In this study,we searched for dispersed repeats(DRs)in the rice(Oryza sativa)genome using the iterative procedure(IP)method.The results revealed that the O.sativa genome contained 79 DR families,comprising 992739 DNA ...In this study,we searched for dispersed repeats(DRs)in the rice(Oryza sativa)genome using the iterative procedure(IP)method.The results revealed that the O.sativa genome contained 79 DR families,comprising 992739 DNA repeats,of which 496762 and 495977 were identified on the forward and reverse DNA strands,respectively.The detected DRs were,on average,374 bp in length and occupied 66.4%of the O.sativa genome.Totally 61%of DRs,identified by the IP method,overlapped with previously annotated dispersed repeats(ADRs)detected using the Extensive De Novo TE Annotator(EDTA)pipeline.展开更多
Objective To evaluate the effect of intranasal immunization with CTA1-DD as mucosal adjuvant combined with H3N2 split vaccine. Methods Mice were immunized intranasally with PBS(negative control), or H3N2 split vaccine...Objective To evaluate the effect of intranasal immunization with CTA1-DD as mucosal adjuvant combined with H3N2 split vaccine. Methods Mice were immunized intranasally with PBS(negative control), or H3N2 split vaccine(3 μg/mouse) alone, or CTA1-DD(5 μg/mouse) alone, or H3N2 split vaccine(3 μg/mouse) plus CTA1-DD(5 μg/mouse). Positive control mice were immunized intramuscularly with H3N2 split vaccine(3 μg/mouse) and alum adjuvant. All the mice were immunized twice, two weeks apart. Then sera and mucosal lavages were collected. The specific HI titers, IgM, IgG, IgA, and IgG subtypes were examined by ELISA. IFN-γ and IL-4 were test by ELISpot. In addition, two weeks after the last immunization, surivival after H3N2 virus lethal challenge was measured. Results H3N2 split vaccine formulated with CTA1-DD could elicit higher Ig M, Ig G and hemagglutination inhibition titers in sera. Furthermore, using CTA1-DD as adjuvant significantly improved mucosal secretory Ig A titers in bronchoalveolar lavages and vaginal lavages. Meanwhile this mucosal adjuvant could enhance Th-1-type responses and induce protective hemagglutination inhibition titers. Notably, the addition of CTA1-DD to split vaccine provided 100% protection against lethal infection by the H3N2 virus. Conclusion CTA1-DD could promote mucosal, humoral and cell-mediated immune responses, which supports the further development of CTA1-DD as a mucosal adjuvant for mucosal vaccines.展开更多
The phyA^m gene encoding acid phytase and optimized neutral phytase phyCs gene were inserted into expression vector pPIC9K in correct orientation and transformed into Pichiapastoris in order to expand the pH profile o...The phyA^m gene encoding acid phytase and optimized neutral phytase phyCs gene were inserted into expression vector pPIC9K in correct orientation and transformed into Pichiapastoris in order to expand the pH profile ofphytase and decrease the cost of production. The fusion phytase phyA^m-phyCs gene was successfully overexpressed in P. pastoris as an active and extracellular phytase. The yield of total extracellular fusion phytase activity is （25.4±0.53） U/ml at the flask scale and （159.1±2.92） U/ml for high cell-density fermentation, respectively. Purified fusion phytase exhibits an optimal temperature at 55 ℃ and an optimal pH at 5.5-6.0 and its relative activity remains at a relatively high level of above 70% in the range ofpH 2.0 to 7.0. About 51% to 63% of its original activity remains after incubation at 75 ℃ to 95 ℃ for 10 min. Due to heavy glycosylation, the expressed fusion phytase shows a broad and diffuse band in SDS-PAGE （sodium dodecyl sulfate-polyacrylamide gel electrophoresis）. After deglycosylation by endoglycosidase H （EndoHf）, the enzyme has an apparent molecular size of 95 kDa. The characterization of the fusion phytase was compared with those ofphyCs andphyA^m.展开更多
The posttranslational modification of proteins with complex carbohydrate moieties(glycosylation)regulates the process of fruit ripening.Exoglycosidases are enzymes that can trim this protein glycosylation and are ther...The posttranslational modification of proteins with complex carbohydrate moieties(glycosylation)regulates the process of fruit ripening.Exoglycosidases are enzymes that can trim this protein glycosylation and are therefore considered to be important targets in the control of fruit ripening and softening.Melting-type peaches are popular seasonal fruits in many Asian regions,but the extremely short shelf-life of the peach fruits significantly hampers their economic value.To investigate the effect of the protein glycosylation and exoglycosidase activities on the development and ripening of the peach fruit,the fruit flesh of the melting peach cultivar'Xia hui 6'at five different maturity stages were analyzed.The N-glycan profile of each sample was characterized and quantified by HILIC-UPLC and MALDI-TOF mass spectrometry,revealing two characteristic N-glycan structures(MMXF and GnGnMXF)which were strongly affected by the state of maturity.Furthermore,it was shown that one of the endogenous exoglycosidase activities analyzed(β-N-acetylhexosaminidase,β-Hex)correlated with the MMXF and GnGnMXF N-glycan structures(p<0.05)in an obverse manner.These findings lay the foundation for further elucidation of the physiological functions of protein glycosylation in peach fruit development and ripening.展开更多
