scholarly journals The Effect of Partial Protein Extraction on the Structure of the Eggs of the Sea Urchin, Arbacia punctulata

1960 ◽  
Vol 7 (1) ◽  
pp. 21-26 ◽  
Author(s):  
R. E. Kane
Keyword(s):  
Nuclear Envelope ◽  
Sea Urchin ◽  
Protein Extraction ◽  
Extraction Procedure ◽  
Cellular Protein ◽  
Soluble Proteins ◽  
Annulate Lamellae ◽  
Cytoplasmic Matrix ◽  
Arbacia Punctulata ◽  
Cell Structures

The structure of the eggs of the sea urchin, Arbacia punctulata, has been investigated after the removal of one-half of the cellular protein. The procedure involves treatment of the eggs with 30 per cent ethanol at -10°C. followed by extraction of the soluble proteins with water. The eggs remain intact, although all of the cytoplasmic matrix is removed. Most cell structures can still be identified, although only the membranes of most remain. The mitochondria lose all of their matrix but retain the inner membranes or cristae. The annulate lamellae appear unaffected by this extraction procedure, remaining intact and apparently undamaged. The nuclear envelope is also retained, although it often undergoes a curious disorganization, apparently as the result of the separation of its two layers. The significance of these observations with respect to the structure of the envelope is discussed.

scholarly journals THE FINE STRUCTURE OF PRONUCLEAR DEVELOPMENT AND FUSION IN THE SEA URCHIN, ARBACIA PUNCTULATA

1968 ◽  
Vol 39 (2) ◽  
pp. 339-368 ◽  
Author(s):  
Frank J. Longo ◽  
Everett Anderson
Keyword(s):  
Nuclear Envelope ◽  
Sea Urchin ◽  
Plasma Membranes ◽  
Light And Electron Microscopy ◽  
Sperm Nucleus ◽  
Sperm Chromatin ◽  
Zygote Nucleus ◽  
Arbacia Punctulata ◽  
Male Pronucleus ◽  
Sperm Aster

Fertilization events following coalescence of the gamete plasma membranes and culminating in the formation of the zygote nucleus were investigated by light and electron microscopy in the sea urchin, Arbacia punctulata. Shortly after the spermatozoon passes through the fertilization cone, it rotates approximately 180° and comes to rest lateral to its point of entrance. Concomitantly, the nonperforated nuclear envelope of the sperm nucleus undergoes degeneration followed by dispersal of the sperm chromatin and development of the pronuclear envelope. During this reorganization of the sperm nucleus, the sperm aster is formed. The latter is composed of ooplasmic lamellar structures and fasciles of microtubules. The male pronucleus, sperm mitochondrion, and flagellum accompany the sperm aster during its migration. As the pronuclei encounter one another, the surface of the female pronucleus proximal to the advancing male pronucleus becomes highly convoluted. Subsequently, the formation of the zygote nucleus commences with the fusion of the outer and the inner membranes of the pronuclear envelopes, thereby producing a small internuclear bridge and one continuous, perforated zygote nuclear envelope.

scholarly journals A CYTOLOGICAL STUDY OF ARTIFICIAL PARTHENOGENESIS IN THE SEA URCHIN ARBACIA PUNCTULATA

1970 ◽  
Vol 47 (1) ◽  
pp. 140-158 ◽  
Author(s):  
Martin I. Sachs ◽  
Everett Anderson
Keyword(s):  
Endoplasmic Reticulum ◽  
Sea Urchin ◽  
Nuclear Division ◽  
Annulate Lamellae ◽  
Cortical Granules ◽  
Smooth Variety ◽  
Mitotic Apparatus ◽  
Arbacia Punctulata ◽  
The Matrix ◽  
Cell Embryo

