Genetically engineered insects with sex-selection and genetic incompatibility enable population suppression.

Ambuj Upadhyay,Siba R Das,Michael Smanski,Maciej Maselko,Anna Janzen,Nathan R Feltman,Adam Sychla

doi:10.7554/elife.71230

Abstract

Engineered Genetic Incompatibility (EGI) is a method to create species-like barriers to sexual reproduction. It has applications in pest control that mimic Sterile Insect Technique when only EGI males are released. This can be facilitated by introducing conditional female-lethality to EGI strains to generate a sex-sorting incompatible male system (SSIMS). Here, we demonstrate a proof of concept by combining tetracycline-controlled female lethality constructs with a pyramus-targeting EGI line in the model insect Drosophila melanogaster. We show that both functions (incompatibility and sex-sorting) are robustly maintained in the SSIMS line and that this approach is effective for population suppression in cage experiments. Further we show that SSIMS males remain competitive with wild-type males for reproduction with wild-type females, including at the level of sperm competition.

Highlights

The most successful large-scale insect control approach to date is Sterile Insect Technique (SIT) (Dyck et al, 2005; Knipling, 1979)
To generate the sex-sorting incompatible male system (SSIMS) line, we made a stock that contains two female lethal (FL) constructs (Das et al, 2020) on the X chromosome and an Engineered Genetic Incompatibility (EGI) construct on the third chromosome (Figure 1)
Following the mating scheme outlined in Supplementary Note 1, we were able to generate viable SSIMS flies, which contained both of the visual markers of the FL genotype (GFP expression) and the EGI genotype (Figure 2a)

Summary

Introduction

The most successful large-scale insect control approach to date is Sterile Insect Technique (SIT) (Dyck et al, 2005; Knipling, 1979). SIT uses irradiation at sub-lethal doses to sterilize massreared insects prior to their targeted environmental release. Such an approach was successfully applied to eradicate the New World Screwworm (Cochliomyia hominivorax) from North and Central. SIT has been successfully applied for the broad-scale control of tephritid fruit flies (e.g. Ceratitis capitata, Zeugodacus cucurbitae, Bactrocera tryoni, and Anastrepha ludens), onion maggots (Delia antiqua), tsetse flies (Glossina spp.), and several coleoptera and lepidoptera species (Dyck et al, 2005). Many batch irradiation approaches do not separate males from females prior to release, and this can both decrease the effectiveness (Rendón et al, 2004), and lead to public health concerns when the female insect is a disease vector (Benedict, 2021)

Methods

Results

Conclusion