APhaFIG 2: Bacterial cells invading the pharynx of day 7 adults.
Bacterial cells can be seen in the lumen at any age and invading into pharyngeal muscle cell cytoplasm as early as day 7 of adulthood.
A. Diagram of the head, grey box shows approximate positions of (B-E).
B. Procorpus region of young adult hermaphrodite. (Image source: N2T [N. Thomson] 402.)
C. Intact bacteria are present in the anterior lumen of this 7-day-old adult. (Image source: N826 [D. Hall] G5875.) Ch, pharyngeal channels; pm, pharyngeal muscle; mc, marginal cell. Bar, 1 micron.
D. Intact bacterial cells are seen inside the pharyngeal muscle cell cytoplasm of this 7-day-old adult, compressing any remaining myofilaments to the lateral edges of the cell, while bacteria tend to dominate the center of each muscle. The marginal cells contain some vacuoles, and are distorted in shape, as the muscle volume swells to accommodate invading bacteria. Intact bacteria are sometimes seen in the anterior lumen of young adults (i.e., APhaFIG 4B) but less frequently within the procorpus region. (Image source: N822 [D. Hall] 4627.) Bar, 5 microns.
E. Enlargement of boxed area in (D). The massive swelling of bacteria in the ventral left pharyngeal muscle has obliterated any evidence for the subventral nerve cord here, and likely abolishes some neural connectivity here for pharyngeal neuron M1 and for the sensory processes of neurons I1L and I2L. (Image source: N822 [D. Hall] 4629.) Bar, 5 microns.
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