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[前沿资讯 ] Programmable gene insertion in human cells with a laboratory-evolved CRISPR-associated transposase 进入全文
science
The ability to install large DNA sequences into specified locations in the human genome has far-reaching implications, including paving the way for single-drug treatments of mutationally diverse loss-of-function genetic diseases. CRISPR-associated transposases (CASTs) are naturally occurring systems that support RNA-programmable insertion of gene-sized DNA but have shown minimal activity in human cells. Witte et al. developed a continuous evolution platform to improve CAST activity, yielding an evolved CAST with more than 200-fold increased activity in human cells. This enzyme enables efficient gene integration across a variety of therapeutically relevant genomic sites in multiple human cell types, representing a versatile new platform for mammalian cell genome editing.
[前沿资讯 ] Leaving synthetic pesticides behind 进入全文
science
"Mitigating pesticide effects will require multiple approaches. Chemical pesticides should be progressively replaced with agroecological measures such as invertebrate biological control agents and biopesticides, many of which are cost-effective, environmentally sound, and practicable (5). Preventative pest management without chemical pesticides can include planting pest-tolerant varieties (6); using light, pheromone, or sticky traps (7); removing pest resources, such as harvest residues and alternative host plants; and altering sowing dates (8). Other strategies include diversifying crops through intercropping or cover cropping; mulching or organic manuring; establishing flower strips that provide food for predators and parasitic wasps; and raising aquatic animals, such as fish, ducks, or frogs, in cropping fields, where they can prey on insect herbivores or weeds (9). Precision agriculture and digital tools could also decrease pesticide use. Robotics, unmanned aerial vehicles (UAVs), artificial intelligence–based computer vision, and data-driven forecasting or advisory systems can all enable timely, targeted interventions (10). Tractor-pulled or autonomous camera–equipped mechanical weeders, for instance, can surgically remove weeds from a standing crop, and UAVs can “precision-drop” natural enemies or deliver biopesticide patch sprays on infestation hotspots. However, the funds and training required to use such technologies limit their accessibility and impact."
[学术文献 ] Chromatin loops are an ancestral hallmark of the animal regulatory genome 进入全文
Nature
In bilaterian animals, gene regulation is shaped by a combination of linear and spatial regulatory information. Regulatory elements along the genome are integrated into gene regulatory landscapes through chromatin compartmentalization1,2, insulation of neighbouring genomic regions3,4 and chromatin looping that brings together distal cis-regulatory sequences5. However, the evolution of these regulatory features is unknown because the three-dimensional genome architecture of most animal lineages remains unexplored6,7. To trace the evolutionary origins of animal genome regulation, here we characterized the physical organization of the genome in non-bilaterian animals (sponges, ctenophores, placozoans and cnidarians)8,9 and their closest unicellular relatives (ichthyosporeans, filastereans and choanoflagellates)10 by combining high-resolution chromosome conformation capture11,12 with epigenomic marks and gene expression data. Our comparative analysis showed that chromatin looping is a conserved feature of genome architecture in ctenophores, placozoans and cnidarians. These sequence-determined distal contacts involve both promoter–enhancer and promoter–promoter interactions. By contrast, chromatin loops are absent in the unicellular relatives of animals. Our findings indicate that spatial genome regulation emerged early in animal evolution. This evolutionary innovation introduced regulatory complexity, ultimately facilitating the diversification of animal developmental programmes and cell type repertoires.
[学术文献 ] Overexpression of StTCP10 Alters Tuber Number and Size in Potato (Solanum tuberosum L.) 进入全文
Plants
Potato (Solanum tuberosum L.), cultivated worldwide for its nutrient-rich underground tubers, represents a crucial staple crop whose yield is primarily determined by both tuber number and tuber size. TCP transcription factors, especially TCP containing miR319 binding sites, play pivotal roles in plant growth and development, yet their functions in potato tuber number and size remain largely unexplored. In this study, we systematically identified 32 TCP genes in potato harboring the conserved TCP domain, among which six were predicted to contain binding sites for Stu-miR319. Semi-quantitative experiments revealed that StTCP10 exhibited the highest expression levels in stolons, swollen stolons, and tuber tissues compared to other StTCP genes containing miR319 binding sites. To elucidate its biological function, we generated StTCP10-overexpressing transgenic potato lines through Agrobacterium-mediated genetic transformation. Phenotypic analysis demonstrated that overexpression of StTCP10 reduced tuber number per plant while enhancing tuber size, with no significant change in total yield. These findings reveal that StTCP10 with Stu-miR319 binding sites plays a critical role in tuber size and mediates the trade-off between tuber size and number, providing novel insights into the molecular breeding aimed at improving tuber size.
