Seeing the unseen: Microarray-based gene expression profiling in vision

Completion of genome sequencing efforts of humans and model organisms(1-3) have provided exciting opportunities for vision research. Questions that were hard to envisage, let alone resolve, suddenly appear within reach. We are on the verge of untangling gene networks that regulate development and cell fate and cellular processes that determine adaptation or apoptosis. Patterns of gene expression specific for a particular cell at a given time can now be determined at the genome level. Microarray and related technologies are revolutionizing vision research by making possible simultaneous analysis of thousands of genes, and hopefully soon, the entire transcriptome.(4) The challenge is to understand how relatively simple variations in DNA sequence and gene expression contribute to complex biological phenomena, including normal development, aging, disease pathogenesis, and differences among individuals. We will briefly review strategies for designing microarray experiments for expression profiling, image processing including normalization, and data analysis including statistics, clustering, and pathway construction.