Accepted articles have already been peer-reviewed and will undergo language editing, typesetting, and proofreading before being published in final form. Upon acceptance, however, articles are citable by their Digital Object Identifier (DOI).
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Abstract:
The recent global outbreak of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has surpassed 130,000,000 infections and 2,880,000 deaths worldwide. Evidence indicates that the RNA of SARS-CoV-2 can be detected on particulate matter (PM), and COVID-19 cases are correlated with levels of air pollutants. However, the mechanisms of PM involvement in the spread of SARS-CoV-2 remain poorly understood. Here, we found that PM exposure increased the expression level of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) in several epithelial cells and increased the adsorption of the SARS-CoV-2 spike protein. In hACE2 mouse model, instillation of PM significantly increased the expression of ACE2 and Tmprss2 and the viral replication in lung. Generally, PM exacerbated the pulmonary lesions caused by SARS-CoV-2 infection in hACE2 mice. In conclusion, our study demonstrated that PM is an epidemic factor of COVID-19 and emphasized the necessity of wearing anti-PM masks to cope with this global pandemic.
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Chronic pollution in aquatic ecosystems can lead to a myriad of adverse effects such as greater susceptibility to pathogens among resident biota. Trifloxystrobin (TFS), a strobilurin fungicide widely used in Asia to control soybean rust, is being increasingly used and could potentially enter aquatic ecosystems where it may impair fishes’ resistance against viral infections. To explore the potential environment risk of TFS, this study characterized the capacities of fish chronically exposed to TFS, and subsequently infected by SVCV (spring viraemia of carp virus). Although there was no significant cytotoxicity of TFS at tested environmental concentrations during the viral challenges, SVCV replication increased significantly in a time dependent manner within epithelioma papulosum cyprini (EPC) cells and zebrafish exposed to 25 μg/L TFS. The data showed the highest level of SVCV load reaching to more than 100 fold that in controls. Intracellular biochemical assays indicated that autophagy was induced by TFS, and associated changes included increases in autophagosomes, LC3-II conversion, accumulation of Beclin-1, and degradation of P62 in EPC cells and zebrafish. In addition, TFS obviously decreased mTor expression and phosphorylation levels, thus indicating that the activation of TFS may be associated with an mTOR-mediated autophagy pathway. Our study provides new insights into the mechanism of TFS induced immunosuppressive effects on non-targeted aquatic hosts, and the results suggest that the existence of TFS in aquatic environments may contribute to outbreaks of viral diseases.
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Scientific research provides essential information for conservation of threatened species. Data deficiency due to insufficient research impedes designing of conservation plans, and research bias may mistakenly direct limited resources to low biodiversity regions or less threatened species. We conducted a systematic review on published papers, grants, and graduate students training for carnivorans in China to identify species bias and gaps. Furthermore, we collected intrinsic and extrinsic features of carnivorans, and identified features that affected research intensity using generalized linear models. We found that the amount of research on carnivorans increased remarkably after 2000, and meanwhile species bias existed. Bears and big cats received the most research attention, while most small- and medium-sized carnivorans received little attention, showing the 80-20 phenomenon. Species with higher level of endemism and protection under Chinese laws received more attention. As a super star in animal conservation in China, the giant panda (<i>Ailuropoda melanoleuca</i>) attracted more than 50% of overall research resources to carnivorans. However, the giant panda showed a spillover effect, defined as a phenomenon that PhD graduates who studied the giant panda as their focal species shifted their research focuses to other species after graduation, which may help to improve research on other species. We suggest investing more in less concerned species, training more graduate students, and reinforcing academic exchanges to improve and strengthen Carnivora research and conservation. Without sounding actions, many carnivorans would continue being data deficient and threatened.
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ABSTRACT Single-cell RNA sequencing (scRNAseq) is useful to explore cell heterogeneity. However, for livestocks, much less is known on the SSCs self-renewal regulation, especially in dairy goats. Here, we described a high-resolution single-cell RNA sequencing atlas derived from dairy goats. We identified 6 somatic cells and 5 spermatogenic cell subtypes. During the spermatogenesis of dairy goats, genes whose expression levels change significantly are mainly enriched in the Notch signaling pathway, the TGF-β signaling pathway, the Hippo signaling pathway, and the signaling pathway that regulates the pluripotency of stem cells. And we detected and screened out specific candidate marker genes (TKTL1 and AES) for spermatogonia and it has been verified. In general, our study provides new insights into goat spermatogenesis and the development of testicular somatic cells.
