Effects of dietary supplementation of Enterococcus faecium postbiotics on growth performance and intestinal health of growing male mink.

Recent studies have demonstrated that postbiotics possess bioactivities comparable to those of probiotics. Therefore, our experiment aimed to evaluate the effects of postbiotics derived from Enterococcus faecium on the growth performance and intestinal health of growing male minks. A total of 120 growing male minks were randomly assigned to 4 groups, each with 15 replicates of 2 minks. The minks in the 4 groups were fed a basal diet supplemented with 0 (control), 0.05, 0.1, and 0.15% postbiotics derived from E. faecium (PEF), respectively. Compared to the control, PEF improved feed/gain (F/G) during the first 4 weeks and the entire 8 weeks of the study (p < 0.05); in addition, 0.1% PEF improved average daily gain (ADG) during the first 4 weeks and the entire 8 weeks of the study (p < 0.05), while 0.15% PEF improved ADG during the first 4 weeks of the study (p < 0.05). Consequently, 0.1% PEF minks displayed greater body weight (BW) at weeks 4 and 8 (p < 0.05), and 0.15% PEF minks had greater BW at week 4 (p < 0.05) than minks in the control. Furthermore, compared to the control, both 0.05 and 0.1% PEF enhanced the apparent digestibility of crude protein (CP) and ether extract (EE) (p < 0.05) in the initial 4 weeks, while both 0.1 and 0.15% PEF enhanced the apparent digestibility of CP and DM in the final 4 weeks (p < 0.05). Additionally, trypsin activity was elevated in the 0.1 and 0.15% PEF groups compared to the control (p < 0.05). In terms of intestinal morphology, PEF increased the villus height and villus/crypt (V/C) in the jejunum (p < 0.05), and both 0.1 and 0.15% PEF decreased the crypt depth and increased the villus height and V/C in the duodenum (p < 0.05) compared to the control group. Supplementation with 0.1% PEF increased the SIgA levels but decreased the IL-2, IL-8, and TNF-α levels in the jejunum (p < 0.05). Compared to the control, E. faecium postbiotics decreased the relative abundances of Serratia and Fusobacterium (p < 0.05). In conclusion, the results indicate that the growth performance, digestibility, immunity, and intestine development of minks are considerably affected by E. faecium postbiotics. In particular, dietary supplementation with 0.1% E. faecium postbiotics provides greater benefits than supplementation with 0.05 and 0.15%.

Identification of consensus homozygous regions and their associations with growth and feed efficiency traits in American mink.

The recent chromosome-based genome assembly and the newly developed 70K single nucleotide polymorphism (SNP) array for American mink (Neogale vison) facilitate the identification of genetic variants underlying complex traits in this species. The objective of this study was to evaluate the association between consensus runs of homozygosity (ROH) with growth and feed efficiency traits in American mink. A subsample of two mink populations (n = 2,986) were genotyped using the Affymetrix Mink 70K SNP array. The identified ROH segments were included simultaneously, concatenated into consensus regions, and the ROH-based association studies were carried out with linear mixed models considering a genomic relationship matrix for 11 growth and feed efficiency traits implemented in ASReml-R version 4. In total, 298,313 ROH were identified across all individuals, with an average length and coverage of 4.16 Mb and 414.8 Mb, respectively. After merging ROH segments, 196 consensus ROH regions were detected and used for genome-wide ROH-based association analysis. Thirteen consensus ROH regions were significantly (P < 0.01) associated with growth and feed efficiency traits. Several candidate genes within the significant regions are known for their involvement in growth and body size development, including MEF2A, ADAMTS17, POU3F2, and TYRO3. In addition, we found ten consensus ROH regions, defined as ROH islands, with frequencies over 80% of the population. These islands harbored 12 annotated genes, some of which were related to immune system processes such as DTX3L, PARP9, PARP14, CD86, and HCLS1. This is the first study to explore the associations between homozygous regions with growth and feed efficiency traits in American mink. Our findings shed the light on the effects of homozygosity in the mink genome on growth and feed efficiency traits, that can be utilized in developing a sustainable breeding program for mink.

Effects of Mink-Origin Enterococcus faecium on Growth Performance, Antioxidant Capacity, Immunity, and Intestinal Microbiota of Growing Male Minks.