[前沿资讯 ] Ansa Biotechnologies Breaks Traditional Synthetic DNA Length Barriers and Redefines Future of Life Science Research 进入全文
Ansa Biotechnologies
"Ansa Biotechnologies, Inc., the trusted partner for DNA synthesis, announced the launch of its 50 kb DNA synthesis early access program, providing customers with extremely long and complex DNA sequences in less than four weeks. DNA products of this length are essential for applications including synthetic genomics, metabolic engineering, agricultural research, and next-generation cell and gene therapies. Ansa will share more information about the early access program and showcase its ultra-rapid and highly accurate enzymatic DNA synthesis technology in booth #312 at the Global Synthetic Biology (SynBioBeta) Conference this week in San Jose, Calif. Ansa’s 50 kb DNA synthesis early access program builds on recent successes and sets a new industry benchmark for synthetic DNA delivery. Researchers can now order large constructs ranging from 7.5 kb to 50 kb. The program is designed to break traditional DNA length barriers, accelerate project timelines, and unlock transformative possibilities in many areas of life science research. “For decades, scientists have been handcuffed by short DNA fragments, forced to stitch sequences together in their own labs through tedious cloning techniques,” said Jason T. Gammack, CEO of Ansa Biotechnologies. “Ansa is now changing the game by delivering longer, more complex DNA, all with a transparent and collaborative service model. This rapid increase in our product length — from only 600 bases a year ago to 7.5 kb more recently and now 50 kb through early access — illustrates our tireless dedication to empowering researchers so they can build without limits and innovate without compromise.” Ansa’s synthesis services are powered by its proprietary enzymatic manufacturing process, which enables the direct synthesis of complex DNA sequences that are often difficult or even impossible to produce with legacy synthesis methods. The sequence-agnostic platform synthesizes DNA strands up to 750 bases long, which are then rapidly assembled into plasmids up to 50 kb. Once synthesized and assembled, constructs are verified using highly accurate long-read sequencing and a proprietary informatics pipeline to ensure that customers receive the exact DNA they ordered. Unlike traditional chemical synthesis, Ansa’s enzymatic approach uses no harsh chemicals, avoiding damage to the DNA molecule and enabling the synthesis of longer, more complex sequences. Entirely manufactured in the USA, Ansa’s DNA products are easy to integrate into any experimental workflow — and are ready to power the next wave of biological innovation. For more information about Ansa’s products, please visit"
[学术文献 ] Expediting genome synthesis of Corynebacterium glutamicum with an artificial chromosome vector 进入全文
Trends in Biotechnology
Recent advances in genome synthesis have relied on scalable DNA assembly and delivery, and efficient recombination techniques. While these methods have enabled rapid progress for Escherichia coli and yeast, they are often inadequate for other microorganisms. Here, we devised a Corynebacterium glutamicum artificial chromosome (CAC), which combines a replicating system from a closely related strain with an innate partitioning system. This CAC vector can efficiently deliver DNA fragments up to 56 kb and maintain stability in C. glutamicum. Leveraging the CAC vector, we developed CAC Excision Enhanced Recombination (CACEXER), a streamlined strategy for iterative genome replacements in C. glutamicum. Using this approach, we integrated 361 kb (11%) of synthetic DNA into the genome, creating semi-synCG-A. This strain paves the way to establish C. glutamicum as the third industrial microorganism, alongside E. coli and Saccharomyces cerevisiae, to undergo large-scale genome synthesis.
