Details

Autor(en) / Beteiligte

• Bang, Betsy G.
• Bang, Frederick B.

Titel

The Urn Cell. Complex of Sipunculus nudus: A Model for Study of Mucus-Stimulating Substances

Ist Teil von

• The Biological bulletin (Lancaster), 1980-12, Vol.159 (3), p.571-581

Ort / Verlag

Marine Biological Laboratory

Erscheinungsjahr

1980

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• The secretory systems of the living urn cell complex of Sipunculus nudus were studied by light and fluorescence microscopy, using vital stains. The complex comprises two morphologically distinct secretory systems which respond to different stimuli, secrete at different rates, and respond differently to vital dyes. One system apparently resides in the ciliated base cell of the complex, the other in a cluster of small secretory "R" cells (presumptive regulatory cells) attached to the central membrane of the base cell. R cells slowly secrete mucus that is selectively sticky for cell debris and foreign particulates. When stimulated by pathogenic bacteria or other defined substances, the other system rapidly synthesizes streams of mucus from four to five synthetic loci. The loci are at rest until stimulated. In vivo the two secretory systems keep S. nudus coelomic fluid sterile and free of debris. Both systems respond in vitro. In in vitro suspensions, R cells are depleted over time; concomitantly, streams of mucus from stimulated loci become longer, suggesting a degree of regulation by R cells. R cells contain large granules of neutral red-staining material, but do not stain with Janus green B. The synthetic loci stain intensely with the purple form of Janus green B but do not stain with neutral red.