Biology subjects

Del Corsano, G.

Publications and source records attributed to Del Corsano, G..

5 recordsLinked to original sources

bioRxiv2025

The nanosd integral gene drive enables population modification of the malaria vector Anopheles gambiae

The modification of mosquito populations at scale through CRISPR-Cas9-mediated homing gene drives is a promising route for malaria vector control. Integral gene drives (IGDs) are designed to utilize the regulatory sequences of endogenous genes to express only the minimal set of components required for gene drive. In this study, we describe the creation and characterization of the nanosd IGD targeting and inserted into the nanos gene of the malaria vector Anopheles gambiae and show that it achieves high rates of gene drive (97.7% in females, 99.0% in males). We find that homozygous nanosd females but not males show impaired fecundity, and a variable loss of ovary phenotype. Transcriptomic analysis of ovaries points to decreased transcript levels of the nanos gene when harbouring Cas9. As a minimal genetic modification, nanosd does not induce widespread transcriptomic perturbations, and its susceptibility to Plasmodium spp. and Onyong nyong virus infection remains similar to wild-type mosquitoes. Importantly, we find that nanosd propagates efficiently in caged mosquito populations and is maintained as a source of Cas9 after the emergence of drive resistant alleles whilst also mobilising a non-autonomous antiparasitic effector modification. The nanosd gene drive shows promise as a genetic tool for malaria vector control via population modification, and we outline steps towards its further optimization.

synthetic biology↗

bioRxiv2024

REL2 overexpression in the Anopheles gambiae midgut causes major transcriptional changes but fails to induce an immune response

The NF-{kappa}B-like transcription factor, REL2, is a key player in the mosquito Immunodeficiency (Imd) pathway and holds promise for controlling malaria parasite infections in genetically modified Anopheles gambiae mosquitoes. We engineered transgenic mosquitoes overexpressing REL2 from within the bloodmeal-inducible zinc carboxypeptidase A1 (CP) host gene in the adult posterior midgut. Our results confirmed elevated REL2 expression in the posterior midgut following a bloodmeal, with the corresponding protein localized within epithelial cell nuclei. While this induced overexpression triggered substantial transcriptional changes, accompanied by notable fitness costs, the resultant reduction in Plasmodium falciparum infection was modest. An in-depth analysis of regulatory regions of differentially regulated genes allowed us to identify direct REL2 target genes and revealed signatures indicative of potential transcriptional repressors. To account for potential impacts of host gene modification, we also created a CP knockout line that caused marginal effects on mosquito fitness. These findings shed light on the observed absence of transcriptional activation and, in some cases, induced repression of antimicrobial peptides (AMPs) presumed to be under Imd pathway control. In conclusion, our study suggests that elevated REL2 expression in the posterior midgut may induce the upregulation of negative immune regulators, facilitating control over an otherwise unrestrained immune response, and that concurrent transcriptional derepression may be needed to effectively induce the mosquito immune response. This work contributes valuable insights into the intricate regulation of midgut immunity in malaria vector mosquitoes.

immunology↗

bioRxiv2022

Gene drive mosquitoes can aid malaria elimination by retarding Plasmodium sporogonic development

Gene drives hold promise for the genetic control of malaria vectors. The development of vector population modification strategies hinges on the availability of effector mechanisms impeding parasite development in transgenic mosquitoes. We augmented a midgut gene of the malaria mosquito Anopheles gambiae to secrete two exogenous antimicrobial peptides, Magainin 2 and Melittin. This small genetic modification, capable of efficient non-autonomous gene drive, hampers oocyst development in both Plasmodium falciparum and Plasmodium berghei. It delays the release of infectious sporozoites while it simultaneously reduces the lifespan of homozygous female transgenic mosquitoes. Modeling the spread of this modification using a large-scale agent-based model of malaria epidemiology reveals that it can break the cycle of disease transmission across a range of endemic settings. One sentence summaryWe developed a gene drive effector that retards Plasmodium development in transgenic Anopheles gambiae mosquitoes via the expression of antimicrobial peptides in the midgut and which is predicted to eliminate malaria under a range of transmission scenarios.

genetics↗

bioRxiv2020

Engineered sex distortion in the global agricultural pest Ceratitis capitata

Genetic sex ratio distorters have potential for the area-wide control of harmful insect populations. Endonucleases targeting the X-chromosome and whose activity is restricted to male gametogenesis have recently been pioneered as a means to engineer such traits. Here we enabled endogenous CRISPR/Cas9 and CRISPR/Cas12a activity during spermatogenesis of the Mediterranean fruit fly Ceratitis capitata, a worldwide agricultural pest of extensive economic significance. In the absence of a chromosome-level assembly, we analysed long and short-read genome sequencing data from males and females to identify two clusters of abundant and X-chromosome specific sequence repeats. When targeted by gRNAs in conjunction with Cas9 they yielded a significant and consistent distortion of the sex ratio in independent transgenic strains and a combination of distorters induced a strong bias towards males (~80%). Our results demonstrate the design of sex distorters in a non-model organism and suggest that strains with characteristics suitable for field application could be developed for a range of medically or agriculturally relevant insect species.

synthetic biology↗

bioRxiv2017

Highly efficient DNA-free gene disruption in the agricultural pest Ceratitis capitata by CRISPR-Cas9 RNPs

The Mediterranean fruitfly Ceratitis capitata (medfly) is an invasive agricultural pest of high economical impact and has become an emerging model for developing new genetic control strategies as alternative to insecticides. Here, we report the successful adaptation of CRISPR-Cas9-based gene disruption in the medfly by injecting in vitro pre-assembled, solubilized Cas9 ribonucleoprotein complexes (RNPs) loaded with gene-specific sgRNAs into early embryos. When targeting the eye pigmentation gene white eye (we), we observed a high rate of somatic mosaicism in surviving G0 adults. Germline transmission of mutated we alleles by G0 animals was on average above 70%, with individual cases achieving a transmission rate of nearly 100%. We further recovered large deletions in the we gene when two sites were simultaneously targeted by two sgRNAs. CRISPR-Cas9 targeting of the Ceratitis ortholog of the Drosophila segmentation paired gene (Ccprd) caused segmental malformations in late embryos and in hatched larvae. Mutant phenotypes correlate with repair by non-homologous end joining (NHEJ) lesions in the two targeted genes. This simple and highly effective Cas9 RNP-based gene editing to introduce mutations in Ceratitis capitata will significantly advance the design and development of new effective strategies for pest control management.

genetics↗