Skeleton construction upon local regression of the sponge body
Skeleton construction upon local regression of the sponge body
复制标题
海绵体局部回归的骨架构建
DOI：
10.1111/dgd.12636
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Funayama Noriko
中科院分区：
文献类型：
--
作者：
Kishimoto Kouji;Sugano‐Yasunaga Wakana;Taniguchi Atsushi;Agata Kiyokazu;Nonaka Shigenori;Funayama Noriko
We previously revealed that the mechanism of demosponge skeleton construction is self‐organization by multiple rounds of sequential mechanical reactions of player cells. In these reactions, “transport cells” dynamically carry fine skeletal elements (spicules) on epithelia surrounding the inner body space of sponges (basal epithelium (basopinacoderm) and the endodermal epithelium (ENCM)). Once spicules pierce ENCM and apical pinacoderm, subsequently they are cemented to the substratum under the sponge body, or connected to other skeleton‐constructing spicules. Thus, the “pierce” step is the key to holding up spicules in the temporary periphery of growing sponges’ bodies. Since sponges can regress as well as grow, here we asked how skeleton construction occurs during local regression of the body. We found that prior to local basopinacoderm retraction (and thus body regression), the body became thinner. Some spicules that were originally carried outward stagnated for a while, and were then carried inwards either on ENCM or basopinacoderm. Spicules that were carried inwards on ENCM pierced epithelia after a short transport, and thus became held up at relatively inward positions compared to spicules carried on outwardly extending basopinacoderm. The switch of epithelia on which transport cells migrate efficiently occurred in thinner body spaces where basopinacoderm and ENCM became close to each other. Thus, the mechanisms underlying this phenomenon are rather mechanical: the combination of sequential reactions of skeleton construction and the narrowed body space upon local retraction of basopinacoderm cause spicules to be held up at more‐inward positions, which might strengthen the basopinacoderm's attachment to substratum.
