Research Report Molecular characterization of the genetic lesion in Dystonia musculorum (dt-Alb) mice Dmitry Goryunov a , Adijat Adebola a , Julius J. Jefferson a , Conrad L. Leung a , Anne Messer b , Ronald K.H. Liem a, ⁎ a Department of Pathology, Columbia University College of Physicians and Surgeons, P&S 15-421, 630 W. 168th Street, New York, NY 10032, USA b Wadsworth Center, David Axelrod Institute, New York State Department of Health, Albany, NY 12201, USA ARTICLE INFO ABSTRACT Article history: Accepted 18 April 2006 Available online 24 May 2006 Dystonia musculorum (dt) is an inherited autosomal recessive neuropathy in mice. Homozygous animals display primarily sensory neurodegeneration resulting in a severe loss of coordination. Several dt strains exist, including spontaneous mutants dt-Alb (Albany), dt-J (Jackson Labs), and dt-Frk (Frankel), and a transgene insertion mutant, Tg4. They contain mutations in the gene encoding Bullous Pemphigoid Antigen 1 (BPAG1), or dystonin. BPAG1 is a member of the plakin family of cytolinker proteins. BPAG1 is alternatively spliced to produce several isoforms, including the major brain-specific isoform, BPAG1a. The neurological phenotype observed in dt-Alb mice is thought to result from the absence of BPAG1a protein in the developing nervous system. The goal of this study was to determine the precise molecular nature of the dt-Alb mutation and examine residual BPAG1 expression in homozygous dt-Alb mice. A combination of molecular biological strategies revealed that the dt-Alb lesion is a deletion–insertion eliminating a large part of the coding region of BPAG1a. The molecular lesion in the dt-Alb BPAG1 allele is expected to render it completely non-functional. Although transcripts corresponding to BPAG1 segments still remaining in homozygous dt-Alb mice could be detected by RT-PCR, there was no positive signal for BPAG1 in the brain of dt-Alb mice by Northern blotting. Western blotting with polyclonal anti-BPAG1 antibodies confirmed the absence of functional BPAG1 protein (full-length or truncated) in the dt-Alb brain. Our identification of the 5′ junction of the dt-Alb insertion makes it possible to genotype dt-Alb animals by standard PCR. © 2006 Elsevier B.V. All rights reserved. Keywords: Dystonia musculorum Dystonin Bullous Pemphigoid Antigen 1 Gene structure Alternative splicing Deletion-insertion Abbreviations: BPAG1, Bullous Pemphigoid Antigen 1 dt, Dystonia musculorum ABD, actin-binding domain MTBD, microtubule-binding domain IFBD, intermediate-filament-binding domain SR, spectrin repeat PRD, plectin repeat domain GAR, Gas2-related GSR, GS-rich CC, coiled coil CH, calponin homology BRAIN RESEARCH 1140 (2007) 179 – 187 ⁎ Corresponding author. Fax: +1 212 305 5498. E-mail address: rkl2@columbia.edu (R.K.H. Liem). Abbreviations: BPAG1, Bullous Pemphigoid Antigen 1; dt, Dystonia musculorum; ABD, actin-binding domain; MTBD, microtubule-binding domain; IFBD, intermediate-filament-binding domain; SR, spectrin repeat; PRD, plectin repeat domain; GAR, Gas2-related; GSR, GS-rich; CC, coiled coil; CH, calponin homology 0006-8993/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.brainres.2006.04.068 available at www.sciencedirect.com www.elsevier.com/locate/brainres