Project description:Genome editing tools with high precision are key to develop improved crops but current technologies to place new DNA into specific locations in plant genomes are low frequency and error-prone. Transposable elements (TEs) evolved to insert their DNA seamlessly into genomes, albeit in a quasi-random pattern. We developed a genome engineering tool that controls the TE insertion site and subsequently the delivery of any cargo attached to this TE. Using our tool, we demonstrated sequence-specific targeted delivery (guided by the CRISPR gRNA) of enhancers, an open reading frame and gene expression cassette into the genome of the model plant Arabidopsis, and we translated this technology to the crop soybean. We have engineered a ‘junk’ TE into a useful and accessible toolkit that enables the sequence-specific targeting of custom DNA into plant genomes.
Project description:Genome editing tools with high precision are key to develop improved crops but current technologies to place new DNA into specific locations in plant genomes are low frequency and error-prone. Transposable elements (TEs) evolved to insert their DNA seamlessly into genomes, albeit in a quasi-random pattern. We developed a genome engineering tool that controls the TE insertion site and subsequently the delivery of any cargo attached to this TE. Using our tool, we demonstrated sequence-specific targeted delivery (guided by the CRISPR gRNA) of enhancers, an open reading frame and gene expression cassette into the genome of the model plant Arabidopsis, and we translated this technology to the crop soybean. We have engineered a ‘junk’ TE into a useful and accessible toolkit that enables the sequence-specific targeting of custom DNA into plant genomes.
Project description:Here, we report a CRISPR/Cas12k-transposon-assisted genome engineering (CTAGE) method that allows for high-throughput site-specific mutagenesis in microbial genomes. Exploiting the powerful CTAGE technique, we construct a site-specific transposon mutant library focusing on all the possible transcription factors (TFs) in Pseudomonas aeruginosa, enabling comprehensive identification of essential genes and new factors for antibiotic resistance.
Project description:We have developed a microarray intended for use in finding all transposons in a region of interest. By selectively amplifying and hybridizing transposon flanking DNA to our array, we can localize all transposons in the region present on our TIP-chip, a dense tiling array. We have tested our technology in yeast and have been successful. Keywords: transposon insertion profiling, genomic DNA, yeast
Project description:The CRISPR-Cas12a platform has attracted interest in the genome editing community because the prototypic Acidaminococcus Cas12a generates a staggered DNA double-strand break upon binding to an AT-rich protospacer-adjacent motif (PAM, 5'-TTTV). The broad application of the platform in primary human cells was enabled by the development of an engineered version of the natural Cas12a protein, called Cas12a Ultra. In this study, we confirmed that CRISPR-Cas12a Ultra ribonucleoprotein complexes enabled allelic gene disruption frequencies of over 90% at multiple target sites in human T cells, hematopoietic stem and progenitor cells (HSPCs), and induced pluripotent stem cells (iPSCs). In addition, we demonstrated for the first time the efficient knock-in potential of the platform in human iPSCs and achieved targeted integration of a GFP marker gene into the AAVS1 safe harbor site and a CSF2RA super-exon into CSF2RA in up to 90% of alleles without selection. Clonal analysis revealed bi-allelic integration in >50% of the screened iPSC clones without compromising their pluripotency and genomic integrity. Thus, in combination with the adeno-associated virus vector system, CRISPR-Cas12a Ultra provides a highly efficient genome editing platform for performing targeted knock-ins in human iPSCs.
Project description:We wanted to identify Francisella tularensis bacterial mutants that are negatively selected in vivo in the lungs of mice. Mice were infected with a Francisella transposon mutant library where each gene in the genome has been mutated via the insertion of a kanamycin resistance cassette with 2 outward facing T7 promoters. 2 days post infection, infected lungs were harvested and the bacteria present in the infected lungs were collected. Bacterial genomic DNA was isolated and subjected to an in vitro T7 transcription reaction, reverse transcribed and the resulting cDNA was hybridized to our Francisella microarray. Infection: The goal of the study was to identify Francisella genes that are negatively selected in the lungs of mice post infection with a Francisella transposon mutant library. Resulting bacterial cDNA was hybridized to the Francisella microarray.