Volume 48, Issue 6, Pages 885-895 (December 2005) Spinal Muscular Atrophy: A Deficiency in a Ubiquitous Protein; a Motor Neuron-Specific Disease Umrao R. Monani Neuron Volume 48, Issue 6, Pages 885-895 (December 2005) DOI: 10.1016/j.neuron.2005.12.001 Copyright © 2005 Elsevier Inc. Terms and Conditions
Figure 1 The Molecular Basis of Proximal Spinal Muscular Atrophy Depicting the Two Major Genes Involved in the Disease, SMN1, and the Modifier, SMN2 All SMA patients are either homozygously deleted for or contain point mutations in SMN1 but always retain at least one copy of the SMN2 gene. For simplicity, the genes are depicted in tandem repeat, although they can exist in a head-to-head or tail-to-tail configuration. Copy number of the genes can vary considerably in the population from 1 through 6. ESE, exonic splicing enhancer; ESS, exonic splicing silencer; FL-SMN, full-length SMN; yellow box in exon 7 denotes putative ESE/ESS. Neuron 2005 48, 885-895DOI: (10.1016/j.neuron.2005.12.001) Copyright © 2005 Elsevier Inc. Terms and Conditions
Figure 2 A chick cortical neuron stained with an antibody against SMN showing abundant nucleocytoplasmic staining as well as the presence of granules (arrows) within neurites and the growth cone. The granules, RNP particles, are found associated with microtubules, indicating movement along the axon, and supports the idea of a motor neuron specific function of the SMN protein (also see Zhang et al., 2003) Neuron 2005 48, 885-895DOI: (10.1016/j.neuron.2005.12.001) Copyright © 2005 Elsevier Inc. Terms and Conditions
Figure 3 Motor Neuron Loss in Type III SMA Mice (A) Cresyl-echt violet section of lumbar spinal motor neurons (arrows) in a 3-month-old type III SMA mouse and its normal littermate, showing reduced cells in the former. (B) Quantification of lumbar spinal motor neurons and motor neurons of the facial nucleus in SMA III and normal mice (n = 3 in each case). Neuron 2005 48, 885-895DOI: (10.1016/j.neuron.2005.12.001) Copyright © 2005 Elsevier Inc. Terms and Conditions