Hepatitis B virus (HBV) is one of the major causes of chronic hepatitis, cirrhosis and liver cancer. In combating HBV infections, HBV diagnosis and vaccination are therefore critical. The hepatitis B virus surface ant...Hepatitis B virus (HBV) is one of the major causes of chronic hepatitis, cirrhosis and liver cancer. In combating HBV infections, HBV diagnosis and vaccination are therefore critical. The hepatitis B virus surface antigen (HBsAg) is a key target molecule in developing vaccines and diagnostic systems. To date, although HBsAg has been expressed in bacteria, yeasts and mammalian cells, there are still limitations in the existing ones, which leave the necessity for searching new HBsAg production methods. In this study, a simple phage display-based method was developed to produce the purified full-length HBsAg molecules for further immunization studies. For this purpose, the HBsAg coding gene was cloned into a pCANTAB5E phagemid vector and expressed on the surface of M13 filamentous phages. The HBsAg-expressing phage nanosystem was then used as immunization agent in BALB/cJ mice. The ELISA results for sera obtained from mice immunized with HBsAg-displaying phage particles revealed an immune response against HBsAg. These results demonstrate the potential use of a full-length antigen to be displayed on phages as cost effective adjuvant-free immunization agents as an alternative to the highly purified and more expensive antigens conjugated with carrier molecules.展开更多
We describe two novel approaches for the determination of glucosamine(GlcN).The first approach is based on the chemical derivatization of GlcN with the non-fluorophor 1,3-diphenyl-1,3-propanedione(DPPD),which results ...We describe two novel approaches for the determination of glucosamine(GlcN).The first approach is based on the chemical derivatization of GlcN with the non-fluorophor 1,3-diphenyl-1,3-propanedione(DPPD),which results in a condensation product with interesting fluorescent properties.The obtained compound was isolated by silica-gel chromatography and its structure elucidated by NMR and mass spectrometry.The second approach is based on a previously undescribed sensitivity of the enzyme glucosamine-6-phosphate deaminase(GPDA)towards GlcN,which resulted in the precipitation of the enzyme.Using a rational enzyme engineering approach and both liquid-based and plate-based screening methods,mutational GPDA variants with significantly improved precipitation properties were identified and characterized.These novel glucosamine detection methods may be a useful addition to the repertoire of currently available glucosamine detection sensors.展开更多
Plant-based systems offer a cost-effective platform for the production of pharmaceutical proteins;however,the instability and rapid degradation of certain proteins,such as epidermal growth factor(EGF),present signific...Plant-based systems offer a cost-effective platform for the production of pharmaceutical proteins;however,the instability and rapid degradation of certain proteins,such as epidermal growth factor(EGF),present significant challenges.To enhance EGF accumulation,we specifically targeted the protein to distinct subcellular compartments.In these experiments,most protein constructs contained a C-terminal hemagglutinin(HA)tag,enabling detection using anti-HA antibodies.Targeting EGF to the chloroplast and retained endoplasmic reticulum(ER)was successful,with significantly higher accumulation observed in the ER compared to the chloroplast(Figure S1A).展开更多
