alt Hacker NewsThis resembles the Chinese HIV CRISPR study because the deleted receptor was CCR5, an immune receptor. This was controversial because we don't know the long term effects of of deleting CCR5.
Viruses often use immune or other surface proteins as receptors presumably because they are important (can't be down-regulated too much).
For the pigs, it looks like they deleted just the SRCR5 domain of the CD163 protein. CD163 is used by macrophages to scavenge the hemoglobin-haptoglobin complex.
A 2017 article (of 6 pigs?) suggests that the engineered pigs are resistant to the virus "while maintaining biological function" although I don't see any experiments comparing hemoglobin-haptoglobin scavenging ability of engineered vs unedited pigs. https://pmc.ncbi.nlm.nih.gov/articles/PMC5322883
This 2024 study (of 40 pigs) found 'no significant difference' in a panel of health measures and meat quality, except that the engineered pigs had statistically significantly more greater backfat depth than the edited animals. https://www.frontiersin.org/journals/genome-editing/articles...
Interestingly, the mean weight of live pigs is slightly higher for edited pigs but lower for dead pigs. Total fat slightly higher for the edited pigs. These numbers are not statistically significant (but only a small number of pigs were tested).
The pigs were assessed at approximately 205 days in age. Pigs can live up to 20 years. Would be good to test the long term effects and the effects over multiple generations.
This paragraph is striking:
> Under the conditions of these studies, neither homozygous nor heterozygous or null pigs inoculated with PRRSV showed the acute clinical signs typically observed in commercial pigs and had overall low depression and respiratory scores (1). This may be explained by the fact that these pigs were sourced from a high-health farm and managed with minimal stress, which differs from disease expression under commercial conditions.
Sounds like the genetic editing is not necessary as long as the farm conditions are good..
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w/r/t the HIV thing - there are HIV immune populations in Scandinavia who have a natural mutation affecting CCR5, so there is at least some reason to believe it’s safe to edit or knock out.
> The pigs were assessed at approximately 205 days in age. Pigs can live up to 20 years. Would be good to test the long term effects and the effects over multiple generations.
It would be good to test for those things if the concern was for the long-term health of the pigs. The concern is whether or not they produce safe meat. Somewhere between most and all of the pork I've eaten in my life came from pigs less than a year old.