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Proceedings of the National Academy of... May 2020Morphogenetic flows in developmental biology are characterized by the coordinated motion of thousands of cells that organize into tissues, naturally raising the question...
Morphogenetic flows in developmental biology are characterized by the coordinated motion of thousands of cells that organize into tissues, naturally raising the question of how this collective organization arises. Using only the kinematics of tissue deformation, which naturally integrates local and global mechanisms along cell paths, we identify the dynamic morphoskeletons behind morphogenesis, i.e., the evolving centerpieces of multicellular trajectory patterns. These features are model- and parameter-free, frame-invariant, and robust to measurement errors and can be computed from unfiltered cell-velocity data. We reveal the spatial attractors and repellers of the embryo by quantifying its Lagrangian deformation, information that is inaccessible to simple trajectory inspection or Eulerian methods that are local and typically frame-dependent. Computing these dynamic morphoskeletons in wild-type and mutant chick and fly embryos, we find that they capture the early footprint of known morphogenetic features, reveal new ones, and quantitatively distinguish between different phenotypes.
Topics: Animals; Animals, Genetically Modified; Biomechanical Phenomena; Chick Embryo; Computer Simulation; Drosophila Proteins; Drosophila melanogaster; Embryo, Nonmammalian; Fibroblast Growth Factors; Gastrula; Green Fluorescent Proteins; Indazoles; Microscopy; Models, Biological; Morphogenesis; Mutation; Twist-Related Protein 1
PubMed: 32381735
DOI: 10.1073/pnas.1908803117 -
Frontiers in Immunology 2021Dysregulation of the immune system is associated with many pathologies, including cardiovascular diseases, diabetes, and cancer. To date, the most commonly used models... (Review)
Review
Dysregulation of the immune system is associated with many pathologies, including cardiovascular diseases, diabetes, and cancer. To date, the most commonly used models in biomedical research are rodents, and despite the various advantages they offer, their use also raises numerous drawbacks. Recently, another model, the chicken embryo and its chorioallantoic membrane, has re-emerged for various applications. This model has many benefits compared to other classical models, as it is cost-effective, time-efficient, and easier to use. In this review, we explain how the chicken embryo can be used as a model for immune-based studies, as it gradually develops an embryonic immune system, yet which is functionally similar to humans'. We mainly aim to describe the avian immune system, highlighting the differences and similarities with the human immune system, including the repertoire of lymphoid tissues, immune cells, and other key features. We also describe the general immune ontogeny. In conclusion, we expect that this review will help future studies better tailor their use of the chicken embryo model for testing specific experimental hypotheses or performing preclinical testing.
Topics: Animals; Chick Embryo; Chorioallantoic Membrane; Cytokines; Gene Expression Regulation, Developmental; Humans; Immune System; Inflammation Mediators; Models, Animal; Receptors, Immunologic; Signal Transduction; Species Specificity
PubMed: 34868080
DOI: 10.3389/fimmu.2021.791081 -
Experimental Animals Feb 2018Angiogenesis is the process of developing new blood vessels from the original vascular network; it is necessary for normal physiological processes, such as embryonic... (Review)
Review
Angiogenesis is the process of developing new blood vessels from the original vascular network; it is necessary for normal physiological processes, such as embryonic development and wound healing. Angiogenesis is also involved in pathological events, including myocardial ischemia and tumor growth. To investigate the molecular mechanisms of this important process, a variety of methods and models are employed. These strategies can also be used to provide insight into the etiology of angiogenesis-related diseases, thereby contributing to the development of new diagnostics and treatments. Commonly used animal models include the chorioallantoic membrane and yolk sac membrane of chick embryos, the mouse retina and aortic ring, and angiogenesis reactors implanted into mice. These animal models have been instrumental in the study of the angiogenic process. For example, the chorioallantoic membrane undergoes robust angiogenesis during the development of chick embryos, and, because its surface is easily accessible, this membrane provides a convenient model for experimentation. Here, we discuss the methods that employ animal models for the imaging and quantification of angiogenesis. In addition, we propose potential novel directions for future investigations in this area.
