The versatility of Shigella effectors

When Shigella infect the intestinal epithelium, they deliver several effectors through the type III secretion system (T3SS) into the surrounding space and directly into the host-cell cytoplasm, where they can mimic and usurp host cellular functions or subvert host-cell signalling pathways and the immune response. Although bacterial strategies and mechanisms of infection vary greatly, recent studies of Shigella effectors have revealed that Shigella possess a highly evolved strategy for infection.     

Use of designer nucleases for targeted gene and genome editing in plants

The ability to efficiently inactivate or replace genes in model organisms allowed a rapid expansion of our understanding of many of the genetic, biochemical, molecular and cellular mechanisms that support life. With the advent of new techniques for manipulating genes and genomes that are applicable not only to single‐celled organisms, but also to more complex organisms such as animals and plants, the speed with which scientists and biotechnologists can expand fundamental knowledge and apply that knowledge to improvements in medicine, industry and agriculture is set to expand in an exponential fashion. At the heart of these advancements will be the use of gene editing tools such as zinc finger nucleases, modified meganucleases, hybrid DNA/RNA oligonucleotides, TAL effector nucleases and modified CRISPR/Cas9. Each of these tools has the ability to precisely target one specific DNA sequence within a genome and (except for DNA/RNA oligonucleotides) to create a double‐stranded DNA break. DNA repair to such breaks sometimes leads to gene knockouts or gene replacement by homologous recombination if exogenously supplied homologous DNA fragments are made available. Genome rearrangements are also possible to engineer. Creation and use of such genome rearrangements, gene knockouts and gene replacements by the plant science community is gaining significant momentum. To document some of this progress and to explore the technology's longer term potential, this review highlights present and future uses of designer nucleases to greatly expedite research with model plant systems and to engineer genes and genomes in major and minor crop species for enhanced food production.     

Targeted activation of BmCyclinE in Bombyx mori using designer TAL effectors

Dear Editor, Artificial expression systems are crucial to functional genomics studies, constructing synthetic genetic circuits, and bioengineering (Werner & Gossen, 2014). They are usually achieved by cloning the coding sequence (CDS) of a target gene into a vector containing natural or engineered regulatory elements. However, this strategy is limited when target genes are hard to clone, for example when the CDS is too long, or expression level is too low.