Fig. 8. Loss of dig-1 causes defects in basement membrane structure. Transverse section of a region in the head of an adult worm is shown. P, pharynx; D, sensory neuron dendrites; M, muscle. Scale bar: 1 µm. In wild-type animals, thin and `fuzzy' basement membrane material is deposited on tissues that neighbor the axons, such as pharynx and muscle (white arrows). In dig-1 mutants, basement membrane is detached and forms disorganized stacks and whorls (white arrowheads). It is unclear if the whorls of basement membrane material derive from muscle or hypodermis, but they appear thinner and simpler than the pharyngeal basement membrane material. dig-1(ky188) (n=6), dig-1(nu345) (n=2) and dig-1(n1321) (n=1) show similar defects, which are never see in N2 wild-type animals (n=5).