Stock S R, Ignatiev K, Dahl T, Barss J, Fezzaa K, Veis A, Lee W K, De Carlo F
Institute for Bioengineering and Nanoscience in Advanced Medicine, Ward 13-130, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611-3008, USA.
J Synchrotron Radiat. 2003 Sep 1;10(Pt 5):393-7. doi: 10.1107/s0909049503013992. Epub 2003 Aug 28.
Two synchrotron X-ray microscopy methods, phase-contrast microradiography (the propagation method) and absorption microCT (high-resolution computed tomography or microtomography), and laser-scanning confocal microscopy (visible wavelength) were used to study a fragment of the keel of a tooth of the sea urchin Lytechinus variegatus. Stripes observed in the phase-contrast images of the fragment were also seen in confocal micrographs. MicroCT showed that the stripes were due to two parallel planar arrays of low-absorption channels within the bulk of the keel. In the phase microradiographs, maximum contrast stripes appear when a channel image from one row coincides with a channel image from the second row; otherwise, contrast is minimal. Long channels do not appear to have been observed previously in keels of sea urchin teeth.
