Identification of genes expressed in a human scleral cDNA library.
OBJECTIVE
Clones established from a human scleral cDNA library were systematically sequenced. Public database sequence comparisons were performed to generate a profile of genes expressed in the human sclera and identify candidate genes for inherited diseases with scleral involvement.


METHODS
A directionally cloned pCMV-PCR cDNA library was constructed from RNA isolated from scleras of human donor eyes with known plano refractive history. Plasmid DNA was extracted from randomly selected cDNA clones, and the insert sequences were determined by 5' end single-pass sequencing. Expressed sequence tags (ESTs) were generated and analyzed with the GenBank BLASTN program to identify sequence homologies to known genes.


RESULTS
A total of 609 ESTs underwent BLAST analysis. Of these, 341 (56%) matched 228 known human genes and 4 non-human genes, 252 matched uncharacterized ESTs, and 16 showed no significant homology to human or non-human known sequences. The most redundant connective tissue-related genes were alphaA-crystalline, Xalpha-1 collagen, and beta-5 integrin. Other extracellular matrix gene matches were biglycan, syndecan, decorin, fibromodulin, proline arginine-rich end leucine-rich repeat protein, transgelin, TIMP-1, and fibulin 1. Human scleral expression of all but decorin and biglycan has not previously been reported.


CONCLUSIONS
This effort provides the first partial list of genes expressed in human sclera. Identification of genes expressed in the sclera contributes to our understanding of scleral biology, and potentially provides positional candidate genes for scleral disorders such as high myopia.
Young
Terri L
TL
Division of Ophthalmology, Children's Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, PA 19104, USA. youngt@email.chop.edu
Guo
Xiaoshan D
XD
King
Richard A
RA
Johnson
Janell M
JM
Rada
Jody A
JA
D000328:Adult; D000368:Aged; D003238:Connective Tissue / Q000378:metabolism; D016208:Databases, Factual; D020224:Expressed Sequence Tags / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005136:Eye Proteins / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000502:physiology*; D020869:Gene Expression Profiling; D015723:Gene Library; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000302:isolation & purification; D012590:Sclera / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D012313:RNA