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Development (Cambridge, England) Mar 2018Organizers, which comprise groups of cells with the ability to instruct adjacent cells into specific states, represent a key principle in developmental biology. The... (Review)
Review
Organizers, which comprise groups of cells with the ability to instruct adjacent cells into specific states, represent a key principle in developmental biology. The concept was first introduced by Spemann and Mangold, who showed that there is a cellular population in the newt embryo that elicits the development of a secondary axis from adjacent cells. Similar experiments in chicken and rabbit embryos subsequently revealed groups of cells with similar instructive potential. In birds and mammals, organizer activity is often associated with a structure known as the node, which has thus been considered a functional homologue of Spemann's organizer. Here, we take an in-depth look at the structure and function of organizers across species and note that, whereas the amphibian organizer is a contingent collection of elements, each performing a specific function, the elements of organizers in other species are dispersed in time and space. This observation urges us to reconsider the universality and meaning of the organizer concept.
Topics: Amphibians; Animals; Birds; Body Patterning; Chick Embryo; Embryo, Mammalian; Embryo, Nonmammalian; Embryonic Induction; Gastrula; Humans; Mammals; Organizers, Embryonic; Rabbits
PubMed: 29523654
DOI: 10.1242/dev.159525 -
The International Journal of... 2021This review highlights the work that my research group has been developing, together with international collaborators, during the last decade. Since we were able to... (Review)
Review
This review highlights the work that my research group has been developing, together with international collaborators, during the last decade. Since we were able to establish the experimental model in Brazil, we have been focused on understanding early embryonic patterns regarding neural induction and axes establishment. In this context, the Wnt pathway appears as a major player and has been much explored by us and other research groups. Here, we chose to review three published works which we consider to be landmarks within the course of our research and also within the history of modern findings regarding neural induction and patterning. We intend to show how our series of discoveries, when painted together, tells a story that covers crucial developmental windows of early differentiation paths of anterior neural tissue: 1. establishing the head organizer in contrast to the trunk organizer in the early gastrula; 2. deciding between neural ectoderm and epidermis ectoderm at the blastula/gastrula stages, and 3. the gathering of prechordal unique properties in the late gastrula/early neurula.
Topics: Animals; Body Patterning; Ectoderm; Embryonic Induction; Gastrula; Gene Expression Regulation, Developmental; Wnt Signaling Pathway; Xenopus Proteins; Xenopus laevis
PubMed: 32930371
DOI: 10.1387/ijdb.200231ja -
The Journal of Cell Biology Jan 2016During embryonic development, tissues undergo major rearrangements that lead to germ layer positioning, patterning, and organ morphogenesis. Often these morphogenetic... (Review)
Review
During embryonic development, tissues undergo major rearrangements that lead to germ layer positioning, patterning, and organ morphogenesis. Often these morphogenetic movements are accomplished by the coordinated and cooperative migration of the constituent cells, referred to as collective cell migration. The molecular and biomechanical mechanisms underlying collective migration of developing tissues have been investigated in a variety of models, including border cell migration, tracheal branching, blood vessel sprouting, and the migration of the lateral line primordium, neural crest cells, or head mesendoderm. Here we review recent advances in understanding collective migration in these developmental models, focusing on the interaction between cells and guidance cues presented by the microenvironment and on the role of cell-cell adhesion in mechanical and behavioral coupling of cells within the collective.
Topics: Animals; Cell Communication; Cell Movement; Embryonic Development; Embryonic Induction; Models, Biological
PubMed: 26783298
DOI: 10.1083/jcb.201508047 -
Experimental Hematology Sep 2005Embryonic stem (ES) cells have the potential to develop into all cell types of the adult body. This capability provides the basis for considering the ES cell system as a... (Review)
Review
Embryonic stem (ES) cells have the potential to develop into all cell types of the adult body. This capability provides the basis for considering the ES cell system as a novel and unlimited source of cells for replacement therapies for the treatment of a wide range of diseases. Before the cell-based therapy potential of ES cells can be realized, a better understanding of the pathways regulating lineage-specific differentiation is required. Current studies suggest that the bone morphogenic protein, transforming growth factor-beta, Wnt, and fibroblast growth factor pathways that are required for gastrulation and germ layer induction in the embryo are also essential for differentiation of ES cells in culture. The current understanding of how these factors influence germ layer induction in both the embryo and in the ES cell differentiation system is addressed in this review.
