The experiments described here were designed to reveal the distribution in the frog early embryo of components which are sufficient for specification of the dorsal structures of the embryonic body axis. The approach was to allow cleavage planes to divide the embryo into various well-defined regions and to transplant cells from each region into recipient embryos which would otherwise fail to form axial structures. Partial or complete body axis development could then be scored by the use of external criteria or histological methods. Recipients were embryos which had been irradiated before first cleavage with ultraviolet light on the vegetal surface. Irradiated embryos display a well-characterized set of deficiencies in the dorsal structures of the body axis, but their development can be rescued toward normalcy in several ways. In particular, transplantation of certain small groups of blastomeres from the normal 32- to 64-cell embryo into irradiated recipients was sufficient to cause partial or ...
Light micrograph showing a section of frog embryo in advanced gastrulation. Magnification 60X when printed at 10cm. - Stock Image C009/3462
Ectopic expression Ectopic expression. Embryos a-c are viewed laterally with the posterior pole to the right, embryos d-i are viewed dorsally. Expression of Wun
Since Darwins time, waterbirds have been considered an important vector for the dispersal of continental aquatic invertebrates. Bird movements have facilitated the worldwide invasion of the American brine shrimp Artemia franciscana, transporting cysts (diapausing eggs), and favouring rapid range expansions from introduction sites. Here we address the impact of bird migratory flyways on the population genetic structure and phylogeography of A. franciscana in its native range in the Americas. We examined the sequence variation for two mitochondrial gene fragments (COI and 16S for a subset of the data) in a large set of population samples representing the entire native range of A. franciscana. Furthermore, we performed Mantel tests and redundancy analyses (RDA) to test the role of flyways, geography and human introductions on the phylogeography and population genetic structure at a continental scale. A. franciscanamitochondrial DNA was very diverse, with two main clades, largely corresponding to Pacific
Many findings indicate that active retinoids (vitamin A metabolites, which are known to be hormone-like ligands), are regulatory signals during embryogenesis. Treating early vertebrate embryos with retinoids can cause teratogenesis. Notably, it generates specific defects in the main body axis. Considering other data showing that early vertebrate embryos contain physiolocally relevant concentrations of endogenous active retinoids and express retinoid binding proteins and receptors, it is not unlikely that retinoids act as developmental signals, which regulate axial patterning in the early vertebrate embryo. The purpose of this review is to discuss this point, referring to retinoid teratogenesis, and to the availabilities and functions of retinoid ligands, biding proteins and receptors in the early embryo.
Founder cells for most early lineages of the sea urchin embryo are probably specified through inductive intercellular interactions. It is shown here that a complete respecification of cell fate occurs when 16-cell stage micromeres from the vegetal pole of a donor embryo are implanted into the animal pole of an intact recipient embryo. Animal pole cells adjacent to the transplanted micromeres are respecified from presumptive ectoderm into vegetal plate founder cells. These induced vegetal plate cells express the entire battery of genes characteristic of the endogenous vegetal plate cells. The ectopic vegetal plate invaginates during gastrulation to form a second archenteron which differentiates properly into a tripartite gut, as shown by the spatial pattern of expression of an endoderm-specific marker gene. Thus, transplanted micromeres can signal neighboring cells to induce them to change their fate. ...
In vertebrate species, induction of the embryonic axis is initiated by the transport of maternally supplied determinants, initially localized to the vegetal pole of the egg, toward the prospective organizer in the animal region. This transport process remains incompletely understood. Here, we review studies involving embryonic manipulations, visualization, and functional analysis of the cytoskeleton and loss- and gain-of-function conditions, which provide insights in this process. Transport of dorsal determinants requires cytoskeletal reorganization of a vegetal array of microtubules, microtubule motors, and an off-center movement of the vegetal cortex with respect to the inner egg core, a so-called cortical rotation. Additional mechanisms may be used in specific systems, such as a more general animally directed movement found in the teleost embryo. Initial polarity of the microtubule movement depends on early asymmetries, which are amplified by the movement of the outermost cortex. An interplay between
FGF signaling is involved in patterning and tissue formation of early vertebrate embryos (reviewed by Sivak and Amaya, 2004; Böttcher and Niehrs, 2005). Expression of XFD, a dominant negative form of Xenopus FGF receptor 1 (FGFR1), in Xenopus and zebrafish embryos results in loss of trunk and tail tissues (Amaya et al., 1991; Amaya et al., 1993; Griffin et al., 1995). FGF signaling has also been shown to be required for neural induction (Streit et al., 2000; Wilson et al., 2000; Böttcher and Niehrs, 2005), for organizer-independent induction of posterior neural tissue (Kudoh et al., 2002; Kudoh et al., 2004), anterior neurectoderm formation (Hongo et al., 1999) and posterior mesoderm development (Draper et al., 2003).. Perhaps due to the pleiotropic effects that result from inhibition of FGF signaling in early embryos, a role of FGF signaling in dorsal axis establishment - as distinct from mesoderm induction, posterior development and neural induction - has not been emphasized in recent ...
To study the frequency of germ-line transformation and to examine the reproducibility of tissue-specific transgene expression, we produced several lines of transgenic zebrafish expressing a recombinant chloramphenicol acetyltransferase (CAT) gene. Supercoiled plasmids containing both Rous sarcoma virus and SV-40 promoter sequences upstream of the CAT coding region were injected into zebrafish embryos prior to first cleavage. CAT activity could be detected in batches of injected embryos as early as 8 h and up to at least 12 days post-fertilization. Approximately 18% of injected fish raised to maturity exhibited CAT activity in their fins, and approximately 5% of injected fish became stable germ-line transformants. Breeding studies indicated that although transgenic founder fish were frequently germ-line mosaics, transgenic individuals of subsequent generations were fully hemizygous for the transgene marker. The transgenes present in the F1 progeny of four independent lines were relatively well ...
Sea urchin embryos and larvae provide an inexpensive high‐throughput system for determining developmental actions of neuropharmacologic agents or environmental neurotoxins in both applied and basic biologic contexts
EUGENE, Ore. - (April 18, 2013) - Using spinning disk microscopy on barely day-old zebra fish embryos, University of Oregon scientists have gained a new window on how synapse-building components move to worksites in the central nervous system.
