Sea urchin oocytes possess elaborate cortical arrays of microfilaments, microtubules, and intermediate filaments

Boyle, Judith A.; Ernst, Susan G.

doi:10.1016/0012-1606(89)90079-1

Cited by 36 publications

(18 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These are very similar to the cortical microtubules described for asteroids (Fig. 10) and echinoids, which have little connection to centrosomes or MTOCs (Boyle and Ernst, 1989;Schroeder and Otto, 1984). Microtubules of the third class run radially from the deep cytoplasm of the oocyte perpendicularly toward the cortex; to date there are no descriptions of these microtubules in any echinoderm oocyte other than the holothurian S. californicus.…”

Section: Fully Formed Oocytesmentioning

confidence: 83%

“…This class of microtubules would appear to be similar to the premeiotic and meiotic asters found in starfish oocytes (Schroeder and Otto, 1984) where they are focused into a centrosome-like pattern. Similar patterns, referred to as microtubule organizing centers (MTOCs), have recently been reported in oocytes of the echinoid Strongylocentrotus droebachiensis (Boyle and Ernst, 1989). The second class consists of the abundant microtubules in the cortex of holothurian oocytes (Fig.…”

Section: Fully Formed Oocytesmentioning

confidence: 89%

“…Otto and Schroeder also reported the presence of two asterlike structures located on the outer lateral surface of the nuclear membrane. A single MTOC was visualized with immunocytochemical techniques applied to cortical preparations from oocytes of the echinoid Stronglocentrotus droebachiensis (Boyle and Ernst, 1989). No similar structures were found in S. californicus oocytes, using TEM alone (Smiley and Cloney, 1985).…”

Section: Fully Formed Oocytesmentioning

confidence: 99%

See 2 more Smart Citations

A review of echinoderm oogenesis

Smiley

1990

J. Elec. Microsc. Tech.

View full text Add to dashboard Cite

This review of the anatomical, histological, biochemical, and molecular biological literature on echinoderm oogenesis includes the entire developmental history of oocytes; from their inception to the time they become ova. This is done from a comparative perspective, with reference to members of the five extant echinoderm classes; crinoids, holothurians, asteroids, ophiuroids, and echinoids. I describe the anatomy and fine structure of the echinoderm ovary, with emphasis on both the cellular relationships of the germ line cells to the somatic cells of the inner epithelium, and on the neuromuscular systems. I review the literature on the growth of oogonia into fully formed oocytes, including the process of vitellogenesis, presenting an ultrastructural analysis of the organelles and extracellular structures found in fully formed echinoderm oocytes. Echinoderm oocyte maturation is reviewed and a description of the ultrastructural, biochemical and molecular biological changes thought to occur during this process is presented. Finally, I discuss oocyte ovulation, the severing of cellular connections between the oocyte and its surrounding somatic epithelial cells.

show abstract

Section: Fully Formed Oocytesmentioning

confidence: 83%

Section: Fully Formed Oocytesmentioning

confidence: 89%

Section: Fully Formed Oocytesmentioning

confidence: 99%

See 1 more Smart Citation

A review of echinoderm oogenesis

Smiley

1990

J. Elec. Microsc. Tech.

View full text Add to dashboard Cite

show abstract

“…Recent work has identified proteins that bridge the GTPase dynamin to the actin cytoskeleton, including profilin, cortactin, and the F-actin-binding protein Abp1 [48,49]. Dynamin is enriched at the plasma membrane in sea urchin oocytes coincident with the thick microfilament meshwork position at the cortex of these cells [40,50]. Here, we demonstrate that MYP-containing endocytic vesicles carry endogenous dynamin.…”

Section: Discussionmentioning

confidence: 75%

The Major Yolk Protein of Sea Urchins Is Endocytosed by a Dynamin-Dependent Mechanism1

