1. Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060–0810, Japan (M.N., H.K., M.A., K.T.Y.); Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113–0033, Japan (N.Y., Y.K.); and Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University, Okayama 700–8530, Japan (T.T.)