Somatic Cell Nuclear Transfer Efficiency via Protamine 1 Chromatin Modification

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Solution Overview

Problem

The low efficiency of Somatic Cells Nuclear Transfer (SCNT) in cloning non-human animals is due to incomplete nuclear reprogramming of somatic cell nuclei, as the oocyte reprogramming machinery struggles to interact with the complex chromatin organization of somatic cells, leading to low success rates in producing viable offspring.

Innovation Solution

Transient expression of human protamine 1 protein or synthetic peptides corresponding to its functional parts in somatic cells induces a chromatin organization similar to that of spermatozoa, allowing for improved nuclear reprogramming when these 'protaminized' nuclei are transferred into enucleated oocytes, enhancing the efficiency of SCNT.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If somatic cell nuclei are transferred into enucleated oocytes using conventional SCNT methods, then cloning can be performed, but the efficiency is very low (1-5% offspring) due to incomplete nuclear reprogramming

Engineering Contradiction:
Improvecloning efficiencyVSAvoidnuclear reprogramming completeness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by treating somatic cells with chromatin-modifying agents (such as bromodomain-containing proteins or histone deacetylase inhibitors) before nuclear transfer. This pre-treatment modifies chromatin structure in advance to make it more receptive to oocyte reprogramming factors, thereby improving subsequent reprogramming efficiency and cloning outcomes

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes chromatin parameters (acetylation levels, condensation state, accessibility) through chemical or biochemical treatments before nuclear transfer. These parameter modifications make somatic chromatin more similar to germ cell chromatin, enabling better recognition and reprogramming by oocyte machinery, thus increasing cloning efficiency from 1-5% to higher rates

Inventive Principle:
Principle #35Parameter changes

2Productivity

If chromatin organization of somatic cells is modified before transfer, then nuclear reprogramming efficiency improves, but the complexity of the procedure increases

Engineering Contradiction:
Improvenuclear reprogramming efficiencyVSAvoidprocedure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent uses intermediary substances (chromatin-modifying proteins, small molecules, or enzymatic agents) that mediate between somatic chromatin and oocyte reprogramming factors. These intermediaries temporarily alter chromatin structure to facilitate interaction with reprogramming machinery, then are removed or degraded, simplifying the overall process compared to permanent genetic modifications

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex mechanical or surgical interventions with biochemical treatments to achieve chromatin modification. Instead of physical manipulation or extensive procedural steps, chemical agents naturally modify chromatin structure through established biological pathways, reducing procedural complexity while maintaining effectiveness

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 significantly increases the proportion of somatic cell nuclei that are reprogrammed to the blastocyst stage, improving the overall efficiency of SCNT and making the process more reliable for non-human animal production, transgenic animal creation, and regenerative medicine applications.

Implementation Method 1

Transient expression of human protamine 1 protein or synthetic peptides corresponding to its functional parts in somatic cells induces a chromatin organization similar to that of spermatozoa

Methodology Applied
Scientific EffectChromatin condensation:

Data Source

PatentEP3134532B1Improved method for reconstructing a non-human animal embryo
Publication Date: 2019.04.17 UNIV DEGLI STUDI DI BERGAMO
  • EP3134532B1 patent drawingFigure 1A~1
  • EP3134532B1 patent drawingFigure 2A~2H
  • EP3134532B1 patent drawingFigure 3A~3Ca2

AI summary

The present invention refers to a method for reconstructing a non-human animal embryo, to a method for generating a non-human animal and to a non-human animal or non-human animal reconstructed embryo obtainable by the methods according to the invention. The method of somatic cell nuclear transfer (SCNT) comprises a step of transiently expressing or inducing the uptake of a protein involved in male sperm maturation, such as protamine or transition protein, in the somatic donor cell before nuclear transfer.