The effects of cytochalasin B on the events of fertilization in the surf clam,Spisula solidissima. I. Polar body formation

1972 ◽  
Vol 182 (3) ◽  
pp. 321-344 ◽  
Author(s):  
Frank J. Longo
Keyword(s):  
Cytochalasin B ◽  
Polar Body ◽  
Spisula Solidissima ◽  
Surf Clam ◽  
Body Formation ◽  
Polar Body Formation

Preimplantation development of gynogenetic diploid mouse embryos

Development ◽  
1982 ◽  
Vol 69 (1) ◽  
pp. 215-222
Author(s):  
Ewa Borsuk
Keyword(s):  
Cytochalasin B ◽  
Polar Body ◽  
Mouse Embryos ◽  
Fertilization In Vitro ◽  
Body Formation ◽  
Male Pronucleus ◽  
Step Procedure ◽  
Gynogenetic Diploid ◽  
Polar Body Formation

Diploid gynogenetic mouse embryos were produced in a three-step procedure: fertilization in vitro, suppression of the 2nd polar body formation by Cytochalasin B, and microsurgical removal of the male pronucleus. The operated eggs were transplanted to the oviduct of recipient females for 72 or 96 h. The overall recovery rate was 73%, but compacted morulae and blastocysts constituted only 28·6% of transplanted eggs. After 72 h blastocysts were rare (3·5%) but 24 h later their incidence increased to 21·2%. In eggs homozygous for T6 chromosome it was possible to prove karyologically that the male pronucleus was effectively removed and that the diploid genome was of purely maternal origin.

INHIBITION OF GERMINAL VESICLE BREAKDOWN AND POLAR BODY FORMATION BY NICOTINAMIDE IN STARFISH AND SURF CLAM OOCYTES*

1979 ◽  
Vol 21 (5) ◽  
pp. 457-464 ◽  
Author(s):  
KIYOSHI SANO ◽  
TAKEO KISHIMOTO ◽  
SUMI L. KOIDE ◽  
HARUO KANATANI ◽  
SAMUEL S. KOIDE
Keyword(s):  
Polar Body ◽  
Germinal Vesicle ◽  
Germinal Vesicle Breakdown ◽  
Surf Clam ◽  
Body Formation ◽  
Polar Body Formation

scholarly journals CHANGES IN THE ORGANIZATION OF TUBULIN DURING MEIOSIS IN THE EGGS OF THE SURF CLAM, SPISULA SOLIDISSIMA

1972 ◽  
Vol 54 (2) ◽  
pp. 266-278 ◽  
Author(s):  
Richard C. Weisenberg
Keyword(s):  
Nuclear Membrane ◽  
Polar Body ◽  
Binding Activity ◽  
Spisula Solidissima ◽  
Isolation Medium ◽  
Surf Clam ◽  
Membrane Breakdown ◽  
First Polar Body ◽  
Polar Body Formation ◽  
Granular Matrix

Polymerized tubulin can be stabilized in Kane's spindle isolation medium (HGL solution), isolated by differential centrifugation and then assayed by colchicine binding activity. In the eggs of the surf clam, Spisula solidissima, the level of particulate tubulin undergoes a series of specific changes during first meiotic division. In either unactivated ("interphase") eggs or metaphase eggs the amount of particulate tubulin was about 13% of the total at 23°C. The amount of particulate tubulin decreased shortly after activation, reaching a minimum value at about 5 min, the time of nuclear membrane breakdown. The particulate tubulin concentration then rose, reaching a maximum at metaphase, and then decreased again during anaphase, reaching a minimum at first polar body formation. In HGL homogenates of unactivated eggs a structure is present which has been shown to contain the interphase particulate tubulin (IPT). This structure consists essentially of a 10–20 µ granular sphere attached to a membranous material which is probably part of the egg cortex. These particles are absent at the time of nuclear membrane breakdown, when the level of particulate tubulin is minimal and when the first signs of spindle formation are visible. Electron microscopy of these particles by negative staining indicates that they are composed of microtubules associated with a granular matrix which may be a polymorphic aggregate of tubulin.

Polar Body Formation in Tubifex Eggs

1990 ◽  
Vol 582 (1 Cytokinesis) ◽  
pp. 260-272 ◽  
Author(s):  
TAKASHI SHIMIZU
Keyword(s):  
Polar Body ◽  
Body Formation ◽  
Polar Body Formation

Memoirs: The Germ-Cell Cycle in Phytophaga destructor Say

1935 ◽  
Vol s2-77 (308) ◽  
pp. 585-604
Author(s):  
MARGOT E. METEALFE
Keyword(s):  
Germ Cells ◽  
Growth Stage ◽  
Germ Line ◽  
Polar Body ◽  
Metaphase Plate ◽  
Body Formation ◽  
Polar Bodies ◽  
Complicated Process ◽  
Female Pronucleus ◽  
Polar Body Formation

1. The somatic cells in both sexes of Phytophaga destructor Say contain four pairs of V-shaped chromosomes, the sex-group being indistinguishable in size or form. 2. The germ-cells in both sexes contain eight pairs of chromosomes. 3. The maturation of the egg follows the normal course of development, eight bivalents being formed. After polar body formation the female pronucleus has eight chromosomes. The polar bodies are never extruded from the egg. 4. Spermatogenesis is a complicated process, the details of which have not been satisfactorily determined. The growth stage appears to take place before the last spermatogonial division. No pairing of chromosome has been observed, and apparently no metaphase plate is formed at meiosis. Eeduction is effected by the expulsion of two buds each containing four chromosomes. Thus only one sperm is produced from each spermatocyte. 5. One or more sperms may enter the egg at fertilization. 6. The germ-line is differentiated from the soma at the eightcell stage. 7. At the fifth cleavage the somatic nuclei eliminate half their number of chromosomes, and are left with eight chromosomes. 8. Migration of the germ nuclei takes place at the sixteencell stage. 9. The relation of the chromosome numbers in the somatic and germ lines is discussed.

Induction of Tetraploidy in Mussels by Suppression of Polar Body Formation.

1993 ◽  
Vol 59 (12) ◽  
pp. 2017-2023 ◽  
Author(s):  
John Scarpa ◽  
Katsuhiko T.Wada ◽  
Akira Komaru
Keyword(s):  
Polar Body ◽  
Body Formation ◽  
Polar Body Formation

scholarly journals Role of Securin, Separase and Cohesins in female meiosis and polar body formation inDrosophila

2015 ◽  
Vol 129 (3) ◽  
pp. 531-542 ◽  
Author(s):  
Zhihao Guo ◽  
Osamah Batiha ◽  
Mohammed Bourouh ◽  
Eric Fifield ◽  
Andrew Swan
Keyword(s):  
Polar Body ◽  
Female Meiosis ◽  
Body Formation ◽  
Polar Body Formation
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