Engineered expression of the invertebrate-specific scorpion toxin AaHIT reduces adult longevity and female fecundity in the diamondback moth Plutella xylostella

TY - JOUR

T1 - Engineered expression of the invertebrate-specific scorpion toxin AaHIT reduces adult longevity and female fecundity in the diamondback moth Plutella xylostella

AU - Harvey-Samuel, Tim

AU - Xu, Xuejiao

AU - Lovett, Erica

AU - Dafa'alla, Tarig

AU - Walker, Adam

AU - Norman, Victoria C.

AU - Carter, Ruth

AU - Teal, Joss

AU - Akilan, Luxziyah

AU - Leftwich, Philip T.

AU - Reitmayer, Christine M.

AU - Siddiqui, Hamid A.

AU - Alphey, Luke

N1 - Publisher Copyright: © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

PY - 2021/6/10

Y1 - 2021/6/10

N2 - BACKGROUND: Previous genetic pest management (GPM) systems in diamondback moth (DBM) have relied on expressing lethal proteins (‘effectors’) that are ‘cell-autonomous’, that is, they do not leave the cell in which they are expressed. To increase the flexibility of future GPM systems in DBM, we aimed to assess the use of a non-cell-autonomous, invertebrate-specific, neurotoxic effector – the scorpion toxin AaHIT. This AaHIT effector was designed to be secreted by expressing cells, potentially leading to effects on distant cells, specifically neuromuscular junctions. RESULTS: Expression of AaHIT caused a ‘shaking/quivering’ phenotype that could be repressed by provision of an antidote (tetracycline): a phenotype consistent with the AaHIT mode-of-action. This effect was more pronounced when AaHIT expression was driven by the Hr5/ie1 promoter (82.44% of males, 65.14% of females) rather than Op/ie2 (57.35% of males, 48.39% of females). Contrary to expectations, the shaking phenotype and observed fitness costs were limited to adults in which they caused severe reductions in mean longevity (−81%) and median female fecundity (−93%). Quantitative polymerase chain reactions of AaHIT expression patterns and analysis of piggyBac-mediated transgene insertion sites suggest that restriction of the observed effects to the adult stages may be due to the influence of the local genomic environment on the tetO-AaHIT transgene. CONCLUSION: We demonstrated the feasibility of using non-cell-autonomous effectors within a GPM context for the first time in Lepidoptera, one of the most economically damaging orders of insects. These findings provide a framework for extending this system to other pest Lepidoptera and to other secreted effectors.

AB - BACKGROUND: Previous genetic pest management (GPM) systems in diamondback moth (DBM) have relied on expressing lethal proteins (‘effectors’) that are ‘cell-autonomous’, that is, they do not leave the cell in which they are expressed. To increase the flexibility of future GPM systems in DBM, we aimed to assess the use of a non-cell-autonomous, invertebrate-specific, neurotoxic effector – the scorpion toxin AaHIT. This AaHIT effector was designed to be secreted by expressing cells, potentially leading to effects on distant cells, specifically neuromuscular junctions. RESULTS: Expression of AaHIT caused a ‘shaking/quivering’ phenotype that could be repressed by provision of an antidote (tetracycline): a phenotype consistent with the AaHIT mode-of-action. This effect was more pronounced when AaHIT expression was driven by the Hr5/ie1 promoter (82.44% of males, 65.14% of females) rather than Op/ie2 (57.35% of males, 48.39% of females). Contrary to expectations, the shaking phenotype and observed fitness costs were limited to adults in which they caused severe reductions in mean longevity (−81%) and median female fecundity (−93%). Quantitative polymerase chain reactions of AaHIT expression patterns and analysis of piggyBac-mediated transgene insertion sites suggest that restriction of the observed effects to the adult stages may be due to the influence of the local genomic environment on the tetO-AaHIT transgene. CONCLUSION: We demonstrated the feasibility of using non-cell-autonomous effectors within a GPM context for the first time in Lepidoptera, one of the most economically damaging orders of insects. These findings provide a framework for extending this system to other pest Lepidoptera and to other secreted effectors.

KW - genetic biocontrol

KW - genetic pest management

KW - neurotoxin

KW - non-cell-autonomous

KW - RIDL

KW - tet-off

UR - http://www.scopus.com/inward/record.url?scp=85102629497&partnerID=8YFLogxK

U2 - 10.1002/ps.6353

DO - 10.1002/ps.6353

M3 - Article

C2 - 33660916

AN - SCOPUS:85102629497

SN - 1526-498X

VL - 77

SP - 3154

EP - 3164

JO - Pest management science

JF - Pest management science

IS - 7

ER -