scholarly journals Obtaining Oviparous Grass Snake, Natrix natrix (Serpentes, Colubridae), embryos at Early Developmental Stages by Caesarean Section

Zoodiversity ◽  
2021 ◽  
Vol 55 (3) ◽  
pp. 217-224
Author(s):  
H. V. Sheverdyukova ◽  
I. R. Merzlikin
Keyword(s):  
Caesarean Section ◽  
Developmental Stages ◽  
Significant Development ◽  
The Past ◽  
Reproductive Ability ◽  
Natrix Natrix ◽  
In The Wild ◽  
Grass Snake ◽  
Gravid Females ◽  
Early Developmental

There is a specific feature in the developmental biology of oviparous snakes: embryos in the eggs, which were just laid, have already undergone significant development. This fact makes it significantly complicated to obtain data on organs’ development at early stages of embryogenesis. In addition, the fertilization time and the duration of snake pregnancy in the wild are unknown. In order to obtain the embryos of an oviparous grass snake Natrix natrix (Linnaeus, 1758) at successive developmental stages with minimal harm to gravid females we used caesarean section. The past known experience of performing caesarean section in snakes and anesthesia in reptiles were used. All the embryos were taken from the upper oviduct of a female simultaneously; in this way we eliminated the influence of medications on embryos’ development. The described method is valuable when it is necessary to obtain snake embryos and to preserve the life of the female and, possibly,its reproductive ability.

scholarly journals Integrated Development Model (IMD): A Systematic Review and Reflection

2016 ◽  
Vol 12 (19) ◽  
pp. 244 ◽  
Author(s):  
Jordan Tovera Salvador
Keyword(s):  
Systematic Review ◽  
Developmental Stages ◽  
Development Model ◽  
Guidance And Counseling ◽  
Integrated Development ◽  
Developmental Models ◽  
The Past ◽  
New Models ◽  
Supervision Model ◽  
Early Developmental

This paper evaluates a recognized supervision model and reflects on how this model has affected one’s personal role as an instructional supervisor. Integrated Development Model of Supervision (IMD) is one of the most sought after developmental models of supervision in the past decades and even up to the present. Developmental models of supervision are usually derived from the idea that the supervisee has the capability to develop from novice to expert with the guidance and counseling of the supervisor. Each of the developmental stages of supervision has specific skills and competencies that are notable and observable amongst the supervisee and supervisor. However, just like any other models of supervision, developmental models have loopholes identified by experts such as: (1) these models are simplistic and vague, (2) emphasizing on the amalgamation of the advances to developmental supervisions, (3) no new models of supervision have emerged, (4) does not allow differing routes to development for dissimilar trainees and (5) does not report any waning on the part of the supervisee. IDM was formulated based from the ambiguities of the early developmental models and to answer the gaps in shifting between each developmental stage.

scholarly journals Rhythmic swaying induced by sound in chimpanzees (Pan troglodytes)

2019 ◽  
Vol 117 (2) ◽  
pp. 936-942 ◽  
Author(s):  
Yuko Hattori ◽  
Masaki Tomonaga
Keyword(s):  
Positive Emotions ◽  
Developmental Stages ◽  
Rhythmic Movement ◽  
Ancient History ◽  
Rhythmic Movements ◽  
Evolutionary Origins ◽  
Physiological Properties ◽  
Close Proximity ◽  
In The Wild ◽  
Early Developmental

Music and dance are universal across human culture and have an ancient history. One characteristic of music is its strong influence on movement. For example, an auditory beat induces rhythmic movement with positive emotions in humans from early developmental stages. In this study, we investigated if sound induced spontaneous rhythmic movement in chimpanzees. Three experiments showed that: 1) an auditory beat induced rhythmic swaying and other rhythmic movements, with larger responses from male chimpanzees than female chimpanzees; 2) random beat as well as regular beat induced rhythmic swaying and beat tempo affected movement periodicity in a chimpanzee in a bipedal posture; and 3) a chimpanzee showed close proximity to the sound source while hearing auditory stimuli. The finding that male chimpanzees showed a larger response to sound than female chimpanzees was consistent with previous literature about “rain dances” in the wild, where male chimpanzees engage in rhythmic displays when hearing the sound of rain starting. The fact that rhythmic swaying was induced regardless of beat regularity may be a critical difference from humans, and a further study should reveal the physiological properties of sound that induce rhythmic movements in chimpanzees. These results suggest some biological foundation for dancing existed in the common ancestor of humans and chimpanzees ∼6 million years ago. As such, this study supports the evolutionary origins of musicality.