Abstract:
Exploring the spatio-temporal patterns of biological diversity is important to understand the species coexistence mechanisms and community assembly rules. This is especially true for functional diversity, which was considered to be more integrative to better understand biodiversity across space and time. In the present study, Tianping Mountain was selected as the study area to investigate the spatio-temporal patterns (i.e., elevational and seasonal) of anuran functional diversity, as well as its environmental determinants. Specifically, ten transects were selected from low to high elevations, and anuran communities were sampled in spring, early summer, midsummer, and Autumn, 2017, respectively. Four functional diversity indices were computed for each transect in each season using eco-morphological functional traits. First, we found that there was an inverse bell shape relationship between functional richness and elevations. Functional evenness exhibited a hump-shape response to the increasing of elevations. In addition, functional divergence and functional specialization increased significantly along an elevational gradient. In terms of the temporal patterns, these indices were not significantly different between seasons. Finally, we found that each index was determined by distinct environmental variables, such as leaf litter cover, water temperature, tree number, and water conductivity. Overall, our results demonstrated the unique patterns of anuran functional diversity in temperate montane forests, providing valuable results to understand the general patterns of anuran diversity on mountains. Importantly, these findings highlighted the importance of microhabitat features in maintaining anuran diversity. Future work should assess how these unique patterns can affect food webs and ecosystem functioning in temperate montane forests.
Abstract:
An outbreak of coronavirus disease 2019 (COVID-19), causing by severe acute respiratory syndrome coronavirus (SARS-CoV-2), has become an unprecedented global health emergency. SARS-CoV-2-infected non-human primates are considered as the gold standard model for COVID-19 research. Here, we showed that northern pig-tailed macaques (Macaca leonina, NPMs) supported SARS-CoV-2 replication and developed typical interstitial pneumonia. Compared with rhesus macaques, NPMs showed rapidly viral clearance in lung tissues, nose swabs, throat swabs and rectal swabs, which might due to higher expression of IFN-α in lung tissue. However, the rapidly viral clearance wasn’t associated with good outcomes. In the second week post infection, NPMs developed persistent or even more severe inflammation and body injuries compared with rhesus macaques. These results suggested that viral clearance might have no relationship with COVID-19 progression and SARS-CoV-2-infected NPMs model might be considered as a critical-ill animal model in COVID-19 research.
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The Chinese Longsnout catfish (Leiocassis longirostris Günther) is one of the most economically important freshwater catfish in China. It is a valuable model for studies on sexual dimorphism, comparative and conservation biology since its wild resources have declined sharply. However, there is a lack of high-quality chromosome-level genome information for comparative genomic analysis and evolutionary studies. Therefore, we constructed the first high-quality chromosome-level reference genome for L. longirostris, which contained a total length of 703.19 Mb with 389 contigs, and a contig N50 of 4.29 Mb. Using the Hi-C data, we successfully generated 82 chromosome-level scaffolds anchored onto 26 chromosomes with a total length of 685.53 Mb (97.44% of the total genome sequences), ranging in size from 17.36 Mb to 43.97 Mb. A total of 23,708 protein-coding genes were identified in the L. longirostris genome. In addition, the phylogenetic analysis indicated that L. longirostris and its closest related species P. fulvidraco diverged approximately 26.6 million years ago. This first high-quality reference genome of L. longirostris will pave the way for genome comparisons and evolution investigations.
