The sterile insect technique(SIT)is a highly effective biologically-based method for the suppression of many insect pest populations.SIT efficacy could be improved by methods of male sterilization that avoid the use o...The sterile insect technique(SIT)is a highly effective biologically-based method for the suppression of many insect pest populations.SIT efficacy could be improved by methods of male sterilization that avoid the use of irradiation that can result in diminished fitness and mating competitiveness.Alternative sterilization methods include conditional disruption of genes for male fertility,or using their sperm-specific promoters to drive the expression of genes for lethal effectors.Testing has begun for the testis-specificβ2-tubulin gene,though additional male fertility genes are required for redundancy or replacement,and for species where theβ2-tubulin isoform does not exist or is not testis-specific.Here we had the goal of identifying and characterizing the sequence and transcriptional expression of two genes in the caribfly,Anastrepha suspensa,that are cognates of D.melanogaster spermatocyte-specific male fertility genes.In Drosophila,wampa encodes a coiled-coil dynein subunit required for axonemal assembly essential to microtubule-based sperm motility,while Prosα6T is a proteasome subunit gene required for spermatid individualization and nuclear maturation.In A.suspensa a cognate to wampa exhibited testis-specific transcript expression,which was minimal in both male and female body tissue.A Prosα6T cognate was not apparent in A.suspensa,but its constitutive isoform,Prosα6,expresses in male testes,but also in male and female body tissue.Thus,for A.suspensa,wampa remains a strong candidate gene for male sterility strategies for SIT including a direct target for gene-editing knockout and use of its promoter for testisspecific toxicity or cell death in conditional expression systems.展开更多
In insects and other ectotherms,cold temperatures cause a coma resulting from loss of neuromuscular function,during which ionic and metabolic homeostasis are progressively lost.Cold adaptation improves homeostasis dur...In insects and other ectotherms,cold temperatures cause a coma resulting from loss of neuromuscular function,during which ionic and metabolic homeostasis are progressively lost.Cold adaptation improves homeostasis during cold exposure,but the ultimate targets of selection are still an open question.Cold acclimation and adaptation remodels mitochondrial metabolism in insects,suggesting that aerobic energy production during cold exposure could be a target of selection.Here,we test the hypothesis that cold adaptation improves the ability to maintain rates of aerobic energy production during cold exposure by using^(31)P NMR on live flies.Using lines of Drosophila melanogaster artificially selected for fast and slow recovery from a cold coma,we show that cold exposure does not lower ATP levels and that cold adaptation does not alter aerobic ATP production during cold exposure.Cold-hardy and cold-susceptible lines both experienced a brief transition to anaerobic metabolism during cooling,but this was rapidly reversed during cold exposure,suggesting that oxidative phosphorylation was sufficient to meet energy demands below the critical thermal minimum,even in cold-susceptible flies.We thus reject the hypothesis that performance under mild low temperatures is set by aerobic ATP supply limitations in D.melanogaster,excluding oxygen and capacity limitation as a weak link in energy supply.This work suggests that the modulations to mitochondrial metabolism resulting from cold acclimation or adaptation may arise from selection on a biosynthetic product(s)of those pathways rather than selection on ATP supply during cold exposure.展开更多
基金supported by the Biotechnology Risk Assessment Research Grants Program,grant no.2020-33522-32271,from the USDA National Institute of Food and Agriculture.
文摘The sterile insect technique(SIT)is a highly effective biologically-based method for the suppression of many insect pest populations.SIT efficacy could be improved by methods of male sterilization that avoid the use of irradiation that can result in diminished fitness and mating competitiveness.Alternative sterilization methods include conditional disruption of genes for male fertility,or using their sperm-specific promoters to drive the expression of genes for lethal effectors.Testing has begun for the testis-specificβ2-tubulin gene,though additional male fertility genes are required for redundancy or replacement,and for species where theβ2-tubulin isoform does not exist or is not testis-specific.Here we had the goal of identifying and characterizing the sequence and transcriptional expression of two genes in the caribfly,Anastrepha suspensa,that are cognates of D.melanogaster spermatocyte-specific male fertility genes.In Drosophila,wampa encodes a coiled-coil dynein subunit required for axonemal assembly essential to microtubule-based sperm motility,while Prosα6T is a proteasome subunit gene required for spermatid individualization and nuclear maturation.In A.suspensa a cognate to wampa exhibited testis-specific transcript expression,which was minimal in both male and female body tissue.A Prosα6T cognate was not apparent in A.suspensa,but its constitutive isoform,Prosα6,expresses in male testes,but also in male and female body tissue.Thus,for A.suspensa,wampa remains a strong candidate gene for male sterility strategies for SIT including a direct target for gene-editing knockout and use of its promoter for testisspecific toxicity or cell death in conditional expression systems.
基金This work was performed in the McKnight Brain Institute at the National High Magnetic Field Laboratory’s AMRIS Facility,which is supported by National Science Foundation Cooperative Agreement No.DMR-1157490 and the State of FloridaThis work was supported in part by an NIH award,S10RR031637,for magnetic resonance instrumentation,and by National Science Foundation(NSF)Grants IOS-1051770(to T.J.M.)+3 种基金IOS-1051890(to D.A.H,A.S.E and D.B.A.)and IOS-1558159 to CMW.A.S.Ereceived partial support from the Georgia Research Alliance,and D.A.H.received support from the IAEA/FAO CRP on Dormancy management to enable mass rearing and increase efficacy of sterile insects and natural enemiesDan Plant provided valuable assistance setting up NMR experiments in AMRIS.Stephanie Dickinson checked the statistical analysesD.B.A was supported by NIH grants U24AG056053 and P30AG050886.
文摘In insects and other ectotherms,cold temperatures cause a coma resulting from loss of neuromuscular function,during which ionic and metabolic homeostasis are progressively lost.Cold adaptation improves homeostasis during cold exposure,but the ultimate targets of selection are still an open question.Cold acclimation and adaptation remodels mitochondrial metabolism in insects,suggesting that aerobic energy production during cold exposure could be a target of selection.Here,we test the hypothesis that cold adaptation improves the ability to maintain rates of aerobic energy production during cold exposure by using^(31)P NMR on live flies.Using lines of Drosophila melanogaster artificially selected for fast and slow recovery from a cold coma,we show that cold exposure does not lower ATP levels and that cold adaptation does not alter aerobic ATP production during cold exposure.Cold-hardy and cold-susceptible lines both experienced a brief transition to anaerobic metabolism during cooling,but this was rapidly reversed during cold exposure,suggesting that oxidative phosphorylation was sufficient to meet energy demands below the critical thermal minimum,even in cold-susceptible flies.We thus reject the hypothesis that performance under mild low temperatures is set by aerobic ATP supply limitations in D.melanogaster,excluding oxygen and capacity limitation as a weak link in energy supply.This work suggests that the modulations to mitochondrial metabolism resulting from cold acclimation or adaptation may arise from selection on a biosynthetic product(s)of those pathways rather than selection on ATP supply during cold exposure.
