Manis Javanica Research Articles

Evaluating angiotensin-converting enzyme 2-mediated SARS-CoV-2 entry across species

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic represents a global threat, and the interaction between the virus and angiotensin-converting enzyme 2 (ACE2), the primary entry receptor for SARS-CoV-2, is a key determinant of the range of hosts that can be infected by the virus. However, the mechanisms underpinning ACE2-mediated viral entry across species remains unclear. Using infection assay, we evaluated SARS-CoV-2 entry mediated by ACE2 of 11 different animal species. We discovered that ACE2 of Rhinolophus sinicus (Chinese rufous horseshoe bat), Felis catus (domestic cat), Canis lupus familiaris (dog), Sus scrofa (wild pig), Capra hircus (goat), and Manis javanica (Malayan pangolin) facilitated SARS-CoV-2 entry into nonsusceptible cells. Moreover, ACE2 of the pangolin also mediated SARS-CoV-2 entry, adding credence to the hypothesis that SARS-CoV-2 may have originated from pangolins. However, the ACE2 proteins of Rhinolophus ferrumequinum (greater horseshoe bat), Gallus gallus (red junglefowl), Notechis scutatus (mainland tiger snake), or Mus musculus (house mouse) did not facilitate SARS-CoV-2 entry. In addition, a natural isoform of the ACE2 protein of Macaca mulatta (rhesus monkey) with the Y217N mutation was resistant to SARS-CoV-2 infection, highlighting the possible impact of this ACE2 mutation on SARS-CoV-2 studies in rhesus monkeys. We further demonstrated that the Y217 residue of ACE2 is a critical determinant for the ability of ACE2 to mediate SARS-CoV-2 entry. Overall, these results clarify that SARS-CoV-2 can use the ACE2 receptors of multiple animal species and show that tracking the natural reservoirs and intermediate hosts of SARS-CoV-2 is complex.

仿生态环境下马来穿山甲的救护饲养试验

仿生态环境下马来穿山甲的救护饲养试验

The high diversity of SARS-CoV-2-related coronaviruses in pangolins alerts potential ecological risks.

Understanding the zoonotic origin and evolution history of SARS-CoV-2 will provide critical insights for alerting and preventing future outbreaks. A significant gap remains for the possible role of pangolins as a reservoir of SARS-CoV-2 related coronaviruses (SC2r-CoVs). Here, we screened SC2r-CoVs in 172 samples from 163 pangolin individuals of four species, and detected positive signals in muscles of four Manis javanica and, for the first time, one M. pentadactyla. Phylogeographic analysis of pangolin mitochondrial DNA traced their origins from Southeast Asia. Using in-solution hybridization capture sequencing, we assembled a partial pangolin SC2r-CoV (pangolin-CoV) genome sequence of 22895 bp (MP20) from the M. pentadactyla sample. Phylogenetic analyses revealed MP20 was very closely related to pangolin-CoVs that were identified in M. javanica seized by Guangxi Customs. A genetic contribution of bat coronavirus to pangolin-CoVs via recombination was indicated. Our analysis revealed that the genetic diversity of pangolin-CoVs is substantially higher than previously anticipated. Given the potential infectivity of pangolin-CoVs, the high genetic diversity of pangolin-CoVs alerts the ecological risk of zoonotic evolution and transmission of pathogenic SC2r-CoVs.

SARS-CoV-2 - an update in virology: A Narrative Review

Background: SARS-CoV-2 is the highly infectious new coronavirus, which has been associated with the pandemic COVID-19. The majority of those pathogenic coronaviruses are benign, namely HCoV-229E, HCoV-NL63, HCoV-OC43 and HCoV-HKU1, and they have been linked to common cases of flu. Two of these viruses namely SARS coronavirus and MERS coronavirus are known to have caused more severe infections. Based on phylogenetic analysis, the Coronaviruses are divided into four groups, which are: Alpha-CoV, Beta -CoV, Gamma-CoV, and Delta -CoV. The Beta- CoV genus is further classified into four lineages, which are referred to as Groups A, B, C, and D. At the genomic level, SARS-CoV-2 has been identified to match with the lineage B of Beta coronavirus. This infection affects the respiratory tract, mainly the lungs' alveoli, and can cause a wide variety of symptoms ranging from discharge from the nose and a sore throat to respiratory distress, septic shock, and failure of multiple organs. To date, millions of people have been affected by the virus. The current mortality rate is around 6%. Early diagnosis is essential to prevent the spread of the infection. An extensive literature review was done using Pubmed, Medline, Pubmed Central, Embase, Goggle Scholar databases from January 20, 2020, till October 20, 2020.
 Conclusion: COVID-19 is the third outbreak of a pathogenic human coronavirus, after MERS and SARS. Its high rate of transmissibility has taken a toll on citizens' personal and professional lives globally. The peculiarities of SARS-CoV-2, regarding its genomic uniqueness and the role of Malayan pangolins as intermediate hosts, still demands more research to determine the degree to which they partake in the generation of the pathogenicity and infectiousness of the virus.