The purpose of this experiment was to explore the effects of dietary Enterococcus faecium (EF) on the growth performance, antioxidant capacity, immunity, and intestinal microbiota of growing male minks. A total of 60 male Regal White minks at 12 weeks of age were randomly assigned to two groups, each with 15 replicates of two minks per replicate. The minks in two groups were fed the basal diets and the basal diets with viable Enterococcus faecium (more than 107 cfu/kg of diet), respectively. Compared with the minks in control, Enterococcus faecium minks had heavier body weight (BW) at week 4 and week 8 of the study (p < 0.05), greater average daily gain (ADG), and a lower feed/gain ratio (F/G) of male minks during the initial 4 weeks and the entire 8-week study period (p < 0.05). Furthermore, Enterococcus faecium increased the apparent digestibility of crude protein (CP) and dry matter (DM) compared to the control (p < 0.05). Moreover, Enterococcus faecium enhanced the serum superoxide dismutase (SOD) activity and decreased the malondialdehyde (MDA) contents (p < 0.05). The results also confirmed that Enterococcus faecium increased the levels of serum immunoglobulin A (IgA), immunoglobulin G (IgG), and the concentrations of secretory immunoglobulin A (SIgA) in the jejunal mucosa while decreasing the interleukin-8 (IL-8) and interleukin-1ß (IL-1ß) levels in the jejunal mucosa (p < 0.05). Intestinal microbiota analysis revealed that Enterococcus faecium increased the species numbers at the OUT level. Compared with the control, Enterococcus faecium had significant effects on the relative abundance of Paraclostridium, Brevinema, and Comamonas (p < 0.05). The results showed that Enterococcus faecium could improve the growth performance, increase the antioxidant capacity, improve the immunity of growing male minks, and also modulate the gut microbiota.

Genomic analysis links the American mink Royal pastel coat phenotype to retroviral element type 1 insertion in the HPS3 gene.

To date, only 10 of the more than 30 fur colours that had been observed in American mink (Neogale vison) have been linked to specific genes. The Royal pastel fur colour is part of a large family of brownish colours that are quite similar to one another, making breeding and selecting processes more difficult. Here we carried out whole-genome sequencing of five American minks with Royal pastel (b/b) phenotypes originating from two distinct mink populations. We identified an insertion of endogenous retroviral element type 1 (ERV1) into the first intron of the gene encoding the HPS3 protein, which regulates the trafficking of tyrosinase-containing vesicles to maturing melanosomes. With Cas9-targeted nanopore sequencing, we reconstructed the full-length sequence of the 11.7 Kb ERV1 insertion and observed hypermethylation that spread to the HPS3 gene promoter region. These findings highlight the role of HPS3 in the formation of melanosomes and melanin, as well as the genetic process regulating the intensity and spectrum of hair colour. Moreover, in mink breeding projects, these data are also useful for tracking economically important fur qualities.

Exploring the role of endogenous retroviruses in seasonal reproductive cycles: a case study of the ERV-V envelope gene in mink.

Introduction: Endogenous retroviruses (ERVs), which originated from exogenous retroviral infections of germline cells millions of years ago and were inherited by subsequent generations as per Mendelian inheritance patterns, predominantly comprise non-protein-coding sequences due to the accumulation of mutations, insertions, deletions, and truncations. Nevertheless, recent studies have revealed that ERVs play a crucial role in diverse biological processes by encoding various proteins. Methods: In this study, we successfully identified an ERV envelope (env) gene in a mink species. A phylogenetic tree of mink ERV-V env and reference sequences was constructed using Bayesian methods and maximum-likelihood inference. Results: Phylogenetic analyses indicated a significant degree of sequence conservation and positive selection within the env-surface open reading frame. Additionally, qRT-PCR revealed diverse patterns of mink ERV-V env expression in various tissues. The expression of mink ERV-V env gene in testicular tissue strongly correlated with the seasonal reproductive cycles of minks. Discussion: Our study suggests that the ERV-V env gene in mink may have been repurposed for host functions.

Analysis of immunoglobulin organization and complexity in mink (Neovison vison).

