Glial loss of the metallo β-lactamase domain containing protein, SWIP-10, induces age- and glutamate-signaling dependent, dopamine neuron degeneration
Fig 2
Electron microscopy confirms missing and deformed cilia of the CEP DA neuron dendrites in swip-10 mutants.
(A) Thin section through the lips of a swip-10 mutant adult all four CEP cilia are formed almost normally in positions DL, DR, VL, VR, forming specialized endings embedded in the lip cuticle. (B) High power TEM image of swip-10 mutant CEPVR cilium, somewhat reduced in overall size, containing normal-looking microtubules and dark staining tubule-associated material (TAM). The nubbin is abnormally enlarged and emerges out of the cuticle in an enlarged tree-like structure, not seen in N2. (C) Midway and more (D) distal through another the defective CEPVR cilium in a different animal, lacking normal TAM or distal microtubules. (E) and (F) show thin sections from a CEPDR cilium where small bits of TAM have abnormally become stuck inside the well-formed axoneme, while beyond the axoneme (F) the malformed cilium consists of large vacuole-filled swelling with no TAM or microtubules, and only a minimal nubbin. Scale bar (0.5 micron) applies to panels B-F. (G) Summary illustration of the variety of distal defects found in the CEP cilium, comparing a wildtype cilium to the left, and three progressively more defective mutant cilia on the right.