The molecular population genetics of shoot development in Arabidopsis thaliana

Studies in Arabidopsis thaliana have provided us with a wealth of information about the genetic pathways that regulate plant morphogenesis. This developmental genetic treasure trove represents a fantastic resource for researchers interested in the microevolution of development. Several laboratories have begun using molecular population genetic analyses to investigate the evolutionary forces that act upon loci that regulate shoot morphogenesis. Much of this work has focused on coding sequence variation in transcription factors; however, recent studies have explored sequence variation in other types of proteins and in promoter regions. Several genes that regulate shoot development contain signatures of selective sweeps associated with positive selection or harbor putative balanced polymorphisms in coding and noncoding sequences. Other regulatory genes appear to be evolving neutrally, but have accumulated potentially deleterious replacement polymorphisms.