Isolation of SARS-CoV-2-related coronavirus from Malayan pangolins.

The current outbreak of coronavirus disease-2019 (COVID-19) poses unprecedented challenges to global health1. The new coronavirus responsible for this outbreak-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-shares high sequence identity to SARS-CoV and a bat coronavirus, RaTG132. Although bats may be the reservoir host for a variety of coronaviruses3,4, it remains unknown whether SARS-CoV-2 has additional host species. Here we show that a coronavirus, which we name pangolin-CoV, isolated from a Malayan pangolin has 100%, 98.6%, 97.8% and 90.7% amino acid identity with SARS-CoV-2 in the E, M, N and S proteins, respectively. In particular, the receptor-binding domain of the S protein of pangolin-CoV is almost identical to that of SARS-CoV-2, with one difference in a noncritical amino acid. Our comparative genomic analysis suggests that SARS-CoV-2 may have originated in the recombination of a virus similar to pangolin-CoV with one similar to RaTG13. Pangolin-CoV was detected in 17 out of the 25 Malayan pangolins that we analysed. Infected pangolins showed clinical signs and histological changes, and circulating antibodies against pangolin-CoV reacted with the S protein of SARS-CoV-2. The isolation of a coronavirus from pangolins that is closely related to SARS-CoV-2 suggests that these animals have the potential to act as an intermediate host of SARS-CoV-2. This newly identified coronavirus from pangolins-the most-trafficked mammal in the illegal wildlife trade-could represent a future threat to public health if wildlife trade is not effectively controlled.

Pathogenicity, tissue tropism and potential vertical transmission of SARSr-CoV-2 in Malayan pangolins.

Malayan pangolin SARS-CoV-2-related coronavirus (SARSr-CoV-2) is closely related to SARS-CoV-2. However, little is known about its pathogenicity in pangolins. Using CT scans we show that SARSr-CoV-2 positive Malayan pangolins are characterized by bilateral ground-glass opacities in lungs in a similar manner to COVID-19 patients. Histological examination and blood gas tests are indicative of dyspnea. SARSr-CoV-2 infected multiple organs in pangolins, with the lungs the major target, and histological expression data revealed that ACE2 and TMPRSS2 were co-expressed with viral RNA. Transcriptome analysis indicated that virus-positive pangolins were likely to have inadequate interferon responses, with relative greater cytokine and chemokine activity in the lung and spleen. Notably, both viral RNA and viral proteins were detected in three pangolin fetuses, providing initial evidence for vertical virus transmission. In sum, our study outlines the biological framework of SARSr-CoV-2 in pangolins, revealing striking similarities to COVID-19 in humans.

Population genomic analysis provides evidence of the past success and future potential of South China tiger captive conservation.

BACKGROUND: Among six extant tiger subspecies, the South China tiger (Panthera tigris amoyensis) once was widely distributed but is now the rarest one and extinct in the wild. All living South China tigers are descendants of only two male and four female wild-caught tigers and they survive solely in zoos after 60 years of effective conservation efforts. Inbreeding depression and hybridization with other tiger subspecies were believed to have occurred within the small, captive South China tiger population. It is therefore urgently needed to examine the genomic landscape of existing genetic variation among the South China tigers. RESULTS: In this study, we assembled a high-quality chromosome-level genome using long-read sequences and re-sequenced 29 high-depth genomes of the South China tigers. By combining and comparing our data with the other 40 genomes of six tiger subspecies, we identified two significantly differentiated genomic lineages among the South China tigers, which harbored some rare genetic variants introgressed from other tiger subspecies and thus maintained a moderate genetic diversity. We noticed that the South China tiger had higher FROH values for longer runs of homozygosity (ROH > 1 Mb), an indication of recent inbreeding/founder events. We also observed that the South China tiger had the least frequent homozygous genotypes of both high- and moderate-impact deleterious mutations, and lower mutation loads than both Amur and Sumatran tigers. Altogether, our analyses indicated an effective genetic purging of deleterious mutations in homozygous states from the South China tiger, following its population contraction with a controlled increase in inbreeding based on its pedigree records. CONCLUSIONS: The identification of two unique founder/genomic lineages coupled with active genetic purging of deleterious mutations in homozygous states and the genomic resources generated in our study pave the way for a genomics-informed conservation, following the real-time monitoring and rational exchange of reproductive South China tigers among zoos.

Virus diversity, wildlife-domestic animal circulation and potential zoonotic viruses of small mammals, pangolins and zoo animals.

Wildlife is reservoir of emerging viruses. Here we identified 27 families of mammalian viruses from 1981 wild animals and 194 zoo animals collected from south China between 2015 and 2022, isolated and characterized the pathogenicity of eight viruses. Bats harbor high diversity of coronaviruses, picornaviruses and astroviruses, and a potentially novel genus of Bornaviridae. In addition to the reported SARSr-CoV-2 and HKU4-CoV-like viruses, picornavirus and respiroviruses also likely circulate between bats and pangolins. Pikas harbor a new clade of Embecovirus and a new genus of arenaviruses. Further, the potential cross-species transmission of RNA viruses (paramyxovirus and astrovirus) and DNA viruses (pseudorabies virus, porcine circovirus 2, porcine circovirus 3 and parvovirus) between wildlife and domestic animals was identified, complicating wildlife protection and the prevention and control of these diseases in domestic animals. This study provides a nuanced view of the frequency of host-jumping events, as well as assessments of zoonotic risk.