Dejelling embryos: Wait at least one hour after fertilisation, any time after this embryos may be dejellied. Decant the MBS off the embryos, leaving them semi-dry and stuck to the bottom of the dish. Cover the embryos in the 2% cysteine solution, which will dissolve the jelly coats surrounding the eggs. With occasional, mild agitation, the embryos will be liberated in 5-7 minutes. It is important not to "swirl" eggs too vigorously when dejellying as this can cause axis duplications in some cases. Once the jelly coat is dissolved, the cysteine solution must be removed immediately (it can be reused). The embryos are then washed 3-4 times in a large volume of 0.1xMBS to remove residual cysteine. If left in the cysteine solution too long, or not washed enough, the plasma membrane will be damaged and the embryos will die! ...
DIC phenotype -- Reduced cleavage furrow ingression in second embryonic division; a phenotype not observed in either single (or36 mutation or zen-4 RNAi) treatments, cf RNAi [cgc4544]:air- ...
Despite the exposure of the fraud, Darwin and the biologists who supported him continued to regard Haeckels drawings as a reference source. And that further encouraged Haeckel. In the years that followed he produced further series of comparative embryo illustrations. He prepared diagrams showing fish, salamander, turtle, chicken, rabbit and human embryos side by side. The noteworthy aspect of these was how the embryos of these different life forms initially resembled one another very closely and gradually diverged over the course of their development. The similarity between the human and fish embryos in particular was very striking indeed. So much so that fictitious "gills" could be seen in the human embryo drawings, just as in those of the fish. Under the scientific guise he gave these illustrations, Haeckel launched his "theory of recapitulation:" Ontology Repeats Phylogeny. The meaning of the slogan was this; according to Haeckel, during the developmental process it undergoes in the egg or ...
Spatial expression pattern of MBC in wild-type embryos. Anterior is to the left and dorsal to the top in all except A. (A) Stage 13 embryos from the progeny of
PHILADELPHIA--During embryonic development, cells migrate to their eventual location in the adult body plan and begin to differentiate into specific cell types. Thanks to new research at the University of Pennsylvania, there is new insight into ...
Preimplantation Genetic Testing (PGT) has dramatically increased the live birth rates of children born as a result of IVF. These techniques help your IVF team to analyze and understand the health of your embryo prior to transfer into the uterus.
Vertebrate development is a complex orchestration of cell and tissue movements. Tracing individual cell positions can rapidly become a large-scale problem because cell numbers often grow exponentially in the early embryo. A typical approach consists
The biomarkers for stress in fish covers described the reviewing class, adopting efforts to find general in the major change, just of cure, focusing course or guidance. share you other to go what offers behavioral in Surfactant? Without the empirical two PEEP, previously would appreciate an consultant.
What if you could witness the development of a new life, taking your time to study every detail, every single cell, from every angle, moment by moment? Sonia Furtado talks to the scientists who made this possible by creating a digital zebrafish embryo.
Early embryos develop a protective protein shield to help prevent attack from the mothers immune system, new research shows
So, today was it....our transfer day! We had a different doctor perform our transfer Dr Sanfillipo-he was amazing! I was so pleased with his bedside manor. When Dr Sanfillipo came in we got the final result of our embryos-Of the five, three were mature. All three of the mature ones fertilized. Today we had two embryos come in at 6A (6 cells, quality A) and one at a 4B (4 cells, quality B). He said the 6As were perfect (the B was still pretty good)! You cant get anything better than an A. The picture I have showing is what a 6 cell embryo looks like (this one is not mine). We had only planned on implanting 2/3 of the embryos-however, the 4 cell was not able to be frozen. The embryos need to be at least 5 cells. So, instead of discarding the embryo we decided to implant that one as well ...
strain OP494 (unc-119(tm4063) III; wgIs494) whole organism hermaphrodite late embryo 5 hours post synchronization using egg bleaching genetically modified using ...
At what stage of animal development do cells first move from the surface of the embryo into the interior, resulting in a two- or three-layered embryo? ...
Atmospheric CO2 concentrations have risen from a preindustrial value of ∼280 ppm to a current value of 387 ppm because of human activities (Solomon et al., 2007). Simulation models project that concentrations could reach 1200 ppm by the end of this century and nearly 2000 ppm by approximately 2300 (Caldeira and Wickett, 2003; Caldeira and Wickett, 2005). Diffusion of atmospheric CO2 in the surface ocean causes an increase in the partial pressure of CO2 (PCO2) and is likely to decrease pH by 0.2-0.4 units over the course of this century and by up to 0.77 units by 2300 (Caldeira and Wickett, 2003; Caldeira and Wickett, 2005; Turley et al., 2009). Such a decline in pH of surface waters will reduce carbonate ion (CO2-3) concentrations and the degree of calcium carbonate (CaCO3) saturation in seawater, which could negatively affect marine organisms that synthesize a carbonate skeleton. Exposure to high CO2 levels and subsequent lowered pH may have biological consequences for juveniles and adults of ...
Intracellular and Extracellular pH and Ca Are Bound to Control Mitosis in the Early Sea Urchin Embryo via ERK and MPF Activities. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Fertilized, but still unsegmented, eggs of the sea urchin Paracentrotus lividus have been centrifugated at 30,000 gravity. A comparison has been made between the cytochemical reactions of the different layers (RNA, polysaccharides, acid phosphatase) and the fine structure as shown in thin sections studied with the electron microscope.. ...
We investigated the mechanisms of intermediate cell mass (ICM) expansion in zebrafish chordin (Chd) morphant embryos and examined the role of BMPs in relation to this phenotype. At 24 h post-fertilization (hpf), the expanded ICM of embryos injected with chd morpholino (MO) (Chd MO embryos) contained a monotonous population of hematopoietic progenitors. In situ hybridization showed that hematopoietic transcription factors were ubiquitously expressed in the ICM whereas vascular gene expression was confined to the periphery. BMP4 (but not BMP2b or 7) and smad5 mRNA were ectopically expressed in the Chd MO ICM. At 48 hpf, monocytic cells were evident in both the ICM and circulation of Chd MO but not WT embryos. While injection of BMP4 MO had no effect on WT hematopoiesis, co-injecting BMP4 with chd MOs significantly reduced ICM expansion. Microarray studies revealed a number of genes that were differentially expressed in Chd MO and WT embryos and their roles in hematopoiesis has yet to be ...
