title: The protein dendrite arborization and synapse maturation 1 (Dasm-1) is dispensable for dendrite arborization.
abstract: The development of a highly branched dendritic tree is essential for the establishment of functional neuronal connections. The evolutionarily conserved immunoglobulin superfamily member, the protein dendrite arborization and synapse maturation 1 (Dasm-1) is thought to play a critical role in dendrite formation of dissociated hippocampal neurons. RNA interference-mediated Dasm-1 knockdown was previously shown to impair dendrite, but not axonal, outgrowth and branching (S. H. Shi, D. N. Cox, D. Wang, L. Y. Jan, and Y. N. Jan, Proc. Natl. Acad. Sci. USA 101:13341-13345, 2004). Here, we report the generation and analysis of Dasm-1 null mice. We find that genetic ablation of Dasm-1 does not interfere with hippocampal dendrite growth and branching in vitro and in vivo. Moreover, the absence of Dasm-1 does not affect the modulation of dendritic outgrowth induced by brain-derived neurotrophic factor. Importantly, the previously observed impairment in dendrite growth after Dasm-1 knockdown is also observed when the Dasm-1 knockdown is performed in cultured hippocampal neurons from Dasm-1 null mice. These findings indicate that the dendrite arborization phenotype was caused by off-target effects and that Dasm-1 is dispensable for hippocampal dendrite arborization.
authors.affiliation: Department of Molecular Neurobiology, Max Planck Institute of Neurobiology, 82152 Munich-Martinsried, Germany.
authors.forename: Archana
authors.initials: A
authors.lastname: Mishra
authors.forename: Boris
authors.initials: B
authors.lastname: Knerr
authors.forename: Sónia
authors.initials: S
authors.lastname: Paixão
authors.forename: Edgar R
authors.initials: ER
authors.lastname: Kramer
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Klein
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology; D003712:Dendrites / Q000378:metabolism*; D005786:Gene Expression Regulation; D006624:Hippocampus / Q000002:abnormalities / Q000187:drug effects / Q000378:metabolism; D007136:Immunoglobulins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D046509:Tissue Culture Techniques
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C486759:Igsf9 protein, mouse; D007136:Immunoglobulins; D009419:Nerve Tissue Proteins