Back to Search Start Over

From Coelomocytes to Colored Aggregates: Cellular Components and Processes Involved in the Immune Response of the HolothuroidCucumaria frondosa

Authors :
Annie Mercier
Jean-François Hamel
Guillaume Caulier
Source :
The Biological Bulletin. 239:95-114
Publication Year :
2020
Publisher :
University of Chicago Press, 2020.

Abstract

While so-called brown bodies were first defined in the 1950s as colorful aggregates of cells in the general cavity of echinoderms and other marine benthic taxa, their distribution and role have not yet been fully clarified. This work characterized free coelomocytes and corresponding aggregates ("bodies") in the hydrovascular system and perivisceral coelom, as well as those attached on the membranes of the viscera, in the holothuroid Cucumaria frondosa. Responses to the presence of foreign particles were investigated, providing novel insights on the immune system. A total of eight coelomocyte cell types was detected, while aggregates were formed of three to six types of coelomocytes. Only red-colored aggregates were found in the hydrovascular system, whereas brown aggregates were confined to the perivisceral coelom. The encapsulation mechanism of foreign particles injected in the hydrovascular system was monitored. Particles were first gathered by phagocytes and vibratile, crystal, and morula cells into a whitish aggregate that was then covered by hemocytes, imparting a red color to the aggregates. After their transfer to the perivisceral coelom, aggregates became brown and were ultimately expelled through the anus. Finally, a range of stressors (i.e., harvesting method, presence of a predator, and physical injury) was found to increase the abundance of aggregates, thus highlighting the role of these bodies in the immune response of C. frondosa.

Details

ISSN :
19398697 and 00063185
Volume :
239
Database :
OpenAIRE
Journal :
The Biological Bulletin
Accession number :
edsair.doi...........a86df9b02f0e100be6b29cd8e57a1353
Full Text :
https://doi.org/10.1086/710355