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Changes in abiotic and biotic factors may potentially affect animals’ efficiency of biological systems, and force them to adjust their behaviors in response to these daily and seasonal variations. From September 2016 to August 2017, we collected data on ranging behavior of four groups of White-headed langurs (Trachypithecus leucocephalus), living in the Guangxi Chongzuo White-Headed Langur National Nature Reserve, Guangxi, southwest China. The objective was to simultaneous analyze how multiple ecological factors affect langurs’ ranging behavior, which would facilitate to understand the potential mechanisms of their adaptation to the limestone habitat. The results showed that the ranging behavior of langurs was significantly affected by diet composition, food availability and climatic factors. Specifically, the moving time and daily path lengths increased with increase in dietary diversity. Furthermore, langurs’ moving time and daily path lengths were positively associated with availability of fruits, relative humidity of forest, and moderated associated with temperature and relative humidity of bare rock. Our study demonstrates that langurs maintain stable moving and feeding times, and a short daily travel distance, likely adopting an energy-conserving behavioral strategy in response to food shortages and high temperature in the fragmented karst forest, and highlights the importance of food availability and temperature to shape the ranging behavior of these karst-dwelling langurs.
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The Dianchi golden-line barbel, Sinocyclocheilus grahami (Regan, 1904), is one of the “Four Famous Fishes” of Yunnan Province, China. Given its economic value, this species has been artificially bred successfully since 2007, with a nationally selected breed (“S. grahami, Bayou No. 1”) certified in 2018. For the future utilization of this species, its growth rate, disease resistance, and wild adaptability need to be improved, which could be achieved with the help of molecular marker-assisted selection (MAS). In the current study, we constructed the first chromosome-level genome of S. grahami, assembled 48 pseudo-chromosomes, and obtained a genome assembly of 1.49 Gb. We also performed QTL-seq analysis of S. grahami using the highest and lowest bulks (i.e., largest and smallest size) in both a sibling and random population. We screened two quantitative trait loci (QTLs) (Chr3, 14.9–39.1 Mb and Chr17, 4.1–27.4 Mb) as the major growth-related locations. Several candidate genes (e.g., map2k5, stat1, phf21a, sox6, and smad6) were also identified, with functions related to growth, such as cell differentiation, neuronal development, skeletal muscle development, chondrogenesis, and immunity. These results built a solid foundation for in-depth MAS studies on the growth traits of S. grahami.

A new species of the genus Atelopus, Atelopus fronterizo   sp. nov.  , from eastern Panama is described herein based on molecular, morphological, and bioacoustic evidence. The new species can be distinguished from its congeners occurring in the region by a combination of the following characters: (1) phalangeal reduction in thumb; (2) SVL (females only) (35.1–50.1; n=13), HW/SVL (0.23–0.34; n=59), EYND/HW (0.27–0.39; n=60), TIBL/SVL (0.41–0.56; n=58), and HAL/SVL (0.22–0.28; n=49); (3) dorsal color pattern with green or yellow background and extensive dark olive blotches forming transversal bands or mottling; (4) advertisement call duration 176–235 ms with 19–34 pulses, average pulse rate 131.69 pulses/s, and dominant frequency 2 422.50–2 606.50 Hz. The new species is nested within the Central American clade of Atelopus. The minimum Kimura‐2‐parameter (K2P) genetic divergence between Atelopus fronterizo   sp. nov.   and its most phylogenetically similar congeners (A. certus and A. glyphus) is >2.6% for 16S and >4.9% for COI (

Table 1

). The phylogenetic relationship is strongly supported by ultrafast bootstrap values for the maximum-likelihood trees of both genetic markers (16S, 96; COI, 100,

Figure 1A

). Bayesian analysis of the concatenated sequences resulted in a tree with similar topology and high posterior probability support (0.99; Supplementary Figure S1). In addition, haplotype networks inferred from COI and 16S (Supplementary Figure S2) showed a well-separated clade containing the new species (two for COI, four for 16S). The number of mutational steps between haplotypes for the new species samples is very low (1–4 in 16S; one in COI), and the minimum number of mutational steps from the nearest species is nine for 16S (distance to A. certus) and 28 for COI (distance to A. glyphus).

