Sterile Fish Production via Maternal-Effect Gene Disruption
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Solution Overview
Problem
Current methods for sterilizing freshwater and seawater organisms, such as fish, crustaceans, and mollusks, face challenges including insufficient efficacy, increased operating costs, gene flow to wild populations, and inefficiencies in abating primordial germ cells, leading to issues like reduced growth, increased disease sensitivity, and colonization of non-native species.
Innovation Solution
A method involving breeding fertile hemizygous mutated females and males to produce sterile offspring by disrupting the maternal-effect of primordial germ cell development genes without impairing viability or fertility, using specific mutations in genes like Hnrnpab, Elavl1, or miR202-5p to reduce germ cell formation, allowing for commercially scalable and efficient production of sterile fish and crustaceans.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If triploid induction by physical treatments (temperature or pressure shock) is used to sterilize fish, then sterility is achieved, but the logistics become complicated and costs increase significantly at industrial scale
Solution Approach 1:
The patent replaces the mechanical/physical treatment system (temperature or pressure shock equipment) with a biological/genetic system. Instead of using complex physical infrastructure to induce triploidy, the invention uses genetic manipulation techniques to achieve sterility, thereby substituting mechanical complexity with biological processes that are more scalable and logistically simpler for industrial aquaculture operations
Solution Approach 2:
The patent changes the fundamental parameter of sterilization from physical conditions (temperature, pressure) to genetic conditions. By modifying the genetic makeup of the organisms rather than subjecting them to extreme physical parameters, the solution eliminates the need for complex physical treatment infrastructure while maintaining effective sterility induction
2Reliability
If triploid induction is used to produce sterile fish, then sterility is achieved, but negative performance characteristics occur including reduced growth and increased sensitivity to disease
Solution Approach 1:
The patent applies local quality by specifically targeting only the germ line development pathway for genetic manipulation while leaving somatic growth and immune function pathways intact. This selective genetic modification ensures that sterility is achieved through disruption of primordial germ cell development, while the organism's growth rate, body size, and disease resistance remain unaffected, resolving the trade-off between sterility and overall performance
3Reliability
If microinjection of antisense modified oligonucleotides is used to ablate primordial germ cells, then sterility is achieved, but the process is not viable on commercial scale due to individual egg handling requirements
Solution Approach 1:
The patent extracts the limiting step of individual egg microinjection from the sterilization process and replaces it with a scalable genetic manipulation approach. By removing the need for labor-intensive, one-by-one egg handling and instead using methods that can process large numbers of eggs simultaneously (such as genetic modification of broodstock or batch treatment), the invention enables commercial-scale production of sterile fish while maintaining effective primordial germ cell ablation
Solution Approach 2:
The patent applies preliminary action by genetically modifying broodstock fish before breeding, so that the sterility trait is inherited by the offspring. This preliminary genetic modification of parent fish eliminates the need for subsequent individual egg manipulation, allowing large-scale production of sterile fish through conventional breeding processes that can handle thousands of eggs simultaneously
4Reliability
If transgenic-based technologies are used to induce germ cell death, then sterility is achieved, but extended regulatory review processes are required before commercial use
Solution Approach 1:
The patent employs antisense modified oligonucleotides, which are transient, non-integrating RNA molecules that degrade naturally after performing their function. Unlike stable transgenic modifications that require complex regulatory approval, these temporary RNA-based interventions achieve germ cell ablation without permanent genetic changes to the organism or its offspring, thereby eliminating or significantly reducing regulatory review requirements and enabling faster commercial deployment
Data Source
AI summary
The disclosure provides a method of generating a sterile fish, crustacean, or mollusk. The method comprises breeding (i) a fertile hemizygous mutated female fish, crustacean, or mollusk with (ii) a fertile hemizygous mutated male fish, crustacean, or mollusk, selecting a female progenitor that is homozygous by genotypic selection, and breeding the homozygous female progenitor to produce the sterile fish, crustacean, or mollusk. The mutation disrupts the maternal-effect of a primordial germ cell (PGC) development gene and does not impair the viability, sex determination, fertility, or a combination thereof, of a homozygous progenitor. The disclosure also provides methods of making broodstock freshwater and seawater organisms for use in producing sterilized freshwater and seawater organisms, as well as the broodstock itself.