Conservation status of large mammals in protected and logged forests of the greater Taman Negara Landscape, Peninsular Malaysia

Abstract. Clements GR, Rostro-García S, Kamler JF, Liang SH, Hashim AKBA. 2021. Conservation status of large mammals in protected and logged forests of the greater Taman Negara Landscape, Peninsular Malaysia. Biodiversitas 22: 272-277. Peninsular Malaysia contains a large community of IUCN Threatened mammal species, although recent records in some protected areas is unknown. The greater Taman Negara Landscape is one of the national priority areas for tiger conservation, but the recent occurrence of large mammals in the landscape has not been sufficiently updated. Here, we conducted systematic camera-trap surveys in protected and logged forests of the Taman Negara Landscape: Merapoh in Taman Negara National Park (TNM), and the Dungun Timber Complex (DTC), respectively. We found that the diversity of large mammals in TNM appeared to be the same between 2000 and 2016. The detection frequencies (DF) of several Threatened species, such as Malayan tiger (Panthera tigris jacksoni), dhole (Cuon alpinus), and Malayan pangolin (Manis javanica), were similar between surveys, suggesting the relative abundance of these species likely remained stable during the past 16 years. However, the DF of Asian elephant (Elephas maximus) and Malayan tapir (Tapirus indicus) were lower compared to 2000. In DTC, overall mammalian diversity was relatively lower than in TNM, primarily due to the non-detection of two large ungulates: gaur (Bos gaurus) and sambar (Rusa unicolor). Nevertheless, we recorded several other Threatened species of mammals, suggesting there is potential for this forest reserve to preserve some of Peninsular Malaysia’s most Threatened mammal species. Our results suggest that the Taman Negara Landscape is still an important global site for the conservation of several Threatened species, and we recommend an increase in wildlife law enforcement efforts to ensure the survival of its large and diverse mammalian community.

Hematology and serum biochemistry of captive Sunda pangolin (Manis javanica) in Wildlife Reserves Singapore.

The Sunda pangolin (Manis javanica) faces threat of extinction due to illegal trafficking of its scales for the purpose of traditional medicine in the Asian region. Ex-situ captive breeding and reintroduction programs have been identified to be a key effort in the conservation of the species. The establishment of blood parameters for captive Sunda pangolins are vital to assess the health in these animals during health assessments. The objective of this study is to establish blood parameters for captive Sunda pangolins and compare the blood parameters with the established blood reference ranges for rescued wild Sunda pangolins in Singapore. Blood parameters for hematology and serum biochemistry were established from 13 clinically normal captive Sunda pangolins. Male captive Sunda pangolins were found to have significantly (P<0.05) higher potassium compared to the female captive Sunda pangolins. Captive Sunda pangolins were found to have significantly (P<0.05) lower white blood cell count (WBC), neutrophil counts, alanine phosphatase (ALP) and phosphorus and significantly (P<0.05) higher PCV, TP, globulin and blood urea nitrogen (BUN) when compared with rescued wild Sunda pangolins from the previous study.

