Methods and Utility of EST and Whole Genome Sequencing

Abstract

Since the Human Genome Project started in 1990 numerous large‐scale genomic sequencing projects have been conducted by different consortia of laboratories. As a result, the complete genetic information of an ever growing number of higher eukaryotes is now available in the public databases, which constitute an invaluable resource for biological research. Although eukaryote genomes are very large, most of their DNA is repetitive and do not code for genes. This is particularly true for plants, where repetitive DNA can account for more than 90 % of the genome, posing a major challenge to pursue full genomic sequencing. Large‐scale sequencing of cDNA (EST sequencing) is an efficient way to specifically sequence expressed genes, although no more than half of the genes can be recovered with this strategy. Gene targeted genomic sequencing approaches, like methylation filtration, overcome some of the limitations of EST sequencing and constitute an affordable alternative for plant genomic sequencing.