Microgravity simulation as a probe for understanding early Xenopus pattern specification

Development ◽  
1985 ◽  
Vol 89 (1) ◽  
pp. 259-274
Author(s):  
Anton W. Neff ◽  
George M. Malacinski ◽  
Hae-Moon Chung
Keyword(s):  
Early Embryo ◽  
Microgravity Environment ◽  
Natural Phenomenon ◽  
Gravity Compensation ◽  
Microgravity Simulation ◽  
Cytoplasmic Organization ◽  
Sperm Penetration ◽  
Gravity Driven ◽  
Speed Rotation ◽  
Pattern Specification

Pattern specification in early amphibians Xenopus) was monitored in embryos subjected to gravity compensation (microgravity simulation) by constant low-speed rotation on a horizontal axis (clinostat). The useful range of clinostat speeds was determined empirically. The results were interpreted in terms of a set of models which account for the reorganization of the egg cytoplasm that follows fertilization and that correlates with the establishment of dorsal/ventral polarity. Large percentages of clinostated eggs displayed a positive result (normal axial structure morphogenesis). Consequently, normal development of amphibian eggs in the microgravity environment of space should be possible. Models which depend upon gravity-driven rearrangements for cytoplasmic organization (e.g. dorsal/ventral polarization) of the early embryo should, therefore, not be favoured. At several clinostat speeds symmetrization of the egg in accordance with the site of sperm penetration, a natural phenomenon, was altered. The results at those clinostat speeds indicate that models which employ sperm entrance as an obligatory feature of the cytoplasmic rearrangements that generate egg polarity are not applicable.

134 THE DISTRIBUTION OF CYTOSKELETON AND CHROMATIN CONFIGURATIONS DURING EARLY EMBRYO DEVELOPMENT OF SWAMP BUFFALO (BUBALUS BUBALIS)

2010 ◽  
Vol 22 (1) ◽  
pp. 226
Author(s):  
M. Techakumphu ◽  
V. Chankitisakul ◽  
K. Thaseephoo ◽  
T. Tharasanit
Keyword(s):  
Embryo Development ◽  
Early Embryo ◽  
Actin Microfilaments ◽  
Dense Network ◽  
Early Embryo Development ◽  
Vitro Fertilization ◽  
Sperm Penetration ◽  
Swamp Buffalo ◽  
Sperm Aster

Microtubules and actin microfilaments have been demonstratedto be actively involved with fertilization and early embryo development. The objective of this study was to examine the redistribution of cytoskeleton and chromatin configurations in swamp buffalo oocytes through the initial cleavage event after in vitro fertilization. Sperm penetration was analysed at 6 h post IVF in 63 oocytes (3 replicates), whereas the chronology embryonic development in terms of the redistribution of cell cytoskeleton and chromatin configurations was studied in a total of 462 oocytes (7 to 8 replicates) at 12, 18, 24, 30, and 48 h after IVF. The oocytes were matured in vitro for 22 h. Then, IVF was performed as described previously (Totey et al. 1993). After fertilization, presumptive zygotes and embryos were fixed at various times (6, 12, 18, 24, 30, and 48 h) to examine spermatozoa penetration, redistribution of the cytoskeleton (microtubules and actin filaments), and chromatin configurations using epifluorescent microscopy. Staining was undertaken with wheat germ agglutinin to visualize the zona pellucida, monoclonal-α-tubulin-TRIT C to show the microtubules, 488 phalloidin to identify microfilaments, and DAPI to label the chromatin. At 6 h after fertilization, sperm penetration was observed in 44.4% of examined oocytes. At 12 h post IVF, maternal chromosomes of fertilized oocytes progressed to the second meiotic division and formed the female pronucleus simultaneously with the decondensation of paternal chromosomes. A dense network of microtubules was observed radiating from the base of the decondensing sperm head (referred to as sperm aster) At 18 h post IVF, the sperm chromatins became the male pronucleus. Simultaneously, the sperm aster increased in size and filled the whole ooplasm. The syngamy of the male and female pronuclei was completed by 24 h post IVF, which was associated with a dense array of microtubules. Cell cleavage was observed by 30 h post IVF. This was apparently facilitated by a dense network of actin microfilaments that formed in the middle of the dividing embryo. These results indicated that microtubules and actin microfilaments undergo changes after fertilization consistent with a crucial role during fertilization in swamp buffalo. The centrosomal material was paternally inherited. This work was supported by TRF-MAG (MRG-WII515S056) and CHE-TRF Senior Research Fund (RTA5080010).

Life after death in the evolution of intelligence

2018 ◽  
Author(s):  
Senarath Dayathilake Kande Lekamalaya
Keyword(s):  
Empirical Research ◽  
Early Embryo ◽  
Natural Phenomenon ◽  
Buddhist Psychology ◽  
Life After Death ◽  
Zero Mass ◽  
Research Findings ◽  
The Universe

To find a scientific solution to the belief of life after death is essential, yet it remains unclear due to unresolved problems in physics, psychology, and neuroscience. Early Buddhist psychology and some empirical research findings might be helpful to get better insight or at least for a hypothesis on these matters. I show that the genomic x-particle might be transferred to a vacant zygote or an early embryo anywhere in the universe/s, as a natural phenomenon, when a brain clinically death. Although its mechanism is yet unknown, I show that the genomic x-particle might be near zero mass and it would travel infinite velocity to find a suitable vacant zygote or an early embryo to life after death. This work is an attempt to review the problem that might not break laws of neuroscience, physics, and psychology.