Mink are susceptible to viruses such as SARS-CoV-2, H1N1 and H9N2, so they are considered a potential animal model for studying human viral infections. Therefore, it is important to study the immune system of mink. Immunoglobulin (Ig) is an important component of humoral immunity and plays an important role in the body's immune defense. In this study, we described the gene loci structure of mink Ig germline by genome comparison, and analysed the mechanism of expression diversity of mink antibody library by 5'RACE and next-generation sequencing (NGS). The results were as follows: the IgH, Igκ and Igλ loci of mink were located on chromosome 13, chromosome 8 and chromosome 3, respectively, and they had 25, 36 and 7 V genes, 3, 5 and 7 J genes and 10 DH genes, respectively. Mink Ig heavy chain preferred the IGHV1, IGHD2 and IGHJ4 subgroups, κ chain mainly use the IGKV1, IGKJ1 and IGHL4 subgroups, and λ chain mainly use the IGLV3 and IGLJ3 subgroups. Linkage diversity analysis revealed that N nucleotide insertion was the main factor affecting the linkage diversity of mink Igs. On the mutation types of mink Ig Somatic Hypermutation (SHM), the high mutation types of heavy chain were mainly G > A, C > T, T > C, A > G, C > A, G > T, A > C, and T > G; the high mutation types of κ chain were G > A and T > C; and the high mutation types of λ chain were G > A and A > G. The objective of this study was to analyse the loci structure and expression diversity of Ig in mink. The results contribute to our comprehension of Ig expression patterns in mink and were valuable for advancing knowledge in mink immunogenetics, exploring the evolution of adaptive immune systems across different species, and conducting comparative genomics research.

Identifying selection signatures for immune response and resilience to Aleutian disease in mink using genotype data.

Aleutian disease (AD) brings tremendous financial losses to the mink industry. Selecting AD-resilient mink has been conducted to control AD. Such selections could have altered the patterns of genetic variation responding to selection pressures. This study aimed to identify selection signatures for immune response (IRE) and resilience to AD. A total of 1,411 mink from an AD-positive facility were used. For IRE, 264 animals were categorized according to the combined results of enzyme-linked immunosorbent assay (ELISA) and counterimmunoelectrophoresis (CIEP). For resilience, two grouping methods were used: 1) general resilience performance (GRP, n = 30) was evaluated based on the feed conversion ratio, Kleiber ratio, and pelt quality; and 2) female reproductive performance (FRP, n = 36) was measured based on the number of kits alive 24 h after birth. Detection methods were the pairwise fixation index, nucleotide diversity, and cross-population extended haplotype homozygosity. A total of 619, 569, and 526 SNPs were identified as candidates for IRE, GRP, and FRP, respectively. The annotated genes were involved in immune system process, growth, reproduction, and pigmentation. Two olfactory-related Gene Ontology (GO) terms were significant (q < 0.05) for all traits, suggesting the impact of AD on the sense of smell of infected mink. Differences in detected genes and GO terms among different color types for IRE indicated variations in immune response to AD among color types. The mitogen-activated protein kinase (MAPK) signaling pathway was significant (q < 0.05) for FRP, suggesting that AD may disrupt MAPK signaling and affect FRP. The findings of this research contribute to our knowledge of the genomic architecture and biological mechanisms underlying AD resilience in mink.

Diverse amdoparvoviruses infection of farmed Asian badgers (Meles meles).

Amdoparvoviruses infect various carnivores, including mustelids, canids, skunks, and felids. Aleutian mink disease virus (AMDV) belongs to the prototypical species Amdoparvovirus carnivoran1. Here, we identified a novel amdoparvovirus in farmed Asian badgers (Meles meles), and we named this virus "Meles meles amdoparvovirus" (MMADV). A total of 146 clinical samples were collected from 134 individual badgers, and 30.6% (41/134) of the sampled badgers tested positive for amdoparvovirus by PCR. Viral DNA was detected in feces, blood, spleen, liver, lung, and adipose tissue from these animals. Viral sequences from eight samples were determined, five of which represented nearly full-length genome sequences (4,237-4,265 nt). Six serum samples tested positive by PCR, CIEP, and IAT, four of which had high antibody titers (> 512) against AMDV-G. Twenty-six of the 41 amdoparvovirus-positive badgers showed signs of illness, and necropsy revealed lesions in their organs. Sequence comparisons and phylogenetic analysis of the viral NS1 and VP2 genes of these badger amdoparvoviruses showed that their NS1 proteins shared 62.6%-88.8% sequence identity with known amdoparvoviruses, and they clustered phylogenetically into two related clades. The VP2 proteins shared 76.6%-97.2% identity and clustered into two clades, one of which included raccoon dog and arctic fox amdoparvovirus (RFAV), and the other of which did not include other known amdoparvoviruses. According to the NS1-protein-based criterion for parvovirus species demarcation, the MMADV isolate from farm YS should be classified as a member of a new species of the genus Amdoparvovirus. In summary, we have discovered a novel MMADV and other badger amdoparvoviruses that naturally infect Asian badgers and are possibly pathogenic in badgers.

