Access to the Maize Genome: An Integrated Physical and Genetic Map

Crop plant research is poised to make revolutionary strides including the following: cloning target genes based on their function and/or their position in the genome; documenting all genes and their interplay; defining and exploring all the existing genetic diversity in a species; and using functional information and syntenic relationships of genes in closely related species to extrapolate gene function in crop plants. The challenge, however, is to develop a set of comprehensive and systematic resources to facilitate these research endeavors. Genomic resources in maize (Zea mays) will undergird sequencing of the maize genome and will complement and contribute to research in the cereals, other grasses, and other crop plants. For maize, developing genomics tools means facing the daunting realities of size and complexity. At approximately 2,500 megabases, the maize genome is comparable in size to that of humans, and the complexity is likely to be greater because of the abundance of multiple families of repetitive elements. Thus, gaining access to the maize genome is best tackled by following Goethe's advice to seek entry to the whole by going to its parts: