Fig. 2. The 3'UTR sequences used in this study. (A) The Hsp70Ab 3'UTR sequence (UGH, UgGH, and UnGH) contains four AUUUA motifs that are often found in AREs. The AU content of the sequence is 76%. The sequence was obtained from the pP{CaSpeR-hs} sequence (Pirrotta, 1988). The 3' end of the sequence is an expected approximate polyadenylation site at 220 bases downstream to the Hsp70Ab stop codon (Dellavalle et al., 1994). (B) The Act5C 3'UTR sequence (UGA, UgGA, and UnGA). The sequence has a single AUUUA motif and 58% AU content. The sequence was obtained from the pP{CaSpeR-hs/act} sequence (Pirrotta, 1988) and is terminated at an expected approximate polyadenylation site (655 bases downstream to the Act5C stop codon) (Bond and Davidson, 1986). The AUUUA motifs are boxed. The underlined sequences are protein coding in the original genes, but constitute 3'UTR in our constructs. All the transgenes have a common 77-base sequence between the GFP stop codon and the sequences shown here.