Figure 12.

TEM analysis of shaft connector structure in vestibular hair bundles of wild-type and Ptprq-CAT-KO mice. Transmission electron micrographs of extrastriolar hair bundles from the utricular macula of heterozygous (a-d, f) and homozygous (e, g) mutant Ptprq-CAT-KO mice at P21. Samples in a-e were fixed in fixatives containing ruthenium red; samples in f and g were fixed in the absence of any contrasting agents. Note the lack of shaft connectors in the homozygous mutant hair bundle (e) and the close apposition of the stereocilia. Details of shaft connector structure in heterozygous Ptprq-CAT-KO mice (b-d) reveal dense particles attached to the membrane by fine stalks. The spacing of stereocilia in the hair bundles of heterozygous(f) and homozygous (g) mutant Ptprq-CAT-KO mice is similar in the absence of ruthenium red. Scale bars: a, e-g, 200 nm; b-d, 50 nm.