Blooms of Microcystis aeruginosa occur frequently in many freshwater ecosystems around the world,but the mechanism of recovery has not been fully understood.In our previous study,three benthic bacterial species(E.sp01...Blooms of Microcystis aeruginosa occur frequently in many freshwater ecosystems around the world,but the mechanism of recovery has not been fully understood.In our previous study,three benthic bacterial species(E.sp013,Ba.spD06,and Ba.spD24)were identifi ed capable of promoting the recruitment of M.aeruginosa.Here,we further investigated the transcriptional response of M.aeruginosa to the benthic bacteria in early phase of recruitment by means of RNA-Seq analysis.In total,5803803 unigenes on average length of 404 bp were obtained from the transcriptome of M.aeruginosa.There were 54982 unigenes identifi ed as benthic bacteria-responsive unigenes based on the expression level analysis.Results of the protein-protein interaction analysis(PPI)show that the hub genes of the benthic bacteria responsive unigenes mediated network were ribosomal proteins of 30S and 50S,and the most signifi cant functional module of the network was related to the ribosome.Both the unigenes encoding the translation initiation factors(IF-2,IF-3)and elongation factors(lepA,fusA,and tufA)were up-regulated to respond benthic bacteria.Therefore,it indicates that the benthic bacteria have a positive infl uence on activating the ribosome during the early recovery stage of M.aeruginosa.展开更多
Advanced DNA structures,such as the G-quadruplex(G4)and the i-motif,are widely but not randomly present in the genomes of many organisms.A G4 structure was identified in the promoter of the silk gland factor-1 gene(SG...Advanced DNA structures,such as the G-quadruplex(G4)and the i-motif,are widely but not randomly present in the genomes of many organisms.A G4 structure was identified in the promoter of the silk gland factor-1 gene(SGFI),which is the main regulatory gene for silk production in Bombyx mori.In this study,a BmSGF1 G4-/-ho-mozygous mutant was generated with the G4 sequence knocked out.The promoter activity of BmSGF1 was lowered in the BmSGF1 G4-/-mutant.Pyridostatin(PDS)stabilized the G4 structure and increased the promoter activity of BmSGF1,whereas anti-sense oligonu-cleotide(ASO)complementary to the G4 sequence suppressed the promoter activity of BmSGF1.Compared with wild-type larvae,the deletion of the BmSGF1 G4 structure de-creased both the expression of BmSGF1 and the fibroin heavy chain gene BmFib-H in the posterior silk gland and the weight of the cocoons.Overall,these results suggest that the promoter G4 structure of BmSGFI participates in the transcription regulation of the BmSGFl gene in the silkworm.展开更多
Copper-ceria sheets catalysts with different loadings of copper（2 wt.%, 5 wt.% and 10 wt.%） supported on ceria nanosheets were synthesized via a depositioneprecipitation（DP） method. The prepared catalysts were sys...Copper-ceria sheets catalysts with different loadings of copper（2 wt.%, 5 wt.% and 10 wt.%） supported on ceria nanosheets were synthesized via a depositioneprecipitation（DP） method. The prepared catalysts were systematically characterized with various structural and textural detections including X-ray diffraction（XRD）, Raman spectra, transmission electron microscopy（TEM）, X-ray absorption fine structure（XAFS）, and temperature-programmed reduction by hydrogen（H2-TPR）, and tested for the CO oxidation reaction. Notably, the sample containing 5 wt.% of Cu exhibited the best catalytic performance as a result of the highest number of active CuO species on the catalyst surface. Further increase of copper content strongly affects the dispersion of copper and thus leads to the formation of less active bulk CuO phase, which was verified by XRD and H2-TPR analysis. Moreover, on the basis of in-situ diffuse reflectance infrared Fourier transform spectroscopy（in-situ DRIFTS） results, the surface Cu~＋ species, which are derived from the reduction of Cu^（2＋）, are likely to play a crucial role in the catalyzing CO oxidation.Consequently, the superior catalytic performance of the copper-ceria sheets is mainly attributed to the highly dispersed CuOx cluster rather than Cu-[Ox]-Ce structure, while the bulk CuO phase is adverse to the catalytic activity of CO oxidation.展开更多
It has been found that the non-B form DNA structures,like G-quadruplex(G4)and i-motif,are involved in many important biological processes.Our previous study showed that the silkworm transcription factor BmLARK binds t...It has been found that the non-B form DNA structures,like G-quadruplex(G4)and i-motif,are involved in many important biological processes.Our previous study showed that the silkworm transcription factor BmLARK binds to the G4 structure in the promoter of the transcription factor BmPOUM2 and regulates its promoter activity.However,the binding mechanism between BmLARK and BmPOUM2 G4 structure remains unclear.In this study,binding domains and key amino acid residues involved in the interaction between BmLARK and BmPOUM2 G4 were studied.The electrophoretic