title: Functional analysis of the ATP-binding cassette (ABC) transporter gene family of Tribolium castaneum.
abstract: BACKGROUND
  The ATP-binding cassette (ABC) transporters belong to a large superfamily of proteins that have important physiological functions in all living organisms. Most are integral membrane proteins that transport a broad spectrum of substrates across lipid membranes. In insects, ABC transporters are of special interest because of their role in insecticide resistance.
  
  
  RESULTS
  We have identified 73 ABC transporter genes in the genome of T. castaneum, which group into eight subfamilies (ABCA-H). This coleopteran ABC family is significantly larger than those reported for insects in other taxonomic groups. Phylogenetic analysis revealed that this increase is due to gene expansion within a single clade of subfamily ABCC. We performed an RNA interference (RNAi) screen to study the function of ABC transporters during development. In ten cases, injection of double-stranded RNA (dsRNA) into larvae caused developmental phenotypes, which included growth arrest and localized melanization, eye pigmentation defects, abnormal cuticle formation, egg-laying and egg-hatching defects, and mortality due to abortive molting and desiccation. Some of the ABC transporters we studied in closer detail to examine their role in lipid, ecdysteroid and eye pigment transport.
  
  
  CONCLUSIONS
  The results from our study provide new insights into the physiological function of ABC transporters in T. castaneum, and may help to establish new target sites for insect control.
authors: Department of Biology/Chemistry, Animal Physiology, University of Osnabrück, Osnabrück 49069, Germany.
authors: Gunnar
authors: G
authors: Broehan
authors: Tobias
authors: T
authors: Kroeger
authors: Marcé
authors: M
authors: Lorenzen
authors: Hans
authors: H
authors: Merzendorfer
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D005123:Eye / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D023281:Genomics; D019476:Insect Proteins / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D050356:Lipid Metabolism / Q000235:genetics; D008297:Male; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics; D034622:RNA Interference; D014231:Tribolium / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D019476:Insect Proteins