Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 11/1/2004
Publication Date: 1/12/2005
Citation: Yamasaki, M., Tenaillon, M., Vroh, I., Schroeder, S., Sanchez-Villeda, H., Doebley, J., Gaut, B., Mcmullen, M.D. 2005. Genomic screen for domestication and improvement genes in maize [abstract]. Plant and Animal Genome Conference. p. 393.
Technical Abstract: Maize (Zea mays ssp. mays) was domesticated from its wild progenitor, teosinte (Zea mays ssp. parviglumis). Plant breeding has improved maize varieties for agricultural productivity and performance. Both of these processes involve selection of specific alleles at genes controlling key agronomic traits, resulting in reduced genetic diversity relative to unselected genes. A segment of 1,127 randomly chosen genes was sequenced in a set of diverse maize inbreds. Thirty-five genes exhibiting zero sequence diversity in the inbreds were further sequenced in diverse sets of maize landrace and teosinte accessions. To identify genes responsible for maize domestication and improvement, the sequence diversity was compared among the maize inbred lines, landraces and teosintes. Hudson-Kreitman-Aguadé tests and coalescent simulations of domestication were performed to test for selection. A gene was considered a domestication gene if the gene was significant for selection in both the landraces and inbreds, indicating that the loss of diversity occurred between teosintes and landraces. A gene was inferred to be an improvement gene if the landraces were not significant but the inbreds were significant for selection, indicating that diversity was reduced by plant breeding during inbred development. Of the 35 genes tested, four domestication and five improvement genes were identified as significant for selection by both analyses. Therefore, genomic screens for evidence of selection offer a means of identifying genes selected for agronomic importance even when gene function and the phenotype of interest are unknown.