Construction of a sensitive pyrogen-testing cell model by site-specific knock-in of multiple genes

A pyrogen test is crucial for evaluating the safety of drugs and medical equipment, especially those involved in injections. As existing pyrogen tests, including the rabbit pyrogen test, the limulus amoebocyte lysate (LAL) test and the monocyte activation test have limitations, development of new models for pyrogen testing is necessary. Here we develop a sensitive cell model for pyrogen test based on the lipopolysaccharides (LPS) signal pathway. TLR4, MD2, and CD14 play key roles in the LPS-mediated pyrogen reaction. We established a new TLR4/MD2/CD14-specific overexpressing knock-in cell model using the CRISPR/CAS9 technology and homologous recombination to detect LPS. Stimulation of our TLR4/CD14/MD2 knock-in cell line model with LPS leads to the release of the cytokines IL-6 and TNF-alpha, with a detection limit of 0.005 EU/ml, which is greatly lower than the lower limit of 0.015 EU/ml detected by the Tachypleus amebocyte lysate (TAL) assay.     

解淀粉芽孢杆菌3-2发酵羽毛产氨基酸

【目的】建立废弃羽毛液体发酵工艺,优化发酵条件,提高羽毛降解率及氨基酸产量,研发新型、高效复合氨基酸肥料。【方法】利用解淀粉芽孢杆菌3-2发酵羽毛,探究温度、发酵时间、羽毛含量、单一碳源、复合碳氮源、金属离子等对废弃羽毛降解效果以及发酵液中氨基酸种类和含量的影响。【结果】废弃羽毛降解率与氨基酸总产量呈负相关。随着发酵时间延长,羽毛降解率增加,当发酵温度为37°C、羽毛添加量为1%、以乳糖为外加碳源、添加Mg2+时,羽毛降解率最高,达到81.92%。随着羽毛添加量增加,氨基酸总含量也增加(在20%范围以内),当发酵温度为37°C、降解时间为108 h、羽毛添加量为10%、乳糖添加量为0.5%、不添加复合碳氮源、不添加金属离子时,氨基酸的种类最全(富含17种氨基酸),总含量最高,达到20.861 g/kg。【结论】利用解淀粉芽孢杆菌3-2发酵废弃羽毛生产氨基酸复合肥料是一种可靠、环保、经济的方法,获得的氨基酸肥料营养齐全。研究结果为新型复合氨基酸肥料的研发提供技术支撑。     

褐巢蛾属分类修订(鳞翅目,巢蛾科,巢蛾亚科)

对褐巢蛾属 Metanomeuta Meyrick进行了修订,重新描述了模式种,讨论了其形态变异;记述2个新种,即岳西褐巢蛾 Metanomeuta yuexiensis sp.nov.和疏刺褐巢蛾 Metanomeutaspinisparsula sp.nov..文中提供了成虫和外生殖器特征图,给出了分种检索表及分布图.模式标本保存在南开大学昆虫标本室.岳西褐巢蛾,新种 Metanomeuta yuexiensis sp.nov.(图3,10,13)该种与金冠褐巢蛾 Metanomeuta fulvicrinis Meyrick外部相似,但可通过外生殖器特征区别:颚形突卵圆形,末端钝圆;雌性后阴片中部微凹,前阴片不明显,囊导管基部2/3具瘤突,交配囊长卵形.正模♂,安徽岳西温泉(30°52'N,116°22'E),1995-08-08,胡祥富采,外生殖器玻片号JQ07191.副模：8♂♂,1♀,安徽岳西温泉,1995-07-25～08-22,胡祥富采. 疏刺褐巢蛾,新种Metanomeuta spinisparsula sp.nov.(图4,11,14)该种与金冠褐巢蛾Metanomeuta fulvicrinis 相似,区别在于:体为深褐色,翅面无任何斑纹;雄性颚形突略呈舌状,末端突出,抱器腹除端部有一枚较大刺突外,无明显小刺或小刺束;雌性导管端片小且非杯状,囊导管仅基部1/2 具瘤突.正模♂,湖南石门县壶瓶山江坪(29°35'N,111°22'E;480m),2002-01-05,于海丽采,外生殖器玻片号JQO6091;副模1♀,采集资料同正模.     

葡萄树新害虫——光滑足距小蠹的形态特征

采用扫描电镜技术研究成都市农泉驿区危害葡萄的小蠹——光滑足距小蠹Xylosandrus germanus(Blandford)的形态特征。该小蠹具有明显的性二型现象。成虫光亮。雌成虫圆柱形,体长2.02～2.26mm,雄成虫较宽扁,体长1.00～1.30mm。在扫描电镜下,可见成虫前胸前缘的刻点毛均从基部分成两叉,但雌成虫略呈锯齿状,雄成虫呈栉齿状。雌成虫具有贮菌器,位于前胸背板的后端下面。雌成虫鞘翅分为沟中和沟间部,后半部细长毛起自沟间部,雄成虫鞘翅不分沟中和沟间部,后半部部分刻点生有细长毛。     

Effects of substrate moisture content, log weight and filter porosity on shiitake (Lentinula edodes) yield

Production costs for shiitake (Lentinula edodes) are on the rise in the United States due to increasing expenses including materials, labor and energy. Increased yield and improved bioconversion of raw materials may improve grower profit margins and may help reduce the cost of shiitake to the consumer. Two crops (Crop 1 and 2) of shiitake were grown to evaluate effects of three substrate moisture contents (50%, 55% and 60%), two log weights (2.7 and 3.2kg) and three porosities of bag filter (low, medium and high) on mushroom yield (g/log) and biological efficiency (BE). Yield data were collected under controlled environmental conditions for two breaks. The formulation with 55% substrate moisture gave the highest yield and BE. Higher mushroom yields were produced from heavier logs (3.2kg), but BE was not significantly affected. Filter porosity significantly affected yield and BE in Crop 1 but not in Crop 2. Significant interactions were observed for log moisture contentxfilter porosity for both crops. There were no significant two-way interactions observed for filter porosityxlog weight or three-way interactions observed for moisture contentxfilter porosityxlog weight. Maximum yields were obtained from 3.2kg logs with a substrate moisture content of ca. 55% using medium or low porosity-filtered bags. This study may provide growers with additional information to better optimize production practices and become more efficient and competitive.     

