Graduate School of Life Science, Hokkaido University, Kita-Ku Kita-10 Nishi-8, Sapporo 0600810, Japan.|Graduate School of Life Science, Hokkaido University, Kita-Ku Kita-10 Nishi-8, Sapporo 0600810, Japan.|Graduate School of Life Science, Hokkaido University, Kita-Ku Kita-10 Nishi-8, Sapporo 0600810, Japan.|Graduate School of Life Science, Hokkaido University, Kita-Ku Kita-10 Nishi-8, Sapporo 0600810, Japan.