Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of regeneration, asexual reproduction, metamorphosis, and the growth and differentiation of stem cells in the adult organism.
Morphogenesis is the biological process that causes a cell, tissue or organism to develop its shape. It is one of three fundamental aspects of developmental biology along with the control of tissue growth and patterning of cellular differentiation.
The cilium is a membrane-bound organelle found on most types of eukaryotic cell. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projection that extends from the surface of the much larger cell body. Eukaryotic flagella found on sperm cells and many protozoans have a similar structure to motile cilia that enables swimming through liquids; they are longer than cilia and have a different undulating motion.
Gap junctions are one of four broad categories of intercellular connections that form between a multitude of animal cell types. First photographed around 1952, it wasn't until 1969 that gap junctions were referred to as gap junctions. Named after the 2-4 nm gap they bridged between cell membranes, they had been characterised in more detail by 1967.
Planarians (triclads) are free-living flatworms of the class Turbellaria, order Tricladida, which includes hundreds of species, found in freshwater, marine, and terrestrial habitats. Planarians are characterized by a three-branched intestine, including a single anterior and two posterior branches. Their body is populated by adult stem cells called neoblasts, which planarians use for regenerating missing body parts. Many species are able to regenerate any missing organ, which has made planarians a popular model in research of regeneration and stem cell biology. The genome sequences of several species are available, as are tools for molecular biology analysis.
Regeneration in biology is the process of renewal, restoration, and tissue growth that makes genomes, cells, organisms, and ecosystems resilient to natural fluctuations or events that cause disturbance or damage. Every species is capable of regeneration, from bacteria to humans. Regeneration can either be complete where the new tissue is the same as the lost tissue, or incomplete after which the necrotic tissue becomes fibrotic.
Symmetry in biology refers to the symmetry observed in organisms, including plants, animals, fungi, and bacteria. External symmetry can be easily seen by just looking at an organism. For example, the face of a human being has a plane of symmetry down its centre, or a pine cone displays a clear symmetrical spiral pattern. Internal features can also show symmetry, for example the tubes in the human body which are cylindrical and have several planes of symmetry.
An asymmetric cell division produces two daughter cells with different cellular fates. This is in contrast to symmetric cell divisions which give rise to daughter cells of equivalent fates. Notably, stem cells divide asymmetrically to give rise to two distinct daughter cells: one copy of the original stem cell as well as a second daughter programmed to differentiate into a non-stem cell fate.
Philip Arden Beachy is Ernest and Amelia Gallo Professor at Stanford University School of Medicine in Palo Alto, California and an Associate at Stanford's Institute of Stem Cell Biology and Regenerative Medicine.
Cerberus is a protein that in humans is encoded by the CER1 gene. Cerberus is a signaling molecule which contributes to the formation of the head, heart and left-right asymmetry of internal organs. This gene varies slightly from species to species but its overall functions seem to be similar.
Nodal homolog is a secretory protein that in humans is encoded by the NODAL gene which is located on chromosome 10q22.1. It belongs to the transforming growth factor beta superfamily. Like many other members of this superfamily it is involved in cell differentiation in early embryogenesis, playing a key role in signal transfer from the primitive node, in the anterior primitive streak, to lateral plate mesoderm (LPM).
Cell polarity refers to spatial differences in shape, structure, and function within a cell. Almost all cell types exhibit some form of polarity, which enables them to carry out specialized functions. Classical examples of polarized cells are described below, including epithelial cells with apical-basal polarity, neurons in which signals propagate in one direction from dendrites to axons, and migrating cells. Furthermore, cell polarity is important during many types of asymmetric cell division to set up functional asymmetries between daughter cells.
Donald E. Ingber is an American cell biologist and bioengineer. He is the founding director of the Wyss Institute for Biologically Inspired Engineering at Harvard University, the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children's Hospital, and Professor of Bioengineering at the Harvard John A. Paulson School of Engineering and Applied Sciences. He is also a member of the American Institute for Medical and Biological Engineering, the National Academy of Engineering, the National Academy of Medicine, the National Academy of Inventors, and the American Academy of Arts and Sciences.
Andrea Hilary Brand is the Herchel Smith Professor of Molecular Biology and a Fellow of Jesus College, Cambridge. She heads a lab investigating nervous system development at the Gurdon Institute and the Department of Physiology, Development and Neuroscience. She developed the GAL4/UAS system with Norbert Perrimon which has been described as “a fly geneticist's Swiss army knife”.
Clifford James Tabin is chairman of the Department of Genetics at Harvard Medical School.
Developmental bioelectricity is the regulation of cell, tissue, and organ-level patterning and behavior by electrical signals during the development of embryonic animals and plants. The charge carrier in developmental bioelectricity is the ion rather than the electron, and an electric current and field is generated whenever a net ion flux occurs. Cells and tissues of all types use flows of ions to communicate electrically. Endogenous electric currents and fields, ion fluxes, and differences in resting potential across tissues comprise a signalling system. It functions along with biochemical factors, transcriptional networks, and other physical forces to regulate cell behaviour and large-scale patterning in processes such as embryogenesis, regeneration, and cancer suppression.
Left-right asymmetry is the process in early embryonic development that breaks the normal symmetry in the bilateral embryo. In vertebrates, left-right asymmetry is established early in development at a structure called the left-right organizer and leads to activation of different signalling pathways on the left and right of the embryo. This in turn cause several organs in adults to develop LR asymmetry, such as the tilt of the heart, the different number lung lobes on each side of the body and the position of the stomach and spleen on the right side of the body. If this process does not occur correctly in humans it can result in the syndromes heterotaxy or situs inversus.
Xenobots, named after the African clawed frog, are synthetic lifeforms that are designed by computers to perform some desired function and built by combining together different biological tissues. There is debate among scientists whether xenobots are robots, organisms, or something else entirely.
Barry James Thompson is an Australian and British developmental biologist and cancer biologist. Thompson is known for identifying genes, proteins and mechanisms involved in epithelial polarity, morphogenesis and cell signaling via the Wnt and Hippo signaling pathways, which have key roles in human cancer.
The Wyss Institute for Biologically Inspired Engineering is a cross-disciplinary research institute at Harvard University focused on bridging the gap between academia and industry by drawing inspiration from nature's design principles to solve challenges in health care and the environment. It is focused on the field of biologically inspired engineering to be distinct from bioengineering and biomedical engineering. The institute also has a focus on applications, intellectual property generation, and commercialization.
