Programming of gastrulation during the second cleavage cycle in Limnaea stagnalis: a study with lithium chloride and actinomycin D

Development ◽  
1967 ◽  
Vol 17 (2) ◽  
pp. 367-374
Author(s):  
W. L. M. Geilenkirchen
Keyword(s):  
Mitotic Cycle ◽  
Developmental Stages ◽  
Continuous Treatment ◽  
Egg Cell ◽  
Rate Of Oxygen Consumption ◽  
Licl Treatment ◽  
Treatment Changes ◽  
Limnaea Stagnalis ◽  
Early Developmental ◽  
Periodic Changes

It is well known that treatment with LiCl can cause abnormal embryonic development, but its mode of action is still uncertain (Gustafson, 1954; Geilenkirchen, 1961; Lallier, 1964). It also remains to be shown whether LiCl enters the egg cell at early developmental stages and acts internally, or does not penetrate into the cell and is active only at the outer surface (Elbers, 1959). LiCl treatment changes the rate of oxygen uptake during the early cleavage cycles in Limnaea. The rate of oxygen consumption varies between the first and the third cleavage in a cyclic fashion with maxima at mitotic prophases (Geilenkirchen, 1961). Continuous treatment with LiCl disturbs the pattern of periodic changes in the rate of uptake (Fig. 2). The influence of LiCl, however, is not the same at all times. It does not start until shortly before prophase of the second mitotic cycle, and this may indicate that until prophase of the second division no processes in which LiCl interferes occur.

Chromatin diminution is strictly correlated to somatic cell behavior in early development of the nematode Parascaris univalens

1995 ◽  
Vol 108 (6) ◽  
pp. 2393-2404
Author(s):  
M.R. Esteban ◽  
G. Giovinazzo ◽  
C. Goday
Keyword(s):  
Somatic Cell ◽  
Early Development ◽  
Cytochalasin B ◽  
Developmental Stages ◽  
Cell Behavior ◽  
Chromatin Diminution ◽  
Developmental Behavior ◽  
Licl Treatment ◽  
The Relationship ◽  
Early Developmental

We have studied the relationship between the occurrence of chromatin diminution and the developmental behavior of somatic blastomeres in early development of the nematode Parascaris univalens. A cytological and immunocytochemical analysis of chromatin diminution was performed in P. univalens embryos exposed to ‘vegetalizing’ (LiCl) and ‘animalizing’ (NaSCN) substances during early developmental stages. We have also analyzed chromatin diminution in embryos displaying only symmetrical ‘somatic-like’ divisions due to a brief cytochalasin B treatment at the pronuclear stage. The results show that LiCl treatment induces chromatin diminution in P0-P4 pregerminal blastomeres while NaSCN treatment prevents it. Pregerminal cells undergoing chromatin diminution in ‘vegetalized’ embryos behaved like somatic cells with respect to division and cleavage patterns. NaSCN treatment results in undiminuted polynucleated embryos that are not capable of cleavage. In cytochalasin B-pulsed embryos, chromatin diminution occurs in all blastomeres. From our results we conclude that chromatin diminution and somatic cell behavior are not separable and constitute strictly correlated events in Parascaris. Moreover, the results indicate that the segregation of the cytoplasmic factors involved in chromatin diminution in early Parascaris development are microfilament-mediated. Here, we also report the formation of a latter pregerminal cell precursor (P5) not susceptible to LiCl-induced chromatin diminution.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

Review of early developmental stages of trilobites and agnostids from the Barrandian area (Czech Republic)

2017 ◽  
Vol 186 (1) ◽  
pp. 103-112
Author(s):  
Lukáš Laibl ◽  
Oldřich Fatka
Keyword(s):  
Czech Republic ◽  
Developmental Stages ◽  
History Of Research ◽  
Early Developmental Stages ◽  
History Of ◽  
Barrandian Area ◽  
Early Developmental

This contribution briefly summarizes the history of research, modes of preservation and stratigraphic distribution of 51 trilobite and five agnostid taxa from the Barrandian area, for which the early developmental stages have been described.

scholarly journals The Effect of an Anthropogenic Magnetic Field on the Early Developmental Stages of Fishes—A Review

2021 ◽  
Vol 22 (3) ◽  
pp. 1210
Author(s):  
Krzysztof Formicki ◽  
Agata Korzelecka-Orkisz ◽  
Adam Tański
Keyword(s):  
Magnetic Fields ◽  
Developmental Stages ◽  
Negative Influence ◽  
Pigment Cells ◽  
Egg Activation ◽  
Industrial Equipment ◽  
Positive Effects ◽  
Early Developmental Stages ◽  
Species Specific ◽  
Early Developmental

