Understanding the genetic basis of developmental processes is a fundamental concern of modern biology. Research in systematic biology can provide important new insights into development by elucidating the genetic basis of changes in morphogenesis that occurred during the transformation of one species into another. Because profound differences in morphology can arise over relatively short periods of time, morphologically diverse organisms can remain interfertile, and thus be amenable to combined genetic and developmental analyses. One example of this phenomenon involves maize (Zea mays ssp. parviglumis), which differ dramatically in adult morphology despite the fact that they are fully interfertile. The proposed research will characterize the genetic and developmental basis of the dramatic morphological differences between maize and teosinte. This will be accomplished by the creation of near-isogenic lines for the genes controlling the morphological differences between these organisms. These near-isogenic lines will be essentially pure teosinte except for single regions of the maize genome that have been introduced into them. The near-isogenic lines will be analyzed to determine the effects of the single regions of the maize genome on morphogenesis. Fine-mapping of regions of the genome with dramatic effects on morphogenesis will be used to investigate whether these regions contain single major loci or several linked loci, each with individually small effects.
