1. K. Yamaguchi, K. Irie, K. Matsumoto, Department of Molecular Biology, Faculty of Science, Nagoya University, Chikusa-ku, Nagoya 464-01, Japan.
2. K. Shirakabe and E. Nishida, Department of Genetics and Molecular Biology, Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto 606-01, Japan.
3. H. Shibuya and N. Ueno, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060, Japan.
4. I. Ohishi and T. Taniguchi, Institute for Molecular and Cellular Biology, Osaka University, Suita-shi, Osaka 565, Japan.