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.2022 Sep;19(194):20220373.
doi: 10.1098/rsif.2022.0373. Epub 2022 Sep 21.

Bioapatite in shark centra studied by wide-angle and by small-angle X-ray scattering

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Bioapatite in shark centra studied by wide-angle and by small-angle X-ray scattering

J S Park et al. J R Soc Interface.2022 Sep.

Abstract

Members of subclass Elasmobranchii possess cartilage skeletons; the centra of many species are mineralized with a bioapatite, but virtually nothing is known about the mineral's organization. This study employed high-energy, small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS, i.e. X-ray diffraction) to investigate the bioapatite crystallography within blocks cut from centra of four species (two carcharhiniform families, one lamniform family and 1-ID of the Advanced Photon Source). All species' crystallographic quantities closely matched and indicated a bioapatite closely related to that in bone. The centra's lattice parametersa andc were somewhat smaller and somewhat larger, respectively, than in bone. Nanocrystallite sizes (WAXS peak widths) in shark centra were larger than typical of bone, and little microstrain was observed. Compared with bone, shark centra exhibited SAXSD-period peaks with largerD magnitudes, andD-period arcs with narrower azimuthal widths. The shark mineral phase, therefore, is closely related to that in bone but does possess real differences which probably affect mechanical property and which are worth further study.

Keywords: X-ray diffraction; centrum; mineralized tissue; shark; small-angle X-ray scattering; wide-angle X-ray scattering.

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Figures

Figure 1.
Figure 1.
(a) Schematic of the swimming motion of a shark showing the caudal portion of the animal and centra within. The anatomical directions are indicated at the top of the panel. In the top portion of the panel and from left to right, the tail is shown swept to the left, at a neutral orientation and swept to the right. The bottom panel shows the resulting compression of a centrum; the grey ‘x' within each of these centra represents the projection of the double cone (corpus calcera). The vertebral column axis ‘vca' is labelled. (b,c) Laboratory microCT-derived three-dimensional rendering of lamniform and of carcharhiniform shark vertebral centra, respectively, derived from data in Morseet al. [4]. These are from a shortfin mako and a sandbar shark, respectively, and the internal structures are similar to but not identical to those in the blocks examined in the present study. The top row shows a view from above of each centra; a sector facing the viewer is rendered transparent so that the cone wall cross-section can be seen. The bottom row shows the same volume but with the clipping plane through the midplane of each centra; this allows the intermedialia structure to be appreciated. The scale bars at the left of each image are 10 mm. L—lamella, W—wedge, cw—cone wall, i—intermedialia.
Figure 2.
Figure 2.
(a) Transverse cross-sections near the centre of a carcharhiniform centrum (left, blue shark) and of a lamniform centrum (right, shortfin mako). Mineralized cartilage ‘mc' and unmineralized cartilage ‘uc’ are indicated. The red boxes indicate the position of the sections from which the blocks in this study were cut, and the red arrows in the carcharhiniform cross-section point to the position of blocks Tg2c and Tg2d from the tiger shark. (b) Schematics of a longitudinal section of a carcharhiniform centrum (left) and a lamniform centrum (right) labelled with the positions of blocks cut from the section; the direction of the arrow indicates the vertical orientation of the block during WAXS/SAXS scanning. The axially oriented blocks were Tg2c, Tg2d, L2c, L2d, 9 and f. The vertex block and nappe blocks were 4 and m, respectively. Note that the lamniform section is derived from microCT data from a shortfin mako with the smaller diameter porosity not shown; the amount of void space in the intermedialia varies considerably across the section (bar L2c contains considerable interlamellar space whereas L2d contains more solid). (c) Schematic of the data collection at beamline 1-ID, APS, with the following indicated: positioning axesx andy, specimen rotation axisω, WAXS detector (GE panel 2) and SAXS detector (CCD detector).
Figure 3.
Figure 3.
(a) WAXS pattern of block Tg2d showing the two-dimensional distribution of intensities intercepted by GE detector 2. The 00.2 and quadruplet (q, unresolved 21.1, 11.2, 30.0 and 20.2) reflections are labelled, as are the radialr and azimuthalη directions. In (a,b), the lighter the pixel, the greater the intensity. (b) Cartesian transformed pattern from (a) showing azimuth vertically andd horizontally. (c) Azimuthally averaged plots of intensity (in arbitrary units) as a function ofd for shark mineralized tissue (top) and for canine bone (bottom). The 22.2 and 00.4 reflections are also labelled.
Figure 4.
Figure 4.
(a) Typical two-dimensional SAXS pattern from shark centra block Tg2c with intensity illustrated by colour (in order of decreasing intensity: white, orange, red, purple and indigo). The two vertical white arrows show the strongestD-period peaks. (b) Plot of intensity as a function of magnitude of the scattering vectorq using integration over azimuths ± 10° from horizontal; the plot averages 30 patterns collected on sample Tg2c.
Figure 5.
Figure 5.
A typical SAXS pattern from each specimen; the area shown is 100 × 100 detector pixels. See also electronic supplementary material, videos S1–S8. Each column consists of patterns from the two blocks of each species' centrum, with the block identified at the lower left of each panel and the maximum intensity (counts) in the pattern at the lower right corner. The green arrow in the upper left corner indicates each block's vertebral column's axis relative to the SAXS detector. The horizontal dashed line labels azimuthal angleη = 0°,η increases counterclockwise and ‘B' identifies the beam stop. The white arrow identifies a prominent, first-orderD-period arc, and an orange arrow labels a highly directional halo of strong scattering normal to the axis of the centre of theD-period arcs. ‘Δη' indicates the azimuthal FWHM intensity of aD-period arc, and ‘1' and ‘2' label two sets of arcs in the pattern from block f (great hammerhead).
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References

    1. Rama S, Chandrakasan G. 1984. Distribution of different molecular species of collagen in the vertebral cartilage of the shark (Carcharius acututs). Conn. Tiss. Res. 12, 111-118. (10.3109/03008208408992776) - DOI - PubMed
    1. Porter ME, Beltran JL, Koob TJ, Summers AP. 2006. Material properties and biochemical composition of mineralized vertebral cartilage in seven elasmobranch species (Chondrichthyes). J. Exp. Biol. 209, 2920-2928. (10.1242/jeb.02325) - DOI - PubMed
    1. Watanabe YY, Lydersen C, Fisk AT, Kovacs KM. 2012. The slowest fish: swim speed and tail-beat frequency of Greenland sharks. J. Exp. Mar. Biol. Ecol. 426/427, 5-11. (10.1016/j.jembe.2012.04.021) - DOI
    1. Morse PE, Stock MK, James KC, Natanson LJ, Stock SR. 2022. Shark vertebral microanatomy and mineral density variation studied with laboratory microComputed Tomography. J. Struct. Biol. 214, 107831. (10.1016/j.jsb.2022.107831) - DOI - PubMed
    1. Porter ME, Diaz C, Sturm JJ, Grotmol S, Summers AP, Long JH Jr. 2014. Built for speed: strain in the cartilaginous vertebral columns of sharks. Zoology 117, 19-27. (10.1016/j.zool.2013.10.007) - DOI - PubMed

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