Abstract
The ability to preselect the sex of livestock is economically beneficial and significantly increases the welfare and proper use of animals. In the poultry industry, for example, almost all males are brutally and unnecessarily killed shortly after hatching1. The labor and associated costs of separation of females from males, as well as the massive killing of males, could be eliminated by using a system producing single-sex progeny. Here, we provide a proof of concept for such a system in mice by crossing two genetically engineered lines. The maternal line encodes a functional Cas9 protein on an autosomal chromosome, whereas the paternal line encodes guide RNAs on the Y chromosome targeting vital mouse genes. After fertilization, the presence of both the Y-encoded guide RNAs from the paternal sperm and the Cas9 protein from the maternal egg target the vital genes in males. We show that this breeding consequently self-destructs solely the males. Our results pave the way for a biased sex production of livestock, thus saving labor, costs, and eliminating substantial animal suffering.
Footnotes
↵† These authors jointly supervised this work.