Wolbachia Influences the Production of Octopamine and Affects Drosophila Male Aggression.
Wolbachia bacteria are endosymbionts that infect approximately 40% of all insect species and are best known for their ability to manipulate host reproductive systems. Though the effect Wolbachia infection has on somatic tissues is less well understood, when present in cells of the adult Drosophila melanogaster brain, Wolbachia exerts an influence over behaviors related to olfaction. Here, we show that a strain of Wolbachia influences male aggression in flies, which is critically important in mate competition. A specific strain of Wolbachia was observed to reduce the initiation of aggressive encounters in Drosophila males compared to the behavior of their uninfected controls. To determine how Wolbachia was able to alter aggressive behavior, we investigated the role of octopamine, a neurotransmitter known to influence male aggressive behavior in many insect species. Transcriptional analysis of the octopamine biosynthesis pathway revealed that two essential genes, the tyrosine decarboxylase and tyramine β-hydroxylase genes, were significantly downregulated in Wolbachia-infected flies. Quantitative chemical analysis also showed that total octopamine levels were significantly reduced in the adult heads.
School of Natural Sciences, Griffith University, Nathan, Queensland, Australia Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan, Queensland, Australia Queensland Brain Institute, University of Queensland, St. Lucia, Queensland, Australia.
Chelsie E
CE
Rohrscheib
School of Natural Sciences, Griffith University, Nathan, Queensland, Australia Department of Evolutionary Biology, University of Arizona, Tucson, Arizona, USA.
Elizabeth
E
Bondy
Queensland Brain Institute, University of Queensland, St. Lucia, Queensland, Australia.
Peter
P
Josh
Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, New South Wales, Australia.
Markus
M
Riegler
Queensland Brain Institute, University of Queensland, St. Lucia, Queensland, Australia.
Darryl
D
Eyles
Queensland Brain Institute, University of Queensland, St. Lucia, Queensland, Australia.
Bruno
B
van Swinderen
School of Natural Sciences, Griffith University, Nathan, Queensland, Australia Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan, Queensland, Australia.
Michael W
MW
Weible
School of Natural Sciences, Griffith University, Nathan, Queensland, Australia Environmental Futures Research Institute, Griffith University, Nathan, Queensland, Australia j.brownlie@griffith.edu.au.
Jeremy C
JC
Brownlie
D000818:Animals; D001522:Behavior, Animal; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics / Q000382:microbiology* / Q000502:physiology*; D005260:Female; D008297:Male; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D009655:Octopamine / Q000096:biosynthesis*; D014445:Tyrosine Decarboxylase / Q000235:genetics / Q000378:metabolism; D020577:Wolbachia / Q000502:physiology*
D029721:Drosophila Proteins; D009655:Octopamine; D006899:Mixed Function Oxygenases; C023205:tyramine beta-hydroxylase; D014445:Tyrosine Decarboxylase