scholarly journals Cytoplasmic organization and compartmentalization in Drosophila early embryo syncytium

2017 ◽  
Vol 145 ◽  
pp. S93
Author(s):  
Sameer Thukral ◽  
Amitabha Nandi ◽  
Richa Rikhy
Keyword(s):  
Early Embryo ◽  
Cytoplasmic Organization

Cytoplasmic Organization in the Receptor Cells of the Crista Ampullaris

1972 ◽  
Vol 30 ◽  
pp. 60-61 ◽  
Author(s):  
Robert F. Dunn
Keyword(s):  
Fine Particles ◽  
Apical Cell ◽  
Apical Region ◽  
Receptor Cells ◽  
Cuticular Plate ◽  
Morphological Organization ◽  
Crista Ampullaris ◽  
Cytoplasmic Organization ◽  
High Degree ◽  
General Appearance

Receptor cells of the cristae in the vestibular labyrinth of the bullfrog, Rana catesbiana, show a high degree of morphological organization. Four specialized regions may be distinguished: the apical region, the supranuclear region, the paranuclear region, and the basilar region.The apical region includes a single kinocilium, approximately 40 stereocilia, and many small microvilli all projecting from the apical cell surface into the lumen of the ampulla. A cuticular plate, located at the base of the stereocilia, contains filamentous attachments of the stereocilia, and has the general appearance of a homogeneous aggregation of fine particles (Fig. 1). An accumulation of mitochondria is located within the cytoplasm basal to the cuticular plate.

Laser scanning confocal microscopic analysis of cytoskeletal and nuclear reorganization in live Drosophila embryos

1993 ◽  
Vol 51 ◽  
pp. 174-175
Author(s):  
William Theurkauf
Keyword(s):  
Laser Scanning ◽  
Microscopic Analysis ◽  
Large Cell ◽  
Early Embryo ◽  
Drosophila Embryo ◽  
Cortical Actin ◽  
Nuclear Reorganization ◽  
Cytoskeletal Elements ◽  
Microtubule Structure ◽  
Drosophila Embryos

Cell division in eucaryotes depends on coordinated changes in nuclear and cytoskeletal components. In Drosophila melanogaster embryos, the first 13 nuclear divisions occur without cytokinesis. During the final four divisions, nuclei divide in a uniform monolayer at the surface of the embryo. These surface divisions are accompanied by dramatic changes in cortical actin and microtubule structure (Karr and Alberts, 1986), and inhibitor studies indicate that these changes are essential to orderly mitosis (Zalokar and Erk, 1976). Because the early embryo is syncytial, fluorescent probes introduced by microinjection are incorporated in structures associated with all of the nuclei in the blastoderm. In addition, the nuclei divide synchronously every 10 to 20 min. These characteristics make the syncytial blastoderm embryo an excellent system for the analysis of mitotic reorganization of both nuclear and cytoskeletal elements. However, the Drosophila embryo is a large cell, and resolution of cytoskeletal filaments and nuclear structure is hampered by out-of focus signal.

Духовное влияние советского строя на иерархов и духовенство в 1960-е—1980-е годы (SPIRITUAL INFLUENCE OF THE SOVIET SYSTEM ON HIERARCHS AND CLERGY IN THE 1960-s – 1980-s)

2020 ◽  
pp. 3-18
Author(s):  
Олег Викторович (Oleg V.) Кириченко (Kirichenko)
Keyword(s):  
Scientific Study ◽  
Natural Phenomenon ◽  
Soviet System ◽  
The West ◽  
The Church

Статья посвящена малоизученному явлению – церковному инакомыслию, которое было порождено влиянием «советской духовности» не только на общество, но и на Церковь. Автор ставит проблему инакомыслия и диссидентства как явлений, выросших в недрах высшей советской номенклатуры и потом уже распространившихся на низшие слои, затронувшие и церковную среду. Апелляция к Западу, как к третейскому судье, была закономерным явлением советской действительности, что требует научной проработки и объяснения. The article is devoted to a little-studied phenomenon – church dissent, which was generated by the influence of "Soviet spirituality" not only on society, but also on the Church. The author poses the problem of dissent and dissidentism as phenomena that grew up in the the higher Soviet nomenclature and then spread to the lower layers, affecting the church environment. An appeal to the West as an arbitrator was a natural phenomenon of Soviet reality, which requires scientific study and explanation.

Diabetes alters the epigenetic landscape of the oocyte and early embryo

2014 ◽  
Author(s):  
Hannah M Brown ◽  
Melissa A White ◽  
Laura A Frank ◽  
Jeremy G Thompson
Keyword(s):  
Early Embryo ◽  
Epigenetic Landscape

Bubble motion in liquid nitrogen under a non-uniform electric field in a microgravity environment

1997 ◽  
Vol 117 (11) ◽  
pp. 1109-1114
Author(s):  
Yoshiyuki Suda ◽  
Kenji Mutoh ◽  
Yosuke Sakai ◽  
Kiyotaka Matsuura ◽  
Norio Homma
Keyword(s):  
Electric Field ◽  
Liquid Nitrogen ◽  
Microgravity Environment ◽  
Uniform Electric Field ◽  
Bubble Motion
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