Chimeric Regulatory Elements for Tissue-Specific Gene Expression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current plant genetic engineering faces challenges in achieving sufficient and localized expression of transgenes in crops, with existing regulatory elements often failing to provide the desired patterns or levels of gene expression, particularly in specific tissues like mesophyll or bundle sheath cells, which are crucial for agronomically important traits such as photosynthetic activity and yield enhancement.
Innovation Solution
The development of chimeric or hybrid regulatory elements derived from Zea mays, specifically combining promoters, enhancers, and leaders from genes like fructose 1-6 bisphosphate aldolase, pyruvate orthophosphate dikinase, and ribulose bisphosphate carboxylase activase, to enhance gene expression in transgenic plants, particularly in leaf and bundle sheath tissues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If constitutive promoters (e.g., P-FMV, P-CaMV 35S, P-Rice Actin 1, P-NOS) are used to drive gene expression, then gene expression is achieved in most or all plant tissues during most or all of the plant's lifespan, but the expression pattern lacks tissue-specificity and cannot provide targeted expression in mesophyll or bundle sheath cells
Solution Approach 1:
The patent segments the regulatory elements from different native promoters (mesophyll-specific and bundle sheath-specific elements) and combines them in chimeric constructs to achieve targeted expression in specific cell types, resolving the contradiction between general expression and tissue-specificity
Solution Approach 2:
The patent creates composite regulatory elements by combining promoter fragments, enhancers, and other cis-acting sequences from different native genes (e.g., PPDK, FDA, RUA) to generate chimeric promoters that provide both strong expression and tissue-specificity, simultaneously achieving high productivity and adaptability
2Adaptability or versatility
If existing native promoters (e.g., FDA promoter, PPDK promoter, RUA promoter) are used to achieve tissue-specific expression in mesophyll or bundle sheath cells, then localized expression is obtained, but the expression level or pattern is insufficient to fully realize the benefits of transgene expression
Solution Approach 1:
The patent merges regulatory elements from multiple native promoters (e.g., combining PPDK promoter elements with FDA promoter elements) to create chimeric promoters that integrate the tissue-specificity of one element with the high expression capability of another, simultaneously achieving both localized expression and high productivity
Solution Approach 2:
The patent modifies expression parameters by combining different regulatory elements to alter both the spatial pattern (tissue-specificity) and the magnitude (expression level) of gene expression, achieving optimal expression characteristics that neither native promoter alone can provide
3Adaptability or versatility
If regulatory elements are combined to create chimeric molecules for enhanced tissue-specific expression, then expression pattern and localization are improved, but the device complexity and construction difficulty increase
Solution Approach 1:
The patent divides complex regulatory regions into functional segments (promoter fragments, enhancers, terminators) that can be independently characterized and then recombined in systematic ways, reducing the complexity of designing and analyzing chimeric constructs while maintaining expression control capabilities
Data Source
AI summary
The present invention provides chimeric regulatory elements constructed from gene regulatory element polynucleotide molecules isolated from the Zea mays genes fructose 1-6 bisphosphate aldolase (FDA), pyruvate orthophosphate dikinase (PPDK), or ribulose bisphosphate carboxylase activase (RUA), useful for expressing transgenes in plants. The invention further discloses compositions, polynucleotide constructs, transformed host cells, transgenic plants and seeds comprising the chimeric gene regulatory molecules, and methods for preparing and using the same.