Characterization of gene expression in human trabecular meshwork using single-pass sequencing of 1060 clones

PURPOSE. TO study the gene expression profile of the human trabecular meshw ork (HTM). METHODS. A polymerase chain reaction (PCR)-amplified cDNA librar y was constructed using RNA from the TM of a 67-year-old normal, perfused h uman eye. A total of 1060 crones were randomly selected for sequencing of o ne end. These sequences were searched against nonredundant Gen-Bank and dbE ST databases for similarity comparison by using a FASTA file and the BLASTc l3 program. Relative expression patterns of those clones that matched other expressed sequence tags (ESTs) were determined using the National Center f or Biotechnology Information (NCBI) Unique Human Gene Sequence Collection ( UniGene) database. RESULTS. Of the 1060 clones analyzed, 519 (48.9%) had se quences identical with known genes, 125 (11.8%) matched ESTs, and 189 (17.8 %) did not match any database sequences. Of the remaining clones, 31 (3%) c orresponded to mitochondrial transcripts and 196 (18.5%) to repetitive and noninformative sequences. It is notable that some of the genes highly repre sented in this library are not ubiquitously expressed in other tissues, whi ch suggests a potentially important role in the HTM. As evidence for the pr esence of true novel genes in the library, one of the clones was fully sequ enced. This clone comprised a complete open reading frame of 966 nucleotide s, and its deduced amino acid sequence corresponded to a protein 33% simila r to the MAS-related G-protein-coupled receptor. CONCLUSIONS. The identific ation of the more highly expressed genes in HTM and the discovery of novel genes expressed in this tissue provides basic information for further resea rch on the. physiology of the TM and for the identification of glaucoma can didate genes.