SARS-CoV-2: taxonomia, origem e constituição

Introdução: O SARS-CoV-2 é um novo coronavírus, responsável pela atual pandemia de COVID-19, o qual já infectou e causou a morte de milhares de pessoas em todo o mundo. Objetivo: Descrever aspectos básicos e fundamentais sobre o SARS-CoV-2, como nome, constituição, possíveis origens e classificação. Método: Revisão bibliográfica exploratória e descritiva, elaborada por meio de pesquisas nas plataformas PubMed, Scopus, Google Acadêmico, e SciELO. Os termos utilizados para a seleção dos materiais foram: “SARS-CoV-2”, “COVID-19”, “spike-protein”, “classification”, “coronavirus” e suas combinações. Resultados: Os coronavírus pertencem à família Coronaviridae, a qual abrange 2 subfamílias, 5 gêneros, 26 subgêneros e 46 espécies de vírus. O SARS-CoV-2 pertence ao gênero Betacoronavirus, subgênero Sarbecovirus, espécie Severe acute respiratory syndrome-related coronavirus, e está relacionado à síndrome respiratória aguda. Sua classificação foi realizada pelo International Committee on Taxonomy of Viruses (ICTV) levando-se em consideração principalmente características moleculares e filogenéticas e não a doença que causa. Este vírus surgiu na China, país em que há o hábito de consumir animais domésticos ou selvagens recentemente abatidos. Especula-se que o morcego-ferradura (Rhinolophus sinicus) seja o seu hospedeiro primário e que o pangolim malaio (Manis javanica) o hospedeiro intermediário. O SARS-CoV-2 é um vírus envelopado, aproximadamente esférico, e os seus vírions têm diâmetros médios de 80 a 120 nm. Possui genoma de RNA não segmentado, fita simples, codificando quatro proteínas principais: glicoproteína espicular (S), proteína do envelope (E), glicoproteína da membrana (M) e proteína do nucleocapsídeo (N). Os coronavírus utilizam a S como principal alvo para neutralizar anticorpos e para se ligar ao receptor enzima conversora de angiotensina 2. Conclusão: O conhecimento aprofundado sobre as características básicas do SARS-CoV-2 é fundamental para a melhor compreensão e entendimento dos aspectos epidemiológicos, clínicos, fisiopatológicos e para o tratamento da COVID-19.

The Illegal Wildlife Trade: Through The Eyes of a One-Year-Old Pangolin (Manis javanica)

This paper explores the literature on the illegal wildlife trade (IWT) by following the journey of a single imagined Sunda pangolin (Manis javanica) through the entire trading process. Literature on IWT frequently refers to non-human animals in terms of collectives, species, or body parts, for example ‘tons of pangolin scales’, rather than as subjective individuals. In contrast, this paper centralizes the experiences of an individual pangolin by using a cross- disciplinary methodology, combining fact with a fictional narrative of subjective pangolin experience, in an empathetic and egomorphic process. The paper draws together known legislation, trade practices, and pangolin biology, structured around the journey of an imagined pangolin. At each stage of IWT, from poaching to consumption, the relationships between various actors are contextualized, helping to untangle the complex networks and relationships (both human-human and human-animal) involved in IWT. Concluding recommendations are made about ways to address IWT, including supporting locals in source areas, educating consumers, and improving law enforcement. It is hoped that this methodology will be applied to further studies of human and non-human animal interactions in this area of research, in order to individualize non-human animals and recognize their subjective experiences.

Novel SARS-CoV-2 encoded small RNAs in the passage to humans.

MotivationThe Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) has recently emerged as the responsible for the pandemic outbreak of the coronavirus disease (COVID-19). This virus is closely related to coronaviruses infecting bats and Malayan pangolins, species suspected to be an intermediate host in the passage to humans. Several genomic mutations affecting viral proteins have been identified, contributing to the understanding of the recent animal-to-human transmission. However, the capacity of SARS-CoV-2 to encode functional putative microRNAs (miRNAs) remains largely unexplored.ResultsWe have used deep learning to discover 12 candidate stem-loop structures hidden in the viral protein-coding genome. Among the precursors, the expression of eight mature miRNAs-like sequences was confirmed in small RNA-seq data from SARS-CoV-2 infected human cells. Predicted miRNAs are likely to target a subset of human genes of which 109 are transcriptionally deregulated upon infection. Remarkably, 28 of those genes potentially targeted by SARS-CoV-2 miRNAs are down-regulated in infected human cells. Interestingly, most of them have been related to respiratory diseases and viral infection, including several afflictions previously associated with SARS-CoV-1 and SARS-CoV-2. The comparison of SARS-CoV-2 pre-miRNA sequences with those from bat and pangolin coronaviruses suggests that single nucleotide mutations could have helped its progenitors jumping inter-species boundaries, allowing the gain of novel mature miRNAs targeting human mRNAs. Our results suggest that the recent acquisition of novel miRNAs-like sequences in the SARS-CoV-2 genome may have contributed to modulate the transcriptional reprogramming of the new host upon infection.