Eggs of the sea urchin Arbacia punctulata were artificially activated with hypertonic seawater. The artificially activated eggs undergo the cortical reaction which is not distinguished by a wavelike progression as in the case of inseminated eggs. The cortical granules are released at random loci at the surface of the egg and result in spaces separated by large cytoplasmic projections. Unreacted cortical granules and ribosomes are found within the matrix comprising the large cytoplasmic projections. No "fertilization cone" is formed. The subsequent release of additional cortical granules results in the formation of a continuous perivitelline space, 15 min following activation. 85 min postactivation, an organization of annulate lamellae, endoplasmic reticulum of the smooth variety, and microtubules around a centriole is observed prior to nuclear division. Before the breakdown of the nuclear envelope a streak stage is formed. The streak is composed of a central core of annulate lamellae and is encompassed by endoplasmic reticulum and vesicular components. Condensation of chromatin is followed by the establishment of the mitotic apparatus. Centrioles were not found in the mature egg; however, they are present after activation prior to the first nuclear division, in the four-cell embryo, multicellular embryo, and at blastula. Artificially activated eggs have been observed to develop to the pluteus stage in more than 50% of the eggs treated.

scholarly journals Electron Microscopy of the Centrifuged Sea Urchin Egg, with a Note on the Structure of the Ground Cytoplasm

1960 ◽  
Vol 7 (1) ◽  
pp. 135-142 ◽  
Author(s):  
Paul R. Gross ◽  
Delbert E. Philpott ◽  
Sylvan Nass
Keyword(s):  
Sea Urchin ◽  
Composite Structures ◽  
Annulate Lamellae ◽  
Cortical Granules ◽  
Clear Zone ◽  
Arbacia Punctulata ◽  
Large Numbers ◽  
Sea Urchin Egg ◽  
Size Number

Centrifuged, unfertilized eggs of the sea urchin, Arbacia punctulata, have been studied with the electron microscope. Subcellular particles were stratified by centrifuging living cells, known to be normally fertilizable, for five minutes at 3,000 g. The layered subcellular particles, including cortical granules, 16 mµ RNP particles, pigment, yolk, mitochondria, and oil droplets, possess characteristic ultrastructural features by which they may be identified in situ. The clear zone contains 16 mµ particles, most of them freely dispersed, scattered mitochondria, and a few composite structures made up of annulate lamellae in parallel layers or in association with dense, spherical aggregates of the RNP particles. Free 16 mµ particles are found, in addition, throughout the cell, in the interstices between the stratified larger particles. They show a tendency to form ramifying aggregates resulting from certain types of injury to the cell. A few vesicular structures, found mainly in the clear zone, have attached RNP particles, and appear to be related to the ER of tissue cells. Other vesicles, bounded by smooth membranes, are found throughout the cell. These are extremely variable in size, number, and distribution; their total number appears to depend upon conditions of fixation. It is suggested that limited formation of such structures is a normal property of the ground cytoplasm in this cell, but that fixed cells with very large numbers of smooth surfaced vesicles have produced the latter as a response to chemical injury. A model of the ground cytoplasm is proposed whose aim is to reconcile the rheological behavior of the living cell with the ultrastructural features observed.

Membranous alterations in the cytoplasm and nucleus in a primitive neuroectodermal tumor of the brain

1978 ◽  
Vol 36 (2) ◽  
pp. 628-629
Author(s):  
C. N. Sun ◽  
C. Araoz ◽  
H. J. White
Keyword(s):  
Nuclear Envelope ◽  
Tumor Cells ◽  
Osmium Tetroxide ◽  
Primitive Neuroectodermal Tumor ◽  
Uranyl Acetate ◽  
Neuroectodermal Tumor ◽  
Annulate Lamellae ◽  
Lead Citrate ◽  
Thin Sections ◽  
The Brain

The ultrastructure of a cerebral primitive neuroectodermal tumor has been reported previously. In the present case, we will present some unusual previously unreported membranous structures and alterations in the cytoplasm and nucleus of the tumor cells.Specimens were cut into small pieces about 1 mm3 and immediately fixed in 4% glutaraldehyde in phosphate buffer for two hours, then post-fixed in 1% buffered osmium tetroxide for one hour. After dehydration, tissues were embedded in Epon 812. Thin sections were stained with uranyl acetate and lead citrate.In the cytoplasm of the tumor cells, we found paired cisternae (Fig. 1) and annulate lamellae (Fig. 2) noting that the annulate lamellae were sometimes associated with the outer nuclear envelope (Fig. 3). These membranous structures have been reported in other tumor cells. In our case, mitochondrial to nuclear envelope fusions were often noted (Fig. 4). Although this phenomenon was reported in an oncocytoma, their frequency in the present study is quite striking.