Dear Editor,Dichogamy is a temporal reproductive strategy in which male and female reproductive organs mature at different times,preventing self-fertilization and promoting outcrossing to maintain genetic diversity an...Dear Editor,Dichogamy is a temporal reproductive strategy in which male and female reproductive organs mature at different times,preventing self-fertilization and promoting outcrossing to maintain genetic diversity and support evolutionary adaptation(Goodwillie et al.,2005;Lee et al.,2018).Dichogamous species have evolved diverse and complex mating strategies,one of which involves the temporal separation of male and female reproductive phases within a single flower.Dichogamy has two main subtypes:protandry(PA)and protogyny(PG).In the context of a bisexual flower,PA occurs when the stamen matures and releases pollen before the stigma becomes receptive.PG is the reverse process,in which the pistil becomes receptive before the anther releases pollen.These phenomena,which were historically referred to as male-female and female-male sequences,have now been renamed PA and PG,respectively(Li et al.,2002;Li et al.,2001a;Li et al.,2001b).A number of Zingiberaceae species exhibit PA and PG morphs in bisexual flowers through stylar behavior(flexistyly)during flowering to encourage outcrossing.展开更多
Cervical spondylosis refers to degenerative changes in the sub-axial cervical spine.Symptoms caused by spondylosis include axial neck pain,cervical radiculopathy,and cervical myelopathy.One of the most commonly used s...Cervical spondylosis refers to degenerative changes in the sub-axial cervical spine.Symptoms caused by spondylosis include axial neck pain,cervical radiculopathy,and cervical myelopathy.One of the most commonly used surgical treatments is anterior cervical discectomy and fusion(ACDF);it is reported that ACDF leads to the development of progressive adjacent segment degeneration(ASD)in over 90%of the patients with up to 25.6%requiring reoperations due to symptomatic ASD.展开更多
Background： The prediction of the prokaryotic promoter strength based on its sequence is of great importance not only in the fundamental research of life sciences but also in the appfied aspect of synthetic biology. ...Background： The prediction of the prokaryotic promoter strength based on its sequence is of great importance not only in the fundamental research of life sciences but also in the appfied aspect of synthetic biology. Much advance has been made to build quantitative models for strength prediction, especially the introduction of machine learning methods such as artificial neural network （ANN） has significantly improve the prediction accuracy. As one of the most important machine learning methods, support vector machine （SVM） is more powerful to learn knowledge from small sample dataset and thus supposed to work in this problem. Methods： To confirm this, we constructed SVM based models to quantitatively predict the promoter strength. A library of 100 promoter sequences and strength values was randomly divided into two datasets, including a training set （≥10 sequences） for model training and a test set （≥ 10 sequences） for model test. Results： The results indicate that the prediction performance increases with an increase of the size of training set, and the best performance was achieved at the size of 90 sequences. After optimization of the model parameters, a high-performance model was finally trained, with a high squared correlation coefficient for fitting the training set （R^2〉 0.99） and the test set （R^2〉 0.98）, both of which are better than that of ANN obtained by our previous work. Conclusions： Our results demonstrate the SVM-based models can be employed for the quantitative prediction of promoter strength.展开更多
Natural products(NPs)continue to play a pivotal role in drug discovery programs.The rapid development of synthetic biology has conferred the strategies of NPs production.Synthetic biology is a new engineering discipli...Natural products(NPs)continue to play a pivotal role in drug discovery programs.The rapid development of synthetic biology has conferred the strategies of NPs production.Synthetic biology is a new engineering discipline that aims to produce desirable products by rationally programming the biological parts and manipulating the pathways.However,there is still a challenge for integrating a heterologous pathway in chassis cells for overproduction purpose due to the limited characterized parts,modules incompatibility,and cell tolerance towards product.Enormous endeavors have been taken for mentioned issues.Herein,in this review,the progresses in naturally discovering novel biological parts and rational design of synthetic biological parts are reviewed,combining with the advanced assembly technologies,pathway engineering,and pathway optimization in global network guidance.The future perspectives are also presented.展开更多
