Programmable Genomic Editing for Functional Genomics Study in Chicken

Genetically modified animals are utilized for scientific researches contributing to a better understanding of biological mechanism and regulatory network. In chicken, we successfully applied piggyBac transposon isolated from the cabbage looper moth to deliver the transgenes into cultured chicken primordial germ cells (PGCs) and finally, transgenic chickens were efficiently generated. The piggyBac transposons with transposase-mediated catalytic process enhanced the chicken genomic integration and the production of transgenic offspring. Additionally, gene targeting techniques have been developed to edit specific loci in the genome. However, the conventional strategy of homologous recombination with a gene-targeted vector has low efficiency and many technical complications. Recently, novel approaches have been designed to efficiently produce animals that are genetically altered in specific genomic sequences; zinc-finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN), and clustered regularly interspaced short palindromic repeats (CRISPR)-associated genome editing technologies. These knockout systems would revolutionize the research field of functional genomics by allowing the analysis of specific gene functions in vivo.