CRISMERE Chromosome Engineering in Mouse and Rat.

CRISPR/Cas9 technology is a versatile tool for engineering biology that has dramatically transformed our ability to manipulate genomes. In this protocol, we use its capacity to generate two double-strand breaks simultaneously, at precise positions in the genome, to generate mouse or rat lines with deletion, inversion, and duplication of a specific genomic segment. The technic is called CRISMERE for CRISpr-MEdiated REarrangement.

Increased On-Target Rate and Risk of Concatemerization after CRISPR-Enhanced Targeting in ES Cells.

The French mouse clinic (Institut Clinique de la Souris; ICS) has produced more than 2000 targeting vectors for 'à la carte' mutagenesis in C57BL/6N mice. Although most of the vectors were used successfully for homologous recombination in murine embryonic stem cells (ESCs), a few have failed to target a specific locus after several attempts. We show here that co-electroporation of a CRISPR plasmid with the same targeting construct as the one that failed previously allows the systematic achievement of positive clones.

Efficient and rapid generation of large genomic variants in rats and mice using CRISMERE.

Modelling Down syndrome (DS) in mouse has been crucial for the understanding of the disease and the evaluation of therapeutic targets. Nevertheless, the modelling so far has been limited to the mouse and, even in this model, generating duplication of genomic regions has been labour intensive and time consuming. We developed the CRISpr MEdiated REarrangement (CRISMERE) strategy, which takes advantage of the CRISPR/Cas9 system, to generate most of the desired rearrangements from a single experiment at much lower expenses and in less than 9 months.