We are extending the Cre/loxP site-specific recombination system to pigs, focussing on conditional and tissue-specific expression of oncogenic mutations to model human cancers. Identifying the location, pattern and extent of Cre recombination in vivo is an important aspect of this technology. Here we report pigs with a dual fluorochrome cassette under the control of the strong CAG promoter that...

objective: lentivirus-derived vectors are among the most promising viral vectors for gene therapy which is currently available, but their use in clinical practice is limited due to associated risk of insertional mutagenesis. gene targeting is an ideal method for gene therapy, but it has low efficiency in comparison to viral vector methods. in this study, we are going to design and construct an ...

A rate-determining step in gene targeting is the generation of the targeting vector. We have developed bacteriophage gene targeting vectorology, which shortens the timeline of targeting vector construction. Using retro-recombination screening, we can rapidly isolate targeting vectors from an embryonic stem cell genomic library via integrative and excisive recombination. We have demonstrated tha...

Embryonic stem cell (ES cell)-based rat knockout technology, although successfully developed in 2010, has seen very limited usage to date due to low targeting efficiency and a lack of optimized procedures. In this study, we performed gene targeting in ES cells from the Sprague-Dawley (SD) and the Fischer 344 (F344) rat strains using an optimized procedure and the self-excising neomycin (neo)-po...

Homology directed repair (HDR)-based genome editing via selectable long flanking arm donors can be hampered by local transgene silencing at transcriptionally silent loci. Here, we report efficient bi-allelic modification of a silent locus in patient-derived hiPSC by using Cas9 nickase and a silencing-resistant donor construct that contains an excisable selection/counter-selection cassette. To i...

CRISPR/Cas9-mediated genome editing is a next-generation strategy for genetic modifications, not only for single gene targeting, but also for multiple targeted mutagenesis. To make the most of the multiplexity of CRISPR/Cas9, we established a system for constructing all-in-one expression vectors containing multiple guide RNA expression cassettes and a Cas9 nuclease/nickase expression cassette. ...

Huntington's disease (HD) is a neurodegenerative disorder caused by accumulation of CAG expansions in the huntingtin (HTT) gene. Hence, decreasing the expression of mutated HTT (mtHTT) is the most upstream approach for treatment of HD. We have developed HTT gene-silencing approaches based on expression cassette-optimized artificial miRNAs (miHTTs). In the first approach, total silencing of wild...

The ATP-binding cassette transporter MDL1 of Saccharomyces cerevisiae has been implicated in mitochondrial quality control, exporting degradation products of misassembled respiratory chain complexes. In the present study, we identified an unusually long leader sequence of 59 amino acids, which targets MDL1 to the inner mitochondrial membrane with its nucleotide-binding domain oriented to the ma...

A series of vectors has been designed to enhance the versatility of targeted homologous recombination. Recombinase-mediated cassette exchange permits sequential targeting at any locus and improves flexibility in making user-defined mutations. Application of RMCE to delete an intronic microRNA gene is described.