|
Neural-crest
The neural crest is a ridge-like structure that is formed transiently between the epidermal ectoderm and neural plate during vertebrate development. Neural crest cells originate from this structure through the epithelial-mesenchymal transition, and in turn give rise to a diverse cell lineage—including melanocytes, craniofacial cartilage and bone, smooth muscle, dentin, peripheral and enteric neurons, adrenal medulla and glia. After gastrulation, the neural crest is specified at the border of the neural plate and the non-neural ectoderm. During neurulation, the borders of the neural plate, also known as the neural folds, converge at the dorsal midline to form the neural tube. Subsequently, neural crest cells from the roof plate of the neural tube undergo an epithelial to mesenchymal transition, delaminating from the neuroepithelium and migrating through the periphery, where they differentiate into varied cell types. The emergence of the neural crest was import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Plate
In embryology, the neural plate is a key Development of the human body, developmental structure that serves as the basis for the nervous system. Cranial to the primitive node of the embryonic primitive streak, Ectoderm, ectodermal tissue thickens and flattens to become the neural plate. The region anterior to the primitive node can be generally referred to as the neural plate. Cells take on a columnar appearance in the process as they continue to lengthen and narrow. The ends of the neural plate, known as the neural folds, push the ends of the plate up and together, folding into the neural tube, a structure critical to brain and spinal cord development. This process as a whole is termed primary neurulation. Signaling proteins are also important in neural plate development, and aid in Cellular differentiation, differentiating the tissue destined to become the neural plate. Examples of such proteins include bone morphogenetic proteins and cadherins. Expression of these proteins i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sven Hörstadius
Sven Hörstadius (1898–1996) was a Swedish embryologist known for his work on sea urchin embryos. He was responsible for an increased understanding of the neural crest. Hörstadius studied under John Runnström at Stockholm University College and was awarded his Ph.D. in 1930. He was appointed professor of zoology at Uppsala University 1942, where he remained until his retirement in 1964, but continued to lecture as an emeritus. He was elected a member of the Royal Swedish Academy of Sciences in 1946 and of the Royal Society in 1952. References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm His Sr
__NOTOC__ Wilhelm His Sr. (9 July 1831 – 1 May 1904) was a Swiss anatomist and professor who invented the microtome. By treating animal tissue with acids and salts to harden it and then slicing it very thinly with the microtome, scientists were able to further study the organization and function of tissues and cells under a microscope. Career His came from a patrician family and studied medicine in Basel, Berlin (under Johannes Peter Müller and Robert Remak), Würzburg (under Rudolf Virchow and Albert von Kölliker), Bern, Vienna and Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci .... He received a doctorate in 1854, and in 1856 received the habilitation (higher doctorate) in Basel. In 1855, he was the first to describe the tubercles in the human foetus which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurocristopathies
Neurocristopathy is a diverse class of pathologies that may arise from defects in the development of tissues containing cells commonly derived from the embryonic neural crest cell lineage. The term was coined by Robert P. Bolande in 1974. After the induction of the neural crest, the newly formed neural crest cells (NCC) delaminate from their tissue of origin and migrate from the entire neural axis of the vertebrate embryo to specific locations where they will give rise to different cell derivatives. The formation of this cell population therefore requires a timely and spatially controlled interplay of inter- and intra-cellular signals. An alteration in the occurrence and timing of these signals leads to a set of syndromes called Neurocristopathies (NCP), which comprises a broad spectrum of congenital malformations affecting an appreciable percentage of newborns. Moreover, since NCC migrate along the embryo, they are susceptible to subtle changes in the environment both during their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DiGeorge Syndrome
DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a syndrome caused by a microdeletion on the long arm of chromosome 22. While the symptoms can vary, they often include congenital heart problems, specific facial features, frequent infections, developmental disability, intellectual disability and cleft palate. Associated conditions include kidney problems, schizophrenia, hearing loss and autoimmune disorders such as rheumatoid arthritis or Graves' disease. DiGeorge syndrome is typically due to the deletion of 30 to 40 genes in the middle of chromosome 22 at a location known as ''22q11.2''. About 90% of cases occur due to a new mutation during early development, while 10% are inherited. It is autosomal dominant, meaning that only one affected chromosome is needed for the condition to occur. Diagnosis is suspected based on the symptoms and confirmed by genetic testing. Although there is no cure, treatment can improve symptoms. This often includes a multidisci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waardenburg–Shah Syndrome
