tokens: Various sequences ( designated X ) from UASs of TEF2 , AgTEF ( TEF gene from Ashbya gossypii ) and ADE2 were inserted between HML - E and HML alpha at HML Delta I ( HML locus deleted for the I silencer ) flanked by the FRT sites for the Flp1p site - specific recombinase ( Fig . 4A and B ) .