ISSN:
1432-0878
Keywords:
Cuticle
;
Rotifer
;
Development
;
Electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Ultrastructural studies of developing Asplanchna brightwelli embryos support the following hypothetical scheme of cuticle formation. First the external hypodermal membrane invaginates, and deposition of a dense intracellular layer commences next to this membrane. Then the rough endoplasmic reticulum synthesizes fibrous protein which is transferred to the Golgi complex. Here polysaccharide is synthesized and added to the protein, and the resulting filamentous complex is enclosed in large irregularly shaped vesicles which bud off from the Golgi elements. Maturation of the filamentous material to condensed cuticle material occurs as the vesicles move to the invaginations. Each vesicle fuses with an invagination, thus forming a hypodermal bulb; then the cuticle material is discharged through the neck of the bulb to its extracellular location. After the bulbs are formed, new, smaller, spherical vesicles begin to bud off from the Golgi elements. They too contain the filamentous complex which is refined to condensed cuticle material as the vesicles near the bulb. These vesicles fuse with the hypodermal bulbs contributing the cuticle and membrane necessary for the growth of the hypodermis of the embryo and newborn animal. Ruthenium red staining has confirmed that the cuticle consists of glycoprotein.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00335425
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