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Yuh Nung Jan, a theoretical physicist turned neurobiologist, has always been fascinated by the nature of intelligence. "What could account for the prodigious mental abilities of a Mozart or an Einstein?" Jan has wondered. "I don't know how to study intelligence in a meaningful way, but knowing how to build a brain ought to be of some help."

For more than 25 years, Yuh Nung has shared a laboratory with his wife, fellow HHMI scientist Lily Jan, at UCSF, where he has worked to understand how neurons become specialized during embryonic development and how such diversity in neural morphology contributes to the wiring of the nervous system. Using the relatively simple nervous system of Drosophila as a model, Yuh Nung hopes to discover the genetic program that controls its development and uncover evolutionarily conserved core programs that control neural development in animals.

When Yuh Nung entered the California Institute of Technology as a graduate student in 1968, he fully intended to study theoretical physics. But a nagging, rather naïve interest in biology, coupled with his first exposure to the field of modern biology, led Yuh Nung to switch gears. His thesis advisor, the late Max Delbrück, a winner of the 1969 Nobel Prize in Medicine or Physiology and himself a physicist turned biologist, was helpful and supportive of this career change. As a graduate student in Delbrück's laboratory, Yuh Nung studied sensory transduction of the fungus Phycomyces, and later, as a postdoctoral fellow in the Caltech laboratory of Seymour Benzer, he began studying the nervous system.

Both Delbrück and Benzer were mentors who greatly influenced Yuh Nung, especially in their style of science. "Both strived to do pioneering work on fundamentally important problems and, at the same time, stayed away from the crowd," he observed.

The Jans' recent research interests have converged on the development and the function of dendrites. They have made significant progress in understanding the mechanisms that control formation, maintenance, and large-scale remodeling of dendritic fields.

Yuh Nung and Lily met at Taiwan University and went together to CalTech, where she, too, began her graduate studies in physics but later switched to biology. Their partnership in marriage and in the laboratory is a natural one, Yuh Nung said. "It is relatively rare in science that two researchers complement each other in ability and in temperament such that the sum of the collaboration is more than the two parts," he commented. "I feel extremely lucky to have such a long-term partnership with my wife."