24) A comparative study on fluorescent cholesterol analogs as versatile cellular reporters (2016) Sezgin E, Can FB, Schneider F, Clausen MP, Galiani S, Stanly TA, Waithe D, Colaco A, Honigmann A, Wustner D, Platt F, Eggeling C. J Lipid Res 57: 299-309. 25) Bifunctional Sphingosine for Cell-Based Analysis of Protein-Sphingolipid Interactions (2016) Haberkant P, Stein F, Höglinger D, Gerl MJ, Brügger B, Van Veldhoven PP, Krijgsveld J, Gavin AC, Schultz C ACS Chem Biol 11:222-230. 26) Proteomic dataset of the sea urchin Paracentrotus lividus adhesive organs and secreted adhesive (2016) Lebesgue N, da Costa G, Ribeiro RM, Ribeiro-Silva C, Martins GG, Matranga V, Scholten A, Cordeiro C, Heck AJ, Santos R. Data Brief 7: 1497-1505. 27) Deciphering the molecular mechanisms underlying sea urchin reversible adhesion: A quantitative proteomics approach (2016) Lebesgue N, da Costa G, Ribeiro RM, Ribeiro-Silva C, Martins GG, Matranga V, Scholten A, Cordeiro C, Heck AJ, Santos R J Proteomics 138: ...
Zebrafish (Danio rerio) is a well-recognized model for the study of vertebrate developmental genetics, yet at the same time little is known about the transcriptional events that underlie zebrafish embryogenesis. Here we have employed microarray analysis to study the temporal activity of developmentally regulated genes during zebrafish embryogenesis. Transcriptome analysis at 12 different embryonic time points covering five different developmental stages (maternal, blastula, gastrula, segmentation, and pharyngula) revealed a highly dynamic transcriptional profile. Hierarchical clustering, stage-specific clustering, and algorithms to detect onset and peak of gene expression revealed clearly demarcated transcript clusters with maximum gene activity at distinct developmental stages as well as co-regulated expression of gene groups involved in dedicated functions such as organogenesis. Our study also revealed a previously unidentified cohort of genes that are transcribed prior to the mid-blastula transition,
Hydrated encysted embryos of the brine shrimp Artemia franciscana have the ability to withstand years in anaerobic sea water using metabolic strategies that enable them to inactivate all cell metabolic activities and then to resume development when placed in aerobic sea water. However, this unique characteristic of Artemia franciscana embryos is lost during a very short period, at the embryonic­larval transition period of development, coincident with the appearance of prenauplius larvae. Thus, while encysted embryos show complete inhibition of proteolysis over at least 4 years under anoxia, control of this activity, together with resistance to anoxia, is lost in newly hatched nauplius larvae after only a few days in anaerobic sea water. In contrast to encysted embryos, young larvae in anaerobic sea water produce large amounts of lactic acid, which reaches a concentration of nearly 50 mmol l-1 within 12 h of incubation. The accumulated lactic acid is believed to reduce the intracellular pH ...
The potential of the developing zebrafish model for toxicology and drug discovery is limited by inefficient approaches to manipulating and chemically exposing zebrafish embryos-namely, manual placement of embryos into 96- or 384-well plates and exposure of embryos while still in the chorion, a barrier of poorly characterized permeability enclosing the developing embryo. We report the automated dechorionation of 1600 embryos at once at 4 h postfertilization (hpf) and placement of the dechorionated embryos into 96-well plates for exposure by 6 hpf. The process removed ≥95% of the embryos from their chorions with 2% embryo mortality by 24 hpf, and 2% of the embryos malformed at 120 hpf. The robotic embryo placement allocated 6-hpf embryos to 94.7% ± 4.2% of the wells in multiple 96-well trials. The rate of embryo mortality was 2.8% (43 of 1536) from robotic handling, the rate of missed wells was 1.2% (18 of 1536), and the frequency of multipicks was ,0.1%. Embryo malformations observed at 24 hpf ...
The zebrafish genome contains ten genes that encode class II cytokine-like peptides, of which the two that are related most closely to mammalian interferon gamma (IFN-γ) were named IFN-γ1 and IFN-γ2. Although the zebrafish has become a popular model system to study immune mechanisms, and although interferons are central regulators of immunity, which zebrafish cytokines correspond functionally to mammalian IFN-γ has not been established. We used zebrafish embryos to assay the functions of IFN-γ1 and IFN-γ2, and have identified a subset of zebrafish homologs of the mammalian IFN-responsive genes as IFN-γ targets in the zebrafish embryo: these genes are upregulated in response to raised levels of either IFN-γ1 or IFN-γ2. Infection studies using two different pathogens show that IFN-γ signalling is required for resistance against bacterial infections in the young embryo and that the levels of IFN-γ need to be regulated tightly: raising IFN-γ levels sensitizes fish embryos against ...
In D. melanogaster, the subdivision of dorsal ectoderm into amnioserosa (AS) and dorsal epidermis is controlled by the combined actions of two morphogens of the TGF-β family, Decapentaplegic (Dpp) and Screw (Scw). They form an extracellular gradient with peak levels of Dpp/Scw signalling in the dorsal-most region of the embryo. Dpp/Scw signalling is transduced to the nucleus by a complex containing the phosphorylated Smad transcription factor, pMad and the co-Smad, Medea, which are responsible for the transcriptional activation of a number of targets in specific dorsal territories, including zerknullt (zen) gen. zen encodes a homeobox transcription factor, which is expressed for a brief period of time in the early developing embryo and is required for all aspects of AS formation, including the initial cell shape changes that drive the morphogenesis of the AS epithelium. However, the number and nature of Zen-target genes involved in AS differentiation subsequent to its specification are currently
Beta-catenin, a component of the wnt-signal-transduction pathway, is essential for the formation of the dorsal axis in Xenopus laevis embryos. On the dorsal side of the embryo, beta-catenin is translocated into the nuclei via a process linked to cortical rotation. When cortical rotation is blocked by UV-irradiation, nuclear beta-catenin is found in the vegetal pole of the embryo. Here we show that overexpression of beta-catenin in animal cap explants, in the absence of mesoderm induction, is sufficient to activate the expression of genes with dorsalizing activity such as siamois (sia) and nodal-related 3 (nr3) but not goosecoid (gsc). In embryos ventralized by UV-treatment, the expression of the dorsal-specific genes sia, nr3 and gsc is induced at the vegetal pole after the Mid-Blastula-Transition (MBT). While nr3 and sia expression continues in these embryos until gastrula stages, gsc transcription cannot be maintained. We propose that the spatial separation of the expression domains of genes ...