Waardenburg syndrome is a group of rare genetic conditions characterised by at least some degree of congenital hearing loss and pigmentation deficiencies, which can include bright blue eyes (or one blue eye and one brown eye), a white forelock or patches of light skin. These basic features constitute type 2 of the condition; in type 1, there is also a wider gap between the inner corners of the eyes called telecanthus, or dystopia canthorum. In type 3, which is rare, the arms and hands are also malformed, with permanent finger contractures or fused fingers, while in type 4, the person also has Hirschsprung's disease. There also exist at least two types (2E and PCWH) that can result in central nervous system (CNS) symptoms such as developmental delay and muscle tone abnormalities. The syndrome is caused by mutations in any of several genes that affect the division and migration of neural crest cells during embryonic development (though some of the genes involved also affec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontonasal Dysplasia
Frontonasal dysplasia (FND) is a congenital malformation of the midface. For the diagnosis of FND, a patient should present at least two of the following characteristics: hypertelorism (an increased distance between the eyes), a wide nasal root, vertical midline cleft of the nose and/or upper lip, cleft of the wings of the nose, malformed nasal tip, encephalocele (an opening of the skull with protrusion of the brain) or V-shaped hair pattern on the forehead. The cause of FND remains unknown. FND seems to be sporadic (random) and multiple environmental factors are suggested as possible causes for the syndrome. However, in some families multiple cases of FND were reported, which suggests a genetic cause of FND.Wu E, Vargevik K, Slavotinek AM (2007) Subtypes of frontonasal dysplasia are useful in determining clinical prognosis. Am J Med Genet A. 143A(24):3069-78. Classification There are multiple classification systems for FND. None of these classification systems have unraveled any ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurocristopathy
Neurocristopathy is a diverse class of pathologies that may arise from defects in the development of tissues containing cells commonly derived from the embryonic neural crest cell lineage. The term was coined by Robert P. Bolande in 1974. After the induction of the neural crest, the newly formed neural crest cells (NCC) delaminate from their tissue of origin and migrate from the entire neural axis of the vertebrate embryo to specific locations where they will give rise to different cell derivatives. The formation of this cell population therefore requires a timely and spatially controlled interplay of inter- and intra-cellular signals. An alteration in the occurrence and timing of these signals leads to a set of syndromes called Neurocristopathies (NCP), which comprises a broad spectrum of congenital malformations affecting an appreciable percentage of newborns. Moreover, since NCC migrate along the embryo, they are susceptible to subtle changes in the environment both during their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Lineage
Cell lineage denotes the developmental history of a tissue or organ from the fertilized egg. This is based on the tracking of an organism's cellular ancestry due to the cell divisions and relocation as time progresses. This starts with the originator cells and finishes with a mature cell that can no longer divide. This type of lineage can be studied by marking a cell (with fluorescent molecules or other traceable markers) and following its progeny after cell division. Some organisms, such as ''C. elegans'', have a predetermined pattern of cell progeny and the adult male will always consist of 1031 cells. This is because cell division in ''C. elegans'' is genetically determined and known as eutely. This causes the cell lineage and cell fate to be highly correlated. Other organisms, such as humans, have variable lineages and somatic cell numbers. ''C. elegans'': model organism As one of the first pioneers of cell lineage, in the 1960s, Dr. Sydney Brenner first began observing ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effector (biology)
In biology, an effector is a general term that can refer to several types of molecules or cells. In the context of biological system regulation, an effector is an element of a regulation loop controlling a regulated quantity. Small molecule effectors * A small molecule that selectively binds to a protein to regulate its biological activity can be called an effector. In this manner, effector molecules act as ligands that can increase or decrease enzyme activity, gene expression, influence cell signaling, or other protein functions. An example of such an effector is oxygen, which is an allosteric effector of hemoglobin - oxygen binding to one of the four hemoglobin subunits greatly increases the affinity of the rest of the subunits to oxygen. Certain drug molecules also fall into this category - for example the antibiotic rifampicin used in the treatment of tuberculosis binds the initiation σ factor subunit of the bacterial RNA polymerase, preventing the transcription of bac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription Factors
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The function of TFs is to regulate—turn on and off—genes in order to make sure that they are expressed in the desired cells at the right time and in the right amount throughout the life of the cell and the organism. Groups of TFs function in a coordinated fashion to direct cell division, cell growth, and cell death throughout life; cell migration and organization (body plan) during embryonic development; and intermittently in response to signals from outside the cell, such as a hormone. There are approximately 1600 TFs in the human genome. Transcription factors are members of the proteome as well as regulome. TFs work alone or with other proteins in a complex, by promoting (as an activator), or blocking (as a repressor) the recruitment o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
