Fig. 2. Mutational analysis of the glp-1 SCR. (A) Base substitution mutations were made within the full-length glp-1 3' UTR in lacZ reporter mRNAs. The 34 nt sub-region of the SCR is shown, and mutations are underlined. The location of the GRE and GDE elements suggested by the data in (B-F) and in Table 1 are shown at the top; arrowheads indicate that these elements may overlap and/or contain additional untested nucleotides. (B) A 4-cell embryo from an animal injected with lacZ mRNA carrying the wild-type glp-1 3' UTR [lacglp(WT)] and stained for ß-gal. Dark staining can be seen in the anterior cells ABa and ABp, but not in posterior cells (arrowheads). (C) A 4-cell embryo from an animal injected with lacglp(LS1) mRNA. Dark staining can be seen in all four cells. (D) A whole mount of a hermaphrodite injected with lacglp(LS2) mRNA; no staining was detected in the distal arm (bracket), oocytes (arrowheads), or embryos (asterisks). (E-G) In situ hybridization to detect injected lacZ reporter mRNA in embryos with a lacZ probe. (E) A 2-cell embryo carrying lacglp(WT) mRNA. (F) A 4-cell embryo carrying lacglp(LS2) mRNA. (G) A 4-cell embryo from a non-injected animal.