title: Genetic, ophthalmic, morphometric and histopathological analysis of the Retinopathy Globe Enlarged (rge) chicken.
abstract: OBJECTIVE
  To identify the locus responsible for rge (retinopathy globe enlarged) in chickens and further characterise the rge phenotype.
  
  
  METHODS
  A colony of chickens carrying the rge mutation was rederived from a single heterozygous animal of the original line. The eyes of blind, heterozygous and normal birds were subjected to ophthalmic, morphometric and histopathological examination to confirm and extend published observations. DNA samples were obtained and subjected to a whole genome linkage search.
  
  
  RESULTS
  From 138 classified backcross progeny, 56 birds were blind and 82 sighted. Heterozygous birds were indistinguishable from wild type, but homozygotes had sluggish or unresponsive pupils, posterior sub-capsular lens opacities and an atrophic pecten. The fundus appeared normal with no significant pigmentary disturbance, but axial length and eye weight were increased. Pathology revealed focal retinal lesions. Linkage analysis placed the rge locus in a small region of chicken chromosome 1.
  
  
  CONCLUSIONS
  rge is a severe recessive retinal dystrophy in chickens, with associated globe enlargement. Linkage mapping has highlighted chicken chromosome 1 in a region most probably homologous to human chromosomes 7q31-35, 21q21 or 22q12-21. Candidate disease loci include RP10 (IMPDH1) and uncharacterised Ushers (USH1E) and glaucoma (GLC1F) loci.
authors.affiliation: Molecular Medicine Unit, St. James's University Hospital, University of Leeds, Leeds, UK.
authors.forename: Chris F
authors.initials: CF
authors.lastname: Inglehearn
authors.forename: David R
authors.initials: DR
authors.lastname: Morrice
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Lester
authors.forename: Graeme W
authors.initials: GW
authors.lastname: Robertson
authors.forename: Moin D
authors.initials: MD
authors.lastname: Mohamed
authors.forename: Ian
authors.initials: I
authors.lastname: Simmons
authors.forename: Louise M
authors.initials: LM
authors.lastname: Downey
authors.forename: Caroline
authors.initials: C
authors.lastname: Thaung
authors.forename: Leslie R
authors.initials: LR
authors.lastname: Bridges
authors.forename: Ian R
authors.initials: IR
authors.lastname: Paton
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Smith
authors.forename: Simon
authors.initials: S
authors.lastname: Petersen-Jones
authors.forename: Paul M
authors.initials: PM
authors.lastname: Hocking
authors.forename: David W
authors.initials: DW
authors.lastname: Burt
mesh_terms: D000818:Animals; D001766:Blindness / Q000235:genetics / Q000473:pathology / Q000662:veterinary*; D002386:Cataract / Q000235:genetics / Q000473:pathology / Q000662:veterinary; D002645:Chickens / Q000235:genetics*; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics; D004247:DNA / Q000032:analysis; D004195:Disease Models, Animal; D005260:Female; D005808:Genes, Recessive; D008040:Genetic Linkage; D005838:Genotype; D006984:Hypertrophy; D007908:Lens, Crystalline / Q000473:pathology; D008297:Male; D009154:Mutation; D009915:Orbit / Q000473:pathology*; D011201:Poultry Diseases / Q000235:genetics* / Q000473:pathology*; D011681:Pupil Disorders / Q000235:genetics / Q000473:pathology / Q000662:veterinary; D012162:Retinal Degeneration / Q000235:genetics / Q000473:pathology / Q000662:veterinary*
chemical_list: D004247:DNA