Toxin-like proteins in the venom of Drosophila parasitoids

Author

Lady V. Cardenas, CUNY City CollegeFollow

Date of Award

2025

Document Type

Thesis

Department

Biology

First Advisor

Shubha Govind

Second Advisor

Rebecca Spokony

Third Advisor

Ana Carvajal

Keywords

Drosophila, Encapsulation, Immune suppression, Parasitoids, toxins, Venom

Abstract

The figitid parasitoid wasps of Drosophila are gaining importance in agriculture due to their ability to kill the resilient soft-fruit pest Drosophila suzukii. Their success and infection strategies vary, and the mechanisms underlying these differences are largely unknown. Some of their venom proteins have been shown to be important in suppressing host defense. Here, we report that Ganaspis brasiliensis, a parasitoid of D. suzukii survives well on Drosophila yakuba, a host species with a strong cellular immunity, and infected flies are unable to mount a strong immune response. To predict possible toxin-like proteins in Ganaspis venoms that might suppress cellular immunity in hosts, or compromise host defenses by other mechanisms, we undertook two lines of bioinformatic studies to understand the predicted functions of select proteins. In the first analysis, we identified 10 putative toxins in the venom of G. hookeri, a relative of G. brasiliensis: one serine protease, six serpins, one alpha/beta hydrolase, one phospholipase A2, and lastly, a Cysteine-rich secretory protein Antigen 5 and Pathogenesis-Related 1 protein. In the second line of work, we identified 46 predicted knottin-like micropeptides expressed in figitid wasp transcriptomes, including G. hookeri and G. brasiliensis. These sequences share structural similarity with LhKNOT, a solo cysteine-rich knottin micropeptide of Leptopilina heterotoma venom. Structural analyses show that LhKNOT and its 41 of the 46 homologs contain a Cation-Polar-Cation Clip, that in heparin-binding proteins, is capable of binding to heparin and other glycosaminoglycans. These results support our recent findings that the venom of Drosophila parasitoids is rich in diverse toxin-like peptides and proteins that are homologous to venom toxins from a wide range of species, from spiders to snakes. Experimental validation of the predicted biochemical functions of these toxin-like proteins in wasp venoms will aid the development of novel agricultural and therapeutic interventions.

Recommended Citation

Cardenas, Lady V., "Toxin-like proteins in the venom of Drosophila parasitoids" (2025). CUNY Academic Works.
https://academicworks.cuny.edu/cc_etds_theses/1208