A transgenic construct containing cDNA encoding the mutant human ubiquitin B, UBB+1 sequence (in the +1 reading frame), under the direction of the mouse Camk2a (calcium/calmodulin-dependent protein kinase II alpha) promoter was injected into fertilized C57BL/6 mouse eggs. Founder line 3413-1 with 13 copies of the transgene was subsequently established. mRNA levels for UBB+1 are 49% of endogenous Ubb mRNA levels. (J:147938)