Brooks¹,

Wessel²

2004

Biology of Reproduction

View full text Add to dashboard Cite

Sea urchin oocytes grow to 10 times their original size during oogenesis by both synthesizing and importing a specific repertoire of proteins to drive fertilization and early embryogenesis. During the vitellogenic growth period, the major yolk protein (MYP), a transferrin-like protein, is synthesized in the gut, transported into the ovary, and actively endocytosed by the oocytes. Here, we begin to dissect this mechanism by first testing the hypothesis that MYP endocytosis is dynamin-dependent. We have identified a sea urchin dynamin cDNA that is highly similar in amino acid sequence, structure, and size to mammalian dynamin I: it contains an N-terminal GTPase domain, a pleckstrin-homology domain, and a C-terminal proline-rich domain. Sea urchin dynamin is enriched at the cortex of oocytes and colocalizes to MYP endocytic vesicles at the oocyte periphery. To test for a functional relationship between MYP endocytosis and dynamin, we used a dominant-negative human dynamin I mutant protein containing an alteration within the GTPase domain (hDyn(K44A)) to specifically compete for dynamin function. Using a fluorescent MYP construct to follow its endocytosis solely, as well as a general endocytosis marker, we demonstrate that the disruption of dynamin function significantly reduces MYP uptake but does not affect fluid-phase endocytosis. Using this specific biochemical approach, we are able to separate distinct pathways of endocytosis during oogenesis and learn that dynamin-mediated endocytosis is responsible for MYP endocytosis but not fluid-phase uptake.

show abstract

“…One class of proteins that possesses similar low solubility are the intermediate filaments (Klymkowsky et al, 1989;Skalli and Goldberg, 1991). Although immunocytochemical studies have shown that mature sea urchin eggs lack an organized network of intermediate filaments (Boyle and Emst, 1989;St-Pierre and Dufiesne, 1990), one intriguing possibility is that G6PDH is associating with less organized arrays of intermediate filament proteins (e.g., dimers, tetramers or protofilaments). Alternatively, the binding elements could be intermediate filament-like proteins not recognized by antibodies directed against intermediate filaments.…”

Section: Regulation Of Pentose Shunt Activity: Redistribution Of G6pdhmentioning

confidence: 99%

Regulation of the pentose phosphate pathway at fertilization in sea urchin eggs

Rees

Swezey

Kibak

et al. 1996

Invertebrate Reproduction & Development

View full text Add to dashboard Cite

After fertilization of sea urchin eggs, there is a rapid increase in cellular levels of NADPH, a metabolite utilized in a variety of biosynthetic reactions during early development. Recent studies have shown that a dramatic increase in the ,activity of the pentose phosphate shunt occurs in vivo shortly after fertilization, consistent with the hypothesis that this metabolic pathway is a major supplier of NADPH in sea urchin zygotes. One mechanism that may account, in part, for this increase in pentose shunt activity is the dissociation of glucose-6-phosphate dehydrogenase (G6PDH), the first enzyme of the shunt, fiom cell structural'elemepts. In vitro, G6PDH is associated with the insoluble matrix obtained fiom homogenates of unfertilized eggs, and in this state, the enzyme is inhibited. Within minutes of fertilization, G6PDH is released as an active, soluble enzyme. A similar solubilization and activation of G6PDH occurs after fertilization of eggs of other marine invertebrates and in mammalian cells in culture stimulated by growth factors. The occurrence of this phenomenon in such diverse cell types, in response to different stimuli, suggests that the redistribution of G6PDH between insoluble and soluble locations may be involved in the regulation of the pentose phosphate shunt during cell activation in general.

show abstract

Sea urchin oocytes possess elaborate cortical arrays of microfilaments, microtubules, and intermediate filaments

Cited by 36 publications

References 48 publications

A review of echinoderm oogenesis

A review of echinoderm oogenesis

The Major Yolk Protein of Sea Urchins Is Endocytosed by a Dynamin-Dependent Mechanism1

Regulation of the pentose phosphate pathway at fertilization in sea urchin eggs

Contact Info

Product

Resources

About