Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by motor neuron loss and skeletal muscle atrophy. The loss of function of the smn1 gene, the main supplier of survival motor neuron protein (SMN) protein in human, leads to reduced levels of SMN and eventually to SMA. Here, we ask if the amphibian Xenopus tropicalis can be a good model system to study SMA. Inhibition of the production of SMN using antisense morpholinos leads to caudal muscular atrophy in tadpoles. Of note, early developmental patterning of muscles and motor neurons is unaffected in this system as well as acetylcholine receptors clustering. Muscular atrophy seems to rather result from aberrant pathfinding and growth arrest and/or shortening of motor axons. This event occurs in the absence of neuronal cell bodies apoptosis, a process comparable to that of amyotrophic lateral sclerosis. Xenopus tropicalis is revealed as a complementary animal model for the study of SMA.
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References
Crawford TO, Pardo CA (1996) The neurobiology of childhood spinal muscular atrophy. Neurobiol Dis 3:97–110. doi:10.1006/nbdi.1996.0010
Melki J (1997) Spinal muscular atrophy. Curr Opin Neurol 10:381–385. doi:10.1097/00019052-199710000-00005
Lefebvre S, Burglen L, Reboullet S, Clermont O, Burlet P, Viollet L, Benichou B, Cruaud C, Millasseau P, Zeviani M et al (1995) Identification and characterization of a spinal muscular atrophy-determining gene. Cell 80:155–165. doi:10.1016/0092-8674(95)90460-3
Lorson CL, Hahnen E, Androphy EJ, Wirth B (1999) A single nucleotide in the SMN gene regulates splicing and is responsible for spinal muscular atrophy. Proc Natl Acad Sci USA 96:6307–6311. doi:10.1073/pnas.96.11.6307
McAndrew PE, Parsons DW, Simard LR, Rochette C, Ray PN, Mendell JR, Prior TW, Burghes AH (1997) Identification of proximal spinal muscular atrophy carriers and patients by analysis of SMNT and SMNC gene copy number. Am J Hum Genet 60:1411–1422. doi:10.1086/515465
Feldkotter M, Schwarzer V, Wirth R, Wienker TF, Wirth B (2002) Quantitative analyses of SMN1 and SMN2 based on real-time lightCycler PCR: fast and highly reliable carrier testing and prediction of severity of spinal muscular atrophy. Am J Hum Genet 70:358–368. doi:10.1086/338627
Lefebvre S, Burlet P, Liu Q, Bertrandy S, Clermont O, Munnich A, Dreyfuss G, Melki J (1997) Correlation between severity and SMN protein level in spinal muscular atrophy. Nat Genet 16:265–269. doi:10.1038/ng0797-265
Liu Q, Dreyfuss G (1996) A novel nuclear structure containing the survival of motor neurons protein. EMBO J 15:3555–3565
Fischer U, Liu Q, Dreyfuss G (1997) The SMN-SIP1 complex has an essential role in spliceosomal snRNP biogenesis. Cell 90:1023–1029. doi:10.1016/S0092-8674(00)80368-2
Meister G, Fischer U (2002) Assisted RNP assembly: SMN and PRMT5 complexes cooperate in the formation of spliceosomal UsnRNPs. EMBO J 21:5853–5863. doi:10.1093/emboj/cdf585
Paushkin S, Gubitz AK, Massenet S, Dreyfuss G (2002) The SMN complex, an assemblyosome of ribonucleoproteins. Curr Opin Cell Biol 14:305–312. doi:10.1016/S0955-0674(02)00332-0
Pellizzoni L, Yong J, Dreyfuss G (2002) Essential role for the SMN complex in the specificity of snRNP assembly. Science 298:1775–1779. doi:10.1126/science.1074962
Briese M, Esmaeili B, Sattelle DB (2005) Is spinal muscular atrophy the result of defects in motor neuron processes? Bioessays 27:946–957. doi:10.1002/bies.20283