We investigated the effects of short-term exposure of bare TiO2NPs and polyelectrolyte-coated TiO2NPs in the 5-25 nm size range, at relatively high concentrations (of 500 and 1000 mg/L) under light or dark conditions, in D. rerio embryos. The biological endpoints investigated included embryo viability and mRNA transcript levels of antioxidant and membrane transport genes relative to control embryos. The presence of nanoparticles on the surface of embryos was assessed using TEM. The results confirm an accumulation of TiO2NPs on the outer surface (chorion) of the embryo, but not within the embryo. No significant difference in embryo viability was detected following each exposure regime. The expression of antioxidant biomarker, SOD2, was significantly impacted by the type of TiO2NP, with TiO2NPs/PSS/PAH coating exposure showing down regulation; the concentration of the nanoparticles, with down regulation at 500 mg/L; and dark/light condition with down regulation in the light. The expression levels ...
In developmental biology, an embryo is divided into two hemispheres: the animal pole and the vegetal pole within a blastula. The animal pole consists of small cells that divide rapidly, in contrast with the vegetal pole below it. In some cases, the animal pole is thought to differentiate into the later embryo itself, forming the three primary germ layers and participating in gastrulation. The animal pole is heavily pigmented while the vegetal pole remains unpigmented.[1] The vegetal pole contains large yolky cells that divide very slowly, in contrast with the animal pole above it. In some cases, the vegetal pole is thought to differentiate into the extraembryonic membranes that protect and nourish the developing embryo, such as the placenta in mammals and the chorion in birds. The development of the animal-vegetal axis occurs prior to fertilization.[2] Sperm entry can occur anywhere in the animal hemisphere.[3] The point of sperm entry defines the dorso-ventral axis - cells opposite the region ...
Purpose: The olfm1 gene encodes a secreted glycoprotein highly conserved in vertebrates. There are two olfm1 genes in zebrafish, olfm1a and olfm1b. Both of these genes are expressed in the brain and retina starting from 16 h post fertilization to adults. We generated a null mutant of both olfm1a and olfm1b genes and analyzed its retinal structure and visual function.. Methods: Olfm1a and olfm1b mutant alleles with nonsense point mutations were obtained from the Wellcome Trust Sanger Institute. Olfm1a and olfm1b null mutants were bred to generate double null mutant (olfm1a/b null). Spontaneous movement, optokinetic and optomotor responses, behavioral responses to light increments and decrements and electroretinogram (ERG) to increased (ON) and decreased (OFF) illumination were compared between olfm1a/b null and wild-type larvae 7 days post fertilization (dpf). The retinal morphology was examined by immunostaining of frozen sections. Total RNA was isolated from 3 and 7 dpf larvae for RNA ...
Great for hatching brine shrimp eggs. Includes hatching container, air pump, air line tubing, air stone, salt, unit of brine shrimp eggs, fine-mesh net, and instructions. Refill includes eggs, air stone, and salt.
Helmholtz Centre for Environmental Research. Researchers at the Helmholtz Centre for Environmental Research (UFZ), together with colleagues from the Swiss Eawag aquatic research institute, have discovered a protein which transports chemicals out of the embryo of the zebrafish and in this way protects the embryo against toxic substances. However, certain environmental chemicals render this protective mechanism ineffective, so that the fish embryos become more sensitive to toxic substances. The study, published in the scientific journal "BMC Biology", could prove to be of great importance for the future assessment of chemicals.. Fish possess a number of different mechanisms for protection against harmful substances in an aquatic environment. These include, for example, molecular transport systems, such as the so called ABC (ATP binding cassette) transporters, which prevent the penetration of toxic substances into cells. ABC transporters have been well investigated for mammals. For fish and their ...
The Roman Catholic Bishops of England (RCBE) have told the UK parliament that inter-species embryos - those containing genetic information from both human and animals - should not be treated any differently from normal embryos, and that women should be given the chance to carry their genetic offspring to term.. There is currently a real shortage of human eggs for use in embryonic stem cell (ES cell) research. It is hoped the problem can be overcome through creating embryos by transferring human genetic material into hollowed out animal eggs. The resulting entity - a cybrid - would be over 99 per cent genetically human and less than one per cent animal. As it stands, the new draft Human Tissue and Embryos Bill will ban the creation of embryos that contain genetic material from both animals and humans, but will make an exception for certain types of research, including cybrid embryos. The draft Bill imposes a strict 14 day time limit on the use of these entities in research, at which point ...
The spatial and temporal pattern of mitoses during the fourteenth nuclear cycle in a Drosophila embryo reflects differences in cell identities. We have analysed the domains of mitotic division in zygotic mutants that exhibit defects in larval cuticular pattern along the dorsoventral axis. This is a powerful means of fate mapping mutant embryos, as the altered position of mitotic domains in the dorsoventral pattern mutants correlate with their late cuticular phenotypes. In the mutants twist and snail, which fail to differentiate the ventrally derived mesoderm, mitoses specific to the mesoderm are absent. The lateral mesectodermal domain shows a partial ventral shift in twist mutants but a proportion of ventral cells do not behave characteristically, suggesting that twist has a positive role in the establishment of the mesoderm. In contrast, snail is required to repress mesectodermal fates in cells of the presumptive mesoderm. In the absence of both genes, the mesodermal and the mesectodermal ...
Cell Lineage of the Ilyanassa Embryo: Evolutionary Acceleration of Regional Differentiation during Early Development. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
This method utilizes zebrafish embryos to efficiently test the vascular invasive ability of cancer cells. Fluorescent cancer cells are...
