Sonic hedgehog protein (SHH) is encoded for by the SHH gene. The protein is named after the character Sonic the Hedgehog.
Neurulation refers to the folding process in vertebrate embryos, which includes the transformation of the neural plate into the neural tube. The embryo at this stage is termed the neurula.
The somites are a set of bilaterally paired blocks of paraxial mesoderm that form in the embryonic stage of somitogenesis, along the head-to-tail axis in segmented animals. In vertebrates, somites subdivide into the dermatomes, myotomes, sclerotomes and syndetomes that give rise to the vertebrae of the vertebral column, rib cage, part of the occipital bone, skeletal muscle, cartilage, tendons, and skin.
Somitogenesis is the process by which somites form. Somites are bilaterally paired blocks of paraxial mesoderm that form along the anterior-posterior axis of the developing embryo in segmented animals. In vertebrates, somites give rise to skeletal muscle, cartilage, tendons, endothelium, and dermis.
The neural plate is a key developmental structure that serves as the basis for the nervous system. Cranial to the primitive node of the embryonic primitive streak, 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.
Fibrodysplasia ossificans progressiva, also called Münchmeyer disease or formerly myositis ossificans progressiva, is an extremely rare connective tissue disease in which fibrous connective tissue such as muscle, tendons, and ligaments turn into bone tissue. It is the only known medical condition where one organ system changes into another. It is a severe, disabling disorder with no cure or treatment.
Bone morphogenetic proteins (BMPs) are a group of growth factors also known as cytokines and as metabologens. Originally discovered by their ability to induce the formation of bone and cartilage, BMPs are now considered to constitute a group of pivotal morphogenetic signals, orchestrating tissue architecture throughout the body. The important functioning of BMP signals in physiology is emphasized by the multitude of roles for dysregulated BMP signalling in pathological processes. Cancerous disease often involves misregulation of the BMP signalling system. Absence of BMP signalling is, for instance, an important factor in the progression of colon cancer, and conversely, overactivation of BMP signalling following reflux-induced esophagitis provokes Barrett's esophagus and is thus instrumental in the development of esophageal adenocarcinoma.
Neural crest cells are a temporary group of cells that arise from the embryonic ectoderm germ layer, and in turn give rise to a diverse cell lineage—including melanocytes, craniofacial cartilage and bone, smooth muscle, peripheral and enteric neurons and glia.
Paraxial mesoderm, also known as presomitic or somitic mesoderm, is the area of mesoderm in the neurulating embryo that flanks and forms simultaneously with the neural tube. The cells of this region give rise to somites, blocks of tissue running along both sides of the neural tube, which form muscle and the tissues of the back, including connective tissue and the dermis.
The neural fold is a structure that arises during neurulation in the embryonic development of both birds and mammals among other organisms. This structure is associated with primary neurulation, meaning that it forms by the coming together of tissue layers, rather than a clustering, and subsequent hollowing out, of individual cells. In humans, the neural folds are responsible for the formation of the anterior end of the neural tube. The neural folds are derived from the neural plate, a preliminary structure consisting of elongated ectoderm cells. The folds give rise to neural crest cells, as well as bringing about the formation of the neural tube.
Bone morphogenetic protein 4 is a protein that in humans is encoded by BMP4 gene. BMP4 is found on chromosome 14q22-q23.
Chordin is a protein with a prominent role in dorsal–ventral patterning during early embryonic development. In humans it is encoded for by the CHRD gene.
The bone morphogenetic protein receptor, type IA also known as BMPR1A is a protein which in humans is encoded by the BMPR1A gene. BMPR1A has also been designated as CD292.
Mesenchyme is a type of loosely organized animal embryonic connective tissue of undifferentiated cells that give rise to most tissues, such as skin, blood or bone. The interactions between mesenchyme and epithelium help to form nearly every organ in the developing embryo.
Growth differentiation factor 6 (GDF6) is a protein that in humans is encoded by the GDF6 gene.
Gremlin is an inhibitor in the TGF beta signaling pathway. It primarily inhibits bone morphogenesis and is implicated in disorders of increased bone formation and several cancers.
Neural crest cells are multipotent cells required for the development of cells, tissues and organ systems. A subpopulation of neural crest cells are the cardiac neural crest complex. This complex refers to the cells found amongst the midotic placode and somite 3 destined to undergo epithelial-mesenchymal transformation and migration to the heart via pharyngeal arches 3, 4 and 6.
Chordin-like 1 is a protein that in humans is encoded by the CHRDL1 gene. Chordin-Like 1 (CHRDL1) is a structural glycoprotein that sits on the X chromosome and specifically encodes Venotropin, which is an antagonistic protein to bone morphogenic protein 4.
(HES7) or bHLHb37 is protein coding mammalian gene found on chromosome 17 in humans. HES7 is a member of the Hairy and Enhancer of Split families of Basic helix-loop-helix proteins. The gene product is a transcription factor and is expressed cyclically in the presomitic mesoderm as part of the Notch signalling pathway. HES7 is involved in the segmentation of somites from the presomitic mesoderm in vertebrates. The HES7 gene is self-regulated by a negative feedback loop in which the gene product can bind to its own promoter. This causes the gene to be expressed in an oscillatory manner. The HES7 protein also represses expression of Lunatic Fringe (LFNG) thereby both directly and indirectly regulating the Notch signalling pathway. Mutations in HES7 can result in deformities of the spine, ribs and heart. Spondylocostal dysostosis is a common disease caused by mutations in the HES7 gene. The inheritance pattern of Spondylocostal dysostosis is autosomal recessive.
The Spemann-Mangold organizer is a group of cells that are responsible for the induction of the neural tissues during development in amphibian embryos. First described in 1924 by Hans Spemann and Hilde Mangold, the introduction of the organizer provided evidence that the fate of cells can be influenced by factors from other cell populations. This discovery significantly impacted the world of developmental biology and fundamentally changed the understanding of early development.
