title: Overlapping expression patterns and redundant roles for AP-2 transcription factors in the developing mammalian retina.
abstract: BACKGROUND
  We have previously shown that the transcription factor AP-2α (Tcfap2a) is expressed in postmitotic developing amacrine cells in the mouse retina. Although retina-specific deletion of Tcfap2a did not affect retinogenesis, two other family members, AP-2β and AP-2γ, showed expression patterns similar to AP-2α.
  
  
  RESULTS
  Here we show that, in addition to their highly overlapping expression patterns in amacrine cells, AP-2α and AP-2β are also co-expressed in developing horizontal cells. AP-2γ expression is restricted to amacrine cells, in a subset that is partially distinct from the AP-2α/β-immunopositive population. To address possible redundant roles for AP-2α and AP-2β during retinogenesis, Tcfap2a/b-deficient retinas were examined. These double mutants showed a striking loss of horizontal cells and an altered staining pattern in amacrine cells that were not detected upon deletion of either family member alone.
  
  
  CONCLUSIONS
  These studies have uncovered critical roles for AP-2 activity in retinogenesis, delineating the overlapping expression patterns of Tcfap2a, Tcfap2b, and Tcfap2c in the neural retina, and revealing a redundant requirement for Tcfap2a and Tcfap2b in horizontal and amacrine cell development.
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Erin A
authors.initials: EA
authors.lastname: Bassett
authors.forename: Anna
authors.initials: A
authors.lastname: Korol
authors.forename: Paula A
authors.initials: PA
authors.lastname: Deschamps
authors.forename: Reinhard
authors.initials: R
authors.lastname: Buettner
authors.forename: Valerie A
authors.initials: VA
authors.lastname: Wallace
authors.forename: Trevor
authors.initials: T
authors.lastname: Williams
authors.forename: Judith A
authors.initials: JA
authors.lastname: West-Mays
mesh_terms: D025042:Amacrine Cells / Q000166:cytology / Q000502:physiology; D000818:Animals; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D038081:Organogenesis / Q000502:physiology; D012160:Retina / Q000196:embryology* / Q000502:physiology; D050656:Transcription Factor AP-2 / Q000235:genetics*
chemical_list: C493668:Tfap2a protein, mouse; C493669:Tfap2b protein, mouse; C583890:Tfap2c protein, mouse; D050656:Transcription Factor AP-2