|Childs, Kevin - TEXAS A&M UNIVERSITY|
|Klein, Patricia - TEXAS A&M UNIVERSITY|
|Morishige, Daryl - TEXAS A&M UNIVERSITY|
|Mullet, John - TEXAS A&M UNIVERSITY|
Submitted to: Plant Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 11, 2001
Publication Date: August 1, 2001
Citation: Childs, K.L., Klein, R.R., Klein, P.E., Morishige, D.T., Mullet, J.E. 2001. Mapping genes on an integrated sorghum genetic and physical map using cDNA selection technology. Plant Journal. 27:243-255. Interpretive Summary: The next major advancement in the improvement of important crop plants hinges on the identification of genes controlling important traits. Genes are tiny packets of genetic blueprint material that are found inside the cells of all plants and animals and control all of the physical characteristics of these organisms. Once the genes controlling important traits are found, naturally occurring changes in these genes can be found and utilized to improve plants. This study details the development of methods that permit efficient identification of plant genes (specifically in sorghum) and allows scientists to find where these genes are located with great precision. Also reported are the results of work focused on building a precise map of sorghum showing where important genes are located. This information will be primarily used by fellow scientists but the work should ultimately result in better adapted, higher producing, and more pest-resistant sorghum varieties available to American farmers.
Technical Abstract: Sorghum is an important target of plant genomics. This cereal has unusual tolerance to adverse environments, a small genome relative to most other grasses, a diverse germplasm, and utility for comparative genomics with rice, corn, and other grasses. In this study, a modified cDNA selection protocol was developed to aid the discovery and mapping of genes across an integrated genetic and physical map of the sorghum genome. Cloned DNA fro the sorghum genome map was isolated and covalently bound in arrayed tubes for efficient liquid handling. Amplifiable DNA sequence tags located adjacent to DNA restriction sites were derived from cDNA and used in two rounds of direct selection. DNA sequence tags selected on a fully sequenced sorghum clone identified 8 of every 10 known and predicted genes encoded by the clone. Based on identity with selected cDNA tag sequences, two sorghum genes and 58 sorghum expression sequence tags were mapped to linkage group B. Additionally, cDNA tags selected on the linkage group B clones had significant sequence similarity to 31 genes from other species. The modified cDNA selection procedure described here will be useful for genome wide gene discovery and expression sequence tag mapping in sorghum and for comparative genomics of sorghum, rice, corn, and other grasses.