Resources and Opportunities National Science Foundation - Sponsored Workshop Report . Maize Genome Sequencing Project 1

In response to a mandate from the maize (Zea mays) genetics community, a National Science Foundationsponsored workshop was held in St. Louis on July 2, 2001, to discuss technical approaches for a Maize Genome Sequencing Project. This workshop included academic, governmental, and industrial scientists with expertise in analysis of human, animal, plant, and microbial genomes as well as observers from federal funding agencies and those representing U.S. corn growers. The participants of the St. Louis workshop were in unanimous agreement that sequencing all maize genes and placing them on a cross-referenced physical-genetic map was an extremely worthy, feasible, and timely goal that can be achieved at a reasonable cost with existing technologies. Maize is one of the most important economic crops in the United States. It is also the best-studied and most tractable genetic system among the cereals, making it the premier model system for studying this important group of crops. A serious limitation to continued advances in both basic and applied research in maize is the lack of a comprehensive understanding of gene content and gene organization within the maize genome. Maize gene sequencing and functional analysis will help elucidate the molecular basis of agronomically important traits and thereby facilitate improvements in maize and other crop species. These agronomic improvements will have enormous impacts on mankind through improving human health, increasing energy production, and protecting our environment. The production of novel compounds in plants, including industrial feed stocks, biofuels, and medicinal compounds will increase the demand for corn and thereby directly benefit the agricultural community. The production of nutritionally enhanced foods that are safer and less allergenic than the foods we eat today will directly benefit consumers. The maize genome is approximately the same size, and at least as complex, as that of the previously sequenced human genome. Various technical approaches for sequencing the maize genome were discussed. All prior genome projects have employed either a minimal tiling path or whole genome shotgun sequencing followed by computer assembly approaches. The highly repetitive nature of the maize genome (large numbers of dispersed highly similar repeats) raised concerns regarding whether the data resulting from a whole genome shotgun sequencing project could be properly assembled into a complete genome sequence with existing bioinformatic tools. This concern, coupled with the high cost of a whole genome shotgun sequencing project on a genome the size of maize, has led the maize community to develop a third option whereby several cutting-edge technologies could be employed to identify, sequence, and assemble all of the genes of the complex maize genome. Such an approach would focus sequencing resources on the genic regions while minimizing the sequencing of the large repetitive component of the maize genome. This gene-enriched sequencing will provide a paradigm for the efficient and cost-effective sequencing of other large, complex genomes of plants and animals that would otherwise be prohibitively expensive to solve by whole genome sequencing. A majority of the participants concluded that a Maize Genome Sequence Project that focused on the gene-rich, low-copy fraction of the genome would be most appropriate. A minority of the participants felt that a full genome shotgun sequence would be the best sequencing approach. A third approach of sequencing gene-rich bacteria artificial chromosomes (BACs) received support from two participants. We invite the community of plant biologists to read the report below and offer your comments, views and suggestions. Please send your remarks via e-mail to the following address ([email protected]) and they will be posted at the Plant Physiology web site (http://www.aspb.org). We are looking forward to a discussion of the important issues raised by this report.