Fig. 2.

Morphological studies of normal andTr^J sciatic nerves. Microscopic sections at equivalent magnifications from normal (A,D), heterozygous Tr^J(B, E, F), and homozygous Tr^J(C) sciatic nerves from 10-d-old (A–C, F) and adult (D, E) mice are shown. Note the marked increase in axon caliber and myelin thickness during nerve development between normal (A, D) andTr^J/+ mice (B,E). Also note the increasing severity of dysmyelination, even at 10 d of age between the +/+,Tr^J/+, andTr^J/Tr^Jnerves (A–C, respectively). Homozygous Tr^J have only small amounts of myelin (C, arrows). AdultTr^J/+ animals have increased endoneurial connective tissue (E, brown material) and occasional tomaculae are observed (bold arrow). Myelinic debris (arrowhead) can be found in longitudinal sections from 10-d-old Tr^J/+ animals (F). Scale bar, 20 μm.