Postfertilization growth of microvilli in the sea urchin egg: New views from eggs that have been quick-frozen, freeze-fractured, and deeply etched

doi:10.1016/0012-1606(81)90463-2

Developmental Biology

Volume 82, Issue 2, March 1981, Pages 393-400

https://doi.org/10.1016/0012-1606(81)90463-2 Get rights and content

Abstract

We have used quick-freezing, freeze-fracture, and deep etching to study postfertilization growth of microvilli in the sea urchin, Strongylocentrotus purpuratus. Between 1 and 2 min postinsemination, we observed rapid growth of numerous finger-like microvilli to about 0.7 μm in length. Subsequently, groups of two to four microvilli became raised off the egg surface on broad cytoplasmic bases. Finally, by 5 min postinsemination, these bases had become interconnected by thin sheets of cytoplasm to form a continuous network of ruffles across the egg surface. Corresponding thin sections of quick-frozen and freeze-substituted eggs showed that these microvilli contained networks of microfilaments. The finger-like processes had bundles of parallel microfilaments that ran their entire length, while the ruffles of cytoplasm contained sheets of crisscrossed microfilaments. These observations support the hypothesis that microvillar growth results from formation of new microfilament networks.

References (27)

J. Bryan et al.
Separation and interaction of the major components of the sea urchin actin gel
J. Mol. Biol
(1978)
Y. Endo
Changes in the cortical layer of sea urchin eggs at fertilization as studied with the electron microscope. 1. Clypeaster japonicus
Exp. Cell Res
(1961)
P. Kidd et al.
The ultrastructure of surface layers isolated from fertilized and chemically-stimulated sea urchin eggs
J. Ultrastruct. Res
(1980)
F.J. Longo
Effects of cytochalasin B on sperm-egg interactions
Develop. Biol
(1978)
J. Runnstrom
The vitelline membrane and cortical particles in sea urchin eggs and their function in maturation and fertilization
Advan. Morphog
(1966)
T.E. Schroeder
Microvilli on sea urchin eggs: A second burst of elongation
Develop. Biol
(1978)
J.A. Spudich et al.
Structure of actin filament bundles from microvilli of sea urchin eggs
J. Mol. Biol
(1979)
M. Veron et al.
Sequential biochemical and morphological events during assembly of the fertilization membrane of the sea urchin
Cell
(1977)
L. Wolpert et al.
An electron microscope study of fertilization of the sea urchin egg, Psammechinus miliaris
Exp. Cell Res
(1961)
E. Anderson
Oocyte differentiation in the sea urchin, Arbacia punctulata, with particular reference to the origin of cortical granules and their participation in the cortical reaction
J. Cell Biol
(1968)

D.A. Begg et al.

pH regulates the polymerization of actin in the sea urchin egg cortex

J. Cell Biol

(1979)

J. Bryan

The isolation of a major structural element of the sea urchin fertilization membrane

J. Cell Biol

(1970)

D.R. Burgess

Polymerized actin in the isolated sea urchin egg cortex

J. Cell Biol

(1977)

Cited by (45)