Eggert C, Chari A, Laggerbauer B, Fischer U (2006) Spinal muscular atrophy: the RNP connection. Trends Mol Med 12:113–121. doi:10.1016/j.molmed.2006.01.005
Miguel-Aliaga I, Chan YB, Davies KE, van den Heuvel M (2000) Disruption of SMN function by ectopic expression of the human SMN gene in Drosophila. FEBS Lett 486:99–102. doi:10.1016/S0014-5793(00)02243-2
Miguel-Aliaga I, Culetto E, Walker DS, Baylis HA, Sattelle DB, Davies KE (1999) The Caenorhabditis elegans orthologue of the human gene responsible for spinal muscular atrophy is a maternal product critical for germline maturation and embryonic viability. Hum Mol Genet 8:2133–2143. doi:10.1093/hmg/8.12.2133
McWhorter ML, Monani UR, Burghes AH, Beattie CE (2003) Knockdown of the survival motor neuron (Smn) protein in zebrafish causes defects in motor axon outgrowth and pathfinding. J Cell Biol 162:919–931. doi:10.1083/jcb.200303168
Hsieh-Li HM, Chang JG, Jong YJ, Wu MH, Wang NM, Tsai CH, Li H (2000) A mouse model for spinal muscular atrophy. Nat Genet 24:66–70. doi:10.1038/71709
Jablonka S, Holtmann B, Meister G, Bandilla M, Rossoll W, Fischer U, Sendtner M (2002) Gene targeting of Gemin2 in mice reveals a correlation between defects in the biogenesis of U snRNPs and motoneuron cell death. Proc Natl Acad Sci USA 99:10126–10131. doi:10.1073/pnas.152318699
Monani UR, Sendtner M, Coovert DD, Parsons DW, Andreassi C, Le TT, Jablonka S, Schrank B, Rossoll W, Prior TW, Morris GE, Burghes AH (2000) The human centromeric survival motor neuron gene (SMN2) rescues embryonic lethality in Smn(-/-) mice and results in a mouse with spinal muscular atrophy. Hum Mol Genet 9:333–339. doi:10.1093/hmg/9.3.333
Winkler C, Eggert C, Gradl D, Meister G, Giegerich M, Wedlich D, Laggerbauer B, Fischer U (2005) Reduced U snRNP assembly causes motor axon degeneration in an animal model for spinal muscular atrophy. Genes Dev 19:2320–2330. doi:10.1101/gad.342005
Carrel TL, McWhorter ML, Workman E, Zhang H, Wolstencroft EC, Lorson C, Bassell GJ, Burghes AH, Beattie CE (2006) Survival motor neuron function in motor axons is independent of functions required for small nuclear ribonucleoprotein biogenesis. J Neurosci 26:11014–11022. doi:10.1523/JNEUROSCI.1637-06.2006
Kariya S, Park GH, Maeno-Hikichi Y, Leykekhman O, Lutz C, Arkovitz MS, Landmesser LT, Monani UR (2008) Reduced SMN protein impairs maturation of the neuromuscular junctions in mouse models of spinal muscular atrophy. Hum Mol Genet 17:2552–2569. doi:10.1093/hmg/ddn156
McGovern VL, Gavrilina TO, Beattie CE, Burghes AH (2008) Embryonic motor axon development in the severe SMA mouse. Hum Mol Genet 17:2900–2909. doi:10.1093/hmg/ddn189
Murray LM, Comley LH, Thomson D, Parkinson N, Talbot K, Gillingwater TH (2008) Selective vulnerability of motor neurons and dissociation of pre- and post-synaptic pathology at the neuromuscular junction in mouse models of spinal muscular atrophy. Hum Mol Genet 17:949–962. doi:10.1093/hmg/ddm367
Kong L, Wang X, Choe DW, Polley M, Burnett BG, Bosch-Marce M, Griffin JW, Rich MM, Sumner CJ (2009) Impaired synaptic vesicle release and immaturity of neuromuscular junctions in spinal muscular atrophy mice. J Neurosci 29:842–851. doi:10.1523/JNEUROSCI.4434-08.2009
Niewkoop PD, Faber F (1994) Normal Table of Xenopus laevis (Daudin). A systematical and chronological survey of the development from fertilized egg till the end of metamophosis. Garland, New York, p 193
