African Swine Fever Virus Interaction with Host Innate Immune Factors.

African swine fever virus (ASFV) adversely affects pig farming owing to its 100% mortality rate. The condition is marked by elevated body temperature, bleeding, and ataxia in domestic pigs, whereas warthogs and ticks remain asymptomatic despite being natural reservoirs for the virus. Breeding ASFV-resistant pigs is a promising solution for eradicating this disease. ASFV employs several mechanisms to deplete the host antiviral response. This review explores the interaction of ASFV proteins with innate host immunity and the various types of machinery encompassed by viral proteins that inhibit and induce different signaling pathways, such as cGAS-STING, NF-κB, Tumor growth factor-beta (TGF-ß), ubiquitination, viral inhibition of apoptosis, and resistance to ASFV infection. Prospects for developing a domestic pig that is resistant to ASFV are also discussed.

Bayesian Phylodynamic Analysis Reveals the Dispersal Patterns of African Swine Fever Virus.

The evolutionary and demographic history of African swine fever virus (ASFV) is potentially quite valuable for developing efficient and sustainable management strategies. In this study, we performed phylogenetic, phylodynamic, and phylogeographic analyses of worldwide ASFV based on complete ASFV genomes, B646L gene, and E183L gene sequences obtained from NCBI to understand the epidemiology of ASFV. Bayesian phylodynamic analysis and phylogenetic analysis showed highly similar results of group clustering between E183L and the complete genome. The evidence of migration and the demographic history of ASFV were also revealed by the Bayesian phylodynamic analysis. The evolutionary rate was estimated to be 1.14 × 10-5 substitution/site/year. The large out-migration from the viral population in South Africa played a crucial role in spreading the virus worldwide. Our study not only provides resources for the better utilization of genomic data but also reveals the comprehensive worldwide evolutionary history of ASFV with a broad sampling window across ~70 years. The characteristics of the virus spatiotemporal transmission are also elucidated, which could be of great importance for devising strategies to control the virus.

Validation of the Reference Genes for the Gene Expression Studies in Different Cell Lines of Pig.

Reverse transcription quantitative real-time polymerase chain reaction is one of the important methods to investigate gene expression in cells and tissues. However, if the data cannot be normalized with appropriate reference genes, the results may be unreliable. In this study, we detected the expression of 15 reference genes in three pig cell lines. The results showed that SDHA and ALDOA were the most stable reference genes in 3D4/21 cells. TOP2B, TBP, and PPIA were the most stable reference genes in PK-15 cells. SDHA and ALDOA were the most stable reference genes in IPEC-J2 cells. In addition, each cell line only needs to use two reference genes to standardize the expression of target genes. Taken together, this study provides a reference for different pig cell lines to select reference genes and also provides a theoretical basis for the use of these cell lines in related functional researches.

The Meishan pig genome reveals structural variation-mediated gene expression and phenotypic divergence underlying Asian pig domestication.

There are wide genomic and phenotypic differences between Asian and European pig breeds, yet the current reference genome is the European Duroc pig genome. A high-quality pig genome is lacking for genetic analysis of agricultural traits in Asian pigs. Here, using a hybrid approach, a high-quality reference genome (MSCAAS v1) for the Asian Meishan breed is assembled with a contig N50 size of 48.05 Mb. MSCAAS v1 outperforms the Duroc genome as a reference genome for Asian breeds. Genomic comparison reveals 49,103 structural variations (SVs) between Meishan and Duroc, 4.02% of which are Asian-specific SVs (AP-SVs). Notably, a 30-Mb hotspot for AP-SVs on chromosome X enriched for genes associated with Asian-pig-specific phenotypes is present in Asian domestic pig breeds, but absent in Asian wild boars, suggesting that Asian domestic breeds share a common ancestor. Interbreed transcriptomics reveals transcriptional suppression roles of AP-SVs in multiple tissues. Finally, transcriptional regulation in the intron of IGF2R is reported, as genomic SV (274-bp deletion) in Tibetan pig limits its growth compared to domestic pig breeds. In summary, this study provides insights regarding the genetic changes underlying pig domestication and presents a benchmark-setting resource for the utilization of agricultural valuable loci in Asian pigs.