title: Retinal function and structure in Ant1-deficient mice.
abstract: OBJECTIVE
  Mutations in ANT, a mitochondrial ATP transporter, are typically associated with myopathy. Because of the high metabolic demands of the retina, the authors examined whether elimination of the Ant1 isoform in a transgenic mouse affects retinal function or morphology.
  
  
  METHODS
  RT-PCR was used to confirm Ant1 expression in retinas of wild-type (WT) or Ant1(-/-) mice. Full-field ERGs were used to test retinal function under dark- and light-adapted conditions and the recovery of the photoresponse to a bright flash. Using histologic methods, the authors assessed the retinal location of ANT and ANT1-β-gal reporter protein, mitochondrial activity with cytochrome c oxidase (COX) and succinate dehydrogenase (SDH) staining, retinal layer thickness, and bipolar cell types using Chx10 and recoverin.
  
  
  RESULTS
  Ant1(-/-) mice had supernormal ERG b-waves under both dark- and light-adapted conditions. X-Gal staining was detected in a subset of cells within the inner retina. The following characteristics were normal in Ant1(-/-) mice compared with age-matched WT mice: recovery of the photoresponse, COX and SDH activity, retinal morphology, and bipolar cell morphology.
  
  
  CONCLUSIONS
  The presence of ANT1 in a subset of inner retinal cells accompanied by supernormal ERG responses suggests that ANT1 may be localized to hyperpolarizing bipolar cells. However, the immunohistochemical techniques used here did not show any differences in bipolar cells. Moderate functional changes coupled with a lack of detectable morphologic changes suggest that ANT1 is not essential for ATP transport in the retina.
authors.affiliation: Rehabilitation Research and Development Center, Atlanta VA Medical Center, Decatur, GA 30033, USA.
authors.forename: M Joseph
authors.initials: MJ
authors.lastname: Phillips
authors.forename: Sarah
authors.initials: S
authors.lastname: Webb-Wood
authors.forename: Amanda E
authors.initials: AE
authors.lastname: Faulkner
authors.forename: Seema B
authors.initials: SB
authors.lastname: Jabbar
authors.forename: Valerie
authors.initials: V
authors.lastname: Biousse
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Newman
authors.forename: Vi T
authors.initials: VT
authors.lastname: Do
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Boatright
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Wallace
authors.forename: Machelle T
authors.initials: MT
authors.lastname: Pardue
mesh_terms: D033741:Adenine Nucleotide Translocator 1 / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D003623:Dark Adaptation; D003576:Electron Transport Complex IV / Q000378:metabolism; D004596:Electroretinography; D007124:Immunoenzyme Techniques; D007625:Kearns-Sayre Syndrome / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008928:Mitochondria / Q000378:metabolism; D010775:Photic Stimulation; D020033:Protein Isoforms / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics; D012160:Retina / Q000166:cytology* / Q000378:metabolism*; D051245:Retinal Bipolar Cells / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013385:Succinate Dehydrogenase / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D033741:Adenine Nucleotide Translocator 1; D020033:Protein Isoforms; D012333:RNA, Messenger; D000255:Adenosine Triphosphate; D013385:Succinate Dehydrogenase; D003576:Electron Transport Complex IV; D001616:beta-Galactosidase