Bacterial contact induces polar plug disintegration to mediate whipworm egg hatching
Fig 3
Collapse of the polar plug precedes hatching mediated by bacteria.
(A, B, C, D) Representative low (left) and high magnification (right) SEM images of T. muris eggs (clear arrowhead) that were exposed to S. aureus for 1 hour (A), E. coli for 1.5 hours (B) and E. faecalis for 1 hour (C) or untreated (D). White arrowheads correspond to bacteria on polar plug regions of the eggs denoted by black arrowheads. Yellow arrow in right panel of (A) and (B) indicates woolly substance present among bacteria. (E) Representative low (left) and high magnification (right) SEM images of hatching T. muris eggs (clear arrowhead) that were exposed to S. aureus for 1 hour (top) and E. coli for 1.5 hours (bottom). White arrowheads correspond to bacteria on polar plug regions of the eggs. Emerging larvae are denoted by white diamonds. (F) Number of bacterial cells visible on polar plugs of T. muris eggs incubated with E. coli, S. aureus, or E. faecalis. Bars showing mean from 2 eggs per condition. (G) Width of collar openings on T. muris eggs that were treated with either E. coli or S. aureus and were either unhatched or in the process of hatching. For low magnification images, scale bar represents 2μm for unhatched egg in (A), (B), (C) and (D) and 10μm for hatched egg in (A) and (B). For high magnification images, scale bar represents 1μm for (A), (B) and (D) and 2μm for (C). Dots represent a single plug and bars show mean and SEM of collar sizes from 4–7 eggs per condition for (G). Two-way ANOVA followed by a Tukey’s multiple comparisons test was used for (G). 4–10 eggs were imaged per condition.