Zinc-finger nucleases (ZFNs) and Transcription activator-like effector nucleases (TALENs) are two types of targeted nucleases generated by joining the restriction enzyme FokI DNA-endonuclease domain with modular DNA-binding units derived from Zinc-Finger domains or TALE domains, respectively, thereby providing DNA sequence specificity for the double strand break (DSB). The endogenous cellular systems would then resolve this DSB, through the non-homologous end joining (NHEJ) process, usually generating mutations around this DSB. Alternatively, a given DNA template with overlapping homology around the DSB may be also provided, resulting in the integration of new DNA sequences, through homologous recombination, according to the homology-driven repair (HDR) process. Combining the target specificity of these nucleases with NHEJ and HDR has allowed the generation of a new wave of transgenic animals carrying mutations at specific loci. These technical developments have probably changed, and certainly expanded, our view about how we can produce nowadays genetically-modified animals.
The great expectation and interest in using ZFNs and TALENs, and their applications in animal transgenesis, will be discussed, extensively, in Guangzhou (China), at the next 11th Transgenic Technology (TT2013) meeting (25-27 February 2013), thanks to the various talks that will be delivered by our invited speakers on this subject.
The use of ZFNs for targeted mutagenesis in mice will be introduced by Dietmar Kappes (Fox Chase Cancer Center, Philadelphia, PA, USA).
The use of ZFNs to produce mono-allelic knockout pigs will be presented by Liangxue Lai (Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, PR China), based on a recent publication from his group:
Generation of PPAR-gamma mono-allelic knockout pigs via zinc-finger nucleases and nuclear transfer cloning.
Yang D, Yang H, Li W, Zhao B, Ouyang Z, Liu Z, Zhao Y, Fan N, Song J, Tian J, Li F, Zhang J, Chang L, Pei D, Chen YE, Lai L.
Cell Res. 2011 Jun;21(6):979-82.
The use of TALENs in zebrafish will be presented by Bo Zhang (College of Life Sciences, Peking University, Beijing, PR China) based on his recent developments:
Heritable gene targeting in zebrafish using customized TALENs.
Huang P, Xiao A, Zhou M, Zhu Z, Lin S, Zhang B.
Nat Biotechnol. 2011 Aug 5;29(8):699-700.
Carlson DF, Tan W, Lillico SG, Stverakova D, Proudfoot C, Christian M, Voytas DF, Long CR, Whitelaw CB, Fahrenkrug SC.
Proc Natl Acad Sci U S A. 2012 Oct 1.
Bedell VM, Wang Y, Campbell JM, Poshusta TL, Starker CG, Krug Ii RG, Tan W, Penheiter SG, Ma AC, Leung AY, Fahrenkrug SC, Carlson DF, Voytas DF, Clark KJ, Essner JJ, Ekker SC.
Nature. 2012 Sep 23. doi: 10.1038/nature11537.