Chromosome labeling with the CRISPR/dCas9 system in live cells. (A) Decondensed chromosomes are found in the interphase nu-cleus, and each of them occupies distinct nuclear spaces known as CTs. On the other hand, condensed chromosomes are found in the nucleus at mitotic phase. Decondensed and condensed chromosomes have different conformations, and these structures of the target chromosome (green) can be observed with the CRISPR/dCas9 label-ing system. (B) The CRISPR/dCas9 system requires dCas9 fused with a fluorescent protein (in this case, EGFP is depicted) and gRNA. dCas9 with the fluorescent protein forms a complex with gRNA, and is directed to a target sequence with PAM. Then, this complex binds to the specific genomic site via gRNA-DNA hybridization, and fluorescent signals at this location can be tracked using various microscopic approaches.