scholarly journals Polar cartilages and formation of Crista sellaris in grass snake, natrix natrix (Ophidia, Colubridae), chondrocranium at the early stages of embryogenesis

2012 ◽  
Vol 46 (5) ◽  
pp. 32-39 ◽  
Author(s):  
H. V. Sheverdyukova
Keyword(s):  
Developmental Stages ◽  
Early Stages ◽  
Natrix Natrix ◽  
Grass Snake ◽  
First Time

Polar Cartilages and Formation of Crista Sellaris in Grass Snake, Natrix natrix (Ophidia, Colubridae), Chondrocranium at the Early Stages of Embryogenesis. Sheverdyukova H. V.- The initial developmental stages of grass snake’s, Natrix natrix Linnaeus, 1758 chondrocranium are described. Three paired structures form the floor of N. natrix’s neurocranium: cranial trabeculae, polar cartilages, and parachordals. The primordiums of polar cartilages and their independent centers of chondrification are identified at the stage 26 of development for the first time for N. natrix and snakes in general. The participation of these structures in the formation of crista sellaris and carotid foramina is proved.

Initiation of placentation in the pig

1984 ◽  
Vol 42 ◽  
pp. 730-731
Author(s):  
J.L. Keys
Keyword(s):  
Electron Microscopy ◽  
Developmental Stages ◽  
Morphological Changes ◽  
Light And Electron Microscopy ◽  
Microscopic Structure ◽  
Initial Attachment ◽  
Tissue Samples ◽  
The Past ◽  
Early Developmental Stages ◽  
Early Developmental

The microscopic structure of the mature placenta in domesticated species has been described in many publications but the early developmental stages have only been studied in detail within the past decade. The earliest date previously cited for initial attachment of the porcine trophoblast to the maternal epithelium is 14 to 18 days of gestation. This investigation was undertaken to establish morphological changes in the maternal epithelium in preparation for this event.Four or 5 nulliparous gilts were slaughtered on each of d10 and d13 of the estrous cycle and pregnancy (d0=1st d of estrus), and tissue samples prepared for correlative light and electron microscopy. Samples were compared between gilts on equivalent days of the cycle/pregnancy in order to determine endometrial changes specific to pregnancy. Sites adjacent to embryos were contrasted with those lacking trophoblastic contact within the same animal to investigate whether epithelial adaptations for attachment are localized to trophoblast proximity or represent a generalized uterine response.

scholarly journals Architecture of the Pancreatic Islets and Endocrine Cell Arrangement in the Embryonic Pancreas of the Grass Snake (Natrix natrix L.). Immunocytochemical Studies and 3D Reconstructions

2021 ◽  
Vol 22 (14) ◽  
pp. 7601
Author(s):  
Magdalena Kowalska ◽  
Weronika Rupik
Keyword(s):  
Endocrine Cells ◽  
Developmental Stages ◽  
Cell Types ◽  
Dorsal Pancreas ◽  
The Core ◽  
Embryonic Pancreas ◽  
Grass Snake ◽  
D Cells ◽  
Different Cell Types ◽  
Early Developmental

During the early developmental stages of grass snakes, within the differentiating pancreas, cords of endocrine cells are formed. They differentiate into agglomerates of large islets flanked throughout subsequent developmental stages by small groups of endocrine cells forming islets. The islets are located within the cephalic part of the dorsal pancreas. At the end of the embryonic period, the pancreatic islet agglomerates branch off, and as a result of their remodeling, surround the splenic “bulb”. The stage of pancreatic endocrine ring formation is the first step in formation of intrasplenic islets characteristics for the adult specimens of the grass snake. The arrangement of endocrine cells within islets changes during pancreas differentiation. Initially, the core of islets formed from B and D cells is surrounded by a cluster of A cells. Subsequently, A, B, and D endocrine cells are mixed throughout the islets. Before grass snake hatching, A and B endocrine cells are intermingled within the islets, but D cells are arranged centrally. Moreover, the pancreatic polypeptide (PP) cells are not found within the embryonic pancreas of the grass snake. Variation in the proportions of different cell types, depending on the part of the pancreas, may affect the islet function—a higher proportion of glucagon cells is beneficial for insulin secretion.

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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