Nanotechnology and its applications to medicine,known as nanomedicine,involve a wide use of nanomaterials to stimulate and guide the regenerative properties of cells.In particular,tissue regeneration can be promoted b...Nanotechnology and its applications to medicine,known as nanomedicine,involve a wide use of nanomaterials to stimulate and guide the regenerative properties of cells.In particular,tissue regeneration can be promoted by enabling a controlled release of therapeutic agents,which can be done using nanoparticles.In this review article,the fundamentals of tissue regeneration are discussed,focusing on epithelial tissue,to demonstrate the importance of delivering therapeutic agents in an efficient,sustained and localized manner.Then,the methods for synthesizing metallic and polymeric nanoparticles are described.While polymeric nanoparticles can be loaded with an agent during synthesis,metallic nanoparticles must first be synthesized to later interact with therapeutic agents.This interaction can be fine-tuned by functionalizing metallic nanoparticles with organic molecules,which results in a more controlled attachment.This review highlights the importance of choosing the appropriate method of synthesis and functionalization,which must be designed considering both the type of tissue to regenerate and the nature of the agent to be transported.展开更多
Although CRISPR/Cas9 has been widely used in insect gene editing,the need for the microinjection of preblastoderm embryos can preclude the technique being used in insect species with eggs that are small,have hard shel...Although CRISPR/Cas9 has been widely used in insect gene editing,the need for the microinjection of preblastoderm embryos can preclude the technique being used in insect species with eggs that are small,have hard shells,and/or are difficult to collect and maintain outside of their normal environment.Such is the case with Sogatella furcifera,the white-backed planthopper(WBPH),a significant pest of Oryza sativa(rice)that oviposits inside rice stems.Egg extraction from the stem runs the risk of mechanical damage and hatching is heavily influenced by the micro-environment of the rice stem.To bypass these issues,we targeted embryos prior to oviposition via direct parental(DIPA)-CRISPR,in which Cas9 and single-guide RNAs(sgRNAs)for the WBPH eye pigment gene tryptophan 2,3-dioxygenase were injected into the hemocoel of adult females.Females at varying numbers of days posteclosion were evaluated to determine at what stage their oocyte might be most capable of taking up the gene-editing components.An evaluation of the offspring indicated that the highest G0 gene-edited efficacy(56.7%)occurred in females injected 2 d posteclosion,and that those mutations were heritably transmitted to the G1 generation.This study demonstrates the potential utility of DIPA-CRISPR for future gene-editing studies in non-model insect species and can facilitate the development of novel pest management applications.展开更多
基金supported by the Russian Science Foundation,Russia(Grant No.24-24-00031).
文摘In this study,we searched for dispersed repeats(DRs)in the rice(Oryza sativa)genome using the iterative procedure(IP)method.The results revealed that the O.sativa genome contained 79 DR families,comprising 992739 DNA repeats,of which 496762 and 495977 were identified on the forward and reverse DNA strands,respectively.The detected DRs were,on average,374 bp in length and occupied 66.4%of the O.sativa genome.Totally 61%of DRs,identified by the IP method,overlapped with previously annotated dispersed repeats(ADRs)detected using the Extensive De Novo TE Annotator(EDTA)pipeline.
基金supported by the Chinese National Science and Technology Major Project for Important Infectious Diseases Control and Prevention [Grant No.2017ZX10105015001002]
文摘Objective To evaluate the effect of intranasal immunization with CTA1-DD as mucosal adjuvant combined with H3N2 split vaccine. Methods Mice were immunized intranasally with PBS(negative control), or H3N2 split vaccine(3 μg/mouse) alone, or CTA1-DD(5 μg/mouse) alone, or H3N2 split vaccine(3 μg/mouse) plus CTA1-DD(5 μg/mouse). Positive control mice were immunized intramuscularly with H3N2 split vaccine(3 μg/mouse) and alum adjuvant. All the mice were immunized twice, two weeks apart. Then sera and mucosal lavages were collected. The specific HI titers, IgM, IgG, IgA, and IgG subtypes were examined by ELISA. IFN-γ and IL-4 were test by ELISpot. In addition, two weeks after the last immunization, surivival after H3N2 virus lethal challenge was measured. Results H3N2 split vaccine formulated with CTA1-DD could elicit higher Ig M, Ig G and hemagglutination inhibition titers in sera. Furthermore, using CTA1-DD as adjuvant significantly improved mucosal secretory Ig A titers in bronchoalveolar lavages and vaginal lavages. Meanwhile this mucosal adjuvant could enhance Th-1-type responses and induce protective hemagglutination inhibition titers. Notably, the addition of CTA1-DD to split vaccine provided 100% protection against lethal infection by the H3N2 virus. Conclusion CTA1-DD could promote mucosal, humoral and cell-mediated immune responses, which supports the further development of CTA1-DD as a mucosal adjuvant for mucosal vaccines.