The number of sources of anthropogenic magnetic and electromagnetic fields generated by various underwater facilities, industrial equipment, and transferring devices in aquatic environment is increasing. These have an effect on an array of fish life processes, but especially the early developmental stages. The magnitude of these effects depends on field strength and time of exposure and is species-specific. We review studies on the effect of magnetic fields on the course of embryogenesis, with special reference to survival, the size of the embryos, embryonic motor function, changes in pigment cells, respiration hatching, and directional reactions. We also describe the effect of magnetic fields on sperm motility and egg activation. Magnetic fields can exert positive effects, as in the case of the considerable extension of sperm capability of activation, or have a negative influence in the form of a disturbance in heart rate or developmental instability in inner ear organs.

scholarly journals Wnt/β-catenin Pathway-Mediated PPARδ Expression during Embryonic Development Differentiation and Disease

2021 ◽  
Vol 22 (4) ◽  
pp. 1854
Author(s):  
Tabinda Sidrat ◽  
Zia-Ur Rehman ◽  
Myeong-Don Joo ◽  
Kyeong-Lim Lee ◽  
Il-Keun Kong
Keyword(s):  
Embryonic Development ◽  
Transcriptional Activation ◽  
Target Gene ◽  
Developmental Stages ◽  
Embryonic Stem ◽  
Hereditary Diseases ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Stem Cell Regulation ◽  
Early Developmental

The Wnt/β-catenin signaling pathway plays a crucial role in early embryonic development. Wnt/β-catenin signaling is a major regulator of cell proliferation and keeps embryonic stem cells (ESCs) in the pluripotent state. Dysregulation of Wnt signaling in the early developmental stages causes several hereditary diseases that lead to embryonic abnormalities. Several other signaling molecules are directly or indirectly activated in response to Wnt/β-catenin stimulation. The crosstalk of these signaling factors either synergizes or opposes the transcriptional activation of β-catenin/Tcf4-mediated target gene expression. Recently, the crosstalk between the peroxisome proliferator-activated receptor delta (PPARδ), which belongs to the steroid superfamily, and Wnt/β-catenin signaling has been reported to take place during several aspects of embryonic development. However, numerous questions need to be answered regarding the function and regulation of PPARδ in coordination with the Wnt/β-catenin pathway. Here, we have summarized the functional activation of the PPARδ in co-ordination with the Wnt/β-catenin pathway during the regulation of several aspects of embryonic development, stem cell regulation and maintenance, as well as during the progression of several metabolic disorders.

scholarly journals Mitochondrial Processes during Early Development of Dictyostelium discoideum: From Bioenergetic to Proteomic Studies

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 638
Author(s):  
Monika Mazur ◽  
Daria Wojciechowska ◽  
Ewa Sitkiewicz ◽  
Agata Malinowska ◽  
Bianka Świderska ◽  
...  
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Coupling Efficiency ◽  
Slime Mold ◽  
Intact Cells ◽  
Life Cycle Stages ◽  
Early Developmental Stages ◽  
Proteomic Study ◽  
And Function ◽  
Early Developmental

The slime mold Dictyostelium discoideum’s life cycle includes different unicellular and multicellular stages that provide a convenient model for research concerning intracellular and intercellular mechanisms influencing mitochondria’s structure and function. We aim to determine the differences between the mitochondria isolated from the slime mold regarding its early developmental stages induced by starvation, namely the unicellular (U), aggregation (A) and streams (S) stages, at the bioenergetic and proteome levels. We measured the oxygen consumption of intact cells using the Clarke electrode and observed a distinct decrease in mitochondrial coupling capacity for stage S cells and a decrease in mitochondrial coupling efficiency for stage A and S cells. We also found changes in spare respiratory capacity. We performed a wide comparative proteomic study. During the transition from the unicellular stage to the multicellular stage, important proteomic differences occurred in stages A and S relating to the proteins of the main mitochondrial functional groups, showing characteristic tendencies that could be associated with their ongoing adaptation to starvation following cell reprogramming during the switch to gluconeogenesis. We suggest that the main mitochondrial processes are downregulated during the early developmental stages, although this needs to be verified by extending analogous studies to the next slime mold life cycle stages.

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