DNA DESIGNS

Shown at the left is a color-coded computer model of DNA, the molecule that carries genetic instructions for all earthly organisms. Humans have perhaps the most complex set of such instructions, called a genome, on the planet. But plants are not far behind them. This complexity makes it difficult for molecular botanists to identify the important genes that govern desirable characteristics in a given plant.

The United States Department of Agriculture is planning a 10-year, $500-million program to map out genes for such traits as drought resistance in crop plants. This means finding out where such genes lie along a strand of DNA.

The National Science Foundation wants to fund a complete map of the genome of a simple weed plant Arabidopsis thaliana to use as a model for research. This would be a 10-year project costing in the range of $70 million.