C-Microtubules in Isolated Mitotic Spindles

1971 ◽  
Vol 9 (3) ◽  
pp. 603-619
Author(s):  
W. D. COHEN ◽  
T. GOTTLIEB
Keyword(s):  
Cross Section ◽  
Sea Urchin ◽  
Cross Sections ◽  
Metaphase Chromosome ◽  
Inverse Relationship ◽  
Mitotic Spindles ◽  
Cylindrical Structure ◽  
Arbacia Punctulata ◽  
Alternate Possibility

Microtubules with incomplete cylindrical structure are present in isolated mitotic spindles of the sea urchin, Arbacia punctulata. In cross-section they appear C-shaped, and are thus similar to the ‘C-microtubules’ or ‘C-filaments’ observed previously in other systems. The C-microtubules are not uniformly distributed within isolated spindles, but are typically numerous in the interzonal region of anaphase spindles and in the metaphase chromosome ‘plate’. In chromosome-to-pole regions they are seen much less frequently, and microtubules with the usual O-configuration predominate. Counts of C- and O-microtubules in anaphase spindle cross-sections of known location show an inverse relationship between the number of C-microtubules present and the total number of microtubules present. The observations suggest that the C-microtubules are not simple artifacts of fixation or isolation, but rather may represent a stage of microtubule disassembly which occurs in the interzone during isolation or during anaphase in vivo. The alternate possibility of assembly is not excluded, however. The significance of C-microtubules is further discussed with respect to their occurrence in other systems, and to potential differences between mitotic microtubules.

scholarly journals THE EXTRACELLULAR RELEASE OF ECHINOCHROME

1946 ◽  
Vol 29 (5) ◽  
pp. 267-275 ◽  
Author(s):  
Herbert Shapiro
Keyword(s):  
Sea Urchin ◽  
Sea Water ◽  
Potassium Content ◽  
Red Pigment ◽  
Anaerobic Conditions ◽  
Outward Diffusion ◽  
Arbacia Punctulata ◽  
Extracellular Release

A study was made of the diffusion of the red pigment echinochrome from the eggs of the sea urchin, Arbacia punctulata, into sea water. Unfertilized eggs retained their pigment, over periods of hours. Outward diffusion of pigment from unfertilized eggs normally is entirely negligible, or does not occur at all. Enchancing the calcium or potassium content of the artificial sea water (while retaining isosmotic conditions) did not induce pigment release. Under anaerobic conditions, unfertilized eggs release pigment in small quantities. Fertilization alone brings about echinochrome release. Fertilized eggs invariably released pigment, whether in normal sea water, or sea water with increased calcium or potassium. This diffusion of the pigment began during the first cleavage, possibly soon after fertilization. The pigment release is not a consequence solely of the cell's permeability to echinochrome (or chromoprotein, or other pigment combination) but is preceded by events leading to a release of echinochrome from the granules in which it is concentrated within the cell. These events may be initiated by activation or by anaerobiosis. The phenomenon was not due to cytolysis.

scholarly journals Endoplasmic reticulum-to-Golgi transitions upon herpes virus infection

F1000Research ◽  
2018 ◽  
Vol 6 ◽  
pp. 1804 ◽  
Author(s):  
Peter Wild ◽  
Andres Kaech ◽  
Elisabeth M. Schraner ◽  
Ladina Walser ◽  
Mathias Ackermann
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Golgi Complex ◽  
Nuclear Membrane ◽  
Progeny Virus ◽  
Cytoplasmic Matrix ◽  
Outer Nuclear Membrane ◽  
Nuclear Membranes ◽  
Perinuclear Space ◽  
Hsv 1

