Contents

10 March 1989
Vol 243, Issue 4896

About The Cover

Photograph of a dwarf plant of Arabidopsis thaliana isolated from a population of transformants that had been generated by infecting seeds with Agrobacterium. Genetic analysis indicates that the recessive mutation that caused this phenotype is due to the insertion of a T-DNA from Agrobacterium into a gene that in the homozygous state confers dwarfism to the plant. The plant pictured was 3.5 centimeters in height. The portion pictured is 3 centimeters in height. See page 1351. [Photograph by DeVere Patton, senior photographer, E. I. du Pont de Nemours & Company, Wilmington, DE 19898]