# Key Ideas from #hplusroadmap IRC Discussion

• Researchers are developing "homing CRISPR barcodes" that evolve within living cells using guide RNAs that direct Cas9 to target its own DNA locus, with applications in lineage tracing and molecular recording.

• Novel neural imaging technologies were discussed, including photochemical imprinting of neural activity onto microbial rhodopsin proteins, quantum defects in diamond for detecting single-neuron action potentials, and genetically encoded voltage indicators (GEVIs).

• RNA imaging advances were highlighted, particularly dual-color RNA visualization using quencher and fluorophore-binding aptamers that create fluorescent turn-on probes for living cells.

• Participants discussed DNA data storage capacity, noting human DNA contains approximately 3 billion base pairs with roughly 3.5 bits per base pair potential storage (including methylation data).

• Research on RNA polymerase ribozymes was examined, with current limitations noted (best variants add only up to 95 nucleotides with limited fidelity) alongside proposals to develop controlled polymerase ribozymes using photosensitive components like azobenzene derivatives.

• Self-replicating RNA enzymes were discussed in the context of the RNA world hypothesis and origins of life research, referencing papers on highly-efficient self-replicating RNA enzymes.

• A novel approach to increase biological reliability was proposed through selection experiments where cells would be forced to survive with their genome temporarily removed, relying solely on previously manufactured components.