Genetic architecture of leaf morphogenesis in Arabidopsis thaliana

In an attempt to identify genes involved in leaf morphogenesis in Arabidops is thaliana, we screened for new mutants showing abnormal leaves and conduc ted genetic analyses of already obtained mutants. Our large-scale mutant se arch, which got close to but did not reach saturation of the genome, showed that the lines obtained fell into 94 complementation groups. Many of these genes were mapped using a high-throughput linkage analysis method, based o n the simultaneous PCR coamplification of 21 polymorphic microsatellites an d the fluorescent semiautomated detection of their products. In addition, i n an attempt to ascertain wether intraspecific variability might be a sourc e of information on the genetic controls underlying plant leaf morphogenesi s, we analyzed variations in the architecture of vegetative leaves in a lar ge sample of Arabidopsis thaliana natural races, concluding that such morph ological traits are unlikely to develop under monogenic controls. Hence, a mapping population of the recombinant inbred lines of Lister and Dean was a nalyzed to identify quantitative trait loci (QTL) harboring naturally occur ring alleles that contribute to natural variations in leaf architecture and to eventually correlate their intervals with the map positions of genes id entified by mutation.