UASt regulatory sequences drive expression of a bicistronic transcript that corresponds to the Hsap\FUS transcript represented by ENST00000254108 (GenBank:NM_004960), mutated so that the canonical Hsap\FUS coding sequence (in the +1 frame) encodes a disease-related variant (it carries the R495X mutation that causes a premature stop codon and which is associated with severe familial and sporadic amyotrophic lateral sclerosis). In addition to being able to encode the canonical Hsap\FUS coding sequence (in the +1 frame), the ENST00000254108 transcript can also encode an alternative 'altFUS' open reading frame (GenBank:BK012000) which overlaps the Hsap\FUS coding sequence in an open reading frame (the +2 frame) shifted by one nucleotide. The altFUS coding sequence in this transgene is not affected by the mutation that results in R495X in the canonical Hsap\FUS coding sequence.