To generate a mouse model exhibiting symptoms similar to those of human amyotrophic lateral sclerosis and/or human frontotemporal lobar degeneration.A mouse model exhibiting symptoms similar to those of human amyotrophic lateral sclerosis and/or human frontotemporal lobar degeneration can be produced by means of generating a mutation in a vertebrate so that expression of a mutant protein with a substitution of tyrosine for alanine at a position corresponding to position 382 of SEQ ID NO. 1 or a mutant protein with a substitution of cysteine for glycine at a position corresponding to position 348 of SEQ ID NO. 1 is regulated by an endogenous TDP-43 gene promoter in at least one allele of an endogenous TDP-43 gene of the vertebrate.