Investigation of epididymal proteins and general sperm membrane characteristics of Formosan pangolin (Manis pentadactyla pentadactyla)

BackgroundFormosan Pangolin (Manis pentadactyla pentadactyla) is one of the three subspecies of Chinese pangolins, it is also an isolated sub-species naturally habitat in Taiwan. Despite earlier report on successful breeding of Sunda (Manis javanica) pangolin, breeding of Formosan pangolins in zoo captive populations is still challenging due to unknown reproductive characterizations of this species in both male and female populations.ResultsWe characterized for the first time, reproductive tract of male Formosan pangolin. We showed pangolin epididymis was a collagen-enriched organ with apparent segmented sub-regions similar to other mammals. However, unlike most mammals exhibited two V-ATPase subunits, Formosan pangolin exhibited only V-ATPase subunit 2. This specific V-ATPase subunit extended its cellular localization throughout the cytoplasm of epididymal clear cells, suggesting pH regulation of luminal microenvironment might be different from other mammals. Electron micrographs showed rod-shaped pangolin sperm cells with multi-lamellar membrane structure at the sperm head. Similar to well-defined capacitation and acrosome reaction membrane changes in other mammals, we reported three distinct patterns (homogenous, punctuated and faded) of pangolin sperm head membrane changes. The concurrent increase in phosphotyrosine protein expression detected at the sperm mid-piece/tail and the emergence of punctuated membrane aggregates likely representing three sperm activation stages, namely inactivated, capacitated and acrosome reacted status of pangolin sperm.ConclusionBy revealing unique epididymal V-ATPase distribution and sperm membrane dynamics in Formosan pangolin, we would understand better the fundamental aspects of reproduction parameters of Formosan pangolin.

The Comparison of Semen Collection in Electroejaculation, Rectal Massage and Combination of Both Methods in the Critically Endangered Malayan Pangolin, Manis javanica.

Simple SummarySemen collection is one of the first few foundational steps towards Assisted Reproductive Technology (ART), however it is rarely conducted in the Malayan pangolin, Manis javanica. Semen was successfully retrieved in pangolins mainly via electroejaculation with the animal under general anesthesia, though facing a minor risk of urine contamination. The objective of this study is to report the success of semen collection with three different collection methods: electroejaculation, rectal massage and a combination of both methods in pangolins. The semen characteristics of the species are described in this study and the good semen qualities suggest future potential uses for ART. This study has found no difference between methods of semen collection. Captive and confiscated animals only differed in the percentages of live spermatozoa with overall good semen characteristics. The results from this study suggest that gamete recovery and biobank are feasible in the Malayan pangolin, which is essential to the management and conservation of this endangered species.This article describes the semen characteristics from different collection methods between captive and confiscated Malayan pangolins, Manis javanica. Semen was collected from 15 pangolins; two captive and 13 confiscated individuals at the mean weight of 9.36 ± 1.94 kg. The three semen collection methods employed were electroejaculation, rectal massage and a combination of both techniques. The semen characteristics (mean ± standard deviation) of the Malayan pangolin are volume (73.75 ± 144.57 µL), pH (7.63 ± 0.53), spermatozoa concentration (997.19 ± 728.98 × 106 /mL), total motility (59.60% ± 30.00%), progressive motility (48.95% ± 30.93%), mass motility (3.50 ± 1.50) and live spermatozoa (80.25% ± 13.45%). There was no significant difference in semen characteristics between the three collection methods. The percentages of live spermatozoa were significantly different, suggesting better samples from captive compared to confiscated animals. However, there was no significant difference in spermatozoa kinetics between the captive and confiscated samples, suggesting the potential of utilizing confiscated individuals for gamete recovery to conserve the genetic pool of pangolins. All three methods of semen collection were successfully performed in pangolins and should be considered; however, electroejaculation remains the most consistent method of obtaining semen from the species.

Molecular Genetics Supports a Potential Fifth Asian Pangolin Species (Mammalia, Pholidota, Manis).

