Host expansion facilitates tephritid flies to expand their ranges.Unraveling the mechanisms of host expansion will help to efficiently control these pests.Our previous works showed mitochondrial complex I genes Ndufs1...Host expansion facilitates tephritid flies to expand their ranges.Unraveling the mechanisms of host expansion will help to efficiently control these pests.Our previous works showed mitochondrial complex I genes Ndufs1,Ndufs3,and Ndufa7 being upregulated during host expansion of Bactrocera tau(Walker),one of the highly hazardous species of tephritids.However,their roles in the host expansion of B.tau remain unknown.Here,using clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease 9(Cas9)editing system for the first time,a stable homozygous Ndufa7 strain(Btndufa7^(-/-)),heterozygous Ndufs1(Btndufs1^(+/-)),and Ndufs3 strains(Btndufs3^(+/-))were obtained from F3 generation of B.tau,after gene knockout.Reduced sizes of larvae and pupae of the Ndufa7 knockout strain were first observed.Notably,the mean values of fitness estimation(pupal numbers,single-pupal weight and emergence rate)and Ndufa7 gene expression in the Ndufa7 knockout strain were slightly reduced on 2 native hosts(summer squash and cucumber),while it sharply decreased on the novel host banana and the potential host pitaya,compared with those of the wild-type strain.Furthermore,the Ndufa7 knockout strain did not survive on the novel host guava.These results suggested that Ndufa7 disturbs the survival on native hosts,expansion to novel hosts,and further expansion to potential hosts of B.tau.Homozygous lethality occurred after the knockout of Ndufs1 or Ndufs3,suggesting that these 2 genes play a role in the early development of B.tau.This study revealed that Ndufa7 is a target gene for the management of tephritids and opens a new avenue for pest control research.展开更多
The Mexican fruit fly,Anastrepha ludens,is a polyphagous pest that is a constant threat to US agriculture because of its proximity to citrus production in border region of the United States and Mexico.Sterile Insect T...The Mexican fruit fly,Anastrepha ludens,is a polyphagous pest that is a constant threat to US agriculture because of its proximity to citrus production in border region of the United States and Mexico.Sterile Insect Technique has been used to manage and eradicate of the Mexican Fruit Fly.SIT,however,requires millions of sterile male flies to be released each week from mass-rearing facilities.The mass-reared colonies must deal with microbial infections that reduce survivorship,fecundity and male-male competition.Meta-transcriptomics joins culturing and next generation DNA sequencing techniques to understand these changing microbial communities.This study uses advances in microbial meta-transcriptome sequencing to analyze the microbial communities from the four major developmental stages of A.ludens.The composition of the microbial communities was analyzed and revealed the large transcriptional presence of the phyla Microsporidia,a known animal pathogen.Clustering and ordination analyses revealed groupings based on developmental phase for egg,larvae and pupa.Adult samples had little clustering;a not unexpected result given the known turn-over in microbial community that occurs in the first 5 d after pupation.The transcriptional activity of three known pathogens of A.ludens between developmental phases were investigated.Two of the three pathogens had significant transcriptional differences between the phases with the larvae phase having the most activity.This increase in transcriptional activity agrees with culture-based surveillance and current mitigation strategies employed in the mass-rearing facility.This result reinforces the utility of transcriptomics in combating microbial threats.展开更多
For almost a decade,natural populations of the South American fruit fly have been targeted for control through Sterile Insect Technique projects.To ensure a sustainable supply of competitive sterile flies for this app...For almost a decade,natural populations of the South American fruit fly have been targeted for control through Sterile Insect Technique projects.To ensure a sustainable supply of competitive sterile flies for this approach,it is essential to understand the effects of domestication when strains of this pest are initially brought into the laboratory to establish colonies as well as the changes occurring after multiple generations of adaptation to conditions used for mass rearing.Using one colony established from a wild population of the Brazil-1 morphotype(WIL)and two from laboratory colonies in Brazil known as the Piracicaba(PL)and Vacaria(VL)strains,this study evaluated genetic diversity in samples from 10 generations after domestication and maintenance under semimass rearing conditions.Another aim of this study was to analyze changes in the genetic makeup of the colonies of the two laboratory strains after refreshment.Eight microsatellite markers were used for the genetic analyses.Results indicated a moderate but significant amount of genetic differentiation between the WIL population and the two laboratory strains.Results also showed that levels of genetic diversity in both the VL and PL strains were maintained at similar levels over a period of more than two years of rearing.Additionally,results suggest that successful creation of admixture via refreshment is more likely to be beneficial in relatively short-term domesticated colonies,and that performing refreshment approximately every six to eight generations could be beneficial to maintain the genetic diversity of A.fraterculus colonies under laboratory mass rearing conditions.展开更多
