title: Expressed sequence tag analysis of adult human iris for the NEIBank Project: steroid-response factors and similarities with retinal pigment epithelium.
abstract: OBJECTIVE
  The iris is a specialized tissue with important roles in the development and function of the eye. It is involved in diseases, including glaucoma and ocular melanoma, and its pigmented cells share an origin with the retinal pigment epithelium (RPE). Expressed sequence tag (EST) analysis of human iris has been performed to explore the repertoire of genes expressed in this tissue.
  
  
  METHODS
  An unamplified, un-normalized cDNA library (designated bx) was constructed from pooled (4-80 years old) human iris tissue. Over 2000 clones were picked and sequenced. Sequences were analyzed and clustered using GRIST (GRouping and Identification of Sequence Tags). The library was then normalized (and designated fg) and a further 2200 clones were sequenced for deeper examination of rarer sequence. Some sequences of interest were investigated further by standard methods.
  
  
  RESULTS
  From bx and fg libraries respectively, 1263 and 1604 clusters of expressed genes have been identified, giving a combined total of almost 2700 potentially unique genes. The most abundant novel transcript in bx is oculoglycan/opticin. Others include glucocorticoid induced leucine zipper protein (GILZ), Ris, a novel member of the Ras family, Iris Ring Finger (IRF), a member of the midline family, melastatin 2 (MLSN2), a member of the transient receptor potential calcium channel family, and iris expressed growth factor (IEGF), a member of the VEGF/PDGF family. Several factors involved in steroid responses are also represented.
  
  
  CONCLUSIONS
  The iris libraries are a rich source of novel as well as known genes, including molecular markers for pigmented cells that are also shared with RPE. A number of transcripts code for proteins involved in steroid response, with interesting implications for control of intraocular pressure. These sequence verified clones provide a nonredundant set for micro-array construction.
authors.affiliation: Section on Molecular Structure and Function, National Eye Institute, National Institutes of Health, Bethesda, MD 20892-2740, USA. graeme@helix.nih.gov
authors.forename: Graeme
authors.initials: G
authors.lastname: Wistow
authors.forename: Steven L
authors.initials: SL
authors.lastname: Bernstein
authors.forename: Sugata
authors.initials: S
authors.lastname: Ray
authors.forename: M Keith
authors.initials: MK
authors.lastname: Wyatt
authors.forename: Amita
authors.initials: A
authors.lastname: Behal
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Touchman
authors.forename: Gerald
authors.initials: G
authors.lastname: Bouffard
authors.forename: Don
authors.initials: D
authors.lastname: Smith
authors.forename: Katherine
authors.initials: K
authors.lastname: Peterson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D018076:DNA, Complementary / Q000032:analysis; D030541:Databases, Genetic; D020224:Expressed Sequence Tags; D005136:Eye Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D007498:Iris / Q000187:drug effects / Q000378:metabolism*; D008875:Middle Aged; D008969:Molecular Sequence Data; D009316:National Institutes of Health (U.S.); D020411:Oligonucleotide Array Sequence Analysis; D009885:Ophthalmology; D010857:Pigment Epithelium of Eye / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014481:United States
chemical_list: D018076:DNA, Complementary; D005136:Eye Proteins; D005938:Glucocorticoids; D012333:RNA, Messenger