CRISPR/Cas9-based programmable genome editing in chickens: concepts, applications and regulatory issues

Area of Science:

• Avian biotechnology
• Genomics
• Molecular biology

Background:

• Genetics and genome sequencing accelerate the development of elite poultry lines.
• Transgenic technologies enable exogenous gene expression in animals.
• Genome editing is transforming avian biotechnology for trait customization.

Purpose of the Study:

• To review the applications of CRISPR/Cas9 in poultry.
• To highlight CRISPR/Cas9 as an efficient tool for studying gene function.
• To discuss the advantages of CRISPR/Cas9 over older genome-editing technologies.

Main Methods:

• Utilizing Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system with guided RNA (gRNA) and Cas9 endonuclease.
• Inducing targeted DNA double-strand breaks for gene knockout via non-homologous end joining.
• Employing transient expression of Cas9 and gRNA via plasmid systems, avoiding permanent genetic integration.

Main Results:

• CRISPR/Cas9 enables precise gene function studies and analysis of non-coding elements.
• The system allows for rapid enhancement of poultry productivity traits like growth and feed efficiency.
• CRISPR/Cas9 facilitates disease resistance improvement against avian influenza and Marek's disease.

Conclusions:

• CRISPR/Cas9 is a powerful and efficient tool for avian biotechnology, offering significant advantages over previous genome-editing methods.
• Applications in poultry include disease resistance, productivity enhancement, ethical solutions for culling, and bio-pharming.
• This technology represents a significant advancement for poultry improvement and functional genomics research.