Topics: Animals; Embryonic Development; Embryonic Induction; Germ Layers; Growth Substances; Mice; Signal Transduction; Stem Cells
PubMed: 16140142
DOI: 10.1016/j.exphem.2005.06.009 -
Experimental Cell Research Feb 2014The question of how the vertebrate embryo gives rise to a nervous system is of paramount interest in developmental biology. Neural induction constitutes the earliest... (Review)
Review
The question of how the vertebrate embryo gives rise to a nervous system is of paramount interest in developmental biology. Neural induction constitutes the earliest step in this process and is tightly connected with development of the embryonic body axes. In the Xenopus embryo, perpendicular gradients of BMP and Wnt signals pattern the dorsoventral and anteroposterior body axes. Both pathways need to be inhibited to allow anterior neural induction to occur. FGF8 and IGF are active neural inducers that together with BMP and Wnt signals are integrated at the level of Smad 1/5/8 phosphorylation. Hedgehog (Hh) also contributes to anterior neural induction. Suppressor-of-fused plays an important role in intertwining the Hh and Wnt pathways. Distinct mechanisms are discussed that establish morphogen gradients and integrate retinoic acid and FGF signals during posterior development. These findings not only improve our understanding of regional specification in neural induction, but have profound implications for mammalian stem cell research and regenerative medicine.
Topics: Animals; Bone Morphogenetic Proteins; Embryonic Induction; Fibroblast Growth Factors; Gene Expression Regulation, Developmental; Humans; Nervous System; Signal Transduction; Wnt Proteins
PubMed: 24315941
DOI: 10.1016/j.yexcr.2013.11.018 -
The EMBO Journal Feb 2001
Review
Topics: Animals; Bone Morphogenetic Proteins; Embryonic Induction; Head; Humans; Proto-Oncogene Proteins; Wnt Proteins; Zebrafish Proteins
PubMed: 11179208
DOI: 10.1093/emboj/20.4.631 -
Molecular Pathology : MP Jun 2003
Topics: Animals; Embryonic Induction; Gene Expression Regulation, Developmental; Hedgehog Proteins; Humans; Phenotype; Trans-Activators
PubMed: 12782757
DOI: 10.1136/mp.56.3.129 -
The International Journal of... Mar 1989
Review
Topics: Animals; Embryonic Induction; Nerve Tissue; Signal Transduction; Synaptic Transmission
PubMed: 2562048
DOI: No ID Found -
Annual Review of Biochemistry 1998Cytoplasmic RNA localization is an evolutionarily ancient mechanism for producing cellular asymmetries. This review considers RNA localization in the context of animal... (Review)
Review
Cytoplasmic RNA localization is an evolutionarily ancient mechanism for producing cellular asymmetries. This review considers RNA localization in the context of animal development. Both mRNAs and non-protein-coding RNAs are localized in Drosophila, Xenopus, ascidian, zebrafish, and echinoderm oocytes and embryos, as well as in a variety of developing and differentiated polarized cells from yeast to mammals. Mechanisms used to transport and anchor RNAs in the cytoplasm include vectorial transport out of the nucleus, directed cytoplasmic transport in association with the cytoskeleton, and local entrapment at particular cytoplasmic sites. The majority of localized RNAs are targeted to particular cytoplasmic regions by cis-acting RNA elements; in mRNAs these are almost always in the 3'-untranslated region (UTR). A variety of trans-acting factors--many of them RNA-binding proteins--function in localization. Developmental functions of RNA localization have been defined in Xenopus, Drosophila, and Saccharomyces cerevisiae. In Drosophila, localized RNAs program the antero-posterior and dorso-ventral axes of the oocyte and embryo. In Xenopus, localized RNAs may function in mesoderm induction as well as in dorso-ventral axis specification. Localized RNAs also program asymmetric cell fates during Drosophila neurogenesis and yeast budding.
Topics: Animals; Biological Transport; Body Patterning; Cell Compartmentation; Embryonic Induction; Evolution, Molecular; RNA, Messenger
PubMed: 9759492
DOI: 10.1146/annurev.biochem.67.1.335 -
Journal of Anatomy Jan 2003The vertebrate limb is one of the most relevant experimental models for analysing cell-cell signalling during patterning of embryonic fields and organogenesis. Recently,... (Review)
Review
The vertebrate limb is one of the most relevant experimental models for analysing cell-cell signalling during patterning of embryonic fields and organogenesis. Recently, the combination of molecular and genetic studies with experimental manipulation of developing limb buds has significantly advanced our understanding of the complex molecular interactions co-ordinating limb bud outgrowth and patterning. Some of these studies have shown that there is a need to revise some of the textbook views of vertebrate limb development. In this review, we discuss how signalling by the polarizing region is established and how limb bud morphogenesis is controlled by both long-range and signal relay mechanisms. We also discuss recent results showing that differential mesenchymal responsiveness to SHH signalling is established prior to its expression by the polarizing region.
Topics: Animals; Bone Morphogenetic Proteins; Embryonic Induction; Fibroblast Growth Factors; Gene Expression; Hedgehog Proteins; Limb Buds; Mesoderm; Morphogenesis; Organizers, Embryonic; Trans-Activators; Vertebrates
PubMed: 12587914
DOI: 10.1046/j.1469-7580.2003.00138.x