基金the National Key Technologies R & D Program of China during the 10th Five-Year Plan Period (No. 2002BA514A-12)the Education Department of Sichuan Province (No. 2006B014)the Innovative Fund for Distinguished Young Scholars of Sichuan Agricultural University, China
文摘The phyA^m gene encoding acid phytase and optimized neutral phytase phyCs gene were inserted into expression vector pPIC9K in correct orientation and transformed into Pichiapastoris in order to expand the pH profile ofphytase and decrease the cost of production. The fusion phytase phyA^m-phyCs gene was successfully overexpressed in P. pastoris as an active and extracellular phytase. The yield of total extracellular fusion phytase activity is （25.4±0.53） U/ml at the flask scale and （159.1±2.92） U/ml for high cell-density fermentation, respectively. Purified fusion phytase exhibits an optimal temperature at 55 ℃ and an optimal pH at 5.5-6.0 and its relative activity remains at a relatively high level of above 70% in the range ofpH 2.0 to 7.0. About 51% to 63% of its original activity remains after incubation at 75 ℃ to 95 ℃ for 10 min. Due to heavy glycosylation, the expressed fusion phytase shows a broad and diffuse band in SDS-PAGE （sodium dodecyl sulfate-polyacrylamide gel electrophoresis）. After deglycosylation by endoglycosidase H （EndoHf）, the enzyme has an apparent molecular size of 95 kDa. The characterization of the fusion phytase was compared with those ofphyCs andphyA^m.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions (grant KYZ201824 to Ting Wang)the National Natural Science Foundation of China (NSFC grants 31471703,31671854,31871793 and 31871754 to Josef Voglmeir and Li Liu).
文摘The posttranslational modification of proteins with complex carbohydrate moieties(glycosylation)regulates the process of fruit ripening.Exoglycosidases are enzymes that can trim this protein glycosylation and are therefore considered to be important targets in the control of fruit ripening and softening.Melting-type peaches are popular seasonal fruits in many Asian regions,but the extremely short shelf-life of the peach fruits significantly hampers their economic value.To investigate the effect of the protein glycosylation and exoglycosidase activities on the development and ripening of the peach fruit,the fruit flesh of the melting peach cultivar'Xia hui 6'at five different maturity stages were analyzed.The N-glycan profile of each sample was characterized and quantified by HILIC-UPLC and MALDI-TOF mass spectrometry,revealing two characteristic N-glycan structures(MMXF and GnGnMXF)which were strongly affected by the state of maturity.Furthermore,it was shown that one of the endogenous exoglycosidase activities analyzed(β-N-acetylhexosaminidase,β-Hex)correlated with the MMXF and GnGnMXF N-glycan structures(p<0.05)in an obverse manner.These findings lay the foundation for further elucidation of the physiological functions of protein glycosylation in peach fruit development and ripening.
文摘Hepatitis B virus (HBV) is one of the major causes of chronic hepatitis, cirrhosis and liver cancer. In combating HBV infections, HBV diagnosis and vaccination are therefore critical. The hepatitis B virus surface antigen (HBsAg) is a key target molecule in developing vaccines and diagnostic systems. To date, although HBsAg has been expressed in bacteria, yeasts and mammalian cells, there are still limitations in the existing ones, which leave the necessity for searching new HBsAg production methods. In this study, a simple phage display-based method was developed to produce the purified full-length HBsAg molecules for further immunization studies. For this purpose, the HBsAg coding gene was cloned into a pCANTAB5E phagemid vector and expressed on the surface of M13 filamentous phages. The HBsAg-expressing phage nanosystem was then used as immunization agent in BALB/cJ mice. The ELISA results for sera obtained from mice immunized with HBsAg-displaying phage particles revealed an immune response against HBsAg. These results demonstrate the potential use of a full-length antigen to be displayed on phages as cost effective adjuvant-free immunization agents as an alternative to the highly purified and more expensive antigens conjugated with carrier molecules.
基金supported in parts by the National Natural Science Foundation of China (grant numbers 31471703,31671854,and 31871754)the 100 Foreign Talents Plan (grant number JSB2014012).
文摘We describe two novel approaches for the determination of glucosamine(GlcN).The first approach is based on the chemical derivatization of GlcN with the non-fluorophor 1,3-diphenyl-1,3-propanedione(DPPD),which results in a condensation product with interesting fluorescent properties.The obtained compound was isolated by silica-gel chromatography and its structure elucidated by NMR and mass spectrometry.The second approach is based on a previously undescribed sensitivity of the enzyme glucosamine-6-phosphate deaminase(GPDA)towards GlcN,which resulted in the precipitation of the enzyme.Using a rational enzyme engineering approach and both liquid-based and plate-based screening methods,mutational GPDA variants with significantly improved precipitation properties were identified and characterized.These novel glucosamine detection methods may be a useful addition to the repertoire of currently available glucosamine detection sensors.
