TALENs: a widely applicable technology for targeted genome editing

Abstract

Preface Engineered nucleases enable the targeted alteration of any DNA sequence in a wide range of cell types and organisms. The newly-developed transcription activator-like effector nucleases (TALENs) comprise a non-specific DNA-cleaving nuclease fused to a DNA-binding domain that can be easily engineered so that TALENs can target essentially any sequence. The capability to quickly and efficiently alter any gene sequence using TALENs promises to have profound impacts on biological research and to yield potential therapeutic strategies for genetic diseases.

A future scenario of the global regulatory landscape regarding genome-edited crops

“…The regulatory stance of the USDA APHIS seems unfavorable because they have applied their GMO regulations to crops generated using genome editing techniques that substantially differ from conventional GMO techniques. It would be vital to interrogate developers about how off-target mutations, which can potentially occur during genome editing (Klug, 2010;Joung and Sander, 2013;Hsu et al, 2014), were investigated in the resultant plants (Araki and Ishii, 2015;Ishii and Araki, 2016;Huang et al, 2016). Although off-target mutations may result in a silent mutation or a loss of function, some could lead to a gain of function through such mechanisms as a frameshift mutation, potentially affecting food safety or the environment (Araki et al, 2014) (Araki and Ishii, 2015;Ishii and Araki, 2016).…”

“…Zinc-finger nucleases (ZFNs), (Klug, 2010) transcription activator-like effector nucleases (TALENs) (Joung and Sander, 2013) and the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 system (Hsu et al, 2014) (so-called genome editing), can create DNA double-strand breaks (DSBs) at target sites, and subsequently add an exogenous gene or copy a variant via homologydirected repair (HDR) together with a DNA template. Genome editing can also create insertions or deletions (indels) of various lengths via non-homologous end-joining (NHEJ) without a DNA template, mostly resulting in gene disruption.…”

Advancing biotechnology with CRISPR/Cas9: recent applications and patent landscape

“…Only recently discovered, CRISPR/Cas9 technology has already been enhanced to the point of fulfilling most of the genome editing and gene regulation currently demanded, ranging from the ability to perform multiple gene insertions, gene knockouts, combinatorial libraries, to advanced fine-tuning of biosynthetic pathways [23,39,47,95]. However, off-targeting remains an important limitation to the Retrotransposons are composed of similar DNA sequences, which ultimately allows to generate a promiscuous gRNA able to target several of these targets at once.…”

“…Until recently, most of the genetic engineering tools developed were based on DNA:protein recognition principles, such as restriction enzymes, sitedirected zinc finger nucleases (ZFs), and TAL effector nucleases (TALENs) [6,47]. However, these tools are commonly experienced with difficulties in design, synthesis, and efficiency which altogether prevented a global widespread adoption, e.g.…”

Translating Lung Function Genome-Wide Association Study (GWAS) Findings

“…The engineered nuclease binds and causes a double-strand break to DNA. Then non-homologous end-joining or homologydirected repair are activated, thus allowing editing of target sites (Joung & Sander, 2013 (Gilbert et al, 2013;Konermann et al, 2015;Maeder et al, 2013;Mali et al, 2013). In those circumstances the Cas9 endonuclease is catalytically inactivated (dCas9).…”