Institution: | (1) Department of Biology, University of Utah, 84112 Salt Lake City, Utah, USA;(2) Departamento de Genética, Facultad de Biologia, Universidad de Sevilla, Avenida Reina Mercedes, Apartado 1095, E-41080 Sevilla, Spain;(3) Present address: Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Ave., 02115 Boston, MA, USA |