Creating sterile broiler and layer breeds for the poultry industries

The poultry industry contributes over 40% of the world’s dietary protein, primarily by producing table eggs from layers and meat from broilers. The industry faces critical challenges, including animal welfare issues related to feed restriction in broiler breeders. These challenges can utilize layer breeds to give rise to broilers. They can be addressed by using a layer of sterile surrogate hosts injected with embryonic Primordial Germ Cells (PGCs) of broiler breeds, which give rise to broiler sperm and eggs in adults. Ablating PGCs or affecting their ability to form gametes results in sterility. Several genes, including DDX4 and Dazl, are known to be required for fertility. Our project aims to silence genes required for fertility using genome editing, thereby creating sterile embryos that can serve as ideal hosts for donor PGCs. Breeding for sterile embryos can be achieved when both parents are heterozygous, having one unmodified copy and one mutated allele of these genes.

As a proof-of-concept, we designed an experiment in which broiler-type PGCs were injected into layer-type surrogate embryos. The resulting layer hens laid eggs from which broiler chicks hatched, thus demonstrating the feasibility of this project. Additionally, by finely calibrating the activity of the CRISPR-Cas9 system, PGCs with one mutated allele and one unmodified allele were created, and the resulting founder chicks are soon expected to hatch. Sterile embryos will be created by crossing between them. Generating sterile surrogates will make a sustainable and economical contribution, addressing the devastating animal welfare issue associated with rearing broiler breeders.

Project Researcher: Dr. Yuval Cinnamon .

Research Partners: Ms Michal Mimon, Dr. Enbal Ben-Tal Cohen , Dr. Tatyana Kushnir , Ms. Olga Genin.