Insects employ various types of gustatory receptors(GRs)to identify nutrient-rich food and avoid toxic substances.The larval gustatory system is the critical checkpoint for food acceptance or rejection.As a specialist...Insects employ various types of gustatory receptors(GRs)to identify nutrient-rich food and avoid toxic substances.The larval gustatory system is the critical checkpoint for food acceptance or rejection.As a specialist herbivore,the larvae of Bactrocera minax feed only on unripe citrus fruits.However,how larvae use GRs to check and adapt to the secondary metabolites in unripe citrus fruits remains unknown.In this study,we first performed developmental expression profiles showing that most BminGRs genes were highly expressed in 1st and 2nd instar larvae and that tissue-specific expression indicated high expression of most BminGRs genes in the mouthparts of 2nd instar larvae.Furthermore,we found that silencing BminGR59f by RNA interference(RNAi)affected the growth of 2nd instar B.minax larvae.Hesperidin and naringin were screened as ligands of BminGR59f via RNAi and cell calcium imaging,and the combination of these two flavones increased the body weight of larvae.In summary,we identified a novel gustatory perception pattern in B.minax for detecting hesperidin and naringin,which boosted the growth of B.minax larvae.These results shed light on how specialist herbivores detect and adapt to host metbolites in adverse environments depending on larval GRs.展开更多
Investigations on microbial symbioses in Tephritidae have increased over the past 30 years owing to the potential use of these relationships in developing new control strategies for economically important fruit flies....Investigations on microbial symbioses in Tephritidae have increased over the past 30 years owing to the potential use of these relationships in developing new control strategies for economically important fruit flies.Bactrocera oleae(Rossi)—the olive fruit fly—is a monophagous species strictly associated with the olive tree,and among all the tephritids,its symbionts are the most investigated.The bacterium Candidatus Erwinia dacicola is the major persistent resident endosymbiont in wild B.oleae populations.Its relationship with B.oleae has been investigated since being identified in 2005.This endosymbiont is vertically transmitted through generations from the female to the egg.It exists at every developmental stage,although it is more abundant in larvae and ovipositing females,and is necessary for both larvae and adults.Studying B.oleae–Ca.E.dacicola,or other B.oleae–microbe interactions,will allow us to develop modern biological control systems for area-wide olive protection and set an example for similar programs in other important food crops.This review summarizes the information available on tephritid–microbe interactions and investigates relationships among fruit flies,bacteria and host plants;however,its focus is on B.oleae and its strict association with Ca.E.dacicola to promote environmentally friendly control strategies for area-wide pest management.展开更多
基金supported by grants from the National Science Foundation of China(32060314,32271563 and 32471568)the Science and Technology Program of Yunnan Province(202401AS070151).
文摘Host expansion facilitates tephritid flies to expand their ranges.Unraveling the mechanisms of host expansion will help to efficiently control these pests.Our previous works showed mitochondrial complex I genes Ndufs1,Ndufs3,and Ndufa7 being upregulated during host expansion of Bactrocera tau(Walker),one of the highly hazardous species of tephritids.However,their roles in the host expansion of B.tau remain unknown.Here,using clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease 9(Cas9)editing system for the first time,a stable homozygous Ndufa7 strain(Btndufa7^(-/-)),heterozygous Ndufs1(Btndufs1^(+/-)),and Ndufs3 strains(Btndufs3^(+/-))were obtained from F3 generation of B.tau,after gene knockout.Reduced sizes of larvae and pupae of the Ndufa7 knockout strain were first observed.Notably,the mean values of fitness estimation(pupal numbers,single-pupal weight and emergence rate)and Ndufa7 gene expression in the Ndufa7 knockout strain were slightly reduced on 2 native hosts(summer squash and cucumber),while it sharply decreased on the novel host banana and the potential host pitaya,compared with those of the wild-type strain.Furthermore,the Ndufa7 knockout strain did not survive on the novel host guava.These results suggested that Ndufa7 disturbs the survival on native hosts,expansion to novel hosts,and further expansion to potential hosts of B.tau.Homozygous lethality occurred after the knockout of Ndufs1 or Ndufs3,suggesting that these 2 genes play a role in the early development of B.tau.This study revealed that Ndufa7 is a target gene for the management of tephritids and opens a new avenue for pest control research.
