title: Identification of odor-processing genes in the emerald ash borer, Agrilus planipennis.
abstract: BACKGROUND
  Insects rely on olfaction to locate food, mates, and suitable oviposition sites for successful completion of their life cycle. Agrilus planipennis Fairmaire (emerald ash borer) is a serious invasive insect pest that has killed tens of millions of North American ash (Fraxinus spp) trees and threatens the very existence of the genus Fraxinus. Adult A. planipennis are attracted to host volatiles and conspecifics; however, to date no molecular knowledge exists on olfaction in A. planipennis. Hence, we undertook an antennae-specific transcriptomic study to identify the repertoire of odor processing genes involved in A. planipennis olfaction.
  
  
  RESULTS
  We acquired 139,085 Roche/454 GS FLX transcriptomic reads that were assembled into 30,615 high quality expressed sequence tags (ESTs), including 3,249 isotigs and 27,366 non-isotigs (contigs and singletons). Intriguingly, the majority of the A. planipennis antennal transcripts (59.72%) did not show similarity with sequences deposited in the non-redundant database of GenBank, potentially representing novel genes. Functional annotation and KEGG analysis revealed pathways associated with signaling and detoxification. Several odor processing genes (9 odorant binding proteins, 2 odorant receptors, 1 sensory neuron membrane protein and 134 odorant/xenobiotic degradation enzymes, including cytochrome P450s, glutathione-S-transferases; esterases, etc.) putatively involved in olfaction processes were identified. Quantitative PCR of candidate genes in male and female A. planipennis in different developmental stages revealed developmental- and sex-biased expression patterns.
  
  
  CONCLUSIONS
  The antennal ESTs derived from A. planipennis constitute a rich molecular resource for the identification of genes potentially involved in the olfaction process of A. planipennis. These findings should help in understanding the processing of antennally-active compounds (e.g. 7-epi-sesquithujene) previously identified in this serious invasive pest.
authors: Department of Entomology, The Ohio State University, Ohio Agricultural and Research Development Center, Wooster, Ohio, United States of America.
authors: Praveen
authors: P
authors: Mamidala
authors: Asela J
authors: AJ
authors: Wijeratne
authors: Saranga
authors: S
authors: Wijeratne
authors: Therese
authors: T
authors: Poland
authors: Sohail S
authors: SS
authors: Qazi
authors: Daniel
authors: D
authors: Doucet
authors: Michel
authors: M
authors: Cusson
authors: Catherine
authors: C
authors: Beliveau
authors: Omprakash
authors: O
authors: Mittapalli
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001517:Coleoptera / Q000235:genetics* / Q000502:physiology; D003463:Cues; D005260:Female; D017344:Genes, Insect / Q000235:genetics*; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009812:Odorants; D018035:Receptors, Odorant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017421:Sequence Analysis; D012726:Sexual Behavior, Animal; D059467:Transcriptome
chemical_list: D019476:Insect Proteins; D018035:Receptors, Odorant; C045648:odorant-binding protein