Highly pathogenic avian influenza A(H5N1) virus infections on fur farms connected to mass mortalities of black-headed gulls, Finland, July to October 2023.

Highly pathogenic avian influenza (HPAI) has caused widespread mortality in both wild and domestic birds in Europe 2020-2023. In July 2023, HPAI A(H5N1) was detected on 27 fur farms in Finland. In total, infections in silver and blue foxes, American minks and raccoon dogs were confirmed by RT-PCR. The pathological findings in the animals include widespread inflammatory lesions in the lungs, brain and liver, indicating efficient systemic dissemination of the virus. Phylogenetic analysis of Finnish A(H5N1) strains from fur animals and wild birds has identified three clusters (Finland I-III), and molecular analyses revealed emergence of mutations known to facilitate viral adaptation to mammals in the PB2 and NA proteins. Findings of avian influenza in fur animals were spatially and temporally connected with mass mortalities in wild birds. The mechanisms of virus transmission within and between farms have not been conclusively identified, but several different routes relating to limited biosecurity on the farms are implicated. The outbreak was managed in close collaboration between animal and human health authorities to mitigate and monitor the impact for both animal and human health.

Pigs are highly susceptible to but do not transmit mink-derived highly pathogenic avian influenza virus H5N1 clade 2.3.4.4b.

ABSTRACTRapid evolution of highly pathogenic avian influenza viruses (HPAIVs) is driven by antigenic drift but also by reassortment, which might result in robust replication in and transmission to mammals. Recently, spillover of clade 2.3.4.4b HPAIV to mammals including humans, and their transmission between mammalian species has been reported. This study aimed to evaluate the pathogenicity and transmissibility of a mink-derived clade 2.3.4.4b H5N1 HPAIV isolate from Spain in pigs. Experimental infection caused interstitial pneumonia with necrotizing bronchiolitis with high titers of virus present in the lower respiratory tract and 100% seroconversion. Infected pigs shed limited amount of virus, and importantly, there was no transmission to contact pigs. Notably, critical mammalian-like adaptations such as PB2-E627 K and HA-Q222L emerged at low frequencies in principal-infected pigs. It is concluded that pigs are highly susceptible to infection with the mink-derived clade 2.3.4.4b H5N1 HPAIV and provide a favorable environment for HPAIV to acquire mammalian-like adaptations.

Development and characterization of a novel specific monoclonal antibody against mink enteritis virus and its antigen epitope analysis.

This study prepared a novel monoclonal antibody (MAb) against mink enteritis parvovirus (MEV) and identified its antigen epitope. The antibody subclass is identified as IgG1, the titers of the MAb is up to 1:1 × 106 and keeps stably after low-temperature storage for 9 months or 11 passages of the MAb cells. The MAb can specifically recognize MEV in the cells in IFA, but not Aleutian disease virus (ADV) or canine distemper virus (CDV). Its antigen epitope was identified as a polypeptide containing 5 key amino acids (378YAFGR382) and the homology in 20 MEV strains, 4 canine parvovirus strains, and 4 feline panleukopenia virus strains was 100%. This study supplies a biological material for developing new methods to detect MEV.

MINK1 deficiency stimulates nucleus pulposus cell pyroptosis and exacerbates intervertebral disc degeneration.