基金supported by AP21PPQS&T00C108 from USDA-APHIS to ELS。
文摘The Mexican fruit fly,Anastrepha ludens,is a polyphagous pest that is a constant threat to US agriculture because of its proximity to citrus production in border region of the United States and Mexico.Sterile Insect Technique has been used to manage and eradicate of the Mexican Fruit Fly.SIT,however,requires millions of sterile male flies to be released each week from mass-rearing facilities.The mass-reared colonies must deal with microbial infections that reduce survivorship,fecundity and male-male competition.Meta-transcriptomics joins culturing and next generation DNA sequencing techniques to understand these changing microbial communities.This study uses advances in microbial meta-transcriptome sequencing to analyze the microbial communities from the four major developmental stages of A.ludens.The composition of the microbial communities was analyzed and revealed the large transcriptional presence of the phyla Microsporidia,a known animal pathogen.Clustering and ordination analyses revealed groupings based on developmental phase for egg,larvae and pupa.Adult samples had little clustering;a not unexpected result given the known turn-over in microbial community that occurs in the first 5 d after pupation.The transcriptional activity of three known pathogens of A.ludens between developmental phases were investigated.Two of the three pathogens had significant transcriptional differences between the phases with the larvae phase having the most activity.This increase in transcriptional activity agrees with culture-based surveillance and current mitigation strategies employed in the mass-rearing facility.This result reinforces the utility of transcriptomics in combating microbial threats.
基金support provided for this research via the FAO/IAEA Coordinated Research Projects"Improvement of Colony Management in Insect Mass-rearing for SIT Applications"(CRP No.D42017)"Improving rearing,handling,and field components for fruit fly SIT application"(CRP No.D41029).
文摘For almost a decade,natural populations of the South American fruit fly have been targeted for control through Sterile Insect Technique projects.To ensure a sustainable supply of competitive sterile flies for this approach,it is essential to understand the effects of domestication when strains of this pest are initially brought into the laboratory to establish colonies as well as the changes occurring after multiple generations of adaptation to conditions used for mass rearing.Using one colony established from a wild population of the Brazil-1 morphotype(WIL)and two from laboratory colonies in Brazil known as the Piracicaba(PL)and Vacaria(VL)strains,this study evaluated genetic diversity in samples from 10 generations after domestication and maintenance under semimass rearing conditions.Another aim of this study was to analyze changes in the genetic makeup of the colonies of the two laboratory strains after refreshment.Eight microsatellite markers were used for the genetic analyses.Results indicated a moderate but significant amount of genetic differentiation between the WIL population and the two laboratory strains.Results also showed that levels of genetic diversity in both the VL and PL strains were maintained at similar levels over a period of more than two years of rearing.Additionally,results suggest that successful creation of admixture via refreshment is more likely to be beneficial in relatively short-term domesticated colonies,and that performing refreshment approximately every six to eight generations could be beneficial to maintain the genetic diversity of A.fraterculus colonies under laboratory mass rearing conditions.
基金This study was funded by National Natural Science Foundation of China(31972270,31661143045)agricultural public welfare industry research from Ministry of Agriculture of People's Republic of China(201503137)+1 种基金the Joint Program of the Israel Science Foundation and the Science Foundation of China(2482/16)the fundamental research funds for the central universities(2662020ZKPY018).
文摘Insects employ various types of gustatory receptors(GRs)to identify nutrient-rich food and avoid toxic substances.The larval gustatory system is the critical checkpoint for food acceptance or rejection.As a specialist herbivore,the larvae of Bactrocera minax feed only on unripe citrus fruits.However,how larvae use GRs to check and adapt to the secondary metabolites in unripe citrus fruits remains unknown.In this study,we first performed developmental expression profiles showing that most BminGRs genes were highly expressed in 1st and 2nd instar larvae and that tissue-specific expression indicated high expression of most BminGRs genes in the mouthparts of 2nd instar larvae.Furthermore,we found that silencing BminGR59f by RNA interference(RNAi)affected the growth of 2nd instar B.minax larvae.Hesperidin and naringin were screened as ligands of BminGR59f via RNAi and cell calcium imaging,and the combination of these two flavones increased the body weight of larvae.In summary,we identified a novel gustatory perception pattern in B.minax for detecting hesperidin and naringin,which boosted the growth of B.minax larvae.These results shed light on how specialist herbivores detect and adapt to host metbolites in adverse environments depending on larval GRs.
文摘Investigations on microbial symbioses in Tephritidae have increased over the past 30 years owing to the potential use of these relationships in developing new control strategies for economically important fruit flies.Bactrocera oleae(Rossi)—the olive fruit fly—is a monophagous species strictly associated with the olive tree,and among all the tephritids,its symbionts are the most investigated.The bacterium Candidatus Erwinia dacicola is the major persistent resident endosymbiont in wild B.oleae populations.Its relationship with B.oleae has been investigated since being identified in 2005.This endosymbiont is vertically transmitted through generations from the female to the egg.It exists at every developmental stage,although it is more abundant in larvae and ovipositing females,and is necessary for both larvae and adults.Studying B.oleae–Ca.E.dacicola,or other B.oleae–microbe interactions,will allow us to develop modern biological control systems for area-wide olive protection and set an example for similar programs in other important food crops.This review summarizes the information available on tephritid–microbe interactions and investigates relationships among fruit flies,bacteria and host plants;however,its focus is on B.oleae and its strict association with Ca.E.dacicola to promote environmentally friendly control strategies for area-wide pest management.
