The invention relates to a genetically modified mouse comprising a heterozygous mutation of Tardbp (TDP-43) gene in that the Asn at amino acid 390 in TDP-43 is substituted with an amino acid that is different from Asn, wherein the genetically modified mouse exhibits Amyotrophic lateral sclerosis (ALS)-like phenotypes, TDP-43 proteinopathies and/or motor neuron degeneration. The invention also so relates to an isolated spinal cord motor neuron differentiated from an embryonic stem cell (ESC) that is obtained from an offspring of a genetically modified mouse according to the invention. Methods for identifying an agent alleviating and/or suppressing ALS-TDP pathogenesis are also disclosed.
