Experimental studies on the columella-capsular interrelationship in the turtle Chelydra serpentina

Development ◽  
1965 ◽  
Vol 14 (3) ◽  
pp. 265-272
Author(s):  
M. J. Toerien
Keyword(s):  
Experimental Studies ◽  
Fundamental Importance ◽  
Chelydra Serpentina ◽  
Reciprocal Effect ◽  
Early Embryos ◽  
Vast Literature ◽  
Different Origins ◽  
Auditory Capsule

The reciprocal effect of two neighbouring structures of different origins on each other during development is of considerable interest to the embryologist. Such a relationship exists between the columella auris and the auditory capsule in the vicinity of the fenestra ovalis. This particular relationship, in addition, embraces an aspect of fundamental importance to the morphologist viz. the possible derivation of part of the columella from the capsule. The vast literature pertaining to this latter aspect and particularly in regard to the development of the human stapes, was recently reviewed in great detail by Strickland, Hanson & Anson (1962). References to literature related to other vertebrates are found in e.g. van der Klaauw (1924), Versluys (1936), and Werner (1960). An earlier paper (Toerien, 1963) deals with the rather specialized problem of Amphibian stapes development The results of certain extirpation procsduivS on early embryos of the turtle {Chelydra serpentina) throw interesting high on the columella-capsule interrelationship.

Morphological and experimental studies of the somitomeric organization of the segmental plate in snapping turtle embryos

Development ◽  
1984 ◽  
Vol 84 (1) ◽  
pp. 35-48
Author(s):  
David S. Packard ◽  
Stephen Meier
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Final Stage ◽  
Experimental Studies ◽  
The Other ◽  
Chelydra Serpentina ◽  
Microscopy Imaging ◽  
Snapping Turtle ◽  
Somite Formation ◽  
Scanning Electron

The segmental plate mesoderm of snapping turtle embryos (Chelydra serpentina) was examined with stereoscanning electron microscopy imaging. A metameric pattern was detected along the entire length of the segmental plates. This pattern consisted of a tandem sequence of mesodermal units, called somitomeres. Each somitomere was oval to cubic in shape and the processes of the constituent mesodermal cells tended to be arranged in concentric rings about the centre of the somitomere. Several experiments from a previous study (Packard, 1980b) of snapping turtle segmental plates were repeated, but, instead of culturing the explants and observing the numbers of somites that formed, the explants were fixed immediately for scanning electron microscopy and the number of somitomeres was counted. The segmental plates were found to contain an average of 6·5 ± 0·7 somitomeres, which is almost identical to the average number of somites formed by such segmental plates when cultured (6·6 ± 1·2). Furthermore, the number of somitomeres was identical in right and left explants removed from the same embryo, and the number of somitomeres was consistent regardless of the length of the segmental plate. Both of these observations are identical to those made previously for somite formation in culture. This association between numbers of somitomeres and somites strongly suggests that one gives rise to the other. Finally, it was demonstrated that for each somite formed by a segmental plate in culture, the segmental plate contained one less somitomere. This showed in a direct manner that turtle somitomeres become somites. It was concluded that the segmental plate mesoderm of snapping turtle embryos is already segmented, and that the ‘segmentation’ seen under a dissecting microscope is actually the final stage of somitomere differentiation into an epithelial somite.

Experimental Studies on the Origin of the Cartilage of the Auditory Capsule and Columella in Ambystoma

Development ◽  
1963 ◽  
Vol 11 (3) ◽  
pp. 459-473
Author(s):  
M. J. Toerien
Keyword(s):  
Nile Blue ◽  
Experimental Studies ◽  
Experimental Results ◽  
Points Of View ◽  
Auditory Capsule

On the basis of earlier experimental results on amphibia and his own observations, Yntema (1955) came to the conclusion that the ‘ear rudiment or the ectoderm surrounding it may be a source of mesectoderm for the ear capsule, at least in the heterotopic position’. This is contrary to another view that the source of the cartilaginous ear capsule is of purely mesentodermal origin. The literature pertaining to these two points of view is reviewed by Yntema (1955) and Benoit (1957). The purpose of the present investigation is to study further the extent of the ectomesenchymal contribution to the auditory capsule in the orthotopic position. Ambystoma punctatum larvae were raised from eggs sent to this institute by Mr Glenn Gentry of Donelson, Tennessee. Some of the eggs were stained with Nile blue sulphate according to the method described by Detwiler (1917).