Genomic insights into selection for heterozygous alleles and woody traits in Populus tomentosa

Heterozygous alleles are widespread in outcrossing and clonally propagated woody plants. The variation in heterozygosity that underlies population adaptive evolution and phenotypic variation, however, remains largely unknown. Here, we describe a de novo chromosome-level genome assembly of Populus tomentosa, an economic and ecologically important native tree in northern China. By resequencing 302 natural accessions, we determined that the South subpopulation (Pop_S) encompasses the ancestral strains of P. tomentosa, while the Northwest subpopulation (Pop_NW) and Northeast subpopulation (Pop_NE) experienced different selection pressures during population evolution, resulting in significant population differentiation and a decrease in the extent of heterozygosity. Analysis of heterozygous selective sweep regions (HSSR) suggested that selection for lower heterozygosity contributed to the local adaptation of P. tomentosa by dwindling gene expression and genetic load in the Pop_NW and Pop_NE subpopulations. Genome-wide association studies (GWAS) revealed that 88 single nucleotide polymorphisms (SNPs) within 63 genes are associated with nine wood composition traits. Among them, the selection for the homozygous AA allele in PtoARF8 is associated with reductions in cellulose and hemicellulose contents by attenuating PtoARF8 expression, and the increase in lignin content is attributable to the selection for decreases in exon heterozygosity in PtoLOX3 during adaptive evolution of natural populations. This study provides novel insights into allelic variations in heterozygosity associated with adaptive evolution of P. tomentosa in response to the local environment and identifies a series of key genes for wood component traits, thereby facilitating genomic-based breeding of important traits in perennial woody plants.     

Piwi/piRNAs control food intake by promoting neuropeptide F expression in locusts

Animal feeding, which directly affects growth and metabolism, is an important physiological process. However, the contribution of PIWI proteins and PIWI‐interacting RNAs (piRNAs) to the regulatory mechanism of animal feeding is unknown. Here, we report a novel function of Piwi and piRNAs in regulating food intake in locusts. Our study shows that the locust can serve as a representative species for determining PIWI function in insects. Knockdown of Piwi1 expression suppresses anabolic processes and reduces food consumption and body weight. The reduction in food intake by knockdown of Piwi1 expression results from decreased expression of neuropeptide NPF1 in a piRNA‐dependent manner. Mechanistically, intronic piRNAs might enhance RNA splicing of NPF1 by preventing hairpin formation at the branch point sites. These results suggest a novel nuclear PIWI/piRNA‐mediated mechanism that controls food intake in the locust nervous system.     

抗蚜基因及其转基因植物的研究进展

在我国目前的环境条件下,蚜虫作为农业害虫和植物病毒的传播者,已经成为严重威胁农业生产发展重要的害虫之一。抗蚜植物基因工程可以有效抑制蚜虫危害,并且随着对生命科学的深入理解和技术手段的日益成熟,得到广泛的关注和重视。抗蚜植物基因工程的核心是抗蚜基因的筛选、转抗蚜基因植物的培育以及生物安全性。本文讨论了多种抗蚜基因,并重点论述雪花莲凝集素和苋菜凝集素基因在目前科学研究和生产实践的应用。     

C-Myc negatively controls the tumor suppressor PTEN by upregulating miR-26a in glioblastoma multiforme cells

The c-Myc oncogene is amplified in many tumor types. It is an important regulator of cell proliferation and has been linked to altered miRNA expression, suggesting that c-Myc-regulated miRNAs might contribute to tumor progression. Although miR-26a has been reported to be upregulated in glioblastoma multiforme (GBM), the mechanism has not been established. We have shown that ectopic expression of miR-26a influenced cell proliferation by targeting PTEN, a tumor suppressor gene that is inactivated in many common malignancies, including GBM. Our findings suggest that c-Myc modulates genes associated with oncogenesis in GBM through deregulation of miRNAs via the c-Myc–miR-26a–PTEN signaling pathway. This may be of clinical relevance.     

Increased accumulation of anthocyanins in transgenic potato tubers by overexpressing the 3GT gene

In order to explore a biotechnological method for improving potato tuber color and creating plants with increased anthocyanin contents, a potato UDP-glucose: flavonoid-3-O-glucosyltransferase (3GT) gene was inserted behind the GBSSI promoter of pBin19, and this construct was introduced into Solanum tuberosum L. cultivar Désirée plants by Agrobacterium-mediated transformation. Six independent transgenic lines overexpressing the 3GT gene were identified by PCR and Southern blot analysis from 18 kanamycin-resistant plants. Due to the expression of 3GT gene, the tuber color and the anthocyanin content were enhanced noticeably in the transgenic plants compared to the wild-type control plants. This result suggests that the 3GT gene can potentially be used to improve potato color and enhance levels of antioxidants in the diet.