Topics: Animals; Aorta; Chick Embryo; Chorioallantoic Membrane; Embryonic Development; Mice; Models, Animal; Myocardial Ischemia; Neoplasms; Neovascularization, Pathologic; Neovascularization, Physiologic; Retina; Wound Healing; Yolk Sac
PubMed: 28757511
DOI: 10.1538/expanim.17-0054 -
Poultry Science Aug 2018The embryonic period represents approximately 33 percent of the total productive life of modern broilers and is very important for attaining quality broiler performance...
The embryonic period represents approximately 33 percent of the total productive life of modern broilers and is very important for attaining quality broiler performance at marketing. In this symposium, recent developments in pre-hatch broiler development were discussed with special focus on maternal nutrition, in ovo nutrition, and the regulation and monitoring of the incubational environment. The symposium was concluded with discussion about the implementation of future innovations in incubation technology.
Topics: Animal Nutritional Physiological Phenomena; Animals; Chick Embryo; Chickens; Nesting Behavior
PubMed: 29788162
DOI: 10.3382/ps/pey137 -
ALTEX 2015Fertilized chicken eggs are suggested as an alternative to mammalian models. The chorioallantoic membrane (CAM) of the chick embryo is widely used for examination of...
Fertilized chicken eggs are suggested as an alternative to mammalian models. The chorioallantoic membrane (CAM) of the chick embryo is widely used for examination of angiogenesis, xenotransplants and for virus production. Unfortunately, it is mostly not taken into account, that the chick embryo's ability to experience pain starts to develop at day 7 of breeding. In our view, this model is only in accordance with the 3 R principles, if an appropriate anesthesia of the chick embryo in potentially painful procedures is provided. Although many experimental approaches are performed on the none-innervated CAM, the euthanasia of the embryo strongly requires a more human technique than the usually used freezing at -20°C, decapitation or in ovo fixation with paraformaldehyde without prior anesthesia. However, protocols regarding feasible and ethical methods for anesthesia and euthanasia of avian embryos are currently not available. Therefore, we established an easy and reliable method for the euthanasia and short-term anesthesia of the chick embryo.
Topics: Anesthesia; Animal Testing Alternatives; Animal Welfare; Animals; Chick Embryo; Chorioallantoic Membrane; Euthanasia; Models, Animal
PubMed: 25592390
DOI: 10.14573/altex.1410031 -
Sensors (Basel, Switzerland) Oct 2020Non-destructive monitoring of chick embryonic growth can provide vital management insights for poultry farmers and other stakeholders. Although non-destructive studies...
Non-destructive monitoring of chick embryonic growth can provide vital management insights for poultry farmers and other stakeholders. Although non-destructive studies on fertility, hatching time and gender have been conducted recently, there has been no available method for embryonic growth observation, especially during the second half of incubation. Therefore, this work investigated the feasibility of using near-infrared (NIR) sensor-based egg opacity values-the amount of light lost when passing through the egg-for indirectly observing embryo growth during incubation. ROSS 308 eggs were selected based on size, mass and shell color for this experiment. To estimate the embryo size precisely, we fit various mathematical growth functions during incubation, based on the opacity value of incubated eggs. Although all the growth models tested performed similarly in fitting the data, the exponential and power functions had better performances in terms of co-efficient of determination (0.991 and 0.994 respectively) and RMSE to explain embryo growth during incubation. From these results, we conclude that the modeling paradigm adopted provides a simple tool to non-invasively investigate embryo growth. These models could be applied to resolving developmental biology, embryonic pathology, industrial and animal welfare issues in the near future.
Topics: Animals; Chick Embryo; Chickens; Eggs; Least-Squares Analysis
PubMed: 33080893
DOI: 10.3390/s20205888 -
STAR Protocols Jun 2021The chick embryo is a favored model for developmental studies owing to its accessibility and ease of manipulation. electroporation provides a highly efficient method...
