Thiamethoxam exposure deregulates short ORF gene expression in the honey bee and compromises immune response to bacteria

Author(s)

Decio, Pamela ^[1] ; Ustaoglu, Pinar ^[2] ; Derecka, Kamila ^[3] ; Hardy, Ian C. W. ^[3] ; Roat, Thaisa C. ^[1] ; Malaspina, Osmar ^[1] ; Mongan, Nigel ^[4] ; Stoger, Reinhard ^[3] ; Soller, Matthias ^[2]

Affiliation

^[1] Sao Paulo State Univ Unesp, Inst Biosci, Rio Claro - Brazil

^[2] Univ Birmingham, Coll Life & Environm Sci, Sch Biosci, Birmingham B15 2TT, W Midlands - England

^[3] Univ Nottingham, Sch Biosci, Loughborough LE12 5RD, Leics - England

^[4] Univ Nottingham, Sch Vet Med & Sci, Loughborough LE12 5RD, Leics - England

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 11, n. 1 JAN 15 2021.
• Web of Science Citations: 1

Abstract

Maximizing crop yields relies on the use of agrochemicals to control insect pests. One of the most widely used classes of insecticides are neonicotinoids that interfere with signalling of the neurotransmitter acetylcholine, but these can also disrupt crop-pollination services provided by bees. Here, we analysed whether chronic low dose long-term exposure to the neonicotinoid thiamethoxam alters gene expression and alternative splicing in brains of Africanized honey bees, Apis mellifera, as adaptation to altered neuronal signalling. We find differentially regulated genes that show concentration-dependent responses to thiamethoxam, but no changes in alternative splicing. Most differentially expressed genes have no annotated function but encode short Open Reading Frames, a characteristic feature of anti-microbial peptides. As this suggested that immune responses may be compromised by thiamethoxam exposure, we tested the impact of thiamethoxam on bee immunity by injecting bacteria. We show that intrinsically sub-lethal thiamethoxam exposure makes bees more vulnerable to normally non-pathogenic bacteria. Our findings imply a synergistic mechanism for the observed bee population declines that concern agriculturists, conservation ecologists and the public. (AU)

• FAPESP's process: 15/22368-5 - Analysis of expression ELAV and Dscam genes in Apis mellifera (Hymenoptera: Apidae) exposed to thiamethoxam
• Grantee: Pâmela Decio Horst
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 14/23197-7 - Cellular stress and activity of biomarkers enzymes in Africanized honeybees Apis mellifera Lineu, 1758 (Hymenoptera, Apidae) exposed to thiamethoxam
• Grantee: Pâmela Decio Horst
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 12/13370-8 - How is the reaction of the Apis mellifera brain to a sublethal dose of thiamethoxam?
• Grantee: Thaisa Cristina Roat
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 13/07251-9 - How is the reaction of the Apis mellifera brain to a sublethal dose of thiamethoxam?
• Grantee: Thaisa Cristina Roat
• Support Opportunities: Scholarships in Brazil - Young Researchers