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A gene on chromosome 3q21-q23 that encodes a member of the ephrin-B receptor subfamily of receptor tyrosine kinases, which “promiscuously” bind membrane-bound ephrin-B family ligands residing on adjacent cells, leading to contact-dependent bidirectional signalling into neighbouring cells. EPHB1 regulates retinal axon guidance, ipsilaterally redirecting ventrotemporal retinal ganglion cells axons at the optic chiasm midline during nervous system development, a process that is thought to require repulsive interaction with EFNB2. In the adult nervous system, EPHB1 and EFNB3 regulate chemotaxis, proliferation and polarity of the hippocampus neural progenitors.

In addition to its role in axon guidance, EPHB1 also plays a key redundant role with other ephrin-B receptors in development and maturation of dendritic spines and synapse formation. It may also regulate angiogenesis and play a role in targeted cell migration by activating the MAPK/ERK cascade, and in adhesion by activating the JNK signalling cascade. EPHB1’s cognate/functional ephrin ligands include EFNB1, EFNB2 and EFNB3.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


Ears–nose and throat, lungs, kidneys An acronym for the organs involved in Wegener's granulomatosis–WG; limited WG spares the kidneys and lacks signs of systemic vasculitis; generalized WG involves the kidneys and/or has signs of systemic vasculitis; disease exacerbation is best monitored by measuring titers of antineutrophil cytoplasmic antibodies by indirect immunofluorescence. See Wegener's granulomatosis.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
2005: Density-dependent effects on physical condition and reproduction in North American elk: an experimental test.--Oecologia 143: 85-93.
Glen Zebarth of the North American Elk Breeders' Association reported for the Working Group.
Pages 557-581 in North American elk: ecology and management (D.
In addition to all of the North American species of deer, Pete also took roe, red, axis, and fallow across parts of Europe and Asia, plus all three species of North American elk Rocky Mountain, Tule, and Roosevelt.
No study of North American elk populations, or forecast of future elk hunting opportunities, could possibly be done today without referring to the expansion of wolves in the West since their reintroduction in 1995.
Pages 389-434 in North American elk: ecology and management (D.
Although reasons for waning populations are numerous and sometimes unclear, competition with North American elk (Cervus elaphus), which are sympatric with mule deer through much of their distribution, may contribute to that decline (Ballard et al., 2001).
Crown points are one thing to look for in Roosevelt's elk that are considered abnormal points and count as deductions in the final score in an American elk. These are points coming off the main beam adjacent to the fourth point.
There are 15, with allowance for taking three on estates, a sound rule because American elk, wapiti, no longer exist free range because of cross-breeding with red deer; and several others are exceptionally difficult.
True or false: North American elk, like ocean-going walrus, and African elephant, wear ivory tusks in their upper palate.
Combining the Rocky Mountain and Manitoba subspecies, there has been a steady increase in the American elk category, from 18 typical entries in the 17th awards to 142 in the 27th and from zero to 49 nontypical.
1979 The social organization of a sedentary population of North American elk: A model for understanding other populations, p.

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