Measuring ecosystem services and ecological sensitivity for comprehensive conservation in Giant Panda National Park

China announced the development of its first 5 national parks in 2021, the primary objective of which is to conserve the natural state and integrity of natural ecosystems. As such, ecosystem services and biodiversity levels are crucial assessment factors for the parks. For Giant Panda National Park (GPNP), we evaluated ecological sensitivity based on water and soil erosion and rocky desertification; ecosystem services based on headwater conservation, soil and water conservation, and biodiversity conservation; and presence of giant panda (Ailuropoda melanoleuca) and sympatric species (e.g., takin [Budorcas taxicolor], Asiatic black bear [Ursus thibetanus]) habitat suitability derived from niche modeling to identify the ecosystem status and assess ecological problems within the park. From our results, we proposed ecologically critical areas to target to meet the park's goals. The suitable habitat for pandas and sympatric species encompassed 62.98% of the park and occurred mainly in the Minshan Mountains. One quarter of the total area (25.67%) contained areas important for ecosystem services. Ecologically sensitive and extremely sensitive areas covered 88.78% of the park and were distributed mainly in Qionglaishan and Minshan Mountains. This coverage indicated that there was much habitat for pandas and sympatric species but that the ecosystems in GPNP are vulnerable. Therefore, ecologically critical areas encompassed all suitable habitats for all the species examined and areas important and extremely important to ecosystem service provision,ecologically sensitive and extremely sensitive areas, encompassed 15.17% of panda habitat, accounted for 16.37% of the GPNP area, and were distributed mainly in the Minshan Mountains. Our results indicated where conservation efforts should be focused in the park and that by identifying ecologically critical areas managers can provide targeted protection for wildlife habitat and ecosystems and effectively and efficiently protect the composite ecosystem. Additionally, our methods can be used to inform development of new national parks.

Single-cell mRNA sequencing of giant panda (Ailuropoda melanoleuca) seminoma reveals the cellular and molecular characteristics of tumour cells

Testicular tumours are zoonoses that can occur in not only human, but other animals, include giant pandas. A middle-aged male giant panda named Fufu was diagnosed with a testicular tumour and underwent surgery to remove the entire left testis. The testis was mainly composed of three substantive parts: normal tissue on the outside, tumour tissue in the middle, and necrosis in the centre. HE stains revealed that the tumour was a seminoma. Single-cell mRNA sequence was applied to characterise cellular states and molecular circuitries of giant panda testicular seminoma. Only germ cell markers expressed in nearly all tumour cells, and the tumour cells appeared to be the same subtype of seminoma cells. We identified four clusters with unique genes expression. They were early apoptosis cells (EAC), inactive cells (IC), active cells subcluster 1 (AC-1) and active cells subcluster 2 (AC-2). We utilised monocle tools and found that IC cells was in the initiation stage, and EAC was one type of terminal stage, suggesting that tumour cells may undergo apoptosis in the future. AC-2 was another type of terminal stage, representing a group of progressive cells. Our study represents the first report to utilise scRNA-seq to characterise the cellular states and molecular circuitries of a giant panda testicular tumour. This investigation proposes CD117 and CD30 as dependable markers for future pathologic diagnosis. Our findings also suggest that CTSV and other genes with unique expression patterns in active and progressive giant panda seminoma cells may act as early prognostic biomarkers.

Characteristics of mesenchymal stem cells and their exosomes derived from giant panda (Ailuropoda melanoleuca) endometrium

Conservation of genetic resources is an important way to protect endangered species. At present, mesenchymal stem cells (MSCs) have been isolated from the bone marrow and umbilical cords of giant pandas. However, the types and quantities of preserved cell resources were rare and limited, and none of MSCs was derived from female reproductive organs. Here, we first isolated MSCs from the endometrium of giant panda. These cells showed fibroblast morphology and expressed Sox2, Klf4, Thy1, CD73, CD105, CD44, CD49f, and CD105. Endometrium mesenchymal stem cells (eMSCs) of giant panda could induce differentiation into three germ layers in vitro. RNA-seq analysis showed that 833 genes were upregulated and 716 genes were downregulated in eMSCs compared with skin fibroblast cells. The results of GO and the KEGG analysis of differentially expressed genes (DEGs) were mainly focused on transporter activity, signal transducer activity, pathways regulating pluripotency of stem cells, MAPK signaling pathway, and PI3K-Akt signaling pathway. The genes PLCG2, FRK, JAK3, LYN, PIK3CB, JAK2, CBLB, and MET were identified as hub genes by PPI network analysis. In addition, the exosomes of eMSCs were also isolated and identified. The average diameter of exosomes was 74.26 ± 13.75 nm and highly expressed TSG101 and CD9 but did not express CALNEXIN. A total of 277 miRNAs were detected in the exosomes; the highest expression of miRNA was the has-miR-21-5p. A total of 14461 target genes of the whole miRNAs were predicted and proceeded with functional analysis. In conclusion, we successfully isolated and characterized the giant panda eMSCs and their exosomes, and analyzed their functions through bioinformatics techniques. It not only enriched the conservation types of giant panda cell resources and promoted the protection of genetic diversity, but also laid a foundation for the application of eMSCs and exosomes in the disease treatment of giant pandas.

