Figure 8.

By immunofluorescence, UNC-94 localizes to the pointed ends of thin filaments and to muscle cell boundaries. (a and b) Adult wild type worms were fixed by the Nonet method²⁴ and either co-incubated with anti-UNC-94 and anti-UNC-89 (M-line marker) as shown in (a), or anti-UNC-94 and anti-α-actinin (dense body marker), as shown in (b). UNC-94 is localized to two closely spaced parallel lines closely flanking the M-lines. (c) Adult wild type worms were fixed by the “constant spring” method²⁵ and co-incubated with anti-UNC-94 and anti-α-actinin. By this method, UNC-94 appears as a broad band, probably due to incomplete fixation. (d) Adult unc-94(sf20) worms (also fixed by the constant spring method) were co-incubated with anti-UNC-94 and anti-α-actinin. Note the absence of staining with anti-UNC-94: this suggests that the staining observed in wild type is due to reaction to UNC-94 and not cross reaction to the related protein, TMD-2. (e) The same animals as shown in (c), but at lower magnification. In this view, UNC-94 extends beyond the rows of dense bodies, likely at muscle cell/cell boundaries (white open arrows). (f) Drawing of C. elegans obliquely striated body wall muscle with the localization of UNC-94 (green) to the pointed ends of thin filaments as indicated by this study. Scale bars, 10μm.