Self-activation by C. elegans promoters. (A) The Y1H Destination plasmids containing the Gateway-cloned promoters Pfog-3 or Phlh-8 were integrated into the genome of YM4271 yeast. Twenty-four double integrant colonies were picked and spotted either onto (1) Sc-His,-Ura media plus increasing amounts of 3AT to determine self-activation of the HIS3 reporter, and onto (2) YEPD plates containing a nitrocellulose filter for a β-Gal assay. Circles indicate colonies that were selected for downstream Y1H experiments. (B) To determine if individual colonies exhibit phenotypic variations after clonal expansion, three Pfog-3 colonies, varying in their extent of self-activation (low = 1, moderate = 2, and high = 3), were picked and restreaked on Sc-His,-Ura media after which they were replica-plated onto selective 20 mM 3AT-containing media.
