ISSN:
1432-0878
Keywords:
Oogenesis
;
Vitelline membrane
;
Locusta migratoria
;
Ultrastructure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Electron microscopic studies on developing follicles of Locusta migratoria show the vitelline membrane to be composed of two ultrastructurally distinguishable components: The vitelline membrane bodies (VMBs) and, in addition, fine granular material, cementing the VMBs together. VMBs form first in the oocyte-near zone within the oocyte-follicle cell space. Subsequently, the second vitelline membrane substance is secreted between the VMBs through apical protrusions of the follicle cells. The possible origin of the VMBs is discussed. Yolk uptake in Locusta seems to occur predominantly by pinocytosis. During oocyte development the oocyte membrane is enlarged by numerous microvilli and folds. In addition pinocytotic vesicles are pinched off. It is supposed that the latter loose their coat and eventually transform into large proteid yolk spheres.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00220669
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