par Gorzelak, P.;Stolarski, J.;Dubois, Philippe 
;Kopp, C.;Meibom, A.
Référence Journal of structural biology, 176, page (119-126)
Publication Publié, 2011
;Kopp, C.;Meibom, A.Référence Journal of structural biology, 176, page (119-126)
Publication Publié, 2011
Article révisé par les pairs
| Résumé : | This paper reports the results of the first dynamic labeling experiment with regenerating spines of sea urchins Paracentrotus lividus using the stable isotope 26Mg and NanoSIMS high-resolution isotopic imaging, which provide a direct information about the growth process. Growing spines were labeled twice (for 72 and 24h, respectively) by increasing the abundance of 26Mg in seawater. The incorporation of 26Mg into the growing spines was subsequently imaged with the NanoSIMS ion microprobe. Stereom trabeculae initially grow as conical micro-spines, which form within less than 1day. These micro-spines fuse together by lateral outgrowths and form a thin, open meshwork (inner stereom), which is subsequently reinforced by addition of layered thickening deposits (outer stereom). The (longitudinal) growth rate of the inner stereom is ca. 125μm/day. A single (ca. 1μm) thickening layer in the stereom trabeculae is deposited during 24h. The thickening process is contemporaneous with the formation micro-spines and involves both longitudinal trabeculae and transverse bridges to a similar degree. Furthermore, the skeleton-forming cells remain active in the previously formed open stereom for at least 10days, and do not migrate upwards until the end of the thickening process. The experimental capability presented here provides a new way to obtain detailed information about the skeleton formation of a multitude of marine, calcite producing organisms. © 2011 Elsevier Inc. |
