First gene-edited calf with reduced susceptibility to a major viral pathogen

Abstract

Bovine viral diarrhea virus (BVDV) is one of the most important viruses affecting the health and well-being of bovine species throughout the world. Here we used CRISPR-mediated homology-directed repair and somatic cell nuclear transfer to produce a live calf with a six amino acid substitution in the BVDV binding domain of bovine CD46. The result was a gene-edited calf with dramatically reduced susceptibility to infection as measured by clinical signs and the lack of viral infection in white blood cells. The edited calf has no off-target edits and appears normal and healthy at 16 months of age without obvious adverse effects from the on-target edit. This precision bred, proof-of-concept animal provides the first evidence that intentional genome alterations in CD46 may reduce the burden of BVDV-associated diseases in cattle, and is consistent with our stepwise, in vitro and ex vivo experiments with cell lines and matched fetal clones.

New Genomic Techniques (NGT) in animals and their agri/food/feed products

“…In collaboration with two US universities and the USDA, Acceligen has produced a cloned NGT cow with reduced susceptibility to Bovine Viral Diarrhoea virus (BVDV). An SDN-3 18 bp substitution in the BVDV 'binding domain' gene (CD46) reduced susceptibility to infection, as measured by clinical signs and the lack of viral infection in white blood cells (Workman et al, 2023). Acceligen has additionally produced 'Thamani' Holsteins that have three stacked mutations: the slick coat mutation in the PRLR gene, in addition to targeted mutations in two candidate genes (FDX2, DHRS4) that are hypothesised to result in resistance to African Trypanosomiasis.…”

“…Tuli breeds into the Holstein breed (Laible et al, 2021), interspecies allele substitutions e.g. African warthog allele into domestic pig (Lillico et al, 2016), in addition to the substitution of an 18 bp sequence coding 6 amino acids that does not exist in the species or in a sexually compatible species (Workman et al, 2023). Likewise, the production of polled cattle necessitates the replacement of a 10 bp sequence in the horned allele of the polled gene with a 212 bp repeat sequence to mimic the naturally-occurring polled allele found in Celtic beef breeds.…”