Fig. 5

Extension of collagen fibers required vimentin.

SHG microscopy showed the formation of SHG projections in (A) control, and that the projections were impaired in the (D) vimentin morphants. To quantify this observation, Z projections of the region posterior to the notochord, at 24 hpw, were used for analysis. (B, E) The contour of the wound edge was traced and measured, indicated by the blue line. To assess differences in fiber angle relative the wound edge of fibers, the SHG images were quantified using CurveAlign software, which identified fiber segments using curvelet transformation and calculated the angle of each of these segments, within 60 microns of the wound edge, relative to the nearest wound edge (see Methods for further details). The identified segments are illustrated in (C) (control) and (F) (vimentin morphant) as dots with small linear extensions, with green being the segments within 60 microns of the wound edge and included in the analysis, as shown in corresponding compass plot, in which the blue arrows indicate the number of segments at a given angle, with 90° being perpendicular and 0^o being parallel to the wound edge. The red double arrow and corresponding red numeral indicate the mean angle of the fiber segments for that caudal fin. There was a decrease in (G) wound contour (reduced fiber extensions) in the vimentin morphants at 24 hpw compared to controls (p=0.0009; ctl MO n = 33 total larvae, vim MO n = 32 total larvae over 4 replicates with 7 to 9 larvae per treatment per replicate; ctrl MO 95% CI = 280.88 to 305.18, vim MO 95% CI = 250.32 to 275.1). (H) The fiber angle measurement indicated a significant decrease in orientation, with fibers exhibiting angles more parallel rather than perpendicular, to the wound edge, in the vimentin morphants at 24 hpw (p=0.0003; ctl MO n = 30 total larvae, vim MO n = 32 total larvae over 4 replicates with 6 to 9 larvae per treatment per replicate; ctl MO 95% CI = 66.12 to 71.36, vim MO 95% CI = 59.21 to 64.31). Scale bars represent 100 µm in A and D. ****p<0..0001, error bars are standard deviation.