The chick embryo is a favored model for developmental studies owing to its accessibility and ease of manipulation. electroporation provides a highly efficient method for screening perturbation phenotypes using a variety of reagents, including CRISPR and morpholinos. Additionally, the chick system lends itself well to rapid medium-throughput enhancer screening. Constructs facilitating tissue-specific protein pull-down can also be transfected using this protocol. Furthermore, bilateral electroporation with control and experimental reagents provides a robust assay for accurately interpreting functional perturbations. For complete details on the use and execution of this protocol, please refer to Williams et al. (2019).
Topics: Animals; Chick Embryo; Chickens; Electroporation; Phenotype; Plasmids
PubMed: 33899011
DOI: 10.1016/j.xpro.2021.100424 -
Poultry Science Jan 1997The hox genes specify regional differences along the anterior-posterior (A/P) axis of the vertebrate embryo. This function appears to reflect an ancestral role of the... (Review)
Review
The hox genes specify regional differences along the anterior-posterior (A/P) axis of the vertebrate embryo. This function appears to reflect an ancestral role of the hox gene complex and is conserved across phyla. During the evolution of vertebrates, this gene complex has been recruited to perform other functions as well, many of which occur later in development. Although mutational analysis in the mouse is well-suited to the study of their early function, that same function limits the utility of mutational analysis in the investigation of later functions. The use of retroviral vectors to alter gene expression in the chick embryo has emerged as an effective way to address these later functions. This paper reviews that approach and its application to the study of the hox genes in the formation of the vertebrate limb.
Topics: Animals; Chick Embryo; Chickens; Extremities; Genes, Homeobox; Genetic Vectors; Multigene Family; Mutation
PubMed: 9037695
DOI: 10.1093/ps/76.1.96 -
Methods in Molecular Biology (Clifton,... 2012The avian embryo is a long-standing model for developmental biology research. It also has proven utility for toxicology research both in ovo and in explant culture. Like... (Review)
Review
The avian embryo is a long-standing model for developmental biology research. It also has proven utility for toxicology research both in ovo and in explant culture. Like mammals, avian embryos have an allantois and their developmental pathways are highly conserved with those of mammals, thus avian models have biomedical relevance. Fertile eggs are inexpensive and the embryo develops rapidly, allowing for high-throughput. The chick genome is sequenced and significant molecular resources are available for study, including the ability for genetic manipulation. The absence of a placenta permits the direct study of an agent's embryotoxic effects. Here, we present protocols for using avian embryos in toxicology research, including egg husbandry and hatch, toxicant delivery, and assessment of proliferation, apoptosis, and cardiac structure and function.
Topics: Animal Husbandry; Animals; Apoptosis; Cell Proliferation; Chick Embryo; Culture Techniques; Developmental Biology; Disease Models, Animal; Echocardiography; Teratology; Toxicity Tests
PubMed: 22669661
DOI: 10.1007/978-1-61779-867-2_7 -
Neural Development Jun 2012The embryonic chick occupies a privileged place among animal models used in developmental studies. Its rapid development and accessibility for visualization and... (Review)
Review
The embryonic chick occupies a privileged place among animal models used in developmental studies. Its rapid development and accessibility for visualization and experimental manipulation are just some of the characteristics that have made it a vertebrate model of choice for more than two millennia. Until a few years ago, the inability to perform genetic manipulations constituted a major drawback of this system. However, the completion of the chicken genome project and the development of techniques to manipulate gene expression have allowed this classic animal model to enter the molecular age. Such techniques, combined with the embryological manipulations that this system is well known for, provide a unique toolkit to study the genetic basis of neural development. A major advantage of these approaches is that they permit targeted gene misexpression with extremely high spatiotemporal resolution and over a large range of developmental stages, allowing functional analysis at a level, speed and ease that is difficult to achieve in other systems. This article provides a general overview of the chick as a developmental model focusing more specifically on its application to the study of eye development. Special emphasis is given to the state of the art of the techniques that have made gene gain- and loss-of-function studies in this model a reality. In addition, we discuss some methodological considerations derived from our own experience that we believe will be beneficial to researchers working with this system.
Topics: Animals; Chick Embryo; Models, Animal; Retina
PubMed: 22738172
DOI: 10.1186/1749-8104-7-22