Recently, two mitochondrial haplotypes, H4 and H8, of Manis sp. were found in two seizures in Hong Kong that do not correspond to Manis javanica, Manis pentadactyla or Manis crassicaudata of Asian pangolin species or any African pangolin species. It was proposed that both haplotypes derived from Manis culionensis, an unknown lineage of M. javanica, or a thus far unidentified Asian pangolin species (Manis sp.). To further investigate these three hypotheses, we used two mitochondrial genes of all eight known extant pangolin species and conducted phylogenetic tree reconstructions, divergence time estimation, and species delimitation analyses. All analyses consistently confirmed that these two haplotypes of Manis sp. constitute a distinct lineage, potentially representing a fifth Asian pangolin species, which originated around the Late Miocene to Early Pliocene (6.95 [4.64-9.85] million years ago). Our study provides genetic support for a potential fifth Asian pangolin species and helps to better understand species diversity of Asian pangolins, which is urgently needed for effective conservation work.

Structural and Functional Analysis of the D614G SARS-CoV-2 Spike Protein Variant

The SARS-CoV-2 spike (S) protein variant D614G supplanted the ancestral virus worldwide, reaching near fixation in a matter of months. Here we show that D614G was more infectious than the ancestral form on human lung cells, colon cells, and on cells rendered permissive by ectopic expression of human ACE2 or of ACE2 orthologs from various mammals, including Chinese rufous horseshoe bat and Malayan pangolin. D614G did not alter S protein synthesis, processing, or incorporation into SARS-CoV-2 particles, but D614G affinity for ACE2 was reduced due to a faster dissociation rate. Assessment of the S protein trimer by cryo-electron microscopy showed that D614G disrupts an interprotomer contact and that the conformation is shifted toward an ACE2 binding-competent state, which is modeled to be on pathway for virion membrane fusion with target cells. Consistent with this more open conformation, neutralization potency of antibodies targeting the S protein receptor-binding domain was not attenuated.

Investigation on the human coronaviruses origin (bats and pangolins): a review

A coronavirus related to SARS-CoV-2 has been isolated from Malayan pangolins illegally imported into Guangdong Province. It is not the precursor of SARS-CoV-2, but a comparison of viral genome sequences provides further evidence that the virus currently infecting humans. Bats and pangolins have been suggested as the natural reservoirs of a large variety of viruses. Some researchers have given attention to other species as the origin of coronaviruses and none have referred to bats and pangolins as the two emerging coronaviruses origin, which have caused unexpected human disease outbreaks recently. Severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV), are suggested to be originated from bats and pangolins. Numerous species of bats and pangolins in China have been observed to harbor genetically diverse SARS-like coronaviruses. Some strains are highly similar to SARS-CoV even in the spike protein and are able to use the same receptor as SARS-CoV for cell entry. Meanwhile, different coronaviruses phylogenetically related to MERS-CoV have been observed in the bats and pangolins species, some might be classified as similar to coronavirus species as MERS-CoV. Coronaviruses genetically related to human coronavirus 229E and NL63 have been found in bats and pangolins, respectively. However, intermediate hosts are suggested to play an important role in the transmission and emergence of these coronaviruses from bats and pangolins to humans. This study further documented that bats and pangolins origin of human coronaviruses are meaningful to predict and prevent a future outbreak of the deadly pandemic.

An update on the origin of SARS-CoV-2: Despite closest identity, bat (RaTG13) and pangolin derived coronaviruses varied in the critical binding site and O-linked glycan residues.

The initial cases of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) occurred in Wuhan, China, in December 2019 and swept the world by 23 June 2020 with 8 993 659 active cases, 469 587 deaths across 216 countries, areas or territories. This strongly implies global transmission occurred before the lockdown of China. However, the initial source's transmission routes of SARS‐CoV‐2 remain obscure and controversial. Research data suggest bat (RaTG13) and pangolin carried CoV were the proximal source of SARS‐CoV‐2. In this study, we used systematic phylogenetic analysis of Coronavirinae subfamily along with wild type human SARS‐CoV, MERS‐CoV, and SARS‐CoV‐2 strains. The key residues of the receptor‐binding domain (RBD) and O‐linked glycan were compared. SARS‐CoV‐2 strains were clustered with RaTG13 (97.41% identity), Pangolin‐CoV (92.22% identity) and Bat‐SL‐CoV (80.36% identity), forms a new clade‐2 in lineage B of beta‐CoV. The alignments of RBD contact residues to ACE2 justified? Those SARS‐CoV‐2 strains sequences were 100% identical by each other, significantly varied in RaTG13 and pangolin‐CoV. SARS‐CoV‐2 has a polybasic cleavage site with an inserted sequence of PRRA compared to RaTG13 and only PRR to pangolin. Only serine (Ser) in pangolin and both threonine (Thr) and serine (Ser) O‐linked glycans were seen in RaTG13, suggesting that a detailed study needed in pangolin (Manis javanica) and bat (Rhinolophus affinis) related CoV.

