Abstract
Abstract: :
Purpose: Public database sequence comparisons were made with insert sequences from a human scleral cDNA library. This allows for confirmation of previously expressed genes, and identification of novel, uncharacterized genes in human sclera. Method: A directionally cloned pCMV-PCR cDNA library was constructed from RNA isolated from sclerae 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: To date, 609 ESTs have undergone BLAST analysis - 341 (56%) matched 232 known 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 alpha-A crystalline, X alpha-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, and fibulin 1. Human scleral expression of all but decorin and biglycan has not previously been reported. Conclusion: This effort provides the first comprehensive list of genes expressed in human sclera. Identification of genes expressed preferentially or exclusively in sclera contributes to our understanding of scleral biology, and provides positional candidate genes for scleral disorders such as high myopia.
Keywords: 417 gene/expression • 574 sclera • 403 extracellular matrix