Prothallia of Adiantum capillus-veneris were grown under white light of 4.8-5.8 W m^-2from fluorescent lamps (FL40SD; Toshiba Lighting and Technology) at 25°C. Total RNA was prepared as described by Kanegae and Wada (1998). To purify poly(A)+ RNA, we used an mRNA purification kit (Amersham Pharmacia Biotech) according to the manufacturer’s instructions as described by Yamauchi et al. (2005).  cDNA libraries were synthesized with CloneMiner cDNA library construction kit (Invitrogen).