Fig. 5.
Polycistronic expression of exogenous reporter and drug-selectable proteins. Proteins were in vitro translated from polycistronic transcripts exactly as in Fig. 4. Proteins in lane 1 were translated from the endogenous sequence of a bicistronic locus in C. zofingiensis as a control (same as Fig. 4, lane 6). In lanes 3 and 4, either the upstream ORF or the downstream ORF of that locus was replaced with a yellow fluorescent protein derivative, mVenus. In lane 2, both the upstream ORF and the downstream ORF of a bicistronic locus from C. reinhardtii (Cre10.g466000/Cre10.g465950) were replaced with mVenus and RPS14-EmR, which confers resistance to the drug emetine. The intensities of each band were normalized relative to the number of methionine, and the ratios of the upstream to the downstream gene product for each pair are presented in the accompanying table.