There is a Japanese legend of an extraordinary strong child ‘Kintaro’, who caught a carp, taller than himself, only with his arms. Carp are familiar to people all over Japan as Koinobori (carp streamer) that is put up in May for their children's healthy growth. In this drawing, Kintaro is showing his extraordinary grip that acts as an external force to drive cellular convergent extension (a process in which a tissue is elongated along a certain axis by cell intercalation in animal development) to elongate the carp's body. The progression status of the convergent extension can be observed by the pattern of the carp's colored scales.
Genome editing technologies have been invented and improved in recent years, and there is a growing expectation that the technologies can be utilized as a tool not only for molecular biological studies, but also for genetic therapies. Among them, CRISPR-Cas9 system that was originally found as a part of the bacterial adaptive immune system gets noticed for its easy introduction. Here, users are only required to design a guide RNA with a 20-nt sequence that is complementary to the target DNA sequence and co-express Cas9 with the RNA in vivo, then Cas9 protein will cleave the target DNA in site-specific manner. This is a portrait of a kabuki actor who plays Cas9 as indicated by the crest “ku” (‘nine’) on kimono he is wearing. The “actor” definitely has a promising future ahead of him.