The application of new breeding technology based on gene editing in pig industry — A review

Abstract

Genome/gene-editing (GE) techniques, characterized by a low technological barrier, high efficiency, and broad application among organisms, are now being employed not only in medical science but also in agriculture/veterinary science. Different engineered CRISPR/Cas9s have been identified to expand the application of this technology. In pig production, GE is a precise new breeding technology (NBT), and promising outcomes in improving economic traits, such as growth, lean or healthy meat production, animal welfare, and disease resistance, have already been documented and reviewed. These promising achievements in porcine gene editing, including the Myostatin gene knockout (KO) in indigenous breeds to improve lean meat production, the uncoupling protein 1 (UCP1) gene knock-in to enhance piglet thermogenesis and survival under cold stress, the generation of GGTA1 and CMAH gene double KO pigs to produce healthy red meat, and the KO or deletion of exon 7 of the CD163 gene to confer resistance to porcine reproductive and respiratory syndrome virus (PRRSV) infection, are described in the present article. Other related approaches for such purposes are also discussed.The current trend of global regulations or legislation for GE organisms is that they are exempted from classification as genetically modified organisms (GMOs) if no exogenes are integrated into the genome, according to product-based and not process-based methods. Moreover, an updated case study in the EU showed that current GMO legislation is not fit for purpose in term of NBTs, which contribute to the objectives of the EU's Green Deal and biodiversity strategies A c c e p t e d A r t i c l e 4 and even meet the United Nations' sustainable development goals for a more resilient and sustainable agri-food system. The GE pigs generated via NBT will be exempted from classification as GMOs, and their global valorization and commercialization can be foreseen.

The transcriptomic insight into the differential susceptibility of African Swine Fever in inbred pigs

“…Machuka et al 15 reported the down-regulation of RELA in the high- and medium-dose groups of ASFV but not differentially expressed in the low dose group. It can be concluded the gene modifications of RELA 43 , 45 – 47 and CD163 43 genes have not been successful for ASFV resistance compared with gene editing for PRRSV 48 or TGEV 49 . Two suggested DEGs can be new potential targets to gene editing for resistance to ASF.…”

Managing prolific sows in tropical environments

“…This can be achieved by genetic selection; an important tool could be the determination of new factors, like mRNA, which have been shown to play an important role the growth and development of animals in recent years and can also indicate differences in heat stress tolerance. The application of new breeding technology based on gene editing in the pig industry has been recently reviewed (Tu et al, 2022).…”

Reappraising host cellular factors involved in attachment and entry to develop antiviral strategies against porcine reproductive and respiratory syndrome virus

“…First of all, modulation of CD163 expression is effective in restraining PRRSV infection. As described above, gene editing via CRISPR-Cas9 has been applied to breed pigs lacking functional CD163, which confers resistance to PRRSV ( Prather et al, 2017 ; Whitworth and Prather, 2017 ; Tu et al, 2022 ). However, considering its significant physiological roles, pigs with deletion or partial deletion of CD163 SRCR5 domain are probably superior to those lacking intact CD163 ( Reiner, 2016 ).…”