mobility shift assay results indicated that the two RNA-recognition motifs(RRM)of BmLARK are simultaneously required for the binding with the G4 structure.Either RRM1 or RRM2 alone could not bind with the G4 structure.The zinc-finger motif was not involved in the binding.A series of mutant proteins with specific amino acid mutations were expressed and used to identify the key amino acid residues involving the interaction.The results indicated thatβsheets,especially theβ1 andβ3 sheets,in the RRM domains of BmLARK played critical roles in the binding with the G4 structure.Several amino acid mutations of RRM1/2 in ribonucleoprotein domain 1(RNP1)(motif inβ3 strand)and RNP2(motif inβ1 strand)caused loss of binding ability,indicating that these amino acids are the key sites for the binding.All the results suggest that RRM domains,particularly their the RNP1 and RNP2 motifs,play important roles not only in RNA recognition,but also in the G4 structure binding.展开更多
Bursicon is a neuropeptide that regulates cuticle sclerotization （hardening and tanning） in insect via a G-protein coupled receptor. However, the signal transduction pathway downstream of the G-protein coupled recep...Bursicon is a neuropeptide that regulates cuticle sclerotization （hardening and tanning） in insect via a G-protein coupled receptor. However, the signal transduction pathway downstream of the G-protein coupled receptor is currently not well known. In our recent microarray analysis, we identified a panel of genes regulated by bursicon in Drosophila. One of the genes, Suppressor of Hairless, or Su（H）, has drawn our attention because its product acts down-stream of the bursicon receptor. In the present study, we cloned the Drosophila homolog, mdSu（H）, from the house fly Musca domestica using 3＇ and 5＇ rapid amplification of complementary DNA ends. Real-time polymerase chain reaction analysis revealed that the level ofmdSu（H） transcript is up-regulated by ~3-fold 1 h after recombinant bursicon injection, which correlates well with the cuticle sclerotization process observed in the recombinant bursicon-injected flies. We infer that Su（H） is an essential gene involved in the insect cuticle sclerotization process.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.31472017,31272339)the Key Projects of Hunan Provincial Science and Technology Department(No.2014FJ2003)+1 种基金the Open Research Fund of Key Laboratory of Tropical Disease Control and Research,Ministry of Education in China(No.2018 kfkt03)the China Postdoctoral Science Foundation(No.2020M682573)。
文摘Blooms of Microcystis aeruginosa occur frequently in many freshwater ecosystems around the world,but the mechanism of recovery has not been fully understood.In our previous study,three benthic bacterial species(E.sp013,Ba.spD06,and Ba.spD24)were identifi ed capable of promoting the recruitment of M.aeruginosa.Here,we further investigated the transcriptional response of M.aeruginosa to the benthic bacteria in early phase of recruitment by means of RNA-Seq analysis.In total,5803803 unigenes on average length of 404 bp were obtained from the transcriptome of M.aeruginosa.There were 54982 unigenes identifi ed as benthic bacteria-responsive unigenes based on the expression level analysis.Results of the protein-protein interaction analysis(PPI)show that the hub genes of the benthic bacteria responsive unigenes mediated network were ribosomal proteins of 30S and 50S,and the most signifi cant functional module of the network was related to the ribosome.Both the unigenes encoding the translation initiation factors(IF-2,IF-3)and elongation factors(lepA,fusA,and tufA)were up-regulated to respond benthic bacteria.Therefore,it indicates that the benthic bacteria have a positive infl uence on activating the ribosome during the early recovery stage of M.aeruginosa.
基金This research was supported by the National Natural Science Foundation of China(31930102,32250710148,32000337,32100383)Shaoguan University high-level talent research start-up funding project(432/9900064607)Research Projects of Shaoguan University(SY2023KJ03).
文摘Advanced DNA structures,such as the G-quadruplex(G4)and the i-motif,are widely but not randomly present in the genomes of many organisms.A G4 structure was identified in the promoter of the silk gland factor-1 gene(SGFI),which is the main regulatory gene for silk production in Bombyx mori.In this study,a BmSGF1 G4-/-ho-mozygous mutant was generated with the G4 sequence knocked out.The promoter activity of BmSGF1 was lowered in the BmSGF1 G4-/-mutant.Pyridostatin(PDS)stabilized the G4 structure and increased the promoter activity of BmSGF1,whereas anti-sense oligonu-cleotide(ASO)complementary to the G4 sequence suppressed the promoter activity of BmSGF1.Compared with wild-type larvae,the deletion of the BmSGF1 G4 structure de-creased both the expression of BmSGF1 and the fibroin heavy chain gene BmFib-H in the posterior silk gland and the weight of the cocoons.Overall,these results suggest that the promoter G4 structure of BmSGFI participates in the transcription regulation of the BmSGFl gene in the silkworm.
