Hedgehogs

Igel, m. hedgehog porcupine Agr.) harrow. Igelit, n. a polyvinyl plastic. T.N. 

Alonso J., Arevalo R., Garciaojeda E., Porteros A., et al. (1995). NADPH-diaphorase active and calbindin d-28k-immunoreactive neurons and fibers in the olfactory-bulb of the hedgehog (Erinaceus europaeus). J Comp Neurol 351, 307-327. 

Raff The ventralizing signals such as Sonic hedgehog that are required for motor neuron development are also required for oligodendrocyte precursors to develop from CNS stem cells, at least in the spinal cord. 

McMahon We can play around with the IGF signalling system and get a smaller skeleton that way. We can also get a small skeleton by manipulating the Hedgehog signalling system. What isn t known is how those two systems talk to one another. I think it is an excellent system to study. If you want to pick a mammalian system, you want to have it such that the arrangement is easy to determine. It is a very stereotypical arrangement of growth and cell movements. 

The best examples of pleiotropy have been provided by developmental biologists. Two examples illustrate the pleiotropic action of developmental genes. Sonic hedgehog participates in the formation of the different cell types that form the neural tube, in limb development and in somitogenesis, a process by which mesodermic cells aggregate to form bones and muscles. 

Wechsler, R. J. and Scott, M. P. (1999), Control of neuronal precursor proliferation in the cerebellum by sonic hedgehog , Neuron, 22, 103-114. 

Chart 2.1 C-nor-D-homosteroids and the first two Hedgehog antagonists in clinical trials... 

It is normally found in southern and Eastern Europe, Central Asia, the Mediterranean, northwestern China, Africa, and the Indian subcontinent. The natural reservoirs are ticks and numerous animal species. Animals (e.g., cattle, sheep, goats, horses, pigs, hares, hedgehogs) infected with this virus usually have no clinical symptoms or suffer only a mild illness. The hemorrhagic fever is highly pathogenic and notable for aerosol transmission. This is a biosafety level 4 agent. 

Figure 14.19 Simplified schematic overview of the directed differentiation of human embryonic stem cells to form differentiated dopamine like neurons. The full pathway details are available in Yan, Y., Yang, D., Zarnowska, E.D., Du, Z., Werbel, B., Valliere, C., etai 2005. Directed differentiation of dopaminergic neuronal subtypes from human embryonic stem cells. Stem Cells 23, 781-790. FGF fibroblast growth factor SHH sonic hedgehog (a regulatory protein)...

Bijlsma, M., Spek, C. and Pepplenbosch, M. Hedgehog an unusual signal transducer. Bioessays 26 387-394, 2004. 

The development of motor neurons and oligodendrocytes is dependent on sonic hedgehog 508... 

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