Disruption of the odorant coreceptor Orco impairs foraging and host finding behaviors in the New World screwworm fly

Author(s):Show less -

Paulo, Daniel F. ^[1] ; Junqueira, Ana C. M. ^[2] ; Arp, Alex P. ^[3] ; Vieira, Andre S. ^[4] ; Ceballos, Jorge ^[5] ; Skoda, Steven R. ^{[6, 7]} ; Perez-de-Leon, Adalberto A. ^[8] ; Sagel, Agustin ^{[6, 7]} ; McMillan, William O. ^[9] ; Scott, Maxwell J. ^[10] ; Concha, Carolina ^[9] ; Azeredo-Espin, Ana M. L. ^[1]

Affiliation

^[1] Univ Estadual Campinas, Inst Biol, Dept Genet Evolut Microbiol & Immunol, UNICAMP, BR-13083875 Campinas, SP - Brazil

^[2] Fed Univ Rio de Janeiro UFRJ, Inst Biol, Dept Genet, BR-21941902 Rio De Janeiro, RJ - Brazil

^[3] USDA ARS, Knipling Bushland US Livestock Insects Res Lab &, Kerrville, TX 78028 - USA

^[4] Univ Estadual Campinas, Inst Biol, Dept Struct & Funct Biol, UNICAMP, BR-13083862 Campinas, SP - Brazil

^[5] Smithsonian Trop Res Inst STRI, Microscopy Lab, Tupper Bldg, Panama City 084303092 - Panama

^[6] USDA ARS, Knipling Bushland US Livestock Insects Res Lab, Screwworm Res Site, Pacora - Panama

^[7] USDA ARS, Vet Pest Genom Ctr, Screwworm Res Site, Pacora - Panama

^[8] USDA ARS, San Joaquin Valley Agr Sci Ctr, Parlier, CA 93648 - USA

^[9] Smithsonian Trop Res Inst STRI, Lab Ecol & Evolutionary Genom, Gamboa - Panama

^[10] North Carolina State Univ, Dept Entomol & Plant Pathol, Campus Box 7613, Raleigh, NC 27695 - USA

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 11, n. 1 MAY 31 2021.
• Web of Science Citations: 0

Abstract

The evolution of obligate ectoparasitism in blowflies (Diptera: Calliphoridae) has intrigued scientists for over a century, and surprisingly, the genetics underlying this lifestyle remain largely unknown. Blowflies use odors to locate food and oviposition sites; therefore, olfaction might have played a central role in niche specialization within the group. In insects, the coreceptor Orco is a required partner for all odorant receptors (ORs), a major gene family involved in olfactory-evoked behaviors. Hence, we characterized the Orco gene in the New World screwworm, Cochliomyia hominivorax, a blowfly that is an obligate ectoparasite of warm-blooded animals. In contrast, most of the closely related blowflies are scavengers that lay their eggs on dead animals. We show that the screwworm Orco orthologue (ChomOrco) is highly conserved within Diptera, showing signals of strong purifying selection. Expression of ChomOrco is broadly detectable in chemosensory appendages, and is related to morphological, developmental, and behavioral aspects of the screwworm biology. We used CRISPR/Cas9 to disrupt ChomOrco and evaluate the consequences of losing the OR function on screwworm behavior. In two-choice assays, Orco mutants displayed an impaired response to floral-like and animal host-associated odors, suggesting that OR-mediated olfaction is involved in foraging and host-seeking behaviors in C. hominivorax. These results broaden our understanding of the chemoreception basis of niche occupancy by blowflies. (AU)

• FAPESP's process: 14/15042-3 - Expression profile analysis of microRNAs during different development stages of the New World Screwworm fly Cochliomyia hominivorax (Diptera: Calliphoridae)
• Grantee: Daniel Fernando Paulo
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 15/02079-9 - Genomics of Cochliomyia hominivorax (Diptera: Calliphoridae): structural and functional analyses.
• Grantee: Ana Maria Lima de Azeredo-Espin
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/05432-7 - Development of an Odorant Co-­receptor Mutant Strain of the New World Screwworm Fly using the CRISPR/Cas9 system: A Functional Investigation on the Evolution of Olfactory Perception in Blowflies.
• Grantee: Daniel Fernando Paulo
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate