Weimin Zhang, PhD, Institute for Systems Genetics, NYU Langone Health
14:00-16:00 p.m., January 31, 2024, GMT+8
B117, Research Building #2
Genetically Engineered Mouse Models (GEMMs) aid in understanding human pathologies and developing new therapeutics, yet faithfully recapitulating human diseases in mice is challenging to design and execute. Advances in genomics have highlighted the importance of non-coding regulatory genome sequences controlling spatiotemporal gene expression patterns and splicing in many human diseases. It is thus apparent that including regulatory genomic regions during the engineering of GEMMs, necessitating large scale genome engineering ability, is preferable for disease modeling. Existing genome engineering methods have limits on the size and efficiency of DNA delivery, hampering routine creation of highly informative GEMMs. Here, we developed mSwAP-In (mammalian Switching Antibiotic resistance markers Progressively for Integration), a method for efficient genome rewriting in mouse embryonic stem cells, and we termed the subsequently derived mouse models as Genomically Rewritten and Tailored (GREAT)-GEMMs. We demonstrated the use of mSwAP-In for genomic humanization of up to 180 kb ACE2 locus (hACE2). We showed the hACE2 model recapitulated human ACE2 expression patterns and splicing, and importantly, presented milder symptoms without mortality when challenged with SARS -CoV-2 compared to the pre existing K18-hACE2 model, thus representing a more authentic model of infection. To exemplify the use of GREAT-GEMMs for studying human transposable elements associated diseases, we created the first humanized mouse model for a rare neurodegenerative disease, X-Linked Dystonia Parkinsonism, which is caused by an SVA insertion into an intron of TAF1 gene. We showed that the SVA element is detrimental to the mouse embryonic stem cells. Additionally, the existence of the SVA led to severe atrophy of striatum in the neuronal conditional humanized mice. The male progeny had significant weight loss over the course of 4-6 weeks, and all died within two months, whereas the female progeny were largely unaffected, reminiscent of the male bias in human patients. Examining TAF1 transcripts in the striatum, we found signs of aberrant splicing and early termination upstream of the SVA site, probably due to RNA polymerase II stalling. Together, the rapid creation of highly information GREAT-GEMMs provides valuable models for studying regulatory elements or disease associated elements that reside in the vast dark genome.
College of Future Technology, PKU