During the tenure of the Marie Sklodoska-Curie fellowship, I have developed a new method for simultaneous reporting lineage information and cellular state to study differentiation trajectories during embryo development. The method, based on CRISPR Cas9 technology, uses several barcoded guide RNAs and a Cre-inducible Cas9 protein. Upon activation, CRISPR-Cas9 is directed to make DNA double-stranded breaks that are subsequently repaired, frequently in an error-prone way, resulting in insertions or deletions. As mutagenesis continues, cells accumulate a combination of mutations that can be used to reconstruct their lineage history. The genetic mutations are captured in a polyA transcript which is sequenced together with the transcriptome and the epigenome of each cell. I have also developed a new computational method to connect molecular states (transcriptome and epigenome) with previous cellular activity (genetic mutations) at single cell resolution, thus directly connecting cell identities with the lineage of origin. A manuscript is currently in preparation, describing how cell’s history complement epigenetic and transcriptional information to characterize cell types and better understanding developmental trajectories.
This work has been presented at seminars at the host Institute and within the Cambridge scientific community. Furthermore, I will present our findings in the Single cell genomics 2022 meeting.