基金funded by the Korean Research Institute Bio-science and Biotechnology(KRIBB)Research Initiative Programs Grant Nos.KGM9942522,KGM1082511,KGM1002521National Research Foundation of Korea(NRF)Grant No.RS-2025-00556557New Breeding Technology Program Grant No.RS-2024-00322156 to H.C.
文摘Plant-based systems offer a cost-effective platform for the production of pharmaceutical proteins;however,the instability and rapid degradation of certain proteins,such as epidermal growth factor(EGF),present significant challenges.To enhance EGF accumulation,we specifically targeted the protein to distinct subcellular compartments.In these experiments,most protein constructs contained a C-terminal hemagglutinin(HA)tag,enabling detection using anti-HA antibodies.Targeting EGF to the chloroplast and retained endoplasmic reticulum(ER)was successful,with significantly higher accumulation observed in the ER compared to the chloroplast(Figure S1A).
基金supported by the Scientific and Technological Innovation Project of the China Academy of Chinese Medical Sciences(CI2023E002)the YEFICRC project of Yunnan provincial key programs(2019ZG009)the National Science and Technology Resource Sharing Service Platform Project(NTPGRC2023-01).
文摘Dear Editor,Dichogamy is a temporal reproductive strategy in which male and female reproductive organs mature at different times,preventing self-fertilization and promoting outcrossing to maintain genetic diversity and support evolutionary adaptation(Goodwillie et al.,2005;Lee et al.,2018).Dichogamous species have evolved diverse and complex mating strategies,one of which involves the temporal separation of male and female reproductive phases within a single flower.Dichogamy has two main subtypes:protandry(PA)and protogyny(PG).In the context of a bisexual flower,PA occurs when the stamen matures and releases pollen before the stigma becomes receptive.PG is the reverse process,in which the pistil becomes receptive before the anther releases pollen.These phenomena,which were historically referred to as male-female and female-male sequences,have now been renamed PA and PG,respectively(Li et al.,2002;Li et al.,2001a;Li et al.,2001b).A number of Zingiberaceae species exhibit PA and PG morphs in bisexual flowers through stylar behavior(flexistyly)during flowering to encourage outcrossing.
基金This study was supported by the National Institutes of Health(1R03AG056897),and the first author was funded by a doctor scholarship(GZSYBS[2017]12)from the Guizhou Provincial People's Hospital,Guiyang,China.
文摘Cervical spondylosis refers to degenerative changes in the sub-axial cervical spine.Symptoms caused by spondylosis include axial neck pain,cervical radiculopathy,and cervical myelopathy.One of the most commonly used surgical treatments is anterior cervical discectomy and fusion(ACDF);it is reported that ACDF leads to the development of progressive adjacent segment degeneration(ASD)in over 90%of the patients with up to 25.6%requiring reoperations due to symptomatic ASD.
基金This work was financially supported by NSFC （Nos. 31471270, 31301017, 31670056 and 31300686）, 973 Program （No. 2014CB745202）, 863 Program （No. SS2015AA020936）, the Guangdong Natural Science Funds for Distinguished Young Scholar （No. S2013050016987）, the Science and Technology Planning Project of Guangdong Province （Nos. 2014B 020201001 and 2014A030304008）, Natural Science Foundation of Guangdong Province （No. 2015A030310317）, the Guangzhou Science and Technology Scheme （Nos. 201508020091 and 201508020092）, and Shenzhen grants （Nos. KQTD2015033117210153, JCYJ20140610152828703, KQJSCX20160301144623, CXZZ20140901004122088, JCYJ20150 521144321007 and JCYJ20140901003939019）.