Molecular detection and characterization of three novel parvoviruses belonging to two different subfamilies in zoo birds

Birds carry a large number of viruses that may cause diseases in animals or humans. At present, information about the virome of zoo birds is limited. In this study, using viral metagenomics, we investigated the fecal virome of zoo birds collected from a zoo in Nanjing, Jiangsu Province, China. Three novel parvoviruses were obtained and characterized. The genomes of the three viruses are 5,909, 4,411, and 4,233 nt in length, respectively, and contain four or five ORFs. Phylogenetic analysis showed that these three novel parvoviruses clustered with other strains and formed three different clades. Pairwise comparison of NS1 amino acid sequences showed that Bir-01-1 shared 44.30-74.92% aa sequence identity with other parvoviruses belonging to the genus Aveparvovirus, while Bir-03-1 and Bir-04-1 shared less than 66.87% and 53.09% aa sequence identity, respectively, with other parvoviruses belonging to the genus Chaphamaparvovirus. Each of these three viruses was identified as a member of a novel species based on the species demarcation criteria for parvoviruses. These findings broaden our knowledge of the genetic diversity of parvoviruses and provide epidemiological data regarding potential outbreaks of parvovirus disease in birds.

Isolation and characterization mesenchymal stem cells from red panda (Ailurus fulgens styani) endometrium

Endometrial mesenchymal stem cells (eMSCs) are undifferentiated endometrial cells with self-renewal, multidirectional differentiation and high proliferation potential. Nowadays, eMSCs have been found in a few species, but it has never been reported in endangered wild animals, especially the red panda. In this study, we successfully isolated and characterized the eMSCs derived from red panda. Red panda eMSCs were fibroblast-like, had a strong proliferative potential and a stable chromosome number. Pluripotency genes including Klf4, Sox2 and Thy1 were highly expressed in eMSCs. Besides, cultured eMSCs were positive for MSC markers CD44, CD49f and CD105 and negative for endothelial cell marker CD31 and haematopoietic cell marker CD34. Moreover, no reference RNA-seq was used to analyse the eMSCs transcriptional expression profile and key pathways. Compared with skin fibroblast cell group, 9104 differentially expressed genes (DEGs) were identified, among which are 5034 genes upregulated, 4070 genes downregulated and the top 20 enrichment pathways of DEGs in Gene Ontology (GO) and the Kyoto Encyclopedia of Genes Genomes (KEGG) mainly associated with G-protein coupled receptor signalling pathway, carbohydrate derivative binding, nucleoside binding, ribosome biogenesis, cell cycle, DNA replication, Ras signalling pathway and purine metabolism. Among the DEGs, some representative genes about promoting MSCs differentiation and proliferation were upregulated and promoting fibroblasts proliferation were downregulated in eMSCs group. Red panda eMSCs also had multiple differentiation ability and could differentiate into adipocytes, chondrocytes and hepatocytes. In conclusion, we, for the first time, isolated and characterized the red panda eMSCs with ability of multiplication and multilineage differentiation in vitro. The new multipotential stem cell could be beneficial not only for the germ plasm resources conservation of red panda, but also for basic or pre-clinical studies in the future.

Gut microbiota composition and metabolomic profiles of wild and captive Chinese monals (Lophophorus lhuysii)

BACKGROUND

The Chinese monal (Lophophorus lhuysii) is an endangered bird species, with a wild population restricted to the mountains in southwest China, and only one known captive population in the world. We investigated the fecal microbiota and metabolome of wild and captive Chinese monals to explore differences and similarities in nutritional status and digestive characteristics. An integrated approach combining 16S ribosomal RNA (16S rRNA) gene sequencing and ultra-high performance liquid chromatography (UHPLC) based metabolomics were used to examine the fecal microbiota composition and the metabolomic profile of Chinese monals.

RESULTS

The results showed that the alpha diversity of gut microbes in the wild group were significantly higher than that in the captive group and the core bacterial taxa in the two groups showed remarkable differences at phylum, class, order, and family levels. Metabolomic profiling also revealed differences, mainly related to galactose, starch and sucrose metabolism, fatty acid, bile acid biosynthesis and bile secretion. Furthermore, strong correlations between metabolite types and bacterial genus were detected.

CONCLUSIONS

There were remarkable differences in the gut microbiota composition and metabolomic profile between wild and captive Chinese monals. This study has established a baseline for a normal gut microbiota and metabolomic profile for wild Chinese monals, thus allowing us to evaluate if differences seen in captive organisms have an impact on their overall health and reproduction.