Dimitrov, L., et. al. Germline Gene Editing in Chickens by Efficient CRISPR-Mediated Homologous Recombination in Primordial Germ Cells. (2016) PLoS ONE 11(4): e0154303. doi:10.1371/journal.pone.0154303. http://www.ncbi.nlm.nih.gov/pubmed/27099923
Genetic modification of birds has proven challenging due limited access to fertilized zygotes. German researchers used CRISPR/Cas9 to overcome this barrier. Primordial germ cells were modified in vitro and subsequently introduced to the germ line. The resulting offspring were modified at the targeted IgH gene demonstrating that editing chicken genomes is possible with CRISPR/Cas9.