NORWALK, Conn.--Perkin-Elmer's third-quarter results announcement last month pointed to positive developments at its Celera Genomics group. By the end of April, Celera had 300 employees and laboratories and related facilities were almost fully built. The company's staff has begun sequencing the Drosophila melanogaster genome and the unit is cooperating with Compaq Computer to build one of the world's largest supercomputing centers. Amgen, Pharmacia & Upjohn, and Novartis Pharma have all signed five-year subscription agreements to Celera databases.