COVID-19: Recent advances in epidemiology, virology, etiopathogenesis, clinical trials and vaccine development

Background:The causative virus of COVID-19 has been named SARS-CoV-2. It is the seventh coronavirus that is pathogenic to humans and the third in the series of human pathogenic beta coronaviruses. Patient zero was identified to have contracted the virus in Wuhan, China. Shortly after the initial identification of the virus and its symptoms, multiple studies concluded that the virus originated from the “Wuhan seafood market”, a notorious market place for illegal wildlife trade based in Wuhan, a city in the Hubei region of the People’s Republic of China. Globally, as of 7:02 pm CEST, 29 May 2020, there have been 5704736 confirmed cases of COVID-19, including 357736 deaths, reported to the WHO. The transmission of COVID-19 is primarily by way of respiratory droplets, which can be developed via means of coughing or sneezing, hence spreading the disease from one person to another person. The research proposed indicates the possibility of bats as being the natural cistern of SARS-CoV-2, hence making COVID-19 a zoonotic disease. The most suspected intermediate host is the Malayan pangolin. SARS-CoV-2 is a single-stranded RNA virus that has an affinity for ACE2 receptors in humans, causing severe pathological symptoms. Symptoms like anorexia, dyspnea, fatigue, pyrexia, cough, headache, dizziness, nausea, productive sputum, abdominal pain, myalgia, sore throat, diarrhea, and vomiting. Vaccines that are currently in the clinical evaluation are the Adenovirus type 5 vector, mRNA-1273, Inactivated alum, ChAdOx, LNP-mRNA, DNA plasmid vaccine with electroporation and Inactivated vaccines. A Phase III randomized multicountry clinical trial comprising of 100 countries known as “Solidarity” (ISRCTN83971151) has been initiated by the WHO to achieve the unified goal of producing an adequate treatment for COVID-19. The present Solidarity trial focuses on the following drugs: Remdesivir, Lopinavir/Ritonavir with or without interferon beta-1a, Chloroquine, or hydroxychloroquine.&#x0D; Conclusion: It is invariably essential to promote research in this field of study and find an appropriate solution to the virus to allow individuals worldwide to lead a secure and healthy life.

Pangolin Indexing System: implications in forensic surveillance of large seizures.

Demand for pangolin scales in East Asia has increased dramatically in the past two decades, raising concern to the pangolin survival and bringing them to the brink of local extinction. Enumerating the number of individuals from the seized pangolin scales primarily goes undocumented, mostly due to the unavailability of the appropriate methods. In this study, we developed a Pangolin Indexing System, a multi-locus STR panel of eight dinucleotide microsatellites that showed promising results in individualization and assignment of scales into Chinese and Indian pangolins. The combined power of exclusion was 0.83 and 0.99 for Chinese and Indian pangolin. The select panel of eight polymorphic STRs exhibited the cumulative probability of identity 3.7 × 10-9 for Indian pangolin and 3.6 × 10-7 for Chinese pangolin and identified 51 unique genotypes from the 74 scales selected from the four pangolin seizures. The study demonstrated the first report of cross-species validation of STRs developed from Malayan pangolin to Indian pangolin and showed the potential application of Pangolin Indexing System in screening of large seizures through DNA profiling from the scales of Indian and Chinese pangolin.

Molecular evolution and phylogenetic analysis of SARS-CoV-2 and hosts ACE2 protein suggest Malayan pangolin as intermediary host.

