Family By Fate [v0.3]
During this time, Kent found the helmet becoming more and more possessive of him, so rather than abandoning his battle against chaos, Kent created the half helm. Although Kent's powers were severely limited, he still had the ability of flight, invulnerability and super strength. However, Kent donned the helmet one last time in order to find the missing Spectre. Dr. Fate discovered that the Spectre was under the control of Kulak and in a titanic battle with the Spectre, he was defeated and the Helmet of Nabu was lost somewhere in the netherverse. It would not be until the early 1960s that Kent Nelson would somehow recover the helmet of Nabu and become Dr. Fate again. In the early 1950s Kent Nelson had retired his fate persona and became a physician, but some time later he had recovered the Helmet of Nabu under never explained events, and in 1955 he fought Khalis, the mad Egyptian priest who once used his Amulet of Anubis. It was not until the 1963 that Kent would rejoin the Justice Society of America. As their Justice Society comrades aged, Kent and Inza seemed immortal. The magic fate held over them, virtually stopped their aging process. Inza and Kent also received a small portion of Ian Karkull's power which gave them even more vitality.
Family By Fate [v0.3]
islet/tailup EVOLUTIONARY HOMOLOGS part 3/3 Expression of Islet Homologs in Chickens and Mammals: Brain and Spinal Cord MotoneuronsMotor neurons located at different positions in the embryonic spinal cord innervate distinct targets inthe periphery, establishing a topographic neural map. The topographic organization of motor projectionsdepends on the generation of subclasses of motor neurons that select specific paths to their targets. A family of LIM homeobox genes has been cloned in the chick. The combinatorialexpression of four of these genes, Islet-1, Islet-2, Lim-1, and Lim-3, defines subclasses of motorneurons that segregate into columns in the spinal cord and select distinct axonal pathways. Thus the combination of LIM domain proteins serve to code motor neuron identity in the spinal cord (Tsuchida, 1994).Sonic hedgehog (Shh) is strongly implicated in the development of ventral structures in the nervous system. Addition of Sonic hedgehog proteinto chick spinal cord explants induces floor plate and motoneuron development. Whether Shh acts directly to induce these cell types or whethertheir induction is mediated by additional factors is unknown. To further investigate the role of Shh in spinal neuron development, low-density cultures of murine spinal cord precursor cells were used. Shh stimulates neuronal differentiation; however, it does not increase the proportion ofneurons expressing the first postmitotic motoneuron marker Islet-1. Moreover, Shh induces Islet-1 expression in neural tube explants,suggesting that it acts in combination with neural tube factors to induce motoneurons. Another factor implicated in motoneuron development isneurotrophin 3 (NT3): when assayed in isolated precursor cultures, it has no effect on Islet-1 expression. However, the combination ofN-terminal Shh and NT3 induces Islet-1 expression in the majority of neurons in low-density cultures of caudal intermediate neural plate.Furthermore, in explant cultures, Shh-mediated Islet-1 expression is blocked by an anti-NT3 antibody. Previous studies have shownexpression of NT3 in the region of motoneuron differentiation and that spinal fusimotor neurons are lost in NT3 knock-out animals. Takentogether, these findings suggest that Shh can act directly on spinal cord precursors to promote neuronal differentiation, but induction of Islet-1expression is regulated by factors additional to Shh, including NT3 (Dutton, 1999). Different neuronal subpopulations derived from in vitro differentiation of embryonic stem (ES) cells have been characterized using as markers the expression of several homeodomain transcription factors. Following treatment of embryo-like aggregates with retinoic acid (RA), Pax-6, a protein expressed by ventral central nervous system (CNS) progenitors, is induced. In contrast, Pax-7 expressed in vivo by dorsal CNS progenitors, and erbB3, a gene expressed by neural crest cells and its derivatives, are almost undetectable. CNS neuronal subpopulations generate expressed combination of markers characteristic of somatic motoneurons (Islet-1/2, Lim-3, and HB-9); cranial motoneurons (Islet-1/2 and Phox2b) and interneurons (Lim-1/2 or EN1). Molecular characterization of neuron subtypes generated from ES cells should considerably facilitate identification of new genes expressed by restricted neuronal cell lineages (Renoncourt, 1998).These LIM homeodomain proteins are expressed prior to the formation of distinct motor axon pathways and before motor columnsappear. Depending on their arrangement in columns and eventual synaptic targets, motor neurons of the chick brain stem are designated as belonging to somatic motor (sm) visceral motor (vm), or branchiomotor (bm) classes or to the ipsilateral or contralateral vestibuloacoustic effect neuronal population. Sm neurons innervate muscle derived from the paraxial mesoderm and prechordal plate mesoderm. Bm, vm and vestibuloacoustic axons extend dorsolaterally for some distance through the neuroepithelium before converging on large single exit points within the dorsal neural tube (alar plate). Bm neurons innervate muscle derived from paraxial mesoderm within the branchial arches, while vm neurons innervate parasympathetic ganglia associated with lacrimal and salivary glands or neuronal plexuses that innervate smooth muscle; vestibuloacoustic efferent neurons innervate the hair cells of the inner ear. Subpopulations of spinal motor neurons within specific locations in the spinal cord and distinct targets in the periphery express different combinations of LIM homeobox genes. Sm neurons of the medial division of the median motor column express Islet-1, Isl-2, and Lim-3, while those of the lateral division of the median motor column and the medial division of the later mot