Background: Herpesvirus capsids are assembled in the nucleus, translocated to the perinuclear space by budding, acquiring tegument and envelope, or released to the cytoplasm via impaired nuclear envelope. One model proposes that envelopment, “de-envelopment” and “re-envelopment” is essential for production of infectious virus. Glycoproteins gB/gH were reported to be essential for de-envelopment, by fusion of the “primary” envelope with the outer nuclear membrane. Yet, a high proportion of enveloped virions generated from genomes with deleted gB/gH were found in the cytoplasm and extracellular space, suggesting the existence of alternative exit routes.Methods: We investigated the relatedness between the nuclear envelope and membranes of the endoplasmic reticulum and Golgi complex, in cells infected with either herpes simplex virus 1 (HSV-1) or a Us3 deletion mutant thereof, or with bovine herpesvirus 1 (BoHV-1) by transmission and scanning electron microscopy, employing freezing technique protocols.Results:  The Golgi complex is a compact entity in a juxtanuclear position covered by a membrane on thecisface. Golgi membranes merge with membranes of the endoplasmic reticulum forming an entity with the perinuclear space. All compartments contained enveloped virions. After treatment with brefeldin A, HSV-1 virions aggregated in the perinuclear space and endoplasmic reticulum, while infectious progeny virus was still produced.Conclusions: The data suggest that virions derived by budding at nuclear membranes are intraluminally transported from the perinuclear space via Golgi -endoplasmic reticulum transitions into Golgi cisternae for packaging. Virions derived by budding at nuclear membranes are infective like Us3 deletion mutants, which  accumulate in the perinuclear space. Therefore, i) de-envelopment followed by re-envelopment is not essential for production of infective progeny virus, ii) the process taking place at the outer nuclear membrane is budding not fusion, and iii) naked capsids gain access to the cytoplasmic matrix via impaired nuclear envelope as reported earlier.

scholarly journals Evaluation of effective protein extraction procedure to profile petiole of Moringa oleifera

2020 ◽  
Vol 7 (2) ◽  
pp. 214
Author(s):  
Zetty Amirah Zulkifli ◽  
Zaidah Rahmat
Keyword(s):  
Moringa Oleifera ◽  
Protein Extraction ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Extraction Procedure ◽  
Electrophoretic Pattern ◽  
Antioxidant Property ◽  
Extraction Methods ◽  
Protein Profiling ◽  
Sds Page

Moringa oleifera is widely known as multipurpose tree since all of its parts confer multiple functions. The leaf is highly favourable among consumers while the petiole is mostly wasted. There are numerous studies on the flavonoid and antioxidant property of the stem and twig. However, study on the petiole has never been done. There-upon, this study was conducted to develop protein profiling of the petiole. In this study, 6 different protein extraction methods were tested on the fresh petiole before its protein quantity and quality were checked via Bradford assay and Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) respectively. The in-solution digestion was then done prior to LC-MS/MS analysis. The protein electrophoretic pattern from the SDS-PAGE proves that method 6 using Tris HCl buffer with incorporation of dithiothreitol (DTT) and phenylmethylsulfonyl fluoride (PMSF) confers the best quality of protein. It produced the highest number of visible individual bands compared to other methods. Meanwhile, 93 proteins were successfully identified via LCMS analysis where the protein, signal response and carbohydrate metabolism categories confer the highest percentage. High quality and content of the protein extracted from the petiole including the antioxidant, anticancer and antidiabetic protein identified suggested that consuming this part of the plant could enhance nutrients of human body.

Pinocytosis in fertilized sea urchin (Arbacia punctulata) eggs

1984 ◽  
Vol 231 (3) ◽  
pp. 413-422 ◽  
Author(s):  
Christopher P. Carron ◽  
Frank J. Longo
Keyword(s):  
Sea Urchin ◽  
Arbacia Punctulata
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