A FULL-LENGTH TY3 GYPSY-TYPE RETROTRANSPOSON IN THE FERN ADIANTUM/

Ty3/gypsy-type LTR-retrotransposons have been found only in lily and m aize but not in cryptogam. In fern Adiantum, we recently found a full- length Ty3/gypsy-type LTR-retrotransposon (ARET-1; 8284 bp). This retr otransposon has both 5' and 3' LTRs (1.2 kb), a primer binding site, a polypurine tract, and an RNA binding motif and its domain arrangement in the pol region is the same as that of Ty3/gypsy-type retrotranspos on. These results suggest that Ty3/gypsy-type retrotransposons are wid espread among vascular plants.