title: Temporal and spatial regulation of integrin vitronectin receptor mRNAs in the embryonic chick retina.
abstract: OBJECTIVE
  To identify integrin vitronectin receptor subunit mRNAs in the developing avian retina and to track their expression.
  
  
  METHODS
  Reverse transcription-polymerase chain reaction was used to identify integrin vitronectin receptor subunit mRNAs expressed in embryonic chick retina. cDNA clones encoding the beta 5 subunit were isolated and sequenced. Expression patterns of mRNAs encoding alpha v, beta 3, and beta 5 subunits were analyzed using northern analysis and in situ hybridization.
  
  
  RESULTS
  Integrin beta 1, beta 3, and beta 5 subunit mRNA were identified in embryonic day 6 chick retina. The sequence of chicken beta 5 was 77% identical to that of human beta 5, and sequences with known signaling functions were highly conserved. Integrin alpha v, beta 3, and beta 5 mRNAs were expressed throughout the development of the embryonic retina, with the highest levels per retina observed around the embryonic day 9. In situ hybridization showed that both beta 3 and beta 5 were expressed throughout the developing retina, particularly in undifferentiated neuroepithelial precursor cells. At later times, beta 3 was expressed uniformly throughout the retina, whereas beta 5 expression was highest in a band throughout the central retina.
  
  
  CONCLUSIONS
  The strong conservation of sequences with known signaling functions in chicken beta 5 suggests that it functions in a manner similar to human beta 5. Spatial expression patterns of vitronectin receptor subunits at early times of development point to a range of possible functions beyond axon outgrowth, including retinoblast proliferation, adhesion, and migration.
authors.affiliation: Neuroscience Research Institute, University of California, Santa Barbara 93106, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Gervin
authors.forename: G M
authors.initials: GM
authors.lastname: Cann
authors.forename: D O
authors.initials: DO
authors.lastname: Clegg
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002642:Chick Embryo; D002645:Chickens; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000032:analysis / Q000302:isolation & purification; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D017403:In Situ Hybridization; D016023:Integrins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D019030:Receptors, Vitronectin / Q000235:genetics / Q000378:metabolism*; D012160:Retina / Q000196:embryology* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D019096:Vitronectin / Q000235:genetics / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D016023:Integrins; D012333:RNA, Messenger; D019030:Receptors, Vitronectin; D019096:Vitronectin