An experimental approach to the development of the ear capsule in the turtle, Chelydra serpentina

Development ◽  
1965 ◽  
Vol 13 (2) ◽  
pp. 141-149
Author(s):  
M. J. Toerien
Keyword(s):  
Recent Work ◽  
Experimental Approach ◽  
Experimental Studies ◽  
Chelydra Serpentina ◽  
Medial Aspect ◽  
Early Stages ◽  
Otic Placode ◽  
Auditory Region

The effects of the elimination of the otic placode or otocyst on the development of the cartilaginous ear capsule and columella auris have been observed in several fishes, amphibians and birds and are summarized by de Beer (1937), Yntema (1955) and Benoit (1957). More recent work includes that of Benoit (1960) and Toerien (1963). Except in the fish Acipenser (Filatow, 1930) the development of a cartilaginous ear capsule is completely suppressed following the removal of the otocyst. The effect of the operation on the development of the columella is not so clear and the resultant deficiency in the medial aspect has been interpreted in various ways. Yntema's (1965) method for using turtle eggs has made the early stages of reptilian embryos available for experimental studies. The purpose of the present investigation, therefore, is to study the effect of the removal of the placode on the development of the auditory region in yet another vertebrate class

scholarly journals The Impact of Transcription Factor Prospero Homeobox 1 on the Regulation of Thyroid Cancer Malignancy

2020 ◽  
Vol 21 (9) ◽  
pp. 3220 ◽  
Author(s):  
Magdalena Rudzińska ◽  
Barbara Czarnocka
Keyword(s):  
Transcription Factor ◽  
Thyroid Cancer ◽  
Protein Structures ◽  
Prognostic Significance ◽  
Experimental Studies ◽  
Cancer Development ◽  
Dependent Manner ◽  
Prox1 Expression ◽  
Different Origins ◽  
The Impact

Transcription factor Prospero homeobox 1 (PROX1) is continuously expressed in the lymphatic endothelial cells, playing an essential role in their differentiation. Many reports have shown that PROX1 is implicated in cancer development and acts as an oncoprotein or suppressor in a tissue-dependent manner. Additionally, the PROX1 expression in many types of tumors has prognostic significance and is associated with patient outcomes. In our previous experimental studies, we showed that PROX1 is present in the thyroid cancer (THC) cells of different origins and has a high impact on follicular thyroid cancer (FTC) phenotypes, regulating migration, invasion, focal adhesion, cytoskeleton reorganization, and angiogenesis. Herein, we discuss the PROX1 transcript and protein structures, the expression pattern of PROX1 in THC specimens, and its epigenetic regulation. Next, we emphasize the biological processes and genes regulated by PROX1 in CGTH-W-1 cells, derived from squamous cell carcinoma of the thyroid gland. Finally, we discuss the interaction of PROX1 with other lymphatic factors. In our review, we aimed to highlight the importance of vascular molecules in cancer development and provide an update on the functionality of PROX1 in THC biology regulation.

scholarly journals CHEMICAL SIGNALS IN VERTEBRATE PREDATOR-PREY SYSTEMS INVOLVING COMMON MUSK TURTLES, STERNOTHERUS ODORATUS, AND THEIR PREDATORS

2014 ◽  
pp. 69-75
Author(s):  
Don Moll ◽  
Neil Dazet
Keyword(s):  
Field Experiments ◽  
Experimental Studies ◽  
Chelydra Serpentina ◽  
Agkistrodon Piscivorus ◽  
Predator Prey ◽  
Snapping Turtle ◽  
Snapping Turtles ◽  
Sternotherus Odoratus ◽  
The Common ◽  
And Control