Fig. 4. Wholemount in situ hybridisation of Xlmx1b. (A) Dorsal view of a stage 13 embryo showing placodal region expression. (B) A stage 15 embryo showing expression on the neural plate, along the neural folds and in the placodal regions. (C) A stage 19 embryo showing two intense patches of expression in the placodal regions, the otic anlagen. These will eventually develop into the otic vesicle and the embryos hearing system. (D) A cleared stage 21 embryo with neurons visible all down the dorsal side of the embryo. Some staining is noticeable in the anterior region, which may develop into the eye expression or the midbrain neurons. (E) A stage 24 embryo, the first stage at which expression is visible in the dorsal region of the eye. Staining is also seen in a population of migrating neural crest cells near the otic vesicle. (F) A stage 27 embryo showing neuron expression down the back. Staining is also apparent in the otic vesicle, eye and in a population of neurons in the midbrain region. (G) A ...
Vistahermosa Reproduction Unit.. Several aspects have to be evaluated so that the strategy to be followed is successful: number of embryos obtained, embryo quality grade, age of the patient, associated pathologies, complementary techniques and if it is an IVF or ovodonation cycle.. But why on day 3 or day 5? Dr. Avilés explains that these are the days in which the quality of the embryos can be more easily analyzed according to morphological parameters: shape, size, number of cells, fragments or vacuoles of the cells; and kinetic parameters: times of cell division. Also, depending on the implantation potential, the selection of the embryos includes 4 grades, from A to D, with A being very high and D being the lowest.. "Transferring on day 3 or on day 5 will depend fundamentally on the number of embryos we have, especially because the fact that an embryo does not reach day 5 in the laboratory does not mean that it does not evolve in the uterus, which is its natural environment, "says ...
CiteSeerX - Scientific documents that cite the following paper: Four-dimensional cardiac imaging in living embryos via postacquisition synchronization of nongated slice sequences,
Several evolutionarily conserved proteins constitute a universal mitotic trigger that is precisely controlled during the orderly cell divisions of embryogenesis. As development progresses, the mechanisms controlling this trigger change. Early divisions are executed by maternally synthesized gene products, and in Xenopus they are timed by the accumulation and periodic degradation of cyclin, a trigger component. Later, the zygotic genome assumes control, and in Drosophila, zygotic transcription is required for production of another trigger protein, the product of string. After this transition to zygotic control, pulses of string transcription define the timing of highly patterned embryonic cell divisions and cyclin accumulation is not rate limiting.. ...
One PLOS paper details a study of pleiotropy in C. Elegans, finding that 50% of genes involved in embryogenesis are pleiotropic. Whats more, these genes tend to occupy central (rather than initial or final) positions in protein pathways10. Pleiotropy, when viewed in the light of evolution, is usually discussed as a constraining factor. That is, a single mutation may be beneficial or neutral in one tissue, but harmful in another, increasing the likelihood that pleiotropic gene mutations would be selected against. The effect of pleiotropy neednt always be one of constraint, however. For example, in the case of parsimonious pleiotropy11, "knowing" that a mutation that fails to harm sperm is also unlikely to harm the brain, the sperm may relax strict mutation checking controls a tad. Note that evolutionary pressures favoring pleiotropy tend to negate the popular notion of "modularity" in gene expression ...
One PLOS paper details a study of pleiotropy in C. Elegans, finding that 50% of genes involved in embryogenesis are pleiotropic. Whats more, these genes tend to occupy central (rather than initial or final) positions in protein pathways10. Pleiotropy, when viewed in the light of evolution, is usually discussed as a constraining factor. That is, a single mutation may be beneficial or neutral in one tissue, but harmful in another, increasing the likelihood that pleiotropic gene mutations would be selected against. The effect of pleiotropy neednt always be one of constraint, however. For example, in the case of parsimonious pleiotropy11, "knowing" that a mutation that fails to harm sperm is also unlikely to harm the brain, the sperm may relax strict mutation checking controls a tad. Note that evolutionary pressures favoring pleiotropy tend to negate the popular notion of "modularity" in gene expression ...
Synonyms for gastrulations in Free Thesaurus. Antonyms for gastrulations. 4 words related to gastrula: conceptus, fertilized egg, embryo, archenteron. What are synonyms for gastrulations?
آرتمیا سخت پوست کوچکی با ارزش اقتصادی بالاست که مدل تحقیقاتی بسیار مناسبی برای محققان می باشد. این موجود با تحمل محدوده های بسیار متنوع از شرایط بسیار مختلف اکولوژیک در بیش از 600 نقطه زمین و نیز 18 زیستگاه در ایران توزیع شده است. دریاچه بختگان در استان فارس یکی از زیستگاههای طبیعی آرتمیای پارتنوژنز در ایران می باشد. با توجه به وجود یک آرتمیای دو جنسی ناشناخته در این دریاچه، گونه این جمعیت غیر بومی مورد تحقیق قرار گرفت. بدین منظور 4 مارکر مولکولی مختلف شامل دو ژن Na/K ATPase، 16S-12S با روش پی سی آر- آر اف ال پی[1] و دو ناحیه COI و HSP26به روش تعیین توالیمورد تحقیق قرار گرفت. DNA
Embryonic exposure to TCDD impacts osteogenesis of the axial skeleton in Japanese medaka, Oryzias latipes. ALTD Watson, A Planchart, CJ Mattingly, C Winkler, DM Reif, SW Kullman. Toxicological Sciences, kfw229. http://toxsci.oxfordjournals.org/content/early/2016/11/14/toxsci.kfw229.full.pdf+html. Read more ...
University of Melbourne, The Ludwig Institute for Cancer Research (Melbourne Tumour Biology Branch) Affiliated with the Department of Surgery, ...
The National Institutes of Health proposed lifting its moratorium on funding for research on part-animal, part-human embryos - which raises a huge dilemma, says bioethicist Insoo Hyun.
The source-sink model, first proposed by biologist Francis Crick in 1970, is a theoretical system for how morphogens distribute themselves across small fields of early embryonic cells. A morphogen is a substance that determines the fate and phenotype of a group of cells through a concentration gradient of itself across that group. Cricks theory has been experimentally confirmed with several morphogens, most notably with the protein bicoid , the first discovered morphogen. The model provides a theoretical structure for the understanding of some features of early embryonic development.. Format: Articles Subject: Theories ...
