Coloration is a crucial trait that allows species to adapt and survive in different environments. Wild boars exhibit alternating black (dark) and yellow (light) longitudinal stripes on their back during their infancy (juvenile stripes), and as adults, they transform into uniform wild-type coat color. Aiming to record the procedure of juvenile stripes disappearing, piglets (WD) with juvenile stripes were produced by crossing a wild boar with Duroc sows, and photos of their coat color were taken from 20 d to 220 d. The pigments in the hairs from the black and yellow stripes were determined. Furthermore, the differentially expressed genes between the black and yellow stripes were investigated in 5 WD with the age of 30 d using whole-transcriptome sequencing to explore the genetic mechanism of the juvenile stripes. The juvenile stripes started to disappear at about 70 d, and stripes were not distinguished with the naked eye at about 160 d; that is, the juvenile stripe completely disappeared. A hotspot of a differentially expressing (DE) region was found on chromosome 13, containing/covering 2 of 13 DE genes and 8 of 10 DE lncRNAs in this region. A network among ZIC4, ssc-miR-532-3p, and ENSSSCG00000056225 might regulate the formation of juvenile stripes. Altogether, this study provides new insights into spatiotemporal coat color pattern.

Echinococcosis is a worldwide disease endemic to the western region of China. In 2023, echinococcosis was detected in one of 27 wild boars (Sus scrofa) in Yili Prefecture, Xinjiang, northwestern China. Histopathological staining and full sequence mitochondrial (mt) analysis were used to determine the infection genotype. Echinococcus granulosus was detected in the wild boar liver, and the cystic lesion characteristics indicated the E. granulosus genotype (G1). This case is the first confirmation of wild boar serving as a transmitter for the G1 genotype of E. granulosus within China. These findings suggest that surveillance is needed to assess the risk of E. granulosus sensu lato transmission to humans and wild animals.

We studied the efficacy of different formulations of polyphenol extracts (mainly containing hydroxytyrosol and tyrosol) from olive mill vegetation water on the microflora on the surfaces of game meat cuts with high or low initial bacterial loads. Meat with a high microbial load (>5 Log cfu/g; mean value = 6.83 ± 0.45 standard deviation) was immersed for 10 or 60 sec into 25% and 10% solutions of microencapsulated freeze-dried and non-encapsulated polyphenolic extracts. Aerobic colony, Enterobacteriaceae, Pseudomonas spp., and lactic acid bacteria counts were determined on treated samples compared to controls after 7 days of storage (in vacuum-packed conditions at +3 °C). Significant differences were registered only for aerobic colony count for a 10% liquid extract treatment (0.64 log reduction). In contrast, the dipping or immersion of game meat with low initial microbial loads (<5 Log cfu/g; mean value = 3.58 ± 0.72 standard deviation) in 10% solutions of the polyphenol extracts effectuated significant reductions in all bacteria counts (p < 0.002) at 7 and 14 days of storage for different extracts, independently from the application methods. The use of the extracts to inhibit bacterial growth in game meat should only be considered if a good hygienic baseline is guaranteed.

With the implementation of ecological engineering projects and related policies in China, wild boar (Sus scrofa) populations have surged, leading to increasingly serious conflicts with humans. We evaluated their potential habitat changes from the perspective of environmental suitability. To elucidate the suitable habitat characteristics for wild boars, we obtained data from 79 sites in five provinces in northwest China using database retrieval, human-wildlife conflict (HWC) incident questionnaires, and document retrieval. Thus, 10 environmental variables with lower correlation were selected, and potentially suitable distribution areas for wild boars under the current climate scenario were predicted based on the maximum entropy model. These areas were superimposed with different land use types in different periods to explore habitat selection. Precipitation seasonality (26.40%), human footprint index (16.50%), and elevation (11.90%) were the main environmental factors affecting wild boar distribution. The areas with high potential suitability for wild boars were mainly in the southeast and northwest of the region (total area of 2.63 × 105 km2). The land use types in the high-suitability zones are mainly woodland and grassland with high coverage, canopy density, and cultivated land borders. This study provides a reference for the effective prevention of HWC and management of wild boars.

