title: Mis-spliced transcripts of nicotinic acetylcholine receptor alpha6 are associated with field evolved spinosad resistance in Plutella xylostella (L.).
abstract: The evolution of insecticide resistance is a global constraint to agricultural production. Spinosad is a new, low-environmental-risk insecticide that primarily targets nicotinic acetylcholine receptors (nAChR) and is effective against a wide range of pest species. However, after only a few years of application, field evolved resistance emerged in the diamondback moth, Plutella xylostella, an important pest of brassica crops worldwide. Spinosad resistance in a Hawaiian population results from a single incompletely recessive and autosomal gene, and here we use AFLP linkage mapping to identify the chromosome controlling resistance in a backcross family. Recombinational mapping with more than 700 backcross progeny positioned a putative spinosad target, nAChR alpha 6 (Pxalpha6), at the resistance locus, PxSpinR. A mutation within the ninth intron splice junction of Pxalpha6 results in mis-splicing of transcripts, which produce a predicted protein truncated between the third and fourth transmembrane domains. Additional resistance-associated Pxalpha6 transcripts that excluded the mutation containing exon were detected, and these were also predicted to produce truncated proteins. Identification of the locus of resistance in this important crop pest will facilitate field monitoring of the spread of resistance and offer insights into the genetic basis of spinosad resistance in other species.
authors.affiliation: Department of Zoology, University of Cambridge, Cambridge, United Kingdom. swb29@cam.ac.uk
authors.forename: Simon W
authors.initials: SW
authors.lastname: Baxter
authors.forename: Mao
authors.initials: M
authors.lastname: Chen
authors.forename: Anna
authors.initials: A
authors.lastname: Dawson
authors.forename: Jian-Zhou
authors.initials: JZ
authors.lastname: Zhao
authors.forename: Heiko
authors.initials: H
authors.lastname: Vogel
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Shelton
authors.forename: David G
authors.initials: DG
authors.lastname: Heckel
authors.forename: Chris D
authors.initials: CD
authors.lastname: Jiggins
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004338:Drug Combinations; D007178:Inbreeding; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007305:Insecticide Resistance; D018942:Macrolides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009036:Moths / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D012326:RNA Splicing; D011978:Receptors, Nicotinic / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D004338:Drug Combinations; D019476:Insect Proteins; D018942:Macrolides; D011978:Receptors, Nicotinic; C104518:nicotinic receptor alpha6; C415329:spinosad