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Biology subjects

Yang, H. Y.

Publications and source records attributed to Yang, H. Y..

2 recordsLinked to original sources

Vesicle-templated self-assembly of freestanding multi-μm DNA shells

In the quest to create increasingly complex synthetic cell-mimicking systems, a wide range of DNA nanostructures have been developed to coat, permeabilize, sculpt, or otherwise functionalize lipid vesicles. In a complementary strategy, DNA architectures have been used as scaffolds to direct the growth of lipid membrane vesicles. Here we introduce a simple and broadly applicable method to realize freestanding, membrane-mimicking DNA shells: DNA shells are first assembled on the outer surface of giant unilamellar vesicles and then liberated by surfactant-mediated liposome removal. The resulting structures faithfully retain the geometry of their membrane template. We demonstrate the approach with two distinct classes of DNA tectons: a complex barrel-shaped DNA origami with programmable inter-subunit interactions, and a simple nanostar-inspired motif composed of only eleven oligonucleotides. The site-specific addressability of the former enable the rational design of binding interfaces, as demonstrated by controlled multilayer formation. The success of both strategies underscores the generality of our approach and the feasibility of creating shell-like compartments from different DNA architectures. This method enables the construction of tunable, DNA-only containers spanning the size range of eukaryotic cells, offering a fundamentally new type of compartmentalization for bottom-up synthetic biology.

synthetic biology↗

Physics and physiology determine strategies of bacterial investment in flagellar motility

Regulatory strategies that allow microorganisms to balance their investment of limited resources in different physiological functions remain poorly understood, particularly for numerous cellular functions that are not directly required for growth. Here, we investigate the allocation of resources to flagellar swimming, the most prominent and costly behavior in bacteria that is not directly required for growth. We show that the dependence of motile behavior on gene expression in Escherichia coli is determined by the hydrodynamics of propulsion, which limits the ability of bacteria to increase their swimming by synthesizing more than a critical number of flagellar filaments. Together with the fitness cost of flagellar biosynthesis, this defines the physiologically relevant range of investment in motility. Gene expression in all E. coli isolates tested falls within this range, with many strains maximizing motility under nutrient-rich conditions, particularly when grown on a porous medium. The hydrodynamics of swimming may further explain the bet-hedging behavior observed at low levels of motility gene expression.

microbiology↗