Four species of porcine circoviruses (PCV1-4) have been reported to circulate in Chinese domestic pigs, while the epizootiology of these viruses in free-ranging wild boars in China remains unknown. In this study, tissue and serum samples collected from diseased or apparently healthy wild boars between 2018 and 2020 in 19 regions of China were tested for the prevalence of PCV1-4 infections. Positive rates of PCV1, PCV2, and PCV3 DNA in the tissue samples of Chinese wild boars were 1.6% (4/247), 58.3% (144/247), and 10.9% (27/247) respectively, with none positive for PCV4. Sequence analysis of viral genome showed that the four PCV1 strains distributed in Hunan and Inner Mongolia shared 97.5%-99.6% sequence identity with global distributed reference strains. Comparison of the ORF2 gene sequences showed that 80 PCV2 strains widely distributed in 18 regions shared 79.5%-100% sequence identity with reference strains from domestic pigs and wild boars, and were grouped into PCV2a (7), PCV2b (31) and PCV2d (42). For PCV3, 17 sequenced strains shared 97.2%-100% nucleotide identity at the genomic level and could be divided into PCV3a (3), PCV3b (2) and PCV3c (12) based on the phylogeny of ORF2 gene sequences. Serological data revealed antibody positive rates against PCV1 and PCV2 of 11.4% (19/167) and 53.9% (90/167) respectively. The data obtained in this study improved our understanding about the epidemiological situations of PCVs infection in free-ranging wild boars in China and will be valuable for the prevention and control of diseases caused by PCVs infection.

As important livestock species, pigs provide essential meat resources for humans, so understanding the genetic evolution behind their domestic history could help with the genetic improvement of domestic pigs. This study aimed to investigate the evolution of convergence and divergence under selection in European and Asian domestic pigs by using public genome-wide data. A total of 164 and 108 candidate genes (CDGs) were obtained from the Asian group (wild boar vs. domestic pig) and the European group (wild boar vs. domestic pig), respectively, by taking the top 5% of intersected windows of a pairwise fixation index (FST) and a cross population extended haplotype homozygosity test (XPEHH). GO and KEGG annotated results indicated that most CDGs were related to reproduction and immunity in the Asian group. Conversely, rich CDGs were enriched in muscle development and digestion in the European group. Eight CDGs were subjected to parallel selection of Eurasian domestic pigs from local wild boars during domestication. These CDGs were mainly involved in olfactory transduction, metabolic pathways, and progesterone-mediated oocyte maturation. Moreover, 36 and 18 haplotypes of INPP5B and TRAK2 were identified in this study, respectively. In brief, this study did not only improve the understanding of the genetic evolution of domestication in pigs, but also provides valuable CDGs for future breeding and genetic improvement of pigs.

UNASSIGNED: Hybridization has been widely used among Chinese wild boars to improve their growth performance and maintain meat quality. Most studies have focused on the genetic basis for such variation. However, the differences in the gut environment between hybrid and purebred boars, which can have significant impacts on their health and productivity, have been poorly understood.
UNASSIGNED: In the current study, metagenomics was used to detect the gut microbial diversity and composition in hybrid Batun (BT, Berkshire × Tunchang) pigs and purebred Tunchang (TC) pigs. Additionally, untargeted metabolomic analysis was used to detect differences in gut metabolic pathways. Furthermore, multiple molecular experiments were conducted to demonstrate differences in intestinal functions.
UNASSIGNED: As a result of hybridization in TC pigs, a microbial change was observed, especially in Prevotella and Lactobacillus. Significant differences were found in gut metabolites, including fatty acyls, steroids, and steroid derivatives. Furthermore, the function of the intestinal barrier was decreased by hybridization, while the function of nutrient metabolism was increased.
UNASSIGNED: Evidences were shown that hybridization changed the gut microbiome, gut metabolome, and intestinal functions of TC pigs. These findings supported our hypothesis that hybridization altered the gut microbial composition, thereby modifying the intestinal functions, even the host phenotypes. Overall, our study highlights the importance of considering the gut microbiome as a key factor in the evaluation of animal health and productivity, particularly in the context of genetic selection and breeding programs.

