MOLECULAR AND CHEMICAL COMPOSITION OF FOSSIL SAND DOLLAR FROM TAIWAN

1. Molecular and Chemical Composition
of Fossil Sand Dollar from Taiwan
Hsiao-Jou Wu1*, and Jih-Pai Lin1
1Department of Geosciences, National Taiwan University, Taipei, Taiwan
*dinosaur@gmail.com
1
This project is supported by a research grant (MOST 110-2116-M-002-016) funded by
Ministry of Science and Technology of Taiwan awarded to JPL
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2. 2
Fossil Sand Dollar in Taiwan
1 mm
200 μm
50 μm
Petaloid Stereom
Most proteomic analyses of sea urchins were focused on the embryonic
period (Killian & Wilt, 2008).
Mann et al. (2008) used SDS-PAGE (sodium dodecyl sulfate
polyacrylamide gel electrophoresis) and mass spectrometer to describe
the detailed categories of proteomes in sea urchin. And they especially
described the proteomes of tests.
Mann et al. (2010) sorted out what the occurrence of different proteins in
each part of sea urchin would be. Among all the proteins, SM30-D and
SM30-E from SM30 group (spicule matrix protein) were reported that
they exist in the tests of adult sea urchins.
(modified from
Killian & Wilt, 1996)
(Lin et al., in press)
(Wang et al., 1984)
embryonic state
A fossil clypeasteroid, Scaphechinus mirabilis, was discovered
from the Pleistocene strata in western Taiwan, and it has been
reported from the Toukoshan Formation in Miaoli County of
Taiwan.
In the stereomic microstructure, the interconnecting pores are
filled with connective tissue, that is organic materials. The goal
of this study is to investigate whether organic materials are
still preserved in fossil tests.
Molecular Analysis
adult state
Occurrence of proteins
in test of sea urchin
(modified from
Mann et al., 2008)
(modified from Mann et al., 2010)
Marker Test
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3. 3
Acid-base Titration SDS-PAGE
(sodium dodecyl sulfate polyacrylamide gel electrophoresis)
Sea Urchin Test
+ HCl
NaOH
Tests of sea urchins are made of
high-magnesium calcite, and the
main chemical composition is CaCO3
and MgCO3. To quantify the weight
percentage, we used acid-base
titration.
Grind into powder
Collect samples
Add into HCl solution
Titrate with NaOH solution
Reach equivalence point
After protein extraction, we
used SDS-PAGE to check the
molecular mass of sample
protein is equal to the
previous researches.
Add into sample loading buffer
Protein extraction
Boil at 95℃
Load into gel
Run the gel
Stain the gel
Destain the gel &
Check results
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4. 4
Species Content of CaCO3 + MgCO3 (%)
1Rotula deciesdigitatus 92.99 ± 0.73
2Laganum laganum 93.95 ± 2.10
3Mellita tenuis 91.11 ± 0.88
4Arachnoides placenta 92.76 ± 0.15
5Scaphechinus mirabilis 89.51 ± 1.15
6Scaphechinus mirabilis
(fossil)
85.57 ± 0.46
Content of CaCO3 + MgCO3
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5. 5
Protein Extraction
(modified from Schroeter et al., 2016)
HCl SDS
Preliminary experiment
The method of protein extraction was designed for chicken bone.
However, the chemical compositions in bones differ from those
in test of sea urchins. The bones are made of calcium phosphate
(Phiraphinyo et al., 2006), while the tests are made of magnesian
calcite (Drozdov et al., 2016). Therefore, we need to try for the
correct protein extraction method to the test and fossil materials.
Picture original website in page 4:
1 http://www.marinespecies.org/photogallery.php?album=694&pic=34294
2 https://www.marinespecies.org/photogallery.php?album=5414&pic=146701
3 http://www.marinespecies.org/aphia.php?p=image&tid=422503&pic=113765
4 https://www.marinespecies.org/photogallery.php?album=5414&pic=146087
5 https://commons.wikimedia.org/wiki/File:Scaphechinus_mirabilis.jpg
References
Drozdov, A. L., Sharmankina, V. V., Zemnukhova, L. A., & Polyakova, N. V. (2016). Chemical composition of spines and tests
of sea urchins. Biology Bulletin, 43(6), 521-531.
Killian, C. E., & Wilt, F. H. (1996). Characterization of the Proteins Comprising the Integral Matrix of Strongylocentrotus
purpuratus Embryonic Spicules (∗). Journal of Biological Chemistry, 271(15), 9150-9159.
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Lin, Y.-J., Fang, J.-N., Chang, C.-C., Cheng, C.-C., & Lin, J.-P. (in press). Stereomic microstructure of Clypeasteroida in thin
section based on new material from Pleistocene strata in Taiwan.
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