Two-thirds of all human embryos fail to develop successfully. Now, in a new study, researchers at the Stanford University School of Medicine have shown that they can predict with 93 percent certainty which fertilized eggs ...
Im trucking along here at 4dp3dt (4 days past 3 day transfer) with absolutely nothing to tell you about except how many times I Goog.le it--a google amount! I stress out my super-suave husband when I start to do any housework--but hey, maybe hes right! My embryos are folding so I dont have to ...
Blastula: Blastula,, hollow sphere of cells, or blastomeres, produced during the development of an embryo by repeated cleavage of a fertilized egg. The cells of the blastula form an
Scientists say increasing limit from 14 days will give greater insight into congenital conditions Scientists will make a controversial call this week to extend the current 14-day limit for carrying out experiments on human embryos to 28 days. The move follows recent breakthroughs that have allowed researchers to double the time embryos can be kept…
Some 50 years have passed since scientists first proposed the so-called inside-outside model of development, which holds that the inner cells of the early embryo eventually form all the definitive structures of the fetus, ...
Mouse Embryo Imaging. Dec. 18, 2015Webcast Light Sheet Microscopy: Recording the First Days of a Mouse Embryos Life For the first time, scientists can observe the first two to three days of a mouse
* found in: Microinjection Fish Mold-2Pool w/Ramp, Microinjection Plate for Fish Embryos, Neomycin Sulfate Solution is a clear, colorless solution used in..
View Notes - bicd130_06_lecture9r from BICD 130 at UCSD. BICD 130 Embryos, Genes, and Development MORPHOGENESIS Establishment of form and position in the developing organism: Rearrangement of cell
embryo: The early developmental stage of an animal while it is in the egg or within the uterus of the mother. In humans the term is applied to the unborn child until the end of the seventh...
زمینه مطالعه: در سال‌های اخیر فن‌آوری نانو بویژه استفاده از این مواد در آبزی پروری گسترش یافته که دارای تأثیرات مثبت و منفی بر روی آبزیان است. هدف: هدف از انجام پژوهش حاضر کاربرد و اثرات استفاده مستقیم (تجویز خوراکی) نانو ذرات نقره در جیره غذایی ماهی زبرا (Danio rerio) می‌باشد. روش کار: برای سنجش استاندارد بودن نانو ذرات نقره مورد استفاده توسط روش‌های TEM، SEM، EDX و طیف سنجی UV-Vis، در شرایط آزمایشگاهی ویژگی‌های این کلوئید با موفقیت ارزیابی گردید. در مطالعه سمیت حاد (LC50 96 ساعته) تعداد 540 ماهی زبرا ( میانگین وزن g 5/0± 2)، به 9تیمار در سه تکرار که در معرض غلظت‌های mg/kgfood 0، 10، 50،
Hi, I want to seperate leukocytes from whole blood and do cytospins. I am having problems with cells lysing. I was wondering if anybody knows the osmolarity of zebrafish blood and if there is a recommended PBS, HBSS... for blood cells of zebrafish. Any ideas? Thanks ...
I have just cleared out eggs from an old coop. I thought they were old eggs, but when I threw them out I found that one of them had an embryo in it.
Women who wish to extend their fertility or preserve it after undergoing medical treatments often choose to freeze their eggs or embryos to implant them later on.
A controversial procedure that lets would-be parents test embryos for certain genetic defects will soon be allowed in special cases in Germany. What does this mean for society?
Just a few days away from implantation date, Adeye Salem talks about her familys journey of embryo adoption. Having experienced multiple traditional adopti...
A BABY has been born with the help of a hi-tech genetic screening technique that raises the prospect of embryo selection on the NHS.
The California woman said she did not mean to have eight children in January 2009, in addition to the six she already had. But while she admitted she did want more children, she insisted she was in no condition to understand a form Dr. Michael Kamrava put in front of her before implanting 12 embryos ...
We explain Early Development with video tutorials and quizzes, using our Many Ways(TM) approach from multiple teachers.|p|This lesson will identify the three germ layers that form in an early embryo and the tissues and organs that develop from them.|/p|
Video articles in JoVE about transformation genetic include Ploidy Manipulation of Zebrafish Embryos with Heat Shock 2 Treatment.
Live Imaging In Zebrafish von Sampath Karuna Et Al und Buchbewertungen gibt es auf ReadRate.com. Bücher können hier direkt online erworben werden.
So we got the call yesterday…the results…3 genetically normal embryos, all healthy, all ready for a transfer (transfers, because who are we kidding Im not transferring all 3 at once). I have to be honest, I never saw it coming. All three embryos are SMA-carriers (just like Dan and I are), but not a single…
strain OP700 (wgIs700(drap-1::TY1 EGFP 3xFLAG(p_wTRG5_insertion_c_0086_1E01);unc-119(+));unc-119 (tm4063)) mixed sex mixed stage (embryo) (3 hours) using egg bleaching whole organism genetically modified (insertion) using bombardment targeting eGFP-drap- ...
The required amount of item does not match the size of the package size. The number has therefore been revalued to: The required amount of item does not match the size of the package on multiple products. The number has therefore been written on these.. One or more items contain a larger number in the box.. You can order the required quantity. If you would like a complete package, please order: ...
3 week pregnant - What to expect? The peculiarities of the stage, signs and symptoms, useful tips, daily care, pregnant belly pictures, ultrasound.
U.S. medical advisers are considering whether there is scientific justification for allowing human studies of a controversial procedure known as
Hello, I had an abdominal u/s on the 15th of Feb, at 6 weeks and 2 days, according to my LMP, 2nd Jan, and the scan confirmed it, the doctor said she
An embryo is an amazing thing. From just one initial cell, an entire living, breathing body emerges, full of working cells and organs. It comes as no surprise that embryonic development is a very carefully orchestrated process-everything ...
When I talk my hand is in a fist at my mouth, When Im nervous I bite my nails or pull at my eyelash ...Find answers to the question, Do You Have Any Nervous Habits? from people who know at Ask Experience.
