Project description:The masked palm civet is distributed through south-east Asia, China and the Himalayas. Because of its potential role in the severe acute respiratory syndrome (SARS) epidemic, it has become important to gather information on this species, and notably to provide a tool to determine the origin of farm and market animals. For this purpose, we studied the genetic variability and the phylogeographic pattern of the masked palm civet Paguma larvata. First, two portions of mitochondrial genes, cytochrome b and the control region, were sequenced for a total of 76 individuals sampled from China, the Indochinese region and the Sundaic region. Results indicated a low genetic variability and suggested a lack of a phylogeographic structure in this species, which do not allow inferring the geographic origin of samples of unknown origin, although it is possible to distinguish individuals from China and the Sundaic region. This low variation is in contrast to the well-marked morphological differentiation between the populations in the Sundaic and Chinese-Indochinese regions. We also used five microsatellite loci to genotype 149 samples from two wild and four farmed populations in China, where the masked palm civet is farmed and where the SARS coronavirus was isolated. These analyses also showed a reduced variability in Chinese civets and showed that farmed populations did not exhibit a lower genetic diversity than wild populations, suggesting frequent introductions of wild individuals into farms.
Project description:The masked palm civet (Paguma larvata) acts as an intermediate host of severe acute respiratory syndrome coronavirus (SARS-CoV), which caused SARS, and transfered this virus from bats to humans. Additionally, P. larvata has the potential to carry a variety of zoonotic viruses that may threaten human health. However, genome resources for P. larvata have not been reported to date. A chromosome-level genome assembly of P. larvata was generated using PacBio sequencing, Illumina sequencing, and Hi-C technology. The genome assembly was 2.44 Gb in size, of which 95.32% could be grouped into 22 pseudochromosomes, with contig N50 and scaffold N50 values of 12.97 Mb and 111.81 Mb, respectively. A total of 21,582 protein-coding genes were predicted, and 95.20% of the predicted genes were functionally annotated. Phylogenetic analysis of 19 animal species confirmed the close genetic relationship between P. larvata and species belonging to the Felidae family. Gene family clustering revealed 119 unique, 243 significantly expanded, and 58 significantly contracted genes in the P. larvata genome. We identified 971 positively selected genes in P. larvata, and one known human viral receptor gene PDGFRA is positively selected in P. larvata, which is required for human cytomegalovirus infection. This high-quality genome assembly provides a valuable genomic resource for exploring virus-host interactions. It will also provide a reliable reference for studying the genetic bases of the morphologic characteristics, adaptive evolution, and evolutionary history of this species.
Project description:The masked palm civet (Paguma larvata) has been suspected to be the host of a SARS-like CoV virus that causes severe acute respiratory syndrome in humans. In China, the palm civet lives wild and is farmed, but even though the species is a potential carrier of the virus, its geographic distribution and genetic diversity have never been studied. We report the isolation and characterization of six polymorphic microsatellite markers for P. larvata. To characterize each locus, two farmed masked palm civet populations from Shanxi and Guangxi provinces in China were genotyped. The number of alleles per locus ranged from 3 to 15, and the observed heterozygosity for these populations was 47.1 and 68.7%, respectively.
Project description:BackgroundThe aim of this study was to gain an understanding of the transcriptomic changes that occur in a wild species when infected with Toxoplasma gondii. The masked palm civet, an artifically domesticated animal, was used as the model of a wild species. Transcriptome analysis was used to study alterations in gene expression in the domesticated masked palm civet after chronic infection with T. gondii.MethodsMasked palm civets were infected with 105 T. gondii cysts and their brain tissue collected after 4 months of infection. RNA sequencing (RNA-Seq) was used to gain insight into the spectrum of genes that were differentially expressed due to infection. Quantitative reverse-transcription PCR (qRT-PCR) was also used to validate the level of expression of a set of differentially expressed genes (DEGs) obtained by sequencing.ResultsDEGs were screened from the sequencing results and analyzed. A total of 2808 DEGs were detected, of which 860 were upregulated and 1948 were downregulated. RNA-Seq results were confirmed by qRT-PCR. DEGs were mainly enriched in cellular process and metabolic process based on gene ontology enrichment analysis. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that transcriptional changes in the brain of infected masked palm civets evolved over the course of infection and that DEGs were mainly enriched in the signal transduction, immune system processes, transport and catabolic pathways. Finally, 10 essential driving genes were identified from the immune signaling pathway.ConclusionsThis study revealed novel host genes which may provide target genes for the development of new therapeutics and detection methods for T. gondii infection in wild animals.
Project description:The masked palm civet (Paguma larvata) is a small carnivore with distinct biological characteristics, that likes an omnivorous diet and also serves as a vector of pathogens. Although this species is not an endangered animal, its population is reportedly declining. Since the severe acute respiratory syndrome (SARS) epidemic in 2003, the public has been particularly concerned about this species. Here, we present the first genome of the P. larvata, comprising 22 chromosomes assembled using single-tube long fragment read (stLFR) and Hi-C technologies. The genome length is 2.41 Gb with a scaffold N50 of 105.6 Mb. We identified the 107.13 Mb X chromosome and one 1.34 Mb Y-linked scaffold and validated them by resequencing 45 P. larvata individuals. We predicted 18,340 protein-coding genes, among which 18,333 genes were functionally annotated. Interestingly, several biological pathways related to immune defenses were found to be significantly expanded. Also, more than 40% of the enriched pathways on the positively selected genes (PSGs) were identified to be closely related to immunity and survival. These enriched gene families were inferred to be essential for the P. larvata for defense against the pathogens. However, we did not find a direct genomic basis for its adaptation to omnivorous diet despite multiple attempts of comparative genomic analysis. In addition, we evaluated the susceptibility of the P. larvata to the SARS-CoV-2 by screening the RNA expression of the ACE2 and TMPRSS2/TMPRSS4 genes in 16 organs. Finally, we explored the genome-wide heterozygosity and compared it with other animals to evaluate the population status of this species. Taken together, this chromosome-scale genome of the P. larvata provides a necessary resource and insights for understanding the genetic basis of its biological characteristics, evolution, and disease transmission control.
Project description:Enterocytozoon bieneusi is a common pathogen in a broad range of vertebrate hosts. To assess the prevalence and genotypes of E. bieneusi in farmed masked palm civet (Paguma larvata), 537 fecal samples from seven provinces in China were tested by nested PCR of the polymorphic internal transcribed spacer (ITS) region. Among of all the samples, 60.0% (325/531) were positive for E. bieneusi, with the highest prevalence in Hebei province (85.0%). Sequence analysis revealed the presence of nine E. bieneusi genotypes, including four known genotypes (SHR1, PL2, PL4, CHG19) and five novel genotypes (PL12 to PL16). Genotypes SHR1 and PL2 were the most common genotypes in seven provinces. Phylogenetic analysis showed that three genotypes (CHG19, PL4 and PL16) were distributed to Group 1, and six genotypes (SHR1, PL2, PL12, PL13, PL14 and PL15) formed a novel clade, which was named group 12. Findings highlight the need to conduct additional research to elucidate the epidemiology of E. bieneusi in farmed masked palm civet.