Two new CRISPR-based approaches for genome editing in plants are reported in Nature Plants this week. The first method, developed by scientists at Zhejiang University, involves engineering a plant negative-strand RNA virus-based vector to enable DNA-free delivery of a complete CRISPR-Cas9 cassette into plants. The team uses their technique to achieve single, multiplex mutagenesis, and chromosome deletions at high frequency in a model allotetraploid tobacco host with minimal to no off-target effects. The second method was developed by a University of Helsinki-led group and combines CRISPR-Cas9 with an XVE-based, cell type-specific inducible system, which allows target genes to be efficiently and conditionally knocked out at any developmental stage. This system, the scientists write, "is well suited to tracing of early molecular and cellular changes before visible phenotypes appear" and can be repurposed for base editing or transcriptional regulation by using different Cas9 variants.
Traditional health data privacy models provide limited protection for genomic data, necessitating continued improvements in both privacy technologies and in regulations and guidelines for such data, a pair of University of California, San Diego researchers write in Nature Genetics this week. In their review article, the team provides an overview of the major privacy threats facing genomics research and discuss the data-protection challenges presented by the emerging direct-to-consumer genetic testing market. They also offer basic privacy-protection techniques for genomic data, highlighting their potential application in direct-to-consumer genetic testing and forensic analyses, and discuss opportunities for improving the design of privacy-protection approaches through the use of new technologies and privacy initiatives for data sharing.
A method for speeding up the super-resolution microscopy technique DNA-PAINT is presented in Nature Methods this week. DNA-PAINT involves tagging small pieces of DNA with a fluorescent dye that transiently binds to matching DNA strands attached to a target molecule, resulting in a blinking that enables stochastic super-resolution microscopy. Despite its benefits, DNA-PAINT is limited by slow imaging speeds that have only been partially addressed by rational sequence design and buffer optimization. To further improve the technique, Ludwig Maximilian University scientists introduced concatenated, periodic DNA sequence motifs that yield up to 100-fold-faster sampling versus traditional DNA-PAINT. They also extend their approach to six orthogonal sequence motifs, enabling speed-optimized multiplexed imaging.