Second harmonic imaging of exocytosis at fertilization
2005, Biophysical Journal
Second harmonic generation offers an important alternative and complement to fluorescence for the imaging of cellular structure and function. Staining the eggs of the sea urchin, Lytechinus pictus, with the styryl dye di-8-ANEPPS, we have observed large changes in both second harmonic generation and two-photon fluorescence after fertilization, consistent with the dynamics of exocytosis of cortical granules. With nonlinear imaging on a scanning microscope, we are able to visualize the wave of exocytosis in real time.
Membrane permeability characteristics and osmotic tolerance limits of sea urchin (Evechinus chloroticus) eggs
2003, Cryobiology
Development of effective cryopreservation protocols relies on knowledge of the fundamental cryobiological characteristics for a particular cell type. These characteristics include osmotic behaviour, membrane permeability characteristics, and osmotic tolerance limits. Here, we report on measures of these characteristics for unfertilised and fertilised eggs of the sea urchin (Evechinus chloroticus). In NaCl solutions of varying osmolalities, sea urchin eggs behaved as ideal linear osmometers. The osmotically inactive volume (v_b) was similar for unfertilised and fertilised eggs, 0.367 ± 0.008 (mean ± SE) and 0.303 ± 0.007, respectively. Estimates of water solubility (L_p) and solute permeability (P_s) and their respective activation energies (E_a) for unfertilised and fertilised eggs were determined following exposure to cryoprotectant (CPA) solutions at different temperatures. Irrespective of treatment, fertilised eggs had higher values of L_p and P_s. The presence of a CPA decreased L_p. Among CPAs, solute permeability was highest for propylene glycol followed by dimethyl sulphoxide and then ethylene glycol. Measures of osmotic tolerance limits of the eggs revealed unfertilised eggs were able to tolerate volumetric changes of −20% and +30% of their equilibrium volume; fertilised eggs were able to tolerate changes ±30%. Using membrane permeability data and osmotic tolerance limits, we established effective methods for loading and unloading CPAs from the eggs. The results of this study establish cryobiological characteristics for E. chloroticus eggs of use for developing an effective cryopreservation protocol. The approach we outline can be readily adapted for determining cryobiological characteristics of other species and cell types, as an aid to successful cryopreservation.
An increase in surface area is not required for cell division in early sea urchin development
2003, Developmental Biology
Cell division requires an increase in surface area to volume ratio. During early development, surface area can increase, volume can decrease, or surface topography can be optimized to allow for division. While exocytosis is thought to be essential for division [Mol. Biol. Cell 10 (1999), 2735; Proc. Natl. Acad. Sci. USA 99 (2002), 3633], exocytosis doesn’t always yield an increase in surface area [Proc. Natl. Acad. Sci. USA 79 (1982), 6712]. We used multiphoton laser scanning microscopy, fluorescence spectroscopy, and electron microscopy to monitor membrane trafficking, surface area, volume, and surface topography during early sea urchin development. Despite extensive membrane trafficking monitored by FM 1-43 fluorescence, we find that the net surface area of the embryo does not change prior to the eight-cell stage. During this period, embryo volume decreases by 15%, and microvilli disappear from interior facing membrane segments. Thus, the first three cell divisions utilize residual membrane liberated by decreasing cytoplasmic volume, and reducing microvilli density on interior facing membranes. Only after the eight-cell stage was a net increase in FM 1-43 fluorescence from the embryo surface detected. Our data suggest that compensatory endocytosis is downregulated after this developmental stage to yield an increase in surface area for cell division.
Structure and function of the egg cortex from oogenesis through fertilization
2002, Developmental Biology
- •
  WHAT IS THE CORTEX?
- •
  The Egg Cortex
- •
  The Scope of This Review
- •
  STORING INFORMATION AND BUILDING THE CORTEX DURING OOGENESIS
- •
  Localizing Maternal Determinants in the Cortex
- •
  Structuring and Positioning Information in the Cortex
- •
  Cortical Polarity and Storage of Information in Other Oocytes
- •
  The Cortex during Vitellogenesis
- •
  MATURATION PREPARES THE CORTEX FOR FERTILIZATION
- •
  Restructuring Cortical Endoplasmic Reticulum and Organelles during Maturation
- •
  Restructuring the Cytoskeleton during Maturation
- •
  Relocalization of Cortical mRNAs and Domains during Maturation
- •
  The Cortex as the Site of Attachment and Fusion of Sperm and Egg
- •
  FERTILIZATION TRANSFORMS THE EGG CORTEX
- •
  Sperm-Induced Calcium Waves and Membranes
- •
  Waves of Exocytosis and Endocytosis at Fertilization
- •
  Fertilization-Induced Microfilament Reorganizations
- •
  The Fertilized Egg Cortex
- •
  WHAT THE CORTEX IS
- •
  The Cortex as a Repository for Spatiotemporal Information
- •
  The Questions That Remain
An analysis of the lamellar structure of sea urchin egg cortical granules using X-ray scattering
2000, FEBS Letters
Cortical granules (CGs) are secretory vesicles associated with egg and oocyte plasma membranes that undergo exocytosis at fertilisation. In the sea urchin Strongylocentrotus purpuratus, the internal organisation of these CGs exhibits a lamellar-type morphology. The different lamellar layers correspond to proteoglycans, structural proteins and enzymes required for fertilisation envelope assembly and modification of the post-fertilisation egg surface. We have studied the lamellar structure of CGs using X-ray scattering and reveal the contrast density variation of the lamellae in the native state. The structure of functionally competent CGs in situ differs significantly from that determined by electron microscopic studies. We observed a strong periodicity of the lamellar structure of 280 Å as opposed to the 590 Å repeat observed previously. Fusion of the CGs produced a loss of the lamellar repeat and the development of a broad peak corresponding to a 20 Å periodicity that may be indicative of the molecular packing in the resulting hydrated gel structure.
Microvilli elongate in response to hydrogen peroxide and to perturbations of intracellular calcium
1997, Experimental Cell Research
Using scanning electron microscopy and fluorescence microscopy, we have found that apical microvilli of diverse cell types, including nonepithelial cells, elongate in culture in response to the oxidative stress of hydrogen peroxide. The microvilli induced in culture on retinal pigment epithelial cells display a 30-nm axial periodicity similar to that described for stable microvilli of intestinal brush border. Microvilli can also be induced to elongate by chelating intracellular Ca²⁺and by the Ca²⁺-uptake inhibitor thapsigargin. Thus a response of microvillar protrusion occurs widely and may be related to depletion of intracellular calcium stores.