基金Project supported by the National Natural Science Foundation of China(21301107,21501109)the Excellent Young Scientists Fund from NSFC(21622106)+3 种基金the Taishan Scholar Project of Shandong Province of China,China Postdoctoral Science Foundation(2014M551891,2015T80706)Doctoral Funding of Shandong Province of China(BS2014CL008)Specialized Research Fund for the Doctoral Program of Higher Education(20130131120009)Postdoctoral Innovation Project Foundation of Shandong Province(201301008)
文摘Copper-ceria sheets catalysts with different loadings of copper（2 wt.%, 5 wt.% and 10 wt.%） supported on ceria nanosheets were synthesized via a depositioneprecipitation（DP） method. The prepared catalysts were systematically characterized with various structural and textural detections including X-ray diffraction（XRD）, Raman spectra, transmission electron microscopy（TEM）, X-ray absorption fine structure（XAFS）, and temperature-programmed reduction by hydrogen（H2-TPR）, and tested for the CO oxidation reaction. Notably, the sample containing 5 wt.% of Cu exhibited the best catalytic performance as a result of the highest number of active CuO species on the catalyst surface. Further increase of copper content strongly affects the dispersion of copper and thus leads to the formation of less active bulk CuO phase, which was verified by XRD and H2-TPR analysis. Moreover, on the basis of in-situ diffuse reflectance infrared Fourier transform spectroscopy（in-situ DRIFTS） results, the surface Cu~＋ species, which are derived from the reduction of Cu^（2＋）, are likely to play a crucial role in the catalyzing CO oxidation.Consequently, the superior catalytic performance of the copper-ceria sheets is mainly attributed to the highly dispersed CuOx cluster rather than Cu-[Ox]-Ce structure, while the bulk CuO phase is adverse to the catalytic activity of CO oxidation.
基金This work was supported by the grants of the Chinese National Natural Science Foundation(Grant no.:31672494,31720103916,31930102)。
文摘It has been found that the non-B form DNA structures,like G-quadruplex(G4)and i-motif,are involved in many important biological processes.Our previous study showed that the silkworm transcription factor BmLARK binds to the G4 structure in the promoter of the transcription factor BmPOUM2 and regulates its promoter activity.However,the binding mechanism between BmLARK and BmPOUM2 G4 structure remains unclear.In this study,binding domains and key amino acid residues involved in the interaction between BmLARK and BmPOUM2 G4 were studied.The electrophoretic mobility shift assay results indicated that the two RNA-recognition motifs(RRM)of BmLARK are simultaneously required for the binding with the G4 structure.Either RRM1 or RRM2 alone could not bind with the G4 structure.The zinc-finger motif was not involved in the binding.A series of mutant proteins with specific amino acid mutations were expressed and used to identify the key amino acid residues involving the interaction.The results indicated thatβsheets,especially theβ1 andβ3 sheets,in the RRM domains of BmLARK played critical roles in the binding with the G4 structure.Several amino acid mutations of RRM1/2 in ribonucleoprotein domain 1(RNP1)(motif inβ3 strand)and RNP2(motif inβ1 strand)caused loss of binding ability,indicating that these amino acids are the key sites for the binding.All the results suggest that RRM domains,particularly their the RNP1 and RNP2 motifs,play important roles not only in RNA recognition,but also in the G4 structure binding.
文摘Bursicon is a neuropeptide that regulates cuticle sclerotization （hardening and tanning） in insect via a G-protein coupled receptor. However, the signal transduction pathway downstream of the G-protein coupled receptor is currently not well known. In our recent microarray analysis, we identified a panel of genes regulated by bursicon in Drosophila. One of the genes, Suppressor of Hairless, or Su（H）, has drawn our attention because its product acts down-stream of the bursicon receptor. In the present study, we cloned the Drosophila homolog, mdSu（H）, from the house fly Musca domestica using 3＇ and 5＇ rapid amplification of complementary DNA ends. Real-time polymerase chain reaction analysis revealed that the level ofmdSu（H） transcript is up-regulated by ~3-fold 1 h after recombinant bursicon injection, which correlates well with the cuticle sclerotization process observed in the recombinant bursicon-injected flies. We infer that Su（H） is an essential gene involved in the insect cuticle sclerotization process.