文摘Background： The prediction of the prokaryotic promoter strength based on its sequence is of great importance not only in the fundamental research of life sciences but also in the appfied aspect of synthetic biology. Much advance has been made to build quantitative models for strength prediction, especially the introduction of machine learning methods such as artificial neural network （ANN） has significantly improve the prediction accuracy. As one of the most important machine learning methods, support vector machine （SVM） is more powerful to learn knowledge from small sample dataset and thus supposed to work in this problem. Methods： To confirm this, we constructed SVM based models to quantitatively predict the promoter strength. A library of 100 promoter sequences and strength values was randomly divided into two datasets, including a training set （≥10 sequences） for model training and a test set （≥ 10 sequences） for model test. Results： The results indicate that the prediction performance increases with an increase of the size of training set, and the best performance was achieved at the size of 90 sequences. After optimization of the model parameters, a high-performance model was finally trained, with a high squared correlation coefficient for fitting the training set （R^2〉 0.99） and the test set （R^2〉 0.98）, both of which are better than that of ANN obtained by our previous work. Conclusions： Our results demonstrate the SVM-based models can be employed for the quantitative prediction of promoter strength.
基金the National Basic Research Program of China(“973”Program,grant No.2012CB721104)the National Natural Science Foundation of China(grant No.31170101).
文摘Natural products(NPs)continue to play a pivotal role in drug discovery programs.The rapid development of synthetic biology has conferred the strategies of NPs production.Synthetic biology is a new engineering discipline that aims to produce desirable products by rationally programming the biological parts and manipulating the pathways.However,there is still a challenge for integrating a heterologous pathway in chassis cells for overproduction purpose due to the limited characterized parts,modules incompatibility,and cell tolerance towards product.Enormous endeavors have been taken for mentioned issues.Herein,in this review,the progresses in naturally discovering novel biological parts and rational design of synthetic biological parts are reviewed,combining with the advanced assembly technologies,pathway engineering,and pathway optimization in global network guidance.The future perspectives are also presented.
基金funded by FONDECYT-CONCYTEC(155-2015-FONDECYT)the partnership Cleveland Clinic-Universidad de Ingenieria y Tecnologia-UTEC。
文摘Nanotechnology and its applications to medicine,known as nanomedicine,involve a wide use of nanomaterials to stimulate and guide the regenerative properties of cells.In particular,tissue regeneration can be promoted by enabling a controlled release of therapeutic agents,which can be done using nanoparticles.In this review article,the fundamentals of tissue regeneration are discussed,focusing on epithelial tissue,to demonstrate the importance of delivering therapeutic agents in an efficient,sustained and localized manner.Then,the methods for synthesizing metallic and polymeric nanoparticles are described.While polymeric nanoparticles can be loaded with an agent during synthesis,metallic nanoparticles must first be synthesized to later interact with therapeutic agents.This interaction can be fine-tuned by functionalizing metallic nanoparticles with organic molecules,which results in a more controlled attachment.This review highlights the importance of choosing the appropriate method of synthesis and functionalization,which must be designed considering both the type of tissue to regenerate and the nature of the agent to be transported.
基金supported by:the National Natural Science Foundation of China(grants 32370527,for PH,and 32260671,for MH)the Scientific Research Foundation of Guizhou University of China(grant 2017-33,for MH)+3 种基金the Program of Talent Cultivation of Guizhou University(grant(2019)05,for PH)the Science and Technology Support of Guizhou province(grant QKH(2017)2956,for MH)the Program of Introducing Talents of Discipline to Universities of China(111 Program,D20023)the Frontiers Science Center for Asymmetric Synthesis and Medicinal Molecules,Department of Education,Guizhou Province(Qianjiaohe KY number(2020)004).
文摘Although CRISPR/Cas9 has been widely used in insect gene editing,the need for the microinjection of preblastoderm embryos can preclude the technique being used in insect species with eggs that are small,have hard shells,and/or are difficult to collect and maintain outside of their normal environment.Such is the case with Sogatella furcifera,the white-backed planthopper(WBPH),a significant pest of Oryza sativa(rice)that oviposits inside rice stems.Egg extraction from the stem runs the risk of mechanical damage and hatching is heavily influenced by the micro-environment of the rice stem.To bypass these issues,we targeted embryos prior to oviposition via direct parental(DIPA)-CRISPR,in which Cas9 and single-guide RNAs(sgRNAs)for the WBPH eye pigment gene tryptophan 2,3-dioxygenase were injected into the hemocoel of adult females.Females at varying numbers of days posteclosion were evaluated to determine at what stage their oocyte might be most capable of taking up the gene-editing components.An evaluation of the offspring indicated that the highest G0 gene-edited efficacy(56.7%)occurred in females injected 2 d posteclosion,and that those mutations were heritably transmitted to the G1 generation.This study demonstrates the potential utility of DIPA-CRISPR for future gene-editing studies in non-model insect species and can facilitate the development of novel pest management applications.