Bronchain OJ, Pollet N, Ymlahi-Ouazzani Q, Dhorne-Pollet S, Helbling JC, Lecarpentier JE, Percheron K, Wegnez M (2007) The olig family: phylogenetic analysis and early gene expression in Xenopus tropicalis. Dev Genes Evol 217:485–497. doi:10.1007/s00427-007-0158-z
Fierro AC, Thuret R, Coen L, Perron M, Demeneix BA, Wegnez M, Gyapay G, Weissenbach J, Wincker P, Mazabraud A, Pollet N (2007) Exploring nervous system transcriptomes during embryogenesis and metamorphosis in Xenopus tropicalis using EST analysis. BMC Genomics 8:118. doi:10.1186/1471-2164-8-118
Liu Q, Fischer U, Wang F, Dreyfuss G (1997) The spinal muscular atrophy disease gene product, SMN, and its associated protein SIP1 are in a complex with spliceosomal snRNP proteins. Cell 90:1013–1021. doi:10.1016/S0092-8674(00)80367-0
Meister G, Buhler D, Pillai R, Lottspeich F, Fischer U (2001) A multiprotein complex mediates the ATP-dependent assembly of spliceosomal U snRNPs. Nat Cell Biol 3:945–949. doi:10.1038/ncb1101-945
Hopwood ND, Pluck A, Gurdon JB (1989) MyoD expression in the forming somites is an early response to mesoderm induction in Xenopus embryos. EMBO J 8:3409–3417
Schiaffino S, Reggiani C (1996) Molecular diversity of myofibrillar proteins: gene regulation and functional significance. Physiol Rev 76:371–423
Chen JF, Mandel EM, Thomson JM, Wu Q, Callis TE, Hammond SM, Conlon FL, Wang DZ (2006) The role of microRNA-1 and microRNA-133 in skeletal muscle proliferation and differentiation. Nat Genet 38:228–233. doi:10.1038/ng1725
Phelps PE, Barber RP, Brennan LA, Maines VM, Salvaterra PM, Vaughn JE (1990) Embryonic development of four different subsets of cholinergic neurons in rat cervical spinal cord. J Comp Neurol 291:9–26. doi:10.1002/cne.902910103
MacDonald SC, Fleetwood IG, Hochman S, Dodd JG, Cheng GK, Jordan LM, Brownstone RM (2003) Functional motor neurons differentiating from mouse multipotent spinal cord precursor cells in culture and after transplantation into transected sciatic nerve. J Neurosurg 98:1094–1103. doi:10.3171/jns.2003.98.5.1094
Yang X, Tomita T, Wines-Samuelson M, Beglopoulos V, Tansey MG, Kopan R, Shen J (2006) Notch1 signaling influences v2 interneuron and motor neuron development in the spinal cord. Dev Neurosci 28:102–117. doi:10.1159/000090757
Layden MJ, Odden JP, Schmid A, Garces A, Thor S, Doe CQ (2006) Zfh1, a somatic motor neuron transcription factor, regulates axon exit from the CNS. Dev Biol 291:253–263. doi:10.1016/j.ydbio.2005.12.009
Buhler D, Raker V, Luhrmann R, Fischer U (1999) Essential role for the tudor domain of SMN in spliceosomal U snRNP assembly: implications for spinal muscular atrophy. Hum Mol Genet 8:2351–2357. doi:10.1093/hmg/8.13.2351
Hannus S, Buhler D, Romano M, Seraphin B, Fischer U (2000) The Schizosaccharomyces pombe protein Yab8p and a novel factor, Yip1p, share structural and functional similarity with the spinal muscular atrophy-associated proteins SMN and SIP1. Hum Mol Genet 9:663–674. doi:10.1093/hmg/9.5.663
Battaglia G, Princivalle A, Forti F, Lizier C, Zeviani M (1997) Expression of the SMN gene, the spinal muscular atrophy determining gene, in the mammalian central nervous system. Hum Mol Genet 6:1961–1971. doi:10.1093/hmg/6.11.1961
La Bella V, Cisterni C, Salaun D, Pettmann B (1998) Survival motor neuron (SMN) protein in rat is expressed as different molecular forms and is developmentally regulated. Eur J Neurosci 10:2913–2923. doi:10.1111/j.1460-9568.1998.00298.x
