The ubiquitously expressed transmembrane enzyme Na,K-ATPase(NKA)is vital in maintaining functionality of cells.The association of α-and β-subunits is believed to be essential for forming a functional enzyme.In the l...The ubiquitously expressed transmembrane enzyme Na,K-ATPase(NKA)is vital in maintaining functionality of cells.The association of α-and β-subunits is believed to be essential for forming a functional enzyme.In the large milkweed bug Oncopeltus fasciatus fourα1-paralogs and four β-subunits exist that can associate into NKA complexes.This diversity raises the question of possible tissue-specific distribution and function.While the α1-subunits are known to modulate cardenolide-resistance and ion-transport efficiency,the functional importance of the β-subunits needed further investigation.We here characterize all four different β-subunits at the cellular,tissue,and whole organismal scales.A knockdown of different β-subunits heavily interferes with molting success resulting in strongly hampered phenotypes.The failure of ecdysis might be related to disrupted septate junction(SJ)formation,also reflected in β2-suppression-induced alteration in tracheal morphology.Our data further suggest the existence of isolated β-subunits forming homomeric or β-heteromeric complexes.This possible standalone and structure-specific distribution of the β-subunits predicts further,yet unknown pump-independent functions.The different effects caused byβknockdowns highlight the importance of the various β-subunits to fulfill tissue-specific requirements.展开更多
Henosepilachna vigintioctopunctata is a serious insect pest which attacks a large number of nightshades and cucurbits in Asian countries,Brazil and Australia.Prolonged application of traditional pesticides has caused ...Henosepilachna vigintioctopunctata is a serious insect pest which attacks a large number of nightshades and cucurbits in Asian countries,Brazil and Australia.Prolonged application of traditional pesticides has caused environmental pollution and exerted deleterious effects on human health.Finding new approaches with high target specificity and low environmental contamination has become an urgent task.RNA interference(RNAi)induced by double-stranded RNA(dsRNA)is expected to be applicable to managing this pest.Here we evaluated the effects of Escherichia co/Z-expressed dsRNAs targeting ecdvsone receptor(EcR)gene via dietary delivery in laboratory and foliar spraying in a greenhouse.The target transcript was successfully knocked down when the 4th-instar larvae had fed on potatofoliage dipped with dsEcR in a laboratory bioassay.Around 85%of the HvEcR RNAi larvae remained as prepupae or became abnormal pupae,and failed to emerge into adults.Ingestion of ds£c7?-immersed foliage by the 3rd-instar larvae effectuated a comparable RNAi response and brought about more severe defects:all the resultant larvae arrested development,remained as prepupae and finally died.For assay in the greenhouse,a ds£c7?-contained E.coli suspension was directly sprayed to the foliage of greenhouse-growing potato plants and the 3rd-and 4th-instar larvae were transferred to the leaves.High RNAi efficacy was obtained and identical RNAi phenotypes were observed in treated larvae.In addition,spraying dsEcR reduced leaf damage.Our results indicate a possibility of practical application of dsEcR as an environmentally friendly RNA pesticide to control H.vigintioctopunctata larvae.展开更多
Insect molting and metamorphosis are regulated by 20-hydroxyecdysone, which activates the ecdysone receptors, followed by expression of a series of transcription factors. Beta Fushi Tarazu-Factor 1 （βFTZ-F1） is one...Insect molting and metamorphosis are regulated by 20-hydroxyecdysone, which activates the ecdysone receptors, followed by expression of a series of transcription factors. Beta Fushi Tarazu-Factor 1 （βFTZ-F1） is one of these ecdysis-related earlyexpressed transcription factors. A βFTZ-F1 complementary DNA （cDNA） was cloned from Spodoptera litura. The full-length cDNA was 2 194 bp in length and the open reading frame ofS1βFTZ-F1 cDNA consisted of 1 659 bp and encoded a 552-amino acid protein with a molecular mass of 61.4 kDa. Homology analysis revealed that S1βFTZ-F 1 protein shared high identities to its homologues from other species. The A/B domains and the D domains were diverse among the insectβFTZ-F 1 proteins, but DNA binding domains （C domain） and the ligand binding domains （E domain） were highly conserved. Northern blot analysis detected a transcript of 2.2 kb in the epidermis of fifth to sixth molting larvae. Reverse transcription polymerase chain reaction revealed that SIβFTZ-F1 gene started to increasingly and periodically express before each molt, followed by a decrease during the intermolt stages.展开更多
