Cade, L., Reyon, D., Hwang, W.Y., Tsai, S.Q., Patel, S., Khayter, C., Joung, J.K., Sander, J.D., Peterson, R.T., and Yeh, J.R. (2012) Highly efficient generation of heritable zebrafish gene mutations using homo- and heterodimeric TALENs. Nucleic acids research. 40(16):8001-8010.
Transcription activator-like effector nucleases (TALENs) are powerful new research tools that enable targeted gene disruption
in a wide variety of model organisms. Recent work has shown that TALENs can induce mutations in endogenous zebrafish genes,
but to date only four genes have been altered, and larger-scale tests of the success rate, mutation efficiencies and germline
transmission rates have not been described. Here, we constructed homodimeric TALENs to 10 different targets in various endogenous
zebrafish genes and found that 7 nuclease pairs induced targeted indel mutations with high efficiencies ranging from 2 to
76%. We also tested obligate heterodimeric TALENs and found that these nucleases induce mutations with comparable or higher
frequencies and have better toxicity profiles than their homodimeric counterparts. Importantly, mutations induced by both
homodimeric and heterodimeric TALENs are passed efficiently through the germline, in some cases reaching 100% transmission.
For one target gene sequence, we observed substantially reduced mutagenesis efficiency for a variant site bearing two mismatched
nucleotides, raising the possibility that TALENs might be used to perform allele-specific gene disruption. Our results suggest
that construction of one to two heterodimeric TALEN pairs for any given gene will, in most cases, enable researchers to rapidly
generate knockout zebrafish.