Intervertebral disc (IVD) degeneration, induced by aging and irregular mechanical strain, is highly prevalent in the elderly population, serving as a leading cause of chronic low back pain and disability. Evolving evidence has revealed the involvement of nucleus pulposus (NP) pyroptosis in the pathogenesis of IVD degeneration, while the precise regulatory mechanisms of NP pyroptosis remain obscure. Misshapen/Nck-interacting kinase (NIK)-related kinase 1 (MINK1), a serine-threonine protein kinase, has the potential to modulate the activation of NLRP3 inflammasome, indicating its pivotal role in governing pyroptosis. In this study, to assess the significance of MINK1 in NP pyroptosis and IVD degeneration, NP tissues from patients with varying degrees of IVD degeneration, and IVD tissues from both aging-induced and lumbar spine instability (LSI) surgery-induced IVD degeneration mouse models, with or without MINK1 ablation, were meticulously evaluated. Our findings indicated a notable decline in MINK1 expression in NP tissues of patients with IVD degeneration and both mouse models as degeneration progresses, accompanied by heightened matrix degradation and increased NP pyroptosis. Moreover, MINK1 ablation led to substantial activation of NP pyroptosis in both mouse models, and accelerating ECM degradation and intensifying the degeneration phenotype in mechanically stress-induced mice. Mechanistically, MINK1 deficiency triggered NF-κB signaling in NP tissues. Overall, our data illustrate an inverse correlation between MINK1 expression and severity of IVD degeneration, and the absence of MINK1 stimulates NP pyroptosis, exacerbating IVD degeneration by activating NF-κB signaling, highlighting a potential innovative therapeutic target in treating IVD degeneration.

Establishment and application of multiplex PCR for rapid detection of three mink diarrhea-associated viruses.

In this report, a multiplex PCR method was developed for the detection of three diarrhea-associated viruses in mink, including circovirus (MCV), bocavirus (MBoV), and enteritis virus (MEV). Three compatible sets of primers specific for each virus were designed respectively based on their conserved sequences. After optimization of the crucial factors such as primer concentration and annealing temperature in single and multiple amplification, three specific fragments were simultaneously amplified with the highest sensitivity and specificity in one PCR reaction. The fragments amplified were 259 bp (MCV)，455 bp (MBoV) and 671 bp (MEV). The sensibility of this one-step multiplex PCR is about 10 times lower than that of regular singleplex PCR. There were no cross-reactions with some relevant pathogens like mink coronavirus, canine distemper virus, and aleutian mink disease virus. In our study we analyzed viral DNA in mink fecal samples by multiplex PCR assay from China, which revealed the occurrence of MCV, MBoV, and MEV as 3.1 %, 5.7 %, and 9.8 %, respectively. The testing results of multiplex PCR agreed with the singleplex PCR results with a coincidence rate of 100 %. These results indicated that the method could provide technical support for rapid detection of the three diarrhea-associated viruses, and epidemiological investigation of mink viral diarrhea.

Muscle Transcriptome Analysis of Mink at Different Growth Stages Using RNA-Seq.

Mink is a kind of small and precious fur animal resource. In this study, we employed transcriptomics technology to analyze the gene expression profile of mink pectoral muscle tissue, thereby elucidating the regulatory mechanisms underlying mink growth and development. Consequently, a total of 25,954 gene expression profiles were acquired throughout the growth and development stages of mink at 45, 90, and 120 days. Among these profiles, 2607 genes exhibited significant differential expression (|log2(fold change)| ≥ 2 and p_adj < 0.05). GO and KEGG enrichment analyses revealed that the differentially expressed genes were primarily associated with the mitotic cell cycle process, response to growth factors, muscle organ development, and insulin resistance. Furthermore, GSEA enrichment analysis demonstrated a significant enrichment of differentially expressed genes in the p53 signaling pathway at 45 days of age. Subsequent analysis revealed that genes associated with embryonic development (e.g., PEG10, IGF2, NRK), cell cycle regulation (e.g., CDK6, CDC6, CDC27, CCNA2), and the FGF family (e.g., FGF2, FGF6, FGFR2) were all found to be upregulated at 45 days of age in mink, which suggested a potential role for these genes in governing early growth and developmental processes. Conversely, genes associated with skeletal muscle development (PRVA, TNNI1, TNNI2, MYL3, MUSTN1), a negative regulator of the cell cycle gene (CDKN2C), and IGFBP6 were found to be up-regulated at 90 days of age, suggesting their potential involvement in the rapid growth of mink. In summary, our experimental data provide robust support for elucidating the regulatory mechanisms underlying the growth and development of mink.