The transcription factor grainy head(Grh)functions in the protection of the epithelium against the external environment by generating strongly adhesive layers,and this function is conserved in vertebrates and inverteb...The transcription factor grainy head(Grh)functions in the protection of the epithelium against the external environment by generating strongly adhesive layers,and this function is conserved in vertebrates and invertebrates.In Drosophila,the top model for holometabolous insects,Grh is necessary during embryonic development,epidermal differentiation,central nervous system specification and epithelial repair.However,the function of this gene in hemimetabolous insect epithelia remains unknown.To examine the function of Grh signaling in regulating epithelium development in Hemimetabola,we focused on the Blattella germanica epidermal layer using a gene knockdown strategy.The spatiotemporal expression pattern of BgGrh was detected,and knockdown of Bg-Grh and BgCad96ca,which provide positive feedback to BgGrh,caused severe defects in new epithelium development and impeded the molting process required to discard the old integument.Knockdown of the expression of BgGrh and BgCad96ca caused increased expression of chitin synthase gene{BgCHSl)and chitinase gene{BgCht5),the upregulations of which should be mediated by the higher level of hormone receptor 3{BgHr3)gene.In conclusion,epithelium development is regulated by Grh signaling,which might represent a potential target for the control of urban pest cockroaches.展开更多
Infections by mosquito-borne diseases represent one of the leading causes of death in third world countries.The rapid progression of resistance to conventional insecticide causes a significant threat to the highly eff...Infections by mosquito-borne diseases represent one of the leading causes of death in third world countries.The rapid progression of resistance to conventional insecticide causes a significant threat to the highly efficient preventive methods currently in place.Insect neuropeptidergic system offers potential targets to control the insect vectors.The essential roles of the neuropeptide ecdysis triggering hormone(ETH)in insect development and reproduction led us to attempt understanding of the fundamentals of the biochemical interaction between ETH and its receptor in the African malaria mosquito Anopheles gambiae.One of two ETH peptides of the African malaria mosquito(AgETH1),a small peptide hormone with 17 amino acid residues(SESPGFFIKLSKSVPRI-NH2),was studied to elucidate its molecular structure.N-termini deletions and mutations of conserved amino acids in the ligand revealed the critical residues for the receptor activation.The solution structure of AgETH1 using 2D 1H-1H nuclear magnetic resonance(NMR)spectroscopy and nuclear overhauser effect(NOE)derived constraints revealed a short alpha helix between residues 3S and 11S.The NMR solution structure of AgETH1 will be of significant assistance for designing a new class of insecticidal compounds that acts on the AgETH receptor aiming for in silico docking studies.展开更多
文摘The ubiquitously expressed transmembrane enzyme Na,K-ATPase(NKA)is vital in maintaining functionality of cells.The association of α-and β-subunits is believed to be essential for forming a functional enzyme.In the large milkweed bug Oncopeltus fasciatus fourα1-paralogs and four β-subunits exist that can associate into NKA complexes.This diversity raises the question of possible tissue-specific distribution and function.While the α1-subunits are known to modulate cardenolide-resistance and ion-transport efficiency,the functional importance of the β-subunits needed further investigation.We here characterize all four different β-subunits at the cellular,tissue,and whole organismal scales.A knockdown of different β-subunits heavily interferes with molting success resulting in strongly hampered phenotypes.The failure of ecdysis might be related to disrupted septate junction(SJ)formation,also reflected in β2-suppression-induced alteration in tracheal morphology.Our data further suggest the existence of isolated β-subunits forming homomeric or β-heteromeric complexes.This possible standalone and structure-specific distribution of the β-subunits predicts further,yet unknown pump-independent functions.The different effects caused byβknockdowns highlight the importance of the various β-subunits to fulfill tissue-specific requirements.
基金This research was supported by the N ational Key R&D Program of China(2017YFD0200900)China A griculture Research System(CARS-09-P22).
文摘Henosepilachna vigintioctopunctata is a serious insect pest which attacks a large number of nightshades and cucurbits in Asian countries,Brazil and Australia.Prolonged application of traditional pesticides has caused environmental pollution and exerted deleterious effects on human health.Finding new approaches with high target specificity and low environmental contamination has become an urgent task.RNA interference(RNAi)induced by double-stranded RNA(dsRNA)is expected to be applicable to managing this pest.Here we evaluated the effects of Escherichia co/Z-expressed dsRNAs targeting ecdvsone receptor(EcR)gene via dietary delivery in laboratory and foliar spraying in a greenhouse.The target transcript was successfully knocked down when the 4th-instar larvae had fed on potatofoliage dipped with dsEcR in a laboratory bioassay.Around 85%of the HvEcR RNAi larvae remained as prepupae or became abnormal pupae,and failed to emerge into adults.Ingestion of ds£c7?-immersed foliage by the 3rd-instar larvae effectuated a comparable RNAi response and brought about more severe defects:all the resultant larvae arrested development,remained as prepupae and finally died.For assay in the greenhouse,a ds£c7?-contained E.coli suspension was directly sprayed to the foliage of greenhouse-growing potato plants and the 3rd-and 4th-instar larvae were transferred to the leaves.High RNAi efficacy was obtained and identical RNAi phenotypes were observed in treated larvae.In addition,spraying dsEcR reduced leaf damage.Our results indicate a possibility of practical application of dsEcR as an environmentally friendly RNA pesticide to control H.vigintioctopunctata larvae.