Copy number variation (CNV) has been widely used to study the evolution of different species. We first discovered different CNVs in 24 Anqingliubai pigs and 6 Asian wild boars using next-generation sequencing at the whole-genome level with 10× depth to understand the relationship between genetic evolution and production traits in wild boars and domestic pigs. A total of 97,489 CNVs were identified and divided into 10,429 copy number variation regions (CNVRs), occupying 32.06% of the porcine genome. Chromosome 1 had the most CNVRs, and chromosome 18 had the least. Ninety-six CNVRs were selected using VST 1% based on the signatures of all CNVRs, and sixty-five genes were identified in the selected regions. These genes were strongly correlated with traits distinguishing groups by enrichment in Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways, such as growth (CD36), reproduction (CIT, RLN), detoxification (CYP3A29), and fatty acid metabolism (ELOVL6). The QTL overlapping regions were associated with meat traits, growth, and immunity, which was consistent with CNV analysis. Our findings increase the understanding of evolved genome structural variations between wild boars and domestic pigs, and provide new molecular biomarkers to guide breeding and the efficient use of available genetic resources.

Hepatitis E virus (HEV) causes infections in humans and a wide range of animal hosts. Wild boar is an important natural reservoir of HEV genotypes 3−6 (HEV-3−HEV-6), but comparative analysis of HEV infections in both feral and farmed wild boars remains limited. In this study, samples from 599 wild boars were collected during 2017−2020, including 121 feral wild boars (collected 121 fecal, 121 serum, and 89 liver samples) and 478 farmed wild boars (collected 478 fecal and 478 serum samples). The presence of anti-HEV IgG antibodies were detected by the HEV-IgG enzyme-linked immunosorbent assay (ELISA) kit. HEV RNA was detected by reverse transcription polymerase chain reaction (RT-PCR), targeting the partial ORF1 genes from fecal and liver samples, and the obtained genes were further genotyped by phylogenetic analysis. The results showed that 76.2% (95% CI 72.1−79.9) of farmed wild boars tested anti-HEV IgG seropositive, higher than that in feral wild boars (42.1%, 95% CI 33.2−51.5, p < 0.001). HEV seropositivity increased with age. Wild boar HEV infection presented a significant geographical difference (p < 0.001), but not between sex (p = 0.656) and age (p = 0.347). HEV RNA in fecal samples was detected in 13 (2.2%, 95% CI 1.2−3.7) out of 599 wild boars: 0.8% (95% CI 0.0−4.5, 1/121) of feral wild boars and 2.5% (95% CI 1.3−4.3, 12/478) of farmed wild boars. Phylogenetic analysis showed that all these viruses belonged to genotype HEV-4, and further grouped into sub-genotypes HEV-4a, HEV-4d, and HEV-4h, of which HEV-4a was first discovered in the wild boar populations in China. Our results suggested that farms could be a setting for amplification of HEV. The risk of HEV zoonotic transmission via rearing and consumption of farmed wild boars should be further assessed.

The phenotypic characteristics of existing domestic pigs (DPs) greatly differ from those of wild boar (WB) populations thousands of years ago. After thousands of years of human domestication, WB and DP have diverged greatly in terms of genetics. Theoretically, worldwide local pigs have independent contributions from their local WBs at the beginning of Sus scrofa domestication. The investigation of the vicissitude of the heredity material between domestic populations and their wild ancestors will help in further understanding the domestication history of domestic animals. In the present study, we performed a genome-wide association scan (GWSA) and phylogeny estimation with a total of 1098 public European Illumina 60K single nucleotide polymorphism data, which included 650 local DPs and 448 WBs. The results revealed that the phylogenetic relationship of WBs corresponds to their geographical distribution and carries large divergence with DPs, and all WB breeds (e.g., HRWB, SBWB, and TIWB) presents a closely linkage with the middle WB (e.g., HRWB, and PLWB). In addition, 64 selected candidate genes (e.g., IDH2, PIP5K1B, SMARCA2, KIF5C, and TJP2) were identified from GWSA. A total of 63 known multiple biological functional pathways were annotated by 22 genes, and ubiquinone and other terpenoid-quinone biosynthesis pathways that belong to the metabolism of cofactors and vitamins were significantly enriched (p < 0.05). The most frequent (28.57%) pathways were classified under metabolism. We confirmed that the middle European WB has made an important genetic contribution to the entire European WB populations. A series of selected genes discovered from this study provides the scientific community with a deeper understanding of the heredity performance of metabolism and emotion and the real purpose behind domestication.