Scientists have developed a gene-editing technique using Crispr-Cas9 to create 'surrogate sires' – male animals that produce sperm carrying the genetic traits of elite donor animals. The method, tested on mice, pigs, goats, and cattle, aims to improve livestock breeding efficiency to address global food insecurity, climate change, and endangered species.
The process involves removing a gene linked to male sterility, rendering the animals sterile, then transplanting sperm-producing stem cells from donors. So far, surrogate mice have fathered healthy offspring with donor genes, providing proof of concept. Researchers are fine-tuning the technique for larger animals and expect data in the coming years.
Study author Jon Oatley of Washington State University emphasised that the surrogate sire acts as a vessel, producing non-gene-edited offspring from unmodified donor genetic material. This differs from controversial genetically modified organisms (GMOs), as gene-editing tweaks existing DNA rather than transferring genes between species.
Regulation remains a major hurdle. In the EU, gene-edited animals are governed by strict GMO laws, while countries like Argentina and Brazil have more lenient rules. Dr Alison Van Eenennaam from the University of California noted that commercialisation is unlikely if regulated as GMOs, and public perception, influenced by activist opposition, could slow adoption.
However, co-author Prof Bruce Whitelaw from the Roslin Institute struck an optimistic note, citing a shift in societal attitudes towards gene-editing. The technology could be commercialised in the UK within three years, potentially bringing premium beef to market.
