Self-assembled DNA Nanotechnology And Its Application In Gene Mapping

Molecular markers refer to heritable and detectable DNA sequences or proteins.With the completion of the Human Genome Project(HGP),DNA molecular markers have become maps and signposts to explore various biological genomes.Mapping the positions and sequences of a gene on a chromosome is one of the important tasks of the HGP.In addition to sequencing,scientists have also developed techniques that directly read gene maps based on imaging microscopes.Compared with fluorescence microscopy,direct-reading technology based on atomic force microscopy(AFM)has the advantage of high resolution.However,the reason for limiting the development of this technology is the lack of recognizable probes.In the field of DNA nanotechnology,based on the programmability of sequence and the stability of the structure,humans have constructed a series of delicate DNA nanostructures and converted the transformation from structure to function with self-assembled DNA nanotechnology.In particular,DNA origami technology can be used to build identifiable nanostructures,which are diverse in shape,stable in structure,and controllable in size,so that they can act as identifiable probes for direct reading of atomic force microscopes.Therefore,this paper aims to solve the important issue that how to construct nanostructures as markers for gene mapping with self-assembled DNA nanotechnology.Firstly,in order to study probes based on DNA Tile structures,the catassembly of DNA nanostructures is studied in collaboration with Tile self-assembly and hybridization chain reaction(HCR).Here,the initiator strands are designed as a catalyst to catalyze HCR to fabricate one-dimensional nanostrings,two-dimensional nanopatterns and three-dimensional nanonetwork.Secondly,linking nanoparticles at specific locations of addressable origami to achieve a large-scale DNA origami structure is studied,which laid the foundation for the construction of identifiable probes.Finally,this paper realizes single-molecule gene mapping with DNA origami probes for labeling with the help of designed ‘diblock’ primers.The genomic positions are scanned by high-resolution AFM and a clear nucleic acid sequence map is obtained.