Identifying and retargeting transcriptional hot spots in the human genome

Mammalian cell line development requires streamlined methodologies that will reduce both the cost and time to identify candidate cell lines. Improvements in site‐specific genomic editing techniques can result in flexible, predictable, and robust cell line engineering. However, an outstanding question in the field is the specific site of integration. Here, we seek to identify productive loci within the human genome that will result in stable, high expression of heterologous DNA. Using an unbiased, random integration approach and a green fluorescent reporter construct, we identify ten single‐integrant, recombinant human cell lines that exhibit stable, high‐level expression. From these cell lines, eight unique corresponding integration loci were identified. These loci are concentrated in non‐protein coding regions or intronic regions of protein coding genes. Expression mapping of the surrounding genes reveals minimal disruption of endogenous gene expression. Finally, we demonstrate that targeted de novo integration at one of the identified loci, the 12^th exon‐intron region of the GRIK1 gene on chromosome 21, results in superior expression and stability compared to the standard, illegitimate integration approach at levels approaching 4‐fold. The information identified here along with recent advances in site‐specific genomic editing techniques can lead to expedited cell line development.     

Die Immunsysteme der Bakterien

The immune systems of bacteria and important applications in biotechnology and medicine At the end of the 70s of the last century, a new technique has been developed allowing the synthesis of genes and the inducible expression of their recombinant proteins using restriction enzymes and vectors, mainly plasmids. This era has been designated as genetic engineering and is being replenished by the CRISPR‐Cas9 technology know as genome editing. This technology is about to revolutionize alterations in the genomes of all types of organisms, including bacteria, fungi, plants, animals and even humans. It allows the introduction and elimination of point mutations and even whole genes in all organisms. Important goals are the genetic optimization of crop plants and animals, fighting against cancer in humans and elimination of human viruses and pathogenic multi‐resistant bacteria. Important drawbacks are OFF‐targets which can cause mutations in any gene or influence their expression.     

The Regulatory Status of Genome‐edited Crops

Genome editing with engineered nucleases (GEEN) represents a highly specific and efficient tool for crop improvement with the potential to rapidly generate useful novel phenotypes/traits. Genome editing techniques initiate specifically targeted double strand breaks facilitating DNA‐repair pathways that lead to base additions or deletions by non‐homologous end joining as well as targeted gene replacements or transgene insertions involving homology‐directed repair mechanisms. Many of these techniques and the ancillary processes they employ generate phenotypic variation that is indistinguishable from that obtained through natural means or conventional mutagenesis; and therefore, they do not readily fit current definitions of genetically engineered or genetically modified used within most regulatory regimes. Addressing ambiguities regarding the regulatory status of genome editing techniques is critical to their application for development of economically useful crop traits. Continued regulatory focus on the process used, rather than the nature of the novel phenotype developed, results in confusion on the part of regulators, product developers, and the public alike and creates uncertainty as of the use of genome engineering tools for crop improvement.     

Whither life? Conjectures on the future evolution of biochemistry

Life has existed on the Earth for approximately four billion years. The sheer depth of evolutionary time, and the diversity of extant species, makes it tempting to assume that all the key biochemical innovations underpinning life have already happened. But we are only a little over halfway through the trajectory of life on our planet. In this Opinion piece, we argue: (i) that sufficient time remains for the evolution of new processes at the heart of metabolic biochemistry and (ii) that synthetic biology is providing predictive insights into the nature of these innovations. By way of example, we focus on engineered solutions to existing inefficiencies in energy generation, and on the complex, synthetic regulatory circuits that are currently being implemented.