Second-Generation Sequencing Supply an Effective Way to Screen RNAi Targets in Large Scale for Potential Application in Pest Insect Control

The key of RNAi approach success for potential insect pest control is mainly dependent on careful target selection and a convenient delivery system. We adopted second-generation sequencing technology to screen RNAi targets. Illumina's RNA-seq and digital gene expression tag profile (DGE-tag) technologies were used to screen optimal RNAi targets from Ostrinia furnalalis. Total 14690 stage specific genes were obtained which can be considered as potential targets, and 47 were confirmed by qRT-PCR. Ten larval stage specific expression genes were selected for RNAi test. When 50 ng/µl dsRNAs of the genes DS10 and DS28 were directly sprayed on the newly hatched larvae which placed on the filter paper, the larval mortalities were around 40∼50%, while the dsRNAs of ten genes were sprayed on the larvae along with artificial diet, the mortalities reached 73% to 100% at 5 d after treatment. The qRT-PCR analysis verified the correlation between larval mortality and the down-regulation of the target gene expression. Topically applied fluorescent dsRNA confirmed that dsRNA did penetrate the body wall and circulate in the body cavity. It seems likely that the combination of DGE-tag with RNA-seq is a rapid, high-throughput, cost less and an easy way to select the candidate target genes for RNAi. More importantly, it demonstrated that dsRNAs are able to penetrate the integument and cause larval developmental stunt and/or death in a lepidopteron insect. This finding largely broadens the target selection for RNAi from just gut-specific genes to the targets in whole insects and may lead to new strategies for designing RNAi-based technology against insect damage

Rab8, POSH, and TAK1 regulate synaptic growth in a Drosophila model of frontotemporal dementia

Mutations in genes essential for protein homeostasis have been identified in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) patients. Why mature neurons should be particularly sensitive to such perturbations is unclear. We identified mutations in Rab8 in a genetic screen for enhancement of an FTD phenotype associated with ESCRT-III dysfunction. Examination of Rab8 mutants or motor neurons expressing a mutant ESCRT-III subunit, CHMP2BIntron5, at the Drosophila melanogaster neuromuscular junction synapse revealed synaptic overgrowth and endosomal dysfunction. Expression of Rab8 rescued overgrowth phenotypes generated by CHMP2BIntron5. In Rab8 mutant synapses, c-Jun N-terminal kinase (JNK)/activator protein-1 and TGF-β signaling were overactivated and acted synergistically to potentiate synaptic growth. We identify novel roles for endosomal JNK-scaffold POSH (Plenty-of-SH3s) and a JNK kinase kinase, TAK1, in regulating growth activation in Rab8 mutants. Our data uncover Rab8, POSH, and TAK1 as regulators of synaptic growth responses and point to recycling endosome as a key compartment for synaptic growth regulation during neurodegenerative processes

An AUV Target-Tracking Method Combining Imitation Learning and Deep Reinforcement Learning

This study aims to solve the problem of sparse reward and local convergence when using a reinforcement learning algorithm as the controller of an AUV. Based on the generative adversarial imitation (GAIL) algorithm combined with a multi-agent, a multi-agent GAIL (MAG) algorithm is proposed. The GAIL enables the AUV to directly learn from expert demonstrations, overcoming the difficulty of slow initial training of the network. Parallel training of multi-agents reduces the high correlation between samples to avoid local convergence. In addition, a reward function is designed to help training. Finally, the results show that in the unity simulation platform test, the proposed algorithm has a strong optimal decision-making ability in the tracking process

The Effect of Directing Groups on the Rate of Rhodium-Catalyzed Decarbonylation Reactions

Carbon-carbon bonds are difficult to activate due to the lack of flexibility of the sigma bonds and steric hindrance which contribute to the stability of the bond. However, the addition of a rhodium catalyst allows for decarbonylation of aryl ketones via carbon-carbon single bond activation. The decarbonylation process is essential to determine the effectiveness of the directing group. Herein, we describe the synthetic pathways for the starting materials, as well as the effects of various nitrogen containing directing groups on the rate of decarbonylation

Male opportunistic mating increases with intensity of female sexual cannibalism in 3 web-building spiders

10.1093/cz/zoab090CURRENT ZOOLOGY681113-119complete

Intestinal Metabolite Compound K of Ginseng Saponin Potently Attenuates Metastatic Growth of Hepatocellular Carcinoma by Augmenting Apoptosis via a Bid-Mediated Mitochondrial Pathway