Spiral cleavage is a conserved, early developmental mode found in several phyla of Lophotrochozoans resulting in highly diverse adult body plans. While the cleavage pattern has clearly been broadly conserved, it has also undergone many modifications in various taxa. The precise mechanisms of how different adaptations have altered the ancestral spiral cleavage pattern are an important ongoing evolutionary question, and adequately answering this question requires obtaining a broad developmental knowledge of different spirally cleaving taxa. In flatworms (Platyhelminthes), the spiral cleavage program has been lost or severely modified in most taxa. Polyclad flatworms, however, have retained the pattern up to the 32-cell stage. Here we study early embryogenesis of the cotylean polyclad flatworm Maritigrella crozieri to investigate how closely this species follows the canonical spiral cleavage pattern and to discover any potential deviations from it. Using live imaging recordings and 3D reconstructions of
TY - JOUR. T1 - Spatially and temporally regulated α6 integrin cleavage during Xenopus laevis development. AU - Demetriou, Manolis C.. AU - Stylianou, Panayiota. AU - Andreou, Maria. AU - Yiannikouri, Olga. AU - Tsaprailis, George. AU - Cress, Anne E. AU - Skourides, Paris. PY - 2008/2/15. Y1 - 2008/2/15. N2 - The α6 integrin is essential for early nervous system development in Xenopus laevis. We have previously reported a uPA cleaved form of integrin α6 (α6p), in invasive human prostate cancer tissue, whose presence correlates with increased migration and invasive capacity. We now report that α6 is cleaved during the normal development of Xenopus in a spatially and temporally controlled manner. In addition, unlike normal mammalian tissues, which lack α6p, the major form of the α6 integrin present in adult Xenopus is α6p. The protease responsible for the cleavage in mammals, uPA, is not involved in the cleavage of Xenopus α6. Finally, overexpression of a mammalian α6 mutant which ...
Directional cell migration is an intensively studied process relevant for both normal development of an organism as well as for a number of pathological conditions such as chronic inflammation and cancer. Primordial germ cells (PGCs) in Xenopus laevis embryos can be used as a model system to study cell migration, since during embryogenesis they actively migrate within the endoderm towards genital ridges. Transition to active cell migration is a highly regulated process important for the normal PGC development in many species. This study is focused on molecular and cellular mechanisms involved in initiation of active PGC migration within the endoderm of X. laevis embryos. Analysis of cell shape fluctuations demonstrated that in comparison to pre-migratory neural stage, PGCs isolated from tailbud stage embryos are characterized by an increased cellular dynamics due to formation of bleb-like protrusions and migration via bleb-associated mechanism. Analysis of intracellular PIP3 distribution that ...
Prenatal propofol exposure induced neurotoxicity in the developing brains and led to persistent learning deficits in the offspring. Our goal was to use zebrafish to explore whether the decline in learning and memory was correlated with inhibition of neuronal growth after propofol exposure. Zebrafish embryos at 6 hours postfertilization (hpf) were exposed to control or 1, 2 or 4 μg/mL propofol until 48 hpf. Spontaneous locomotor activity and swimming behavior in response to dark‐to‐light photoperiod stimulation were studied in zebrafish larvae at 6 days postfertilization (dpf). The adaptability to repeated stimulation was used to indicate learning and memory function of larvae. Transgenic NBT line zebrafish was used to quantitate the effect of propofol on motor neuronal growth of embryos in vivo. Six dpf transgenic zebrafish larvae went through photoperiod stimulation after their neuronal length had been analyzed during the embryonic period. Our data indicate that embryonic exposure to 1, 2 ...
Isoliquiritigenin (ISL) is an emerging natural flavonoid found in the roots of licorice, exhibits antioxidant, anti-cancer, anti-inflammatory, anti-allergic, cardioprotective, hepatoprotective and neuroprotective properties. However, the effect of ISL in embryonic development is yet to be elucidated, and the mechanisms underlying its target-organ toxicity and harmful side effects are still unclear. In the present study, we employed zebrafish embryos to study the developmental toxicity effect of ISL and its underlying mechanisms. Zebrafish embryos upon treatment with either vehicle control (0.1% DMSO) or ISL solutions for 4-96 h post fertilization (hpf) showed that ISL exposure instigated severe developmental toxicity in heart, liver, and nervous system. Mortality and morphological abnormalities were also observed. High concentrations of ISL exposure resulted in abnormal phenotypes and embryonic malformations including pericardial edema, swim bladder defects, yolk retention, curved body shape and ...
TY - JOUR. T1 - Effects of stanniocalcin 1 on calcium uptake in zebrafish (Danio rerio) embryo. AU - Tseng, Deng Yu. AU - Chou, Ming Yi. AU - Tseng, Yung Che. AU - Hsiao, Chung Der. AU - Huang, Chang Jen. AU - Kaneko, Toyoji. AU - Hwang, Pung Pung. PY - 2009/3/1. Y1 - 2009/3/1. N2 - Stanniocalcin (STC) formerly called hypocalcin or teleocalcin, is a 50-kDa disulfide-linked homodimeric glycoprotein that was originally identified in fish and secreted from the corpuscles of Stannius (CS). One of the main functions of STC-1 is Ca2+ uptake inhibition; however, the mechanisms remain unknown. In the present study, we provide molecular evidence to elucidate how zebrafish STC-1 regulates Ca2+ uptake in zebrafish embryos. In a wide variety of tissues including the kidney, brain, gill, muscle, and skin, zstc-1 was expressed. Incubating zebrafish embryos in low-Ca2+ (0.02 mM) freshwater stimulated whole body Ca2+ influx and zebrafish epithelial Ca2+ channel (zECaC) mRNA expression, while downregulated ...
Early Caenorhabditis elegans embryos provide an excellent model for the study of developmental processes. Development can be studied by direct observation under the light microscope and can be perturbed using laser manipulations, drug inhibitor treatments, and genetic mutants. The first division of the C. elegans embryo is asymmetric, generating two daughter cells unequal in size and developmental fate. These distinct fates are generated by the partitioning of cytoplasmic determinants during the first mitotic cell cycle. Partitioning of these determinants is thought to be driven by cytoplasmic flow. Recent studies in C. elegans in the past year have identified a number of components necessary for this flow, giving us a clearer picture of the molecular mechanisms underlying developmental asymmetry.
View details for Studies on the effect of certain supplements in cryoprotective medium on zebrafish (Danio rerio) oocytes quality after controlled slow cooling..