View all citing articles on Scopus

^☆: This study was carried out during tenure of a postdoctoral fellowship from the Pharmaceutical Manufacturer's Association Foundation (to D.E.C.) and was suported by grants (to J.E.H.) from the USPHS (NS 11979) and the Muscular Dystrophy Association.

View full text

Article preview

Developmental Biology

Abstract

References (27)

Separation and interaction of the major components of the sea urchin actin gel

J. Mol. Biol

Changes in the cortical layer of sea urchin eggs at fertilization as studied with the electron microscope. 1. Clypeaster japonicus

Exp. Cell Res

The ultrastructure of surface layers isolated from fertilized and chemically-stimulated sea urchin eggs

J. Ultrastruct. Res

Effects of cytochalasin B on sperm-egg interactions

Develop. Biol

The vitelline membrane and cortical particles in sea urchin eggs and their function in maturation and fertilization

Advan. Morphog

Microvilli on sea urchin eggs: A second burst of elongation

Develop. Biol

Structure of actin filament bundles from microvilli of sea urchin eggs

J. Mol. Biol

Sequential biochemical and morphological events during assembly of the fertilization membrane of the sea urchin

Cell

An electron microscope study of fertilization of the sea urchin egg, Psammechinus miliaris

Exp. Cell Res

Oocyte differentiation in the sea urchin, Arbacia punctulata, with particular reference to the origin of cortical granules and their participation in the cortical reaction

J. Cell Biol

pH regulates the polymerization of actin in the sea urchin egg cortex

J. Cell Biol

The isolation of a major structural element of the sea urchin fertilization membrane

J. Cell Biol

Polymerized actin in the isolated sea urchin egg cortex

J. Cell Biol

Cited by (45)

Second harmonic imaging of exocytosis at fertilization

Membrane permeability characteristics and osmotic tolerance limits of sea urchin (Evechinus chloroticus) eggs

An increase in surface area is not required for cell division in early sea urchin development

Structure and function of the egg cortex from oogenesis through fertilization

An analysis of the lamellar structure of sea urchin egg cortical granules using X-ray scattering

Microvilli elongate in response to hydrogen peroxide and to perturbations of intracellular calcium

Brief notePostfertilization growth of microvilli in the sea urchin egg: New views from eggs that have been quick-frozen, freeze-fractured, and deeply etched☆

Abstract

J. Mol. Biol

Exp. Cell Res

J. Ultrastruct. Res

Develop. Biol

Advan. Morphog

Develop. Biol

J. Mol. Biol

Cell

Exp. Cell Res

Oocyte differentiation in the sea urchin, Arbacia punctulata, with particular reference to the origin of cortical granules and their participation in the cortical reaction

J. Cell Biol

pH regulates the polymerization of actin in the sea urchin egg cortex

J. Cell Biol

The isolation of a major structural element of the sea urchin fertilization membrane

J. Cell Biol

Polymerized actin in the isolated sea urchin egg cortex

J. Cell Biol

Brief note
Postfertilization growth of microvilli in the sea urchin egg: New views from eggs that have been quick-frozen, freeze-fractured, and deeply etched☆