Recent Advances in the Application of CRISPR/Cas9 Gene Editing System in Poultry Species.

Collins N Khwatenge,Samuel N Nahashon

doi:10.3389/fgene.2021.627714

Abstract

CRISPR/Cas9 system genome editing is revolutionizing genetics research in a wide spectrum of animal models in the genetic era. Among these animals, is the poultry species. CRISPR technology is the newest and most advanced gene-editing tool that allows researchers to modify and alter gene functions for transcriptional regulation, gene targeting, epigenetic modification, gene therapy, and drug delivery in the animal genome. The applicability of the CRISPR/Cas9 system in gene editing and modification of genomes in the avian species is still emerging. Up to date, substantial progress in using CRISPR/Cas9 technology has been made in only two poultry species (chicken and quail), with chicken taking the lead. There have been major recent advances in the modification of the avian genome through their germ cell lineages. In the poultry industry, breeders and producers can utilize CRISPR-mediated approaches to enhance the many required genetic variations towards the poultry population that are absent in a given poultry flock. Thus, CRISPR allows the benefit of accessing genetic characteristics that cannot otherwise be used for poultry production. Therefore CRISPR/Cas9 becomes a very powerful and robust tool for editing genes that allow for the introduction or regulation of genetic information in poultry genomes. However, the CRISPR/Cas9 technology has several limitations that need to be addressed to enhance its use in the poultry industry. This review evaluates and provides a summary of recent advances in applying CRISPR/Cas9 gene editing technology in poultry research and explores its potential use in advancing poultry breeding and production with a major focus on chicken and quail. This could aid future advancements in the use of CRISPR technology to improve poultry production.

Highlights

GENE EDITING TOOLSThe poultry industry is undergoing a gene editing revolution that will change the poultry genome in the near future through targeted gene editing of the poultry species (Hwang and Han, 2018)
zinc finger nuclease (ZFNs) and transcription activator-Like effector nucleases (TALENs) differ from clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 since both use proteins that are fused together as a DNA binding domain while the CRISPR/Cas system requires the use of a specific RNA sequence molecule for DNA binding instead of the fused proteins (Kim and Kim, 2014; Razzaq and Masood, 2018)
The CRISPR/ Cas9 technology uses a specific RNA sequence called guide RNA which binds to another target sequence of DNA followed by the cleavage of Cas9 where binding has occurred

Summary

INTRODUCTION

The poultry industry is undergoing a gene editing revolution that will change the poultry genome in the near future through targeted gene editing of the poultry species (Hwang and Han, 2018). There is a possibility of using adenoviral vectors for delivery of CRISPR/Cas into the bird blastoderm in eggs resulting in chimeras that generate offspring having targeted mutations (Lee et al, 2019c) This technique of generating genome-edited poultry could fast-track many avian research studies with potential applications in poultry production. The use of poultry-specific CRISPR/Cas designed vectors containing inserted avian-specific promoters for the expression of guide RNA and Cas protein can efficiently introduce targeted gene modifications in poultry species (Ahn et al, 2017) This type of CRISPR vector can be applied in many poultry species to generate efficient knockout avian cell lines and knockout birds for various purposes.

LIMITATIONS

Findings

CONCLUDING REMARKS