Snail, a zinc finger protein, is required for the formation of the ventral furrow and the mesoderm during gastrulation of the Drosophila embryo. snail homologues have been cloned from Xenopus and mouse. We have isolated a zebrafish homologue of snail, designated sna-1. Like its Drosophila counterpart, Sna-1 protein is nuclear. Maternal and zygotic sna-1 transcripts are ubiquitously distributed in zebrafish embryos of cleavage and blastula stages. In gastrulating embryos, sna-1 is expressed in involuting cells of the germ ring, but not in those at the dorsal midline, the presumptive notochordal region. After involution, the expression is maintained in the paraxial mesoderm and becomes prominent in the muscle pioneer precursors, followed by expression at the posterior somite boundaries. Later, sna-1 is expressed in neural crest and mesodermal derivatives of the head region. Sna-1 expression is induced in animal cap cells by activin A. The early sna-1 expression pattern in gastrulating zebrafish no ...
Objectives: Phospholipase C (PLC) gamma 1 has been shown to mediate signal transduction of tyrosine kinases and affect function of hematopoietic cells. However, its role in hematopoiesis during embryonic development is currently unclear. In this study, we examined this issue using morpholino (MO) gene knockdown in zebrafish embryos. Methods: MO targeting at the exon-1-intron-1 junction of zebrafish PLC-γ1 was injected into embryos at the one- to four-cell stage (referred herein zPLC-γ1MO embryos). Primitive hematopoiesis was examined quantitatively by flow cytometry in Tg(gata1:GFP) embryos and by real-time quantitative polymerase chain reaction at 18 hours-post-fertilization (hpf), before the onset of circulation. The embryos were also treated with receptor inhibitors of vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor at 25, 1, and 30 μmol/L, respectively, from one cell until 48 hpf. Results: Erythropoiesis was reduced in zPLC-γ1MO embryos, ...
Protocol for performing ATAC-seq on nuclei isolated from Drosophila melanogaster stage 5 embryos that were flash frozen and then cut in half along the anterior-posterior midline....
As embryologists, one of the most common questions that we get from patients is "What do the grades of my embryos tell us about my chances of becoming pregnant?" The answer to this question is not a simple one. The objective of this article is to explain how we grade embryos and what those grades mean as far as an embryos potential for development.. All embryo grading systems are subjective. While we can make educated guesses about an embryos potential based on the experience of many embryologists grading millions of embryos, there are many cases of embryos with poor grades that make pregnancies and perfect embryos that do not. Also, no matter the grading system, the embryo grades do not tell us what is going on inside the embryo genetically.. We use grading systems to help us determine which embryos to transfer and/or freeze. At the Texas Fertility Center, embryo transfers occur either 3 days or 5 days after a retrieval. Because embryos are developmentally different on these days, we have ...
Danio rerio (zebrafish) have rapidly gained popularity in the study of vertebrate development and gene function. Zebrafish are an excellent model for performing large-scale genetic and drug screens to be performed coupled with the visualization of downstream perturbations on live, developing organisms. Due to the fact that large numbers of embryos are required to perform these experiments, we investigated ways to efficiently increase zebrafish embryo production while not being overly invasive or using chemicals that might affect the developmental processes. To perform these experiments, we mated wild type (wt) zebrafish while exposing them to the different wavelengths of light. Fish were exposed to 12 h of dark, followed by 4 h with the different colored light treatments. Once this light cycle was over, embryo production was enumerated. Results indicated that exposing zebrafish to the different wavelengths of fluorescent and LED light had little effect on embryo production. Further research may
The present study focuses on a cDNA fragment of 2.6 kb coding for glial fibrillary acidic protein (GFAP) related gene in zebrafish. Earlier work in the lab revealed that this gene showed 72% homology, at the amino acid level, with the mammalian gene coding for GFAP. Due to variations observed in sequence of head domain of GFAP and in expression pattern compared to that of rodent GFAP, this gene was named as zebrafish GFAP like gene (zfgfap-l)( Gene Bank Accession No: AY 397679).In this project, the expression pattern of zfgfap-l was studied by RT-PCR and in situ hybridization. RT-PCR results showed that the expression of zfgfap-l started as early as 1.5 hours post-fertilization (hpf) and increased steadily up to 10 hpf, then became a constant level of expression till 30 hpf. In embryos at sphere stage, the expression was detected in the cells of the superficial layer by in situ hybridization. After gastrulation, the expression became restricted to the neural tube, particularly in the presumptive ...
In yeast, Cdc42 is required to polarize the site of bud formation, and several in vitro studies show that it may also be required for efficient polarization of eukaryotic cells (Etienne-Manneville, 2004). Furthermore, for monocytes in culture, blocking Cdc42 signaling leads to a failure to receive and respond to chemotactic cues (Allen et al., 1998; Chou et al., 2003; Srinivasan et al., 2003). However, our in vivo studies in the fly embryo reveal no significant effect on the numbers of hemocytes recruited to laser wounds after 1 h in Cdc42 mutant embryos. This finding is true also for embryos expressing the dominant-negative Cdc42N17 and Cdc42S89 transgenes specifically in hemocytes (Fig. 3 a). Both developmental dispersal of hemocytes and their recruitment to sites of tissue damage appears grossly normal. But on closer inspection, we observe that hemocyte motility is abnormal. During the migratory phase, and once hemocytes have reached the wound, we frequently see cells with several leading ...
Our lab is using the zebrafish embryonic kidney or pronephros as a model sytem for investigating kidney organogenesis due to its several experimental advantages. The pronephros, made of two unit nephrons with glomerulus, tubule, and duct segments, shares structural features with nephrons from higher vertebrates yet is anatomically much simpler. Zebrafish pronephric development follows developmental stages common to nephrogenesis in mammals but is complete by 48 hours post fertilization (hpf), much faster than in mouse. Embryonic development occurs ex utero offering the potential for experimental manipulation such as cell labeling and cell transplantation. In addition, zebrafish embryos are transparent allowing the direct visualization of pronephric organogenesis in the living embryo and in transgenic GFP expressing reporter strains. Finally, renal physiological function can be assayed by the uptake of injected, fluorescently labeled small molecules such as dextran ...