基金Acknowledgments This study was supported by grants of the ＂973＂ National Basic Research Program of China （2010CB 126100）, Natural Science Foundation of Guangdong Province （No. 06105204）.
文摘Insect molting and metamorphosis are regulated by 20-hydroxyecdysone, which activates the ecdysone receptors, followed by expression of a series of transcription factors. Beta Fushi Tarazu-Factor 1 （βFTZ-F1） is one of these ecdysis-related earlyexpressed transcription factors. A βFTZ-F1 complementary DNA （cDNA） was cloned from Spodoptera litura. The full-length cDNA was 2 194 bp in length and the open reading frame ofS1βFTZ-F1 cDNA consisted of 1 659 bp and encoded a 552-amino acid protein with a molecular mass of 61.4 kDa. Homology analysis revealed that S1βFTZ-F 1 protein shared high identities to its homologues from other species. The A/B domains and the D domains were diverse among the insectβFTZ-F 1 proteins, but DNA binding domains （C domain） and the ligand binding domains （E domain） were highly conserved. Northern blot analysis detected a transcript of 2.2 kb in the epidermis of fifth to sixth molting larvae. Reverse transcription polymerase chain reaction revealed that SIβFTZ-F1 gene started to increasingly and periodically express before each molt, followed by a decrease during the intermolt stages.
基金This work was supported by the National Natural Science Foundation of China(Grant No.31702055,No.31572325 and No.31702021)CR.SL and ED,by the Natural Science Foundation of Guangdong Province(Grant No.2020A1515011267)+4 种基金CR,by the National Key Research and Development Project(Grant No.2019YFD1002102)CR and YL,by the Department of Science and Technology in Guangdong Province(Grant No.2019B090905003 and 2019A0102006)Shenzhen Science and Technology Program(Grant No.KQTD20180411143628272)SL.The strategies for cockroach management mentioned in this work have been included in a Chinese patent application(201910977154.9201910976989.2).
文摘The transcription factor grainy head(Grh)functions in the protection of the epithelium against the external environment by generating strongly adhesive layers,and this function is conserved in vertebrates and invertebrates.In Drosophila,the top model for holometabolous insects,Grh is necessary during embryonic development,epidermal differentiation,central nervous system specification and epithelial repair.However,the function of this gene in hemimetabolous insect epithelia remains unknown.To examine the function of Grh signaling in regulating epithelium development in Hemimetabola,we focused on the Blattella germanica epidermal layer using a gene knockdown strategy.The spatiotemporal expression pattern of BgGrh was detected,and knockdown of Bg-Grh and BgCad96ca,which provide positive feedback to BgGrh,caused severe defects in new epithelium development and impeded the molting process required to discard the old integument.Knockdown of the expression of BgGrh and BgCad96ca caused increased expression of chitin synthase gene{BgCHSl)and chitinase gene{BgCht5),the upregulations of which should be mediated by the higher level of hormone receptor 3{BgHr3)gene.In conclusion,epithelium development is regulated by Grh signaling,which might represent a potential target for the control of urban pest cockroaches.
基金supported by National Institutes of Health(NIH)grants NIH-NIAID R21 AI135457 and AI163423,1S10OD026726 and USDA-NIFA,GRANT13066347thank the Terry Johnson Cancer Research Center of Kansas State University and K-INBRE(NIH Grant P20GM103418)programs for supporting NMR studies.Contribution number 22-200-J from the Kansas Agricultural Experiment Station.
文摘Infections by mosquito-borne diseases represent one of the leading causes of death in third world countries.The rapid progression of resistance to conventional insecticide causes a significant threat to the highly efficient preventive methods currently in place.Insect neuropeptidergic system offers potential targets to control the insect vectors.The essential roles of the neuropeptide ecdysis triggering hormone(ETH)in insect development and reproduction led us to attempt understanding of the fundamentals of the biochemical interaction between ETH and its receptor in the African malaria mosquito Anopheles gambiae.One of two ETH peptides of the African malaria mosquito(AgETH1),a small peptide hormone with 17 amino acid residues(SESPGFFIKLSKSVPRI-NH2),was studied to elucidate its molecular structure.N-termini deletions and mutations of conserved amino acids in the ligand revealed the critical residues for the receptor activation.The solution structure of AgETH1 using 2D 1H-1H nuclear magnetic resonance(NMR)spectroscopy and nuclear overhauser effect(NOE)derived constraints revealed a short alpha helix between residues 3S and 11S.The NMR solution structure of AgETH1 will be of significant assistance for designing a new class of insecticidal compounds that acts on the AgETH receptor aiming for in silico docking studies.