An emergence of a novel coronavirus, causative agent of COVID19, named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), occurred due to cross-species transmission. Coronaviruses are a large family of viruses able to infect a great number of hosts. Entrance of SARS-CoV-2 depends on the surface (S) protein interaction with host ACE2 protein and cleavage by TMPRSS2. ACE2 could be a species-specific barrier that interferes with bat-to-human coronavirus cross-species transmission. Molecular analysis supported bats as natural hosts for SARS-CoV and involved them in MERS-CoV origin. The genomic similarity between bat RaTG13 CoV strain and SARS-CoV-2 implicates bats in the origin of the new outbreak. Additionally, there is a hypothesis for the zoonotic transmission based on contact with Malayan pangolins by humans in Huanan seafood market in Wuhan, China. To investigate bats and pangolin as hosts in SARS-CoV-2 cross-species transmission, we perform an evolutionary analysis combining viral and host phylogenies and divergence of ACE2 and TMPRSS2 amino acid sequences between CoV hosts. Phylogeny showed SARS-like-CoV-2 strains that infected pangolin and bats are close to SARS-CoV-2. In contrast to TMPRSS2, pangolin ACE2 amino acid sequence has low evolutionary divergence compared with humans and is more divergent from bats. Comparing SARS-CoV with SARS-CoV-2 origins, pangolin has yet lower ACE2 evolutionary divergence with humans than civet—the main intermediary host of SARS-CoV. Thus, pangolin has become an opportune host to intermediates bat-to-human SARS-CoV-2 jump and entry.Electronic supplementary materialThe online version of this article (10.1007/s42770-020-00321-1) contains supplementary material, which is available to authorized users.

Investigating the use of sensory information to detect and track prey by the Sunda pangolin (Manis javanica) with conservation in mind

Pangolins are of conservation concern as one of the most heavily poached, yet least understood mammals. The Sunda pangolin (Manis javanica) in particular is a critically endangered species. Here, we investigate the behaviour of these pangolins, for the first time, using a battery of cognitive tasks based on a manipulation of available sensory information. In an object-choice task in which only one of two containers was baited with food, the pangolins were able to find the food with olfactory information alone (N = 2), but not with visual or acoustic information alone (N = 1). The single subject tested on all three domains was further tested on how he used smell to find food by providing him with an opportunity to find it from a controlled distance or by using scent trails as a guide. The results suggest that our subject may have the capacity to exploit scent trails left by prey which can be tracked to a final source, though we found no evidence to suggest that he had the ability to initiate hunts based on distant prey odors. Despite the small sample size, this is the first controlled experiment to investigate pangolin foraging behaviour and cognition, which may have implications for the future protection of pangolin habitat based on the location of prey species.

Covid-19: natural or anthropic origin?

Abstract Viruses similar to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have been discovered in bats of the genus Rhinolophus and in the Sunda pangolin, Manis javanica Desmarest, 1822, suggesting that these animals have played a key role in the emergence of the Covid-19 outbreak in the city of Wuhan, China. In this paper, we review the available data for sarbecoviruses (viruses related to SARS-CoV [2002–2003 outbreak] and SARS-CoV-2) to propose all possible hypotheses on the origin of Covid-19, i. e., involving direct transmission from horseshoe bats to humans, indirect transmission via the pangolin or another animal, with interspecies contamination between either wild animals or animals kept in cage. Present evidence indicates that Rhinolophus bats are the natural reservoir of all sarbecoviruses, and that two divergent SARS-CoV-2-like viruses have circulated in southern China (at least in Guangxi and Guangdong provinces) between August 2017 and March 2019 in captive pangolins destined for sale in wildlife markets. We performed a genetic analysis of seven seized pangolins found to be positive for SARS-CoV-2-like virus using mitochondrial DNA sequences extracted from Sequence Reads Archive data. The results reveal that the same SARS-CoV-2-like virus can be found in animals with distinct haplotypes, which means that they were probably captured in different Southeast Asian regions. Our interpretation is that some pangolins were contaminated in captivity (by other pangolins or by another species to be determined), suggesting that illegal trade of living wild mammals is at the origin of the Covid-19 outbreak. To definitely validate this hypothesis, it is however necessary to discover a virus almost identical to SARS CoV-2 (at least 99% of identity) in animals sold in wet markets. Although pangolins are good candidates, other mammals, such as small carnivores, should not be overlooked.