title: A search for protein biomarkers links olfactory signal transduction to social immunity.
abstract: BACKGROUND
  The Western honey bee (Apis mellifera L.) is a critical component of human agriculture through its pollination activities. For years, beekeepers have controlled deadly pathogens such as Paenibacillus larvae, Nosema spp. and Varroa destructor with antibiotics and pesticides but widespread chemical resistance is appearing and most beekeepers would prefer to eliminate or reduce the use of in-hive chemicals. While such treatments are likely to still be needed, an alternate management strategy is to identify and select bees with heritable traits that allow them to resist mites and diseases. Breeding such bees is difficult as the tests involved to identify disease-resistance are complicated, time-consuming, expensive and can misidentify desirable genotypes. Additionally, we do not yet fully understand the mechanisms behind social immunity. Here we have set out to discover the molecular mechanism behind hygienic behavior (HB), a trait known to confer disease resistance in bees.
  
  
  RESULTS
  After confirming that HB could be selectively bred for, we correlated measurements of this behavior with protein expression over a period of three years, at two geographically distinct sites, using several hundred bee colonies. By correlating the expression patterns of individual proteins with HB scores, we identified seven putative biomarkers of HB that survived stringent control for multiple hypothesis testing. Intriguingly, these proteins were all involved in semiochemical sensing (odorant binding proteins), nerve signal transmission or signal decay, indicative of the series of events required to respond to an olfactory signal from dead or diseased larvae. We then used recombinant versions of two odorant-binding proteins to identify the classes of ligands that these proteins might be helping bees detect.
  
  
  CONCLUSIONS
  Our data suggest that neurosensory detection of odors emitted by dead or diseased larvae is the likely mechanism behind a complex and important social immunity behavior that allows bees to co-exist with pathogens.
authors.affiliation: Department of Biochemistry & Molecular Biology, Centre for High-Throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, BC, V6T 1Z4, Canada. marta.guarna@outlook.com.
authors.forename: Maria Marta
authors.initials: MM
authors.lastname: Guarna
authors.affiliation: Beaverlodge Research Farm, Agriculture & Agri-Food Canada, Beaverlodge, AB, T0H 0C0, Canada. Andony.Melathopoulos@dal.ca.|Current address: Dalhousie University, Halifax, NS, Canada. Andony.Melathopoulos@dal.ca.
authors.forename: Andony P
authors.initials: AP
authors.lastname: Melathopoulos
authors.affiliation: Kettle Valley Queens, Grand Forks, BC, Canada. lizandterry@gmail.com.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Huxter
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy. imma.iovinella@gmail.com.
authors.forename: Immacolata
authors.initials: I
authors.lastname: Iovinella
authors.affiliation: Department of Biochemistry & Molecular Biology, Centre for High-Throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, BC, V6T 1Z4, Canada. robert.rparker@gmail.com.|Current address: Macquarie University, Sydney, NSW, Australia. robert.rparker@gmail.com.
authors.forename: Robert
authors.initials: R
authors.lastname: Parker
authors.affiliation: Department of Biochemistry & Molecular Biology, Centre for High-Throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, BC, V6T 1Z4, Canada. nstoynov@mail.ubc.ca.
authors.forename: Nikolay
authors.initials: N
authors.lastname: Stoynov
authors.affiliation: Department of Biochemistry & Molecular Biology, Centre for High-Throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, BC, V6T 1Z4, Canada. amytam0517@hotmail.com.
authors.forename: Amy
authors.initials: A
authors.lastname: Tam
authors.affiliation: Department of Biochemistry & Molecular Biology, Centre for High-Throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, BC, V6T 1Z4, Canada. kyungmee@mail.ubc.ca.
authors.forename: Kyung-Mee
authors.initials: KM
authors.lastname: Moon
authors.affiliation: Department of Biochemistry & Molecular Biology, Centre for High-Throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, BC, V6T 1Z4, Canada. queeniecwt@gmail.com.
authors.forename: Queenie W T
authors.initials: QW
authors.lastname: Chan
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy. ppelosi.obp@gmail.com.
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
authors.affiliation: Department of Statistics, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada. rickw@stat.ubc.ca.
authors.forename: Rick
authors.initials: R
authors.lastname: White
authors.affiliation: Beaverlodge Research Farm, Agriculture & Agri-Food Canada, Beaverlodge, AB, T0H 0C0, Canada. Steve.Pernal@AGR.GC.CA.
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Pernal
authors.affiliation: Department of Biochemistry & Molecular Biology, Centre for High-Throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, BC, V6T 1Z4, Canada. foster@chibi.ubc.ca.
authors.forename: Leonard J
authors.initials: LJ
authors.lastname: Foster
mesh_terms: D000383:Agriculture; D000818:Animals; D001516:Bees / Q000235:genetics* / Q000469:parasitology; D001522:Behavior, Animal / Q000502:physiology*; D060467:Disease Resistance / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007814:Larva; D009490:Neurosecretory Systems; D016818:Nosema / Q000472:pathogenicity; D009812:Odorants; D054817:Pollination / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics; D057077:Varroidae / Q000235:genetics / Q000472:pathogenicity