The purpose of Dr. Meinke's research is to identify genes with essential functions during plant embryo development. The approach is to isolate and characterize embryo-lethal mutants of Arabidopsis thaliana. He here proposes to 1) continue the analysis of embryonic lethals with interesting patterns of abnormal development; 2) attempt to identify genes with important developmental rather than housekeeping functions; and 3) develop strategies for the molecular isolation of mutant genes. Several different models have been proposed to facilitate the identification of genes with important developmental functions. He plans to test these models by isolating additional mutants with unusual patterns of development, defects in genes expressed only during embryogenesis, lethal phases that correspond to a critical stage in morphogenesis, and arrested embryos that are green rather than white. Three different approaches to molecular analysis of embryonic lethals will be pursued in collaboration with other laboratories; 1) gene tagging with T-DNA following seed transformation; 2) gene tagging with maize transposable elements; and 3) chromosome walking and molecular complementation through transformation. He proposes to focus his attention on three mutants with particularly interesting phenotypes; the biotin auxotroph (bio1); a fused cotyledon/rootless mutant (emb30); and a green blimp mutant with no apical meristems (emb22). Additional mutants will be mapped in preparation for gene isolation through chromosome walking. %%% Developmental mutants have been used in a variety of animal systems to identify genes with important developmental functions. This proposal extends that approach to the genetically approachable plant, Arabidopsis.