Twelve natural estrogens in urines of six threatened or endangered mammalian species in Zoo Park: implications and their potential risk.

This work was the first to report twelve natural estrogens (NEs) in the urines of six threatened or endangered mammalians in a Zoo Park of Guangzhou (i.e., panda, gorilla, elephant, African lion, jaguar, and leopard). Ten out of twelve NEs were detected at least in one urine sample of the six mammalians studied, including the four major NEs (i.e., estrone (E1), 17ß-estradiol (E2), 17α-estradiol (αE2), estriol (E3)), and six other NEs (i.e., 4-hydroxyestrone (4OHE1), 2-hydroxyestradiol (2OHE2), 4-hydroxyestradiol (4OHE2), 16α-hydroxyestrone (16α-OHE1), 16ketoestradiol (16ketoE2), and 17epiestriol (17epiE3)). The six studied mammalians, ranked in the order of high to low urinary concentration of total NEs, were jaguar, African lion, gorilla, elephant, panda, and leopard, with respective urinary concentrations of 110.4, 86.4, 71.4, 66.0, 55.9, and 52.8 ng/mL. According to the average urinary concentration of NE in the six mammalians ranked from high to low, the top five NEs detected were 16α-OHE1, 4OHE1, E1, E3, and 17epiE3, respectively. These clearly indicated the occurrence of NEs other than the four major types in urines of animals in a Zoo Park. Moreover, the daily excretion rates of the five detected NEs by one elephant ranged from 1162-2254 µg/d with a total daily excretion rate of 8260 µg/d, suggesting that the total urinary excretion of NEs by one adult elephant was equivalent to that by 170 premenopausal women or 506 adult men. Consequently, it appears from this study that NEs in the urines of zoo animals should be considered an emerging source of NEs.

Author Correction: 863 genomes reveal the origin and domestication of chicken.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

863 genomes reveal the origin and domestication of chicken.

Despite the substantial role that chickens have played in human societies across the world, both the geographic and temporal origins of their domestication remain controversial. To address this issue, we analyzed 863 genomes from a worldwide sampling of chickens and representatives of all four species of wild jungle fowl and each of the five subspecies of red jungle fowl (RJF). Our study suggests that domestic chickens were initially derived from the RJF subspecies Gallus gallus spadiceus whose present-day distribution is predominantly in southwestern China, northern Thailand and Myanmar. Following their domestication, chickens were translocated across Southeast and South Asia where they interbred locally with both RJF subspecies and other jungle fowl species. In addition, our results show that the White Leghorn chicken breed possesses a mosaic of divergent ancestries inherited from other subspecies of RJF. Despite the strong episodic gene flow from geographically divergent lineages of jungle fowls, our analyses show that domestic chickens undergo genetic adaptations that underlie their unique behavioral, morphological and reproductive traits. Our study provides novel insights into the evolutionary history of domestic chickens and a valuable resource to facilitate ongoing genetic and functional investigations of the world's most numerous domestic animal.

Complete mitochondrial genome of the Thai Red Junglefowl (Gallus gallus) and phylogenetic analysis.

In this study, we sequenced the complete mitochondrial genome (mitogenome) of the Thai Red Junglefowl (RJF; Gallus gallus) using the next-generation sequencing (NGS) platform of the Ion Torrent PGM. Samples were taken from Mae Wang District, Chiang Mai Province, northern Thailand. Our data showed the complete mitogenome to be 16 785 bp in length, composed by 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and one control region. The genome nucleotide composition was 30.3% A, 23.7% T, 32.5% C, and 13.5% G, resulting in a high percentage of A+T (50.4%). Phylogenetic analysis revealed that the mitogenome belonged to haplogroup X, whereas those of all domestic chickens belong to haplogroups A to G. This newly released mitogenome sequence will advance further evolutionary and population genetics study of the RJF and domestic chicken. The availability of the G. gallus mitogenome will also contribute to further conservation genetics research of a unique species, listed as 'data deficient' in Thailand.

Identification of a novel mtDNA lineage B3 in chicken (Gallus gallus domesticus).

In this study, we sequenced the complete mitochondrial DNA genome (mitogenome) of the Zhengyang Yellow chicken (Gallus gallus domesticus) by next-generation sequencing technology. Samples were taken from Zhumadian city, Henan Province, China. The complete mitogenome was 16 785 bp in size, and had a nucleotide composition of 30.3% (A), 23.7% (T), 32.5% (C), and 13.5% (G), with a high AT content of 54.0%. The assembled mitogenome exhibited typical mitochondrial DNA (mtDNA) structure, including a non-coding control region, two rRNA genes, 13 protein-coding genes, and 22 tRNA genes. Phylogenetic analysis indicated that this mitogenome defined a novel sub-haplogroup B3 within haplogroup B. These results should provide essential information for chicken domestication and insight into the evolution of genomes.