Hahnen E, Schonling J, Rudnik-Schoneborn S, Zerres K, Wirth B (1996) Hybrid survival motor neuron genes in patients with autosomal recessive spinal muscular atrophy: new insights into molecular mechanisms responsible for the disease. Am J Hum Genet 59:1057–1065
Schrank B, Gotz R, Gunnersen JM, Ure JM, Toyka KV, Smith AG, Sendtner M (1997) Inactivation of the survival motor neuron gene, a candidate gene for human spinal muscular atrophy, leads to massive cell death in early mouse embryos. Proc Natl Acad Sci USA 94:9920–9925. doi:10.1073/pnas.94.18.9920
Burnett BG, Munoz E, Tandon A, Kwon DY, Sumner CJ, Fischbeck KH (2009) Regulation of SMN protein stability. Mol Cell Biol 29:1107–1115. doi:10.1128/MCB.01262-08
Cifuentes-Diaz C, Frugier T, Melki J (2002) Spinal muscular atrophy. Semin Pediatr Neurol 9:145–150. doi:10.1053/spen.2002.33801
Frugier T, Nicole S, Cifuentes-Diaz C, Melki J (2002) The molecular bases of spinal muscular atrophy. Curr Opin Genet Dev 12:294–298. doi:10.1016/S0959-437X(02)00301-5
Murray N, Zheng YC, Mandel G, Brehm P, Bolinger R, Reuer Q, Kullberg R (1995) A single site on the epsilon subunit is responsible for the change in ACh receptor channel conductance during skeletal muscle development. Neuron 14:865–870. doi:10.1016/0896-6273(95)90230-9
Acknowledgement
The authors wish to thank Christophe de Medeiros for animal care. We express our gratitude to Dr. Nacira Tabti for very stimulating discussions. The support of Gregory Lemkine from Watchfrog is gratefully acknowledged. This work was funded by grants from Genopole, the Conseil General de l’Essonne (ASTRE T-REX), CNRS, and under the auspice of the X-OMICS European coordinated action from FP6.
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Qods Ymlahi-Ouazzani and Odile Bronchain contributed equally to the work
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ESM Fig. 1
X. laevis smn mRNA rescues the smn morphant phenotype in X. tropicalis. a Lateral views of MoSMNd (30 ng)-injected tail bud embryos; b lateral views of MoSMNd and X. laevis smn mRNA (1 ng) co-injected tail bud embryos.
ESM Fig. 2
Patterning of muscle and motoneuron axons is not affected in smn morphant embryos. Lateral views, dorsal to the top, anterior to the right, of either wild-type (left column) or morphant (right column, using 15 ng of MoSMNd) tail bud stage embryos after whole-mount in situ hybridization using probes indicated on the left.
ESM Fig. 3
Patterns of apoptosis are not affected in smn morphant embryos. Transverse sections of tadpoles at the level of the trunk (stage 35) or tail (stage 45) are shown, dorsal to the top. Apoptosis was detected by a TUNEL staining (in green), and cells were counterstained using hoechst (violet). sc spinal cord, no notochord, so somites. No differences were observed in staining between control and morphant tadpoles.
smn loss of function induces a paralysis in X. tropicalis tadpoles. (MOV 3292 kb)
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Ymlahi-Ouazzani, Q., J. Bronchain, O., Paillard, E. et al. Reduced levels of survival motor neuron protein leads to aberrant motoneuron growth in a Xenopus model of muscular atrophy. Neurogenetics 11, 27–40 (2010). https://doi.org/10.1007/s10048-009-0200-6
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DOI: https://doi.org/10.1007/s10048-009-0200-6