Figure 2. GFP expression driven by a
daf-16beta enhancer/promoter element. Fluorescent micrographs of
daf-16(mgDf47) animals that carry a
daf-16-rescuing translational GFP fusion Ex[
daf-16beta::GFP::DAF-16B] transgene. (a) An L1 animal showing GFP expression in neurons; four fluorescent neurons are marked by arrowheads. (b) A late L4 animal. GFP was expressed in the pharynx (marked by triangles), somatic gonad (with an arrow pointing to the vulva), and in neurons in the tail (marked by an arrowhead). Transgene array Ex[
daf-16beta::GFP::DAF-16B] was made as a complex extrachromosomal array in order to get better stability of transgene expression [21]. GR1329
daf-16(mgDf47) animals were transformed with a mixture of PvuII-digested worm genomic DNA (100 μg/ml) and
daf-16beta::GFP::DAF-16B minigene (0.25 μg/ml, in the form of PCR products). Higher concentrations of
daf-16beta::GFP::DAF-16B drastically reduced the viability of transgenic embryos (data not shown). DNA templates used: R13H8, a genomic cosmid clone from A. Coulson, and pPD117.01, a GFP vector. PCR primer sequences and procedures for fusions are available at
http://whitney.caltech.edu/~raymond/daf16.html or upon request.