Figure 1.

The T2SS of A. veronii is required for secretion of a pro-proliferative factor that stimulates intestinal epithelial cell proliferation. (a) Schematic of the larval zebrafish intestine, highlighting the proximal 210 μm region in which proliferative epithelial cells were quantified, as marked by incorporation of the nucleotide analog EdU. (b) Representative transverse section of the proximal zebrafish intestine stained to reveal cells that incorporated EdU.(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 from A. veronii with a functional or deleted T2SS. 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.