It was recently shown that compound K (CK), an intestinal bacterial metabolite of ginseng saponin, exhibits antihepatocellular carcinoma (HCC) activity, and Bid is a potential drug target for HCC therapy. This paper reports a novel mechanism of CK-induced apoptosis of HCC cells via Bid-mediated mitochondrial pathway. OK dramatically inhibited HCC cells growth in concentration- and time-dependent manners, and a high dose of OK could induce HCC cell apoptotic cell death. Furthermore, the effective dose of CK potently attenuated the subcutaneous tumor growth and spontaneous HOC metastasis in vivo. At the molecular level, immunohistochemical staining revealed that Bid expression in subcutaneous tumor and liver metastasis tissues decreased dramatically in OK-treated groups compared to untreated controls, which also implies that Bid may play a critical role in the growth and progression of HCC. Further study shows that translocation of full-length Bid to the mitochondria from nuclei during cytotoxic apoptosis was associated with the release of cytochrome c from mitochondria, indicating that full-length Bid is sufficient for the activation of mitochondrial cell death pathways in response to CK treatment in HCC cells. Taken together, the results not only reveal a Bid-mediated mitochondrial pathway in HCC cells induced by CK but also suggest that OK may become a potential cytotoxic drug targeting Bid in the prevention and treatment of HCC

Intestinal Metabolite Compound K of Ginseng Saponin Potently Attenuates Metastatic Growth of Hepatocellular Carcinoma by Augmenting Apoptosis via a Bid-Mediated Mitochondrial Pathway

It was recently shown that compound K (CK), an intestinal bacterial metabolite of ginseng saponin, exhibits antihepatocellular carcinoma (HCC) activity, and Bid is a potential drug target for HCC therapy. This paper reports a novel mechanism of CK-induced apoptosis of HCC cells via Bid-mediated mitochondrial pathway. OK dramatically inhibited HCC cells growth in concentration- and time-dependent manners, and a high dose of OK could induce HCC cell apoptotic cell death. Furthermore, the effective dose of CK potently attenuated the subcutaneous tumor growth and spontaneous HOC metastasis in vivo. At the molecular level, immunohistochemical staining revealed that Bid expression in subcutaneous tumor and liver metastasis tissues decreased dramatically in OK-treated groups compared to untreated controls, which also implies that Bid may play a critical role in the growth and progression of HCC. Further study shows that translocation of full-length Bid to the mitochondria from nuclei during cytotoxic apoptosis was associated with the release of cytochrome c from mitochondria, indicating that full-length Bid is sufficient for the activation of mitochondrial cell death pathways in response to CK treatment in HCC cells. Taken together, the results not only reveal a Bid-mediated mitochondrial pathway in HCC cells induced by CK but also suggest that OK may become a potential cytotoxic drug targeting Bid in the prevention and treatment of HCC

The Role of Soil Salinization in Shaping the Spatio-Temporal Patterns of Soil Organic Carbon Stock

Soil salinization is closely related to land degradation, and it is supposed to exert a significant negative effect on soil organic carbon (SOC) stock dynamics. This effect and its mechanism have been examined at site and transect scales in previous studies while over a large spatial extent, the salinity-induced changes in SOC stock over space and time have been less quantified, especially by machine learning and remote sensing techniques. The main focus of this study is to answer the following question: to what extent can soil salinity exert an additional effect on SOC stock over time at a larger spatial scale? Thus, we employed the extreme gradient boosting models (XGBoost) combined with field site-level measurements from 433 sites and 41 static and time-varying environmental covariates to construct methods capable of quantifying the salinity-induced SOC changes in a typical inland river basin of China between the 1990s and 2020s. Results showed that the XGBoost models performed well in predicting the soil electrical conductivity (EC) and SOC stock at 0–20 cm, with the R2 value reaching 0.85 and 0.81, respectively. SOC stock was found to vary significantly with increasing soil salinity following an exponential decay function (R2 = 0.27), and salinity sensitivity analysis showed that soils in oasis were expected to experience the largest carbon loss (−137.78 g m−2), which was about 4.84, 14.37, and 25.95 times higher than that in the saline, bare, and sandy land, respectively, if the soil salinity increased by 100%. In addition, the decrease in the soil salinity (−0.32 dS m−1) from the 1990s to the 2020s was estimated to enhance the SOC stock by 0.015 kg m−2, which contributed an additional 10% increase to the total SOC stock enhancement. Overall, the proposed methods can be applied for quantification of the direction and size of the salinity effect on SOC stock changes in other salt-affected regions. Our results also suggest that the role of soil salinization should not be neglected in SOC changes projection, and soil salinization control measures should be further taken into practice to enhance soil carbon sequestration in arid inland river basins