Rathke’s gland secretions (RGS) of Common Musk Turtles have a variety of proposed functions including predator deterrence and attraction, but experimental studies testing these hypotheses are lacking. This study used laboratory and field experiments to test whether RGS had attraction or repellent effects on two natural predators, the Cottonmouth (Agkistrodon piscivorus), and the Common Snapping Turtle (Chelydra serpentina). In a laboratory experiment, we examined latency to feed and consumption times for Cottonmouths offered RGS-treated minnows and control minnows. In a field study, we investigated the ratio of snapping turtles appearing in traps with and without RGS-treated bait. The latency to feed times for Cottonmouths offered RGS-treated minnows were not significantly different from those offered control minnows. However, prey consumption times for Cottonmouths feeding on RGS-treated minnows were significantly greater than those feeding on control minnows. These results suggest that the RGS may lengthen the time of a predation sequence, possibly allowing the turtle more time to escape from the predator. The number of snapping turtles appearing in traps with RGS-treated bait was significantly greater than the number of snapping turtles in traps without RGS-treated bait. These results support the predator attraction hypothesis, where the signal may attract additional predators that interfere with a predation event, providing an opportunity for the prey to escape.

Performance of Low Solidity and Conventional Diffuser Systems for Centrifugal Compressors

1996 ◽  
Author(s):  
Naresh K. Amineni ◽  
Abraham Engeda ◽  
William C. Hohlweg ◽  
Gregory L. Direnzi
Keyword(s):  
Gas Turbines ◽  
Experimental Studies ◽  
Maximum Efficiency ◽  
Michigan State University ◽  
Aircraft Engines ◽  
State University ◽  
Centrifugal Compressors ◽  
Vaned Diffuser ◽  
The Family ◽  
Vast Literature

Centrifugal compressors have the widest compressor application area, covering aircraft engines, small stationary gas turbines, process and refinery industries, the refrigeration industry, and turbochargers. Despite the vast literature coverage of diffuser systems for centrifugal compressors, there are not more than twenty publications in the open literature on the family of vaned diffusers known as Low Solidity Vaned Diffuser (LSVD). This is highly surprising, in light of the fact, that practically all process and refrigeration compressors manufacturers, at one time or another, have attempted to design and test LSVD. Therefore with the strong belief that any work on LSVD either theoretical or experimental will be welcomed, this paper presents the performance of two newly designed LSVD. Comparative experimental studies on diffuser systems for centrifugal compressors, performed at the Michigan State University Turbomachinery Lab are presented. A vaneless, a conventional vaned and two low solidity vaned diffusers were tested. The results are compared for the effect of the diffuser systems on the stage performance, the maximum efficiency, and the operating range of the compressor. The effect of the vane number in low solidity vaned diffuser on the performance is also discussed.

scholarly journals Stem cells transplantation in the treatment of patients with cerebral palsy

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Petriv T. ◽  
◽  
Tatarchuk M. ◽  
Tsymbaliuk Y. ◽  
Tsymbaliuk V. ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cerebral Palsy ◽  
Experimental Studies ◽  
Current State ◽  
Cell Technologies ◽  
Degree Of Disability ◽  
Stem Cells Transplantation ◽  
Different Origins ◽  
High Degree

Cerebral palsy remains a significant problem today, despite scientific and technological progress. The high degree of disability and unsatisfactory quality of life of patients in this category, necessitates the search for and implementation of the latest treatments, one of which is cell transplantation. The use of regenerative cell technologies in the treatment of patients with cerebral palsy is extremely promising. Numerous experimental studies have significantly expanded the understanding of the mechanisms of the effect of the use of stem cells in cerebral palsy. Clinical applications of stem cells of different origins are safe, which is one of the prerequisites for continuing research in this area. This review is devoted to the use of regenerative cell technologies in the treatment of cerebral palsy, the current state and prospects of the approach to the treatment of cerebral palsy with stem cells.

scholarly journals Vertical transmission at the pathogen-symbiont interface: Serratia symbiotica and aphids

2020 ◽  
Author(s):  
Julie Perreau ◽  
Devki J. Patel ◽  
Hanna Anderson ◽  
Gerald P. Maeda ◽  
Katherine M. Elston ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Experimental Studies ◽  
Oral Route ◽  
Early Embryo ◽  
Host Cells ◽  
Bacterial Symbionts ◽  
Early Embryos ◽  
Pea Aphids ◽  
Serratia Symbiotica ◽  
Gut Pathogens

