Fig. 3

Comparative analysis of plasmid-based and genome-integrated display systems. (a) Flow cytometry comparison of Saccharomyces boulardii (Sb) strains expressing A2 through plasmid-based (green) or genome-integrated (red) systems. Frequency (Freq.) represents the percentage of yeGFP-positive (yeGFP+) events gated using a negative control (parental Sb strain labeled with antibodies). (b) Flow cytometry comparison of wild-type (WT) Sb and LIP02 strains containing the genome-integrated A2 cassette. Events in quadrant Q2 (Alexa 555-positive, yeGFP-positive) are color-coded to emphasize differences in display efficiency. Frequencies were calculated based on 10,000 cells analyzed per sample. (c) Confocal microscopy images of WT and LIP02 strains containing genome-integrated A2 and labeled with Alexa 594 antibody. The yeGFP signal (green) and Alexa 594 signal (red) indicate successful expression and display of the A2 cassette. Negative controls include the parental strain (WT Sb) subjected to identical labeling and imaging conditions. White boxes highlight regions of interest, with zoomed-in views shown on the right