Applications of DNA tiling arrays to experimental genome annotation and regulatory pathway discovery

Microarrays have become a popular and important technology for surveying global patterns in gene expression and regulation. A number of innovative experiments have extended microarray applications beyond the measurement of mRNA expression levels, in order to uncover aspects of large-scale chromosome function and dynamics. This has been made possible due to the recent development of tiling arrays, where all non-repetitive DNA comprising a chromosome or locus is represented at various sequence resolutions. Since tiling arrays are designed to contain the entire DNA sequence without prior consultation of existing gene annotation, they enable the discovery of novel transcribed sequences and regulatory elements through the unbiased interrogation of genomic loci. The implementation of such methods for the global analysis of large eukaryotic genomes presents significant technical challenges. Nonetheless, tiling arrays are expected to become instrumental for the genome-wide identification and characterization of functional elements. Combined with computational methods to relate these data and map the complex interactions of transcriptional regulators, tiling array experiments can provide insight toward a more comprehensive understanding of fundamental molecular and cellular processes.