAcv)、大蕉、粉蕉(ABB)、粉大蕉(ABB)、龙牙蕉(AAB)以及四倍体香蕉(AAAB)等是否含有B基因组。     

Hesperetin attenuates hypoxia/reoxygenation-induced apoptosis in H9c2 cells via inhibition of calcium overload

AIM: To investigate the effect of hesperetin on hypoxia/reoxygenation (H/R)-induced apoptosis in the H9c2 cells and to clarify the underlying mechanism. METHODS: The H/R model was established and the H9c2 cells were pretreated with hesperetin for 4 h. The cell viability and cell damage were measured by CCK-8 assay and lactate dehydrogenase (LDH) detection. The apoptosis was analyzed by Hoechst 33258 staining and flow cytometry. The intracellular calcium fluorescence intensity was measured by fluorescence microscopy and flow cytometry. The calcium-ATPase activity and the level of adenosine triphosphate (ATP) were measured by ELISA. The mitochondrial membrane potential was measured by JC-1 staining. The protein expression levels of Bcl-2, Bax and cytochrome C (Cyt-C) were determined by Western blot. RESULTS: Hesperetin reduced the apoptosis of the H9c2 cells induced by H/R, decreased intracellular Ca²⁺ fluorescence intensity, elevated Ca²⁺-ATPase activity, inhibited the mitochondrial membrane potential depolarization and increased the level of ATP (P<0.05). In addition, hesperetin significantly reduced the release of Cyt-C protein from mitochondria to cytoplasma and increased the Bcl-2/Bax ratio (P<0.05). After using the calcium ion inhibitor nimodipine, the percentage of the cells with mitochondrial membrane depolarization was decreased, the ATP level was increased and the protein expression of mitochondrion-related apoptosis molecules were decreased (P<0.05). CONCLUSION: Hesperetin reduces the apoptosis of the H9c2 cells induced by H/R, which may be related to inhibition of calcium overload and improvement of mitochondrial function.     

不同动物部分组织基因组甲基化程度的差异分析

应用甲基敏感扩增多态性(MSAP)技术,检测和分析了猪、牛、羊、小鼠、鸡和鸭基因组的甲基化程度。结果表明,对CCGG位点,实验中检测的几种动物的甲基化程度多数在0.40￣0.50之间(不包括牛);不同动物来源相同组织基因组的甲基化程度不同,相同动物不同组织基因组的甲基化模式具有特异性;同一种动物,组织基因组的甲基化程度一般都高于血液基因组;另外,哺乳动物与禽类基因组甲基化程度未发现较大的差别,但哺乳动物基因组全甲基化位点较多,半甲基化位点较少。     

Novel Alkaloids from Marine Actinobacteria: Discovery and Characterization

The marine environment is an excellent resource for natural products with therapeutic potential. Its microbial inhabitants, often associated with other marine organisms, are specialized in the synthesis of bioactive secondary metabolites. Similar to their terrestrial counterparts, marine Actinobacteria are a prevalent source of these natural products. Here, we discuss 77 newly discovered alkaloids produced by such marine Actinobacteria between 2017 and mid-2021, as well as the strategies employed in their elucidation. While 12 different classes of alkaloids were unraveled, indoles, diketopiperazines, glutarimides, indolizidines, and pyrroles were most dominant. Discoveries were mainly based on experimental approaches where microbial extracts were analyzed in relation to novel compounds. Although such experimental procedures have proven useful in the past, the methodologies need adaptations to limit the chance of compound rediscovery. On the other hand, genome mining provides a different angle for natural product discovery. While the technology is still relatively young compared to experimental screening, significant improvement has been made in recent years. Together with synthetic biology tools, both genome mining and extract screening provide excellent opportunities for continued drug discovery from marine Actinobacteria.     

猪乙脑病毒HW株的全基因组克隆及分析

流行性乙型脑炎(Japanese encephalitis virus,JEV)是一种中枢系统人畜共患急性传染病,由蚊为媒介传播,以高热和狂暴或沉郁等神经症状为特征[1],猪患乙型脑炎的主要症状表现为怀孕母猪流产,产死胎或弱仔,公猪则患睾丸炎,仔猪呈神经症状,使养猪业遭受巨大损失。1988年我国学者方