Figure 4.

Secreted GbpA proteins are sufficient to increase intestinal epithelial proliferation in GF zebrafish. (a) CSF from engineered E. coli expressing no recombinant protein or IPTG-inducible GbpA^Av and from the V. cholerae gbpA complementation strain expressing arabinose-inducible GbpA^Vc were incubated with chitin beads, rinsed, and the protein content of the flow through (FT) and chitin bead (C) fractions were separated by SDS-PAGE and visualized with Coomassie Brilliant Blue. (b) Quantification of proximal intestinal epithelial cell proliferation in 8 dpf CV larvae and 8 dpf GF larvae untreated or exposed from 6 dpf to CFS of E. coli expressing full length GbpA^Av, domain 1 of GbpA^Av, or purified full length GbpA^Av protein. (c) Quantification of proximal intestinal epithelial cell proliferation in 8 dpf CV larvae and 8 dpf GF larvae untreated or exposed from 6 dpf to CFS of WT V. cholerae, the gbpA deletion strain, and the gbpA complementation strain expressing arabinose-inducible GbpA^Vc. Boxplot whiskers represent range. Groups with different letter designations are statistically different with a p value of < 0.05 whereas groups with the same letter are not significantly different.