PHF8 is a histone H3K9me2 demethylase regulating rRNA synthesis

histone H3 离氨酸 9 的 Dimethylation (H3K9me2 ) 是与抄写压抑联系的一个重要 epigenetic 标记。这里，我们识别了 PHF8， JmjC-domain-containing 蛋白质，为这个镇压标记特定的 histone demethylase。Recombinant 全身的野类型蛋白质能把 methylation 从 H3K9me2 移开，但是到丙氨酸 H247A 的保存 histidine 的变化废除 demethylase 活动。Overexpressed 外长的 PHF8 是 colocalized， B23 染色。内长的 PHF8 也是有 B23 和 fibrillarin 的 colocalized，二生长得很好的核蛋白质，建议那 PHF8 在核是局部性的并且可以调整 rRNA 抄写。确实， PHF8 跳了到 rDNA 基因的倡导者区域。减少的 PHF8 击倒 rRNA 的表示，和基因的 overexpression 导致了 rRNA 的 upregulation 抄本。附随地， H3K9me2 水平在 PHF8 击倒的房间在 rDNA 基因的倡导者区域被提高并且当野类型然而并非催化地不活跃的 H247A 变异的 PHF8 是 overexpressed 时，显著地减少了。因此，我们的学习为调整 rRNA 抄写的 H3K9me2 识别了 histone demethylase。

A Microfluidic System with Active Mixing for Improved Real-Time Isothermal Amplification

To improve the performance of real-time recombinase polymerase amplification(RPA),a microfluidic system with active mixing is developed to optimize the reaction dynamics.Instead of adopting a single typical reaction chamber,a specific reactor including a relatively large chamber in center with two adjacent zig-zag channels at two sides is integrated into the microfluidic chip.Active mixing is achieved by driving the viscous reagent between the chamber and the channel back and forth periodically with an outside compact peristaltic pump.To avoid reagent evapora-tion,one end of the reactor is sealed with paraffin oil.A hand-held companion device is developed to facilitate real-time RPA amplification within 20 min.The whole area of the reactor is heated with a resistance heater to provide uniform reaction temperature.To achieve real-time monitoring,a compact fluorescence detection module is integrated into the hand-held device.A smartphone with custom application software is adopted to control the hand-held device and display the real-time fluorescence curves.The performances of two cases with and without active on-chip mixing are compared between each other by detecting African swine fever viruses.It has been demonstrated that,with active on-chip mixing,the amplification efficiency and detection sensitivity can be signifi-cantly improved.

Grazing greatly reduces the temporal stability of soil cellulolytic fungal community in a steppe on the Tibetan Plateau

Excessive livestock grazing degrades grasslands ecosystem stability and sustainability by reducing soil organic matter and plant productivity. However, the effects of grazing on soil cellulolytic fungi, an important indicator of the degradation process for soil organic matter,remain less well understood. Using T-RFLP and sequencing methods, we investigated the effects of grazing on the temporal changes of cellulolytic fungal abundance and community structure in dry steppe soils during the growing months from May to September, on the Tibetan Plateau using T-RFLP and sequencing methods. The results demonstrated that the abundance of soil cellulolytic fungi under grazing treatment changed significantly from month to month, and was positively correlated with dissolved organic carbon(DOC) and soil temperature, but negatively correlated with soil p H. Contrastingly, cellulolytic fungal abundance did not change within the fencing treatment(ungrazed conditions). Cellulolytic fungal community structure changed significantly in the growing months in grazed soils,but did not change in fenced soils. Grazing played a key role in determining the community structure of soil cellulolytic fungi by explaining 8.1% of the variation, while p H and DOC explained 4.1% and 4.0%, respectively. Phylogenetically, the cellulolytic fungi were primarily affiliated with Ascomycota(69.65% in relative abundance) and Basidiomycota(30.35%).Therefore, grazing substantially reduced the stability of soil cellulolytic fungal abundance and community structure, as compared with the fencing treatment. Our finding provides a new insight into the responses of organic matter-decomposing microbes for grassland managements.

Algorithm of Micro-Grooving and Imaging Processing for the Generation of High-Resolution Structural Color Images

The use of submicron structures for structural coloration of surfaces has broad applications for color filters,projection displays,virtual reality,and anti-counterfeiting.Currently,structural color images lack high resolution due to low manufacturing accuracy.In this study,the axial-feed fly cutting(AFC)method is proposed to fabricate submicron grooves for the diffraction of visible light to create structural color images.We establish the relationship between the color information in the pixels of the original image and the parameters of the array units corresponding to the pixels.An algorithm to determine groove spacing and the tool path is established,and array units with the desired groove spacing are machined to reproduce the structural color images.The submicron grooves fabricated by AFC have high quality and good consistency.Due to the excellent diffraction performance of the machined grooves,images with high saturation and resolution can be reproduced.It is verified that images with various colors can be efficiently fabricated using the proposed method and algorithm.