DEpiFIG 2: Dauer seam cell showing enhanced autophagy.
A. Low power micrograph of a dauer animal (daf-2(e1370) mutant). Here the seam cell is locally enlarged in size to accommodate the nucleus (N), and the cell lies directly apposed to the cuticular alae. The seam cell cytoplasm on the lower right side of the panel holds a cluster of interesting inclusions, shown at higher magnification in panel B. Autophagy is greatly enhanced in the seam cell during dauer formation (Meléndez et al., 2003). The seam cell and the neighboring hypodermis (top right corner of this panel) are also filled with large vacuoles at this stage.
B. Arrows indicate several autophagosomes at various stages of processing. Each autophagosome is bordered by two concentric membranes, with small bits of cytoplasm enclosed within the inner membrane for degradation.
C. Another section through the daf-2 seam cell at a position far away from the nucleus shows the seam greatly reduced in volume, but still enclosing several autophagosomes.
N, nucleus, M, mitochondrion, V, vacuole. Scale bar in A is 1 micron. Scale bars in B & C are each 0.5 micron. (Image source: Hall lab. A. F3, W390; B. F3, W391; C. H2, W426.)