Draft genome sequence analysis of a mcr-1-producing Klebsiella pneumoniae ST661 isolated from a mink in China.

OBJECTIVES: Klebsiella pneumoniae is a major opportunistic pathogen that is a member of the Enterobacteriaceae. Klebsiella pneumoniae causes pneumonia in mink and has become the primary infectious disease that limits mink farming. In this study, we report the draft genome sequence of a multidrug-resistant (MDR) strain of K. pneumoniae that harbours the mcr-1 gene isolated from a mink in China. METHODS: The agar microdilution method was used to determine the minimum inhibitory concentration of the strain. The entire genomic DNA was sequenced using an Illumina MiSeq platform. A multilocus sequence type (MLST) and a core genome SNP phylogenetic tree analysis with a heatmap of the resistance genes and virulence genes were performed. RESULTS: The size of the genome was 5451.826 kb, and it included one chromosome and one plasmid. The draft genome of K. pneumoniae indicated that the isolate was a member of MLST 661. Four types of virulence genes were detected. The results of antimicrobial susceptibility testing showed multiple drug resistance, and 17 resistance genes were identified. CONCLUSION: The genome sequence reported in this study will help to reveal the key role of antibiotic resistance and pathogenic mechanisms. It will provide useful information for the role of mobile genetic elements in the adaptive translocation and spread of antimicrobial resistance.

Prevalence of Toxoplasma gondii in Wild American Mink (Neogale vison): The First Serological Study in Germany and Poland.

Toxoplasma gondii is an obligate intracellular protozoan that causes toxoplasmosis in warm-blooded animals. Although most infections in humans and animals are subclinical, an infection can nevertheless be fatal. One of the important characteristics in the epidemiology of this parasite is waterborne transmission. The American mink (Neogale vison), a mammal closely adapted to freshwater ecosystems, is a potential sentinel for T. gondii. We analysed meat juice from the heart of 194 wild minks collected between 2019 and 2022 in five study areas from Germany and Poland and tested for the presence of antibodies against T. gondii. The analysis was performed using a commercial enzyme-linked immunosorbent assay test (ELISA). Antibodies were detected in 45.36% (88/194, 95% confidence interval (CI): 38.39-52.41%) of the analysed animals. While the prevalence values ranged from 37.50% to 49.30%, there was no significant difference in seroprevalence between the study areas. Juveniles were less likely to carry T. gondii antibodies than adults (odds ratio: 0.216), whereas there was no significant difference in prevalence between the sexes (odds ratio: 0.933). The results of our study show that contact with T. gondii is widespread in minks, and the parasite is common in inland freshwater ecosystems in Germany and Poland. This indicates that watercourses play an important role in the spread of T. gondii oocysts.

Serum protein electrophoresis in European mink (Mustela lutreola): reference intervals and comparison of agarose gel electrophoresis and capillary zone electrophoresis.

BACKGROUND: Knowledge of reference intervals for blood analytes, including serum protein fractions, is of great importance for the identification of infectious and inflammatory diseases and is often lacking in wild animal species. MATERIAL AND METHODS: Serum samples were obtained from European minks enrolled in the breeding program (n = 55). Agarose gel electrophoresis (AGE) and capillary zone electrophoresis (CZE) were used to separate and identify protein fractions. Albumin, α1, α2, ß, and γ-globulins fractions were identified in all mink sera by both electrophoresis methods. Reference intervals (90% CI) were determined following the 2008 guidelines of the Clinical Laboratory Standard Institute. The methods were compared using Passing-Bablok regression, Bland-Altman analysis, and Lin's concordance correlation. RESULTS: A significant bias was found between methods for α1, α2, and γ-globulin. Lin's concordance correlation was considered unacceptable for α1, α2, and ß-globulins. Differences for gender between methods were found for albumin and α2-globuins, which were higher for males than females. γ-globulins were higher for adults than young minks using both methods; however, α1 and α2-globulins were lower. CONCLUSION: Both methods are adequate for identifying serum protein disorders, but the AGE and CZE methods are not equivalent. Therefore, reference intervals for each technique are required.

