title: Gene targeting of mouse Tardbp negatively affects Masp2 expression.
abstract: Amyotrophic Lateral Sclerosis (ALS) is a devastating adult onset neurodegenerative disease affecting both upper and lower motor neurons. TDP-43, encoded by the TARDBP gene, was identified as a component of motor neuron cytoplasmic inclusions in both familial and sporadic ALS and has become a pathological signature of the disease. TDP-43 is a nuclear protein involved in RNA metabolism, however in ALS, TDP-43 is mislocalized to the cytoplasm of affected motor neurons, suggesting that disease might be caused by TDP-43 loss of function. To investigate this hypothesis, we attempted to generate a mouse conditional knockout of the Tardbp gene using the classical Cre-loxP technology. Even though heterozygote mice for the targeted allele were successfully generated, we were unable to obtain homozygotes. Here we show that although the targeting vector was specifically designed to not overlap with Tardbp adjacent genes, the homologous recombination event affected the expression of a downstream gene, Masp2. This may explain the inability to obtain homozygote mice with targeted Tardbp.
authors.affiliation: Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada.
authors.forename: Samar
authors.initials: S
authors.lastname: Dib
authors.affiliation: Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada.
authors.forename: Shangxi
authors.initials: S
authors.lastname: Xiao
authors.affiliation: Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada.
authors.forename: Denise
authors.initials: D
authors.lastname: Miletic
authors.affiliation: Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada.
authors.forename: Janice
authors.initials: J
authors.lastname: Robertson
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000818:Animals; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation; D018390:Gene Targeting; D005804:Genes, Lethal; D006579:Heterozygote; D059765:Homologous Recombination; D006801:Humans; D019426:Integrases / Q000235:genetics / Q000378:metabolism; D008297:Male; D050606:Mannose-Binding Protein-Associated Serine Proteases / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D009046:Motor Neurons / Q000378:metabolism / Q000473:pathology
chemical_list: D004268:DNA-Binding Proteins; D019426:Integrases; D050606:Mannose-Binding Protein-Associated Serine Proteases; C578077:Tardbp protein, mouse; C045073:Cre recombinase; C491340:MASP-2 protein, mouse
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