Insulin-like Factor Gene Silencing for Male Monosex Prawn Production

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Solution Overview

Problem

Current methods for producing male monosex populations of decapod crustaceans, such as Macrobrachium rosenbergii, are inefficient and require high technical skills, involving tedious procedures like manual segregation and microsurgical removal of the androgenic gland, which are not economically beneficial.

Innovation Solution

An isolated nucleic acid molecule encoding an insulin-like factor specifically expressed in the androgenic gland of Macrobrachium rosenbergii is used, along with double-stranded RNAs complementary to the insulin-like factor gene, to silence its expression, leading to temporary prevention of appendix masculina regeneration and inhibition of spermatogenesis, resulting in functional sex reversal from males to neofemales.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual segregation and microsurgical removal of the androgenic gland are used to produce male monosex populations, then male monosex populations can be produced, but the process requires high technical skills and is tedious and inefficient

Engineering Contradiction:

Improveefficiency of producing male monosex populationsVSAvoidtechnical skill requirement and operational complexity

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The patent replaces manual mechanical procedures (microsurgical removal of androgenic gland) with a molecular biological approach using double-stranded RNA injection to silence the insulin-like factor gene. This substitution eliminates the need for complex surgical skills and manual segregation, making the process simpler and more scalable for producing male monosex populations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the approach from physical manipulation of tissues to genetic parameter manipulation by injecting dsRNA that targets the insulin-like factor gene. This parameter change from mechanical to molecular level enables efficient gene silencing without requiring high technical skills for surgical procedures.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the insulin-like factor gene expression is silenced using double-stranded RNA, then functional sex reversal from males to neofemales is achieved, but the process requires identification and synthesis of specific gene sequences

Engineering Contradiction:

Improveefficiency of sex reversal processVSAvoidmolecular biology procedure complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent uses double-stranded RNA that is complementary to the insulin-like factor gene sequence, effectively creating a molecular copy that targets and silences the specific gene. This copying approach enables precise gene silencing without requiring complex molecular biology equipment, as the dsRNA can be synthesized from the known gene sequence and injected to achieve sex reversal.

Inventive Principle:

Principle #26Copying

3Productivity

If traditional methods are used, then male monosex populations can be produced, but the process is not economically beneficial

Engineering Contradiction:

Improveproduction efficiency of male monosex populationsVSAvoideconomic benefit

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent employs double-stranded RNA injection as a disposable, simple procedure that does not require expensive surgical equipment or highly trained personnel. The dsRNA can be synthesized from the identified gene sequence and injected into prawns to achieve sex reversal, providing an economically beneficial alternative to costly and complex surgical methods.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method enables the production of all-male populations, which grow faster and mature sooner than females, providing an economically advantageous and technically improved means of producing male monosex populations.

Implementation Method 1

administering to post-larvae M. rosenbergii males double stranded RNAs, in which one of the strands comprises a nucleotide sequence that is complementary to at least a portion of the open reading frame of an insulin-like factor gene of the androgenic gland (AG) of M. rosenbergii, resulted in silencing the expression of the insulin-like factor gene in these M. rosenbergii freshwater prawns

Methodology Applied

Scientific EffectRNA interference:

Data Source

PatentUS9049850B2Insulin-like gene of prawns and uses thereof

Publication Date: 2015.06.09 BEN GURION UNIVERSITY OF THE NEGEV

AI summary

Nucleic acid molecules encoding an insulin-like factor of the androgenic gland of the freshwater prawn Macrobrachium rosenbergii (M. rosenbergii) are disclosed. Also disclosed are methods of silencing the expression of the insulin-like factor gene in decapod crustaceans order, particularly in M. rosenbergii, useful for producing male monosex populations.