AbstractMany insects possess beneficial bacterial symbionts that occupy specialized host cells and are maternally transmitted. As a consequence of their host-restricted lifestyle, these symbionts often possess reduced genomes and cannot be cultured outside hosts, limiting their study. The bacterial species Serratia symbiotica was originally described by noncultured strains that live as mutualistic symbionts of aphids and are vertically transmitted through transovarial endocytosis within the mother’s body. More recently, culturable strains of S. symbiotica were discovered that retain a larger set of ancestral Serratia genes, are gut pathogens in aphid hosts, and are principally transmitted via a fecal-oral route. We find that these culturable strains, when injected into pea aphids, replicate in the hemolymph and are pathogenic. Unexpectedly, they are also capable of maternal transmission via transovarial endocytosis: using GFP-tagged strains, we observe that pathogenic S. symbiotica, but not Escherichia coli, are endocytosed into early embryos. Furthermore, pathogenic S. symbiotica strains are compartmentalized into specialized aphid cells in a similar fashion to mutualistic S. symbiotica strains during later stages of embryonic development. Thus, cultured, pathogenic strains of S. symbiotica have the latent capacity to transition to lifestyles as mutualistic symbionts of aphid hosts. This capacity is blocked by pathogenicity: their hosts die before infected progeny are born. To transition into stably inherited symbionts, culturable S. symbiotica strains may need to adapt to regulate their titer, limit their pathogenicity, and/or provide benefits to aphids that outweigh their cost.ImportanceInsects have evolved various mechanisms to reliably transmit their beneficial bacterial symbionts to the next generation. Sap-sucking insects, including aphids, transmit symbionts by endocytosis of the symbiont into cells of the early embryo within the mother’s body. Experimental studies of this process are hampered by the inability to culture or genetically manipulate host-restricted, symbiotic bacteria. Serratia symbiotica is a bacterial species that includes strains ranging from obligate, heritable symbionts to culturable gut pathogens. We demonstrate that culturable S. symbiotica strains, that are aphid gut pathogens, can be maternally transmitted by endocytosis. Cultured S. symbiotica therefore possess a latent capacity for evolving a host-restricted lifestyle and can be used to understand the transition from pathogenicity to beneficial symbiosis.

Examining pattern formation in mouse, chicken and frog embryos with an En-specific antiserum

Development ◽  
1991 ◽  
Vol 111 (2) ◽  
pp. 287-298 ◽  
Author(s):  
C.A. Davis ◽  
D.P. Holmyard ◽  
K.J. Millen ◽  
A.L. Joyner
Keyword(s):  
Electron Microscopy ◽  
Pattern Formation ◽  
Experimental Studies ◽  
Neural Plate ◽  
Limb Bud ◽  
Good Marker ◽  
Early Embryos ◽  
Whole Mount ◽  
Anterior Neural Plate ◽  
Scanning Electron

We have raised an antiserum, designated alpha Enhb-1, to a portion of the mouse En-2 protein containing the homeodomain. The antiserum detects both the En-1 and En-2 proteins in mouse, chick and Xenopus embryos by Western blot analysis. Using whole-mount immunohistochemistry, combined in some cases with scanning electron microscopy, we have examined the distribution of the proteins in the early embryos of these species. The major features of expression were similar. The initial production of En protein occurred, just before or during the formation of the first somites, in a band of the anterior neural plate in the prospective mid/hindbrain region. Later in development En-1 protein accumulated in the ventral ectoderm of the developing mouse and chick limb buds, indicating that a dorsal-ventral polarity is present as soon as any limb bud swelling is apparent and that, at least in the mouse, this polarity is established independently of the apical ectodermal ridge. In all three species, alpha Enhb-1 bound to a subset of ventro-lateral differentiating neurons in the spinal cord and hindbrain and their pattern of birth in the mouse reflected the division of the hindbrain into rhombomeres. En-1 protein also accumulated in a lateral stripe of dermatome in the mouse and chick, indicating a dorsal-ventral subdivision of this tissue. The results show that En expression is a good marker for pattern formation in a variety of tissues and will be useful in experimental studies designed to characterize further these processes.

Sign in / Sign up

Export Citation Format

Share Document