Extrachromosomal Circular DNA Tethering for High Gene Copy Number Expression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for introducing heritable genetic traits into plants are limited by the integration of genetic constructs into the host genome, which restricts gene expression and copy number, and there is a need for efficient mechanisms to confer agronomically useful traits such as herbicide resistance and adaptability.
Innovation Solution
The use of extrachromosomal circular plant DNA (eccDNA) that tethers to endogenous chromosomes for stable extrachromosomal replication, allowing for high copy numbers of target genes and traits to be expressed, transmitted to progeny, and modulated for adaptive evolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If genetic constructs are integrated into the host genome, then heritable genetic traits can be introduced, but gene expression and copy number are restricted
Solution Approach 1:
The patent separates the genetic construct from the host genome by using extrachromosomal circular DNA (eccDNA) that exists independently outside the chromosome. This segmentation allows multiple copies of the genetic construct to be maintained without integrating into the complex host genome structure, thereby increasing gene copy number while avoiding genomic integration complexity
Solution Approach 2:
The patent uses an origin of replication sequence as an intermediary element that enables eccDNA to replicate autonomously in the host cell without integrating into the genome. This intermediary mechanism allows the genetic construct to be maintained and expressed at high copy numbers independently of the host chromosome
2Productivity
If extrachromosomal circular DNA is used for high copy number expression, then gene expression is enhanced, but stable transmission to progeny must be ensured
Solution Approach 1:
The patent combines features of both extrachromosomal and chromosomal DNA by designing eccDNA that can tether to host chromosomes during cell division. This merging approach allows the eccDNA to maintain high copy number expression while also ensuring reliable transmission to progeny through chromosome-associated segregation mechanisms
Solution Approach 2:
The patent creates a dynamic system where eccDNA can switch between extrachromosomal existence and chromosome tethering states. During interphase, eccDNA exists as independent circular DNA for high expression; during mitosis, it tethers to chromosomes for stable inheritance. This dynamic behavior resolves the contradiction between high productivity and reliable transmission
3Stability of the object's composition
If eccDNA tethers to chromosomes for stable maintenance, then inheritance is improved, but mechanisms for rapid adaptation must be preserved
Solution Approach 1:
The patent implements periodic switching between stable chromosome tethering and autonomous extrachromosomal replication. During normal conditions, eccDNA tethers to chromosomes for stable maintenance; under selective pressure, it can detach and amplify independently, enabling rapid adaptation. This periodic action between stability and adaptability modes resolves the contradiction
Data Source
AI summary
Methods of modifying plants by amplifying native or introducing extrachromosomal circular plant DNA comprising one or more exogenous or endogenous genes conferring an agronomically useful trait when expressed in a plant, or disrupting the association or tethering of endogenous extrachromosomal circular plant DNA with endogenous chromosomes in a plant to change one or more plant traits.