Characterization of runs of homozygosity islands in American mink using whole-genome sequencing data.

The genome-wide analysis of runs of homozygosity (ROH) islands can be an effective strategy for identifying shared variants within a population and uncovering important genomic regions related to complex traits. The current study performed ROH analysis to characterize the genome-wide patterns of homozygosity, identify ROH islands and annotated genes within these candidate regions using whole-genome sequencing data from 100 American mink (Neogale vison). After sequence processing, variants were called using GATK and Samtools pipelines. Subsequent to quality control, 8,373,854 bi-allelic variants identified by both pipelines remained for further analysis. A total of 34,652 ROH segments were identified in all individuals, among which shorter segments (0.3-1 Mb) were abundant throughout the genome, approximately accounting for 84.39% of all ROH. Within these segments, we identified 63 ROH islands housing 156 annotated genes. The genes located in ROH islands were associated with fur quality (EDNRA, FGF2, FOXA2 and SLC24A4), body size/weight (MYLK4, PRIM2, FABP2, EYS and PHF3), immune capacity (IL2, IL21, PTP4A1, SEMA4C, JAK2, CCNA2 and TNIP3) and reproduction (ADAD1, KHDRBS2, INSL6, PGRMC2 and HSPA4L). Furthermore, Gene Ontology and KEGG pathway enrichment analyses revealed 56 and 9 significant terms (FDR-corrected p-value < 0.05), respectively, among which cGMP-PKG signalling pathway, regulation of actin cytoskeleton, and calcium signalling pathway were highlighted due to their functional roles in growth and fur characteristics. This is the first study to present ROH islands in American mink. The candidate genes from ROH islands and functional enrichment analysis suggest possible signatures of selection in response to the mink breeding targets, such as increased body length, reproductive performance and fur quality. These findings contribute to our understanding of genetic characteristics, and provide complementary information to assist with implementation of breeding strategies for genetic improvement in American mink.

Study of Canine Distemper Virus Presence in Catalonia's Wild Carnivores through H Gene Amplification and Sequencing.

Canine distemper virus (CDV) is recognised worldwide as an important pathogen in both domestic and wild carnivores. Few data are available on its impact and spread on the wildlife/wildlife-domestic animal-environment interface. This study, aimed at developing a conservation-oriented control strategy, analysed 89 sick or deceased animals from 2019 to 2023 at the Wildlife Rehabilitation Centre in Torreferrussa. RT-PCR and sequencing of the partial H gene were used to detect and analyse CDV in tissues. The total positive percentage was 20.22% (18/89), comprising 13 red foxes (44.8%), 4 European badgers (28.6%), and 1 American mink (4.5%), while 24 Eurasian otters tested negative. Phylogenetic analysis indicated that all of the CDV strains belong to the European lineage. Geographically distant individuals and different species shared the same viral strain, suggesting a strong capacity of CDV for interspecies and long-distance transmission. This calls for further research, particularly focusing on potential impacts of CDV on endangered carnivores.

SARS-CoV-2 Outbreaks on Mink Farms-A Review of Current Knowledge on Virus Infection, Spread, Spillover, and Containment.

Many studies have been conducted to explore outbreaks of SARS-CoV-2 in farmed mink and their intra-/inter-species spread and spillover to provide data to the scientific community, protecting human and animal health. Studies report anthropozoonotic introduction, which was initially documented in April 2020 in the Netherlands, and subsequent inter-/intra-species spread of SARS-CoV-2 in farmed mink, likely due to SARS-CoV-2 host tropism capable of establishing efficient interactions with host ACE2 and the mink hosts' ability to enhance swift viral transmission due to their density, housing status, and occupational contacts. Despite the rigorous prevention and control measures adopted, transmission of the virus within and between animal species was efficient, resulting in the development of mink-associated strains able to jump back and forth among the mink hosts and other animal/human contacts. Current knowledge recognizes the mink as a highly susceptible animal host harboring the virus with or without clinical manifestations, furthering infection transmission as a hidden animal reservoir. A One Health approach is, thus, recommended in SARS-CoV-2 surveillance and monitoring on mink farms and of their susceptible contact animals to identify and better understand these potential animal hosts.