CAMBRIDGE, MAWhile attempting to isolate a gene believed to be key to the development of the autoimmune disorder myasthenia gravis Monday, MIT geneticists Dr. Stephen Burch and Dr. Caryn Song made a breakthrough discovery: each other. "I was examining some cellular tissue when my electron microscope broke," Burch said. "Caryn offered to share her microscope, and each of us looked at the tissue through one of the eyepieces. At one point, our cheeks lightly touched, and I looked over and realized how beautiful she looks without her glasses. I always saw Caryn as a respected colleague. For the first time, I saw her as a woman." A process of trial-and-error sexual experimentation commenced later that evening, continuing well into the night.