ISSN:
1615-6102
Keywords:
Ascidian
;
Cellulose microfibril
;
Hemocoel
;
Polyandrocarpa misakiensis
;
Tunic cord
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary A specialized structure of tunic cord inPolyandrocarpa misakiensis is investigated by electron microscopy. The tunic cord is a cord-like coiled structure of 5–30 μm in diameter and 0.1–9.0 mm in length. The tunic cords originate and elongate from the dorsal tunic, and their termini have a swollen and ornamented structure. Scanning and transmission electron micrographs and the electron diffractogram show that the tunic cords are composed of bundled microfibrils of cellulose I with high crystallinity. The tunic cord is completely surrounded by single-layered epidermal cells, which have been found as the site of cellulose biosynthesis. A number of tunic cords are connected to the internal tunic of the siphon by forming “eyelet” structures at their termini. These observations suggest that the tunic cords act as a connector between dorsal and internal tunic of the siphon.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01282297
Permalink
