Format

Send to

Choose Destination
Zoolog Sci. 2002 Mar;19(3):253-61.

Biomineralization of the spicules of sea urchin embryos.

Author information

1
Dept of Molecular Cell Biology, University of California, Berkeley 94720-3200, USA. wilt@socrates.berkeley.edu

Abstract

The formation of calcareous skeletal elements by various echinoderms, especially sea urchins, offers a splendid opportunity to learn more about some processes involved in the formation of biominerals. The spicules of larvae of euechinoids have been the focus of considerable work, including their developmental origins. The spicules are composed of a single optical crystal of high magnesium calcite and variable amounts of amorphous calcium carbonate. Occluded within the spicule is a proteinaceous matrix, most of which is soluble; this matrix constitutes about 0.1% of the mass. The spicules are also enclosed by an extracellular matrix and are almost completely surrounded by cytoplasmic cords. The spicules are deposited by primary mesenchyme cells (PMCs), which accumulate calcium and secrete calcium carbonate. A number of proteins specific, or highly enriched, in PMCs, have been cloned and studied. Recent work supports the hypothesis that proteins found in the extracellular matrix of the spicule are important for biomineralization.

PMID:
12125922
DOI:
10.2108/zsj.19.253
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for BioOne
Loading ...
Support Center