| add3 (arrested development 3) is a temperature-sensitive mutation in the plant Arabidopsis thaliana affecting leaf morphology. When an add3 mutant plant is grown at 21°C, leaves with non-expanding tips and margins exhibiting white mottled patches were observed. However, add3 plants grown at 29°C show an increase in expression of this phenotype. Leaf blade margin expansion is severely inhibited in these leaves (Kuttab, 2001). Hence, we hypothesized that ADD3 plays a key role during the normal differentiation and development of the margins of Arabidopsis leaves.; In this project, add3 was characterized genetically and molecularly by refinement of the physical-genetic map using molecular markers with genetic polymorphisms on chromosome 5. The high-resolution map required placement of known and newly designed molecular markers on a Bacterial Artificial Chromosome (BAC) contig. A candidate gene was identified using information from the Arabidopsis genome sequencing project. The high-resolution map around the add3 locus will facilitate the eventual cloning of the ADD3 gene. |
