spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by BOTTKE, W.
Right arrow Articles by KEIL, I.
Right arrow Search for Related Content
PubMed
Right arrow Articles by BOTTKE, W.
Right arrow Articles by KEIL, I.

Journal of Cell Science, Vol 53, 173-191, Copyright © 1982 by Company of Biologists

Submitted on May 28, 1981

Coated Vesicle-Mediated Transport and Deposition of Vitellogenic Ferritin in the Rapid Growth Phase of Snail Oocytes

W. BOTTKE 1, I. SINHA 1, and I. KEIL 1

1 Zoologisches Institut der Universitát Badestra{beta}e 9, 4400 Münster, FRG

The main yolk component in oocytes of the pulmonate freshwater snails Planorbarius corneus L. and Lymnaea stagnalis L. consists of the iron storage protein ferritin and iron-free apoferritin. Both compounds are deposited in the yolk in the form of large paracrystalloids, tubular structures and randomly dispersed particles. In addition, the plasm contains lysosome-like inclusions with depositions of haemosiderin. Haemosiderin is interpreted as the product of proteolytic degradation of ferritin. During the rapid growth phase of the oocytes vitellogenic ferritin is transported across the basement lamina and taken up by adsorptive endocytosis via coated pits and vesicles. Formation of yolk bodies occurs by fusion of ferritin-containing vacuoles and empty vesicles that are probably derived from the Golgi apparatus. Uptake of ferritin is restricted to the basal region of the oocyte. No involvement of the follicle cells in synthesis and deposition of ferritin could be detected. Secretory cells of the midgut gland are the most likely site of synthesis of vitellogenic ferritin.

Under conditions of iron overload large masses of ferritin are encountered in the basement lamina of the oocytes. However, no significant increase in the uptake of ferritin could be observed. With the use of a tannic acid-glutaraldehyde fixation procedure a hitherto unobserved filamentous or rod-like material was detected inside the lamina and in coated pits. This material is probably also taken up by the oocytes and integrated into yolk platelets.

Though ferritin is a rather unusual vitellogenic protein, the mode of its uptake and deposition in the oocyte plasm is highly reminiscent of that of typical hormone-induced vitellogenins in other animal groups.

Submitted on May 28, 1981




This article has been cited by other articles:


Home page
 Biol. Bull.Home page
P. G. Beninger, G. Le Pennec, and M. Le Pennec
Demonstration of Nutrient Pathway From the Digestive System to Oocytes in the Gonad Intestinal Loop of the Scallop Pecten maximus L.
Biol. Bull., August 1, 2003; 205(1): 83 - 92.
[Abstract] [Full Text] [PDF]


© The Company of Biologists Ltd 1982