DNA studies of endangered or extinct species often rely on ancient or degraded remains. The majority of ancient DNA (aDNA) extraction protocols focus on skeletal elements, with skin and hair samples rarely explored. Similar to that found in bones and teeth, DNA extracted from historical or ancient skin and fur samples is also extremely fragmented with low endogenous content due to natural degradation processes. Thus, the development of effective DNA extraction methods is required for these materials. Here, we compared the performance of two DNA extraction protocols (commercial and custom laboratory aDNA methods) on hair and skin samples from decades-old museum specimens to Iron Age archaeological material. We found that apart from the impact sample-specific taphonomic and handling history has on the quantity and quality of DNA preservation, skin yielded more endogenous DNA than hair of the samples and protocols tested. While both methods recovered DNA from ancient soft tissue, the laboratory method performed better overall in terms of DNA yield and quality, which was primarily due to the poorer performance of the commercial binding buffer in recovering aDNA.
The Eremias multiocellata-przewalskii species complex is a viviparous group in the genus Eremias, and a well-known representative of taxonomically complicated taxa. Within this complex, a new species – E. dzungarica (Orlova et al., 2017) – has been described recently from western Mongolia and eastern Kazakhstan, with an apparent distribution gap in northwestern China. In this study, we used an integrative taxonomic framework to address whether E. dzungarica indeed occurs in China. Thirty specimens previously classified as E. multiocellata were collected in eastern Kazakhstan and the adjacent Altay region in China. The cytochrome c oxidase I (COI) barcodes were sequenced and compiled with those from Orlova et al. (2017) and analyzed with the standard and diverse barcoding techniques. We detected an absence of a barcoding gap in this complex, which indicates potential cryptic species in Eremias sp. 3 with high intraspecific diversity and multiple recently evolved species in Clade A. Both BIN and GMYC suggested an unrealistically large number of species (23 and 26, respectively), while ABGD, mPTP and BPP indicated a more conservative number of species (10, 12, and 15, respectively), largely concordant with the previously defined species-level lineages according to phylogenetic trees. Based on molecular phylogeny and morphological examination, all 30 individuals collected in this study were reliably identified as E. dzungarica – a distinct species – confirming the occurrence of this species in the Altay region, Xinjiang, China. Potentially owing to the larger sample size in this study, our morphological analyses revealed many inconsistencies with the original descriptions of E. dzungarica, which were primarily associated with sexual dimorphism and a broader range of values for various traits.
During a terrestrial vertebrate survey of the Dabie Mountains in Anhui Province, eastern China, we collected four Asian shrew mole specimens (hereafter, shrew moles). Based on published literature and comparison with previously collected materials, the four specimens were similar to shrew moles from the mountains of Southwest China; however, no species in this group has been previously recorded from the Dabie Mountains. The genetic and morphological characteristics of the specimens were analyzed, based upon which a new species of shrew mole is described, named Uropsilus dabieshanensis sp. nov.
As small heat shock proteins, α-crystallins function as molecular chaperones and inhibit the misfolding and aggregation of β/γ-crystallins. Genetic mutations of CRYAA are associated with protein aggregation and cataract occurrence. One possible process underlying cataract formation is that endoplasmic reticulum stress (ERS) induces the unfolded protein response (UPR), leading to apoptosis. However, the pathogenic mechanism related to this remains unexplored. Here, we successfully constructed a cataract-causing CRYAA (Y118D) mutant mouse model, in which the lenses of the CRYAA-Y118D mutant mice showed severe posterior rupture, abnormal morphological changes, and aberrant arrangement of crystallin fibers. Histological analysis was consistent with the clinical pathological characteristics. We also explored the pathogenic factors involved in cataract development through transcriptome analysis. In addition, based on key pathway analysis, up-regulated genes in CRYAA-Y118D mutant mice were implicated in the ERS-UPR pathway. This study showed that prolonged activation of the UPR pathway and severe stress response can cause proteotoxic and ERS-induced cell death in CRYAA-Y118D mutant mice.
The loach tribe Yunnanilini from China is reviewed here using morphological characters and complete mitochondrial genomes of select species. Molecular data suggest that the tribe Yunnanilini is not monophyletic and can be divided into three clades. Species of the Yunnanilus nigromaculatus group form an independent genus and are placed in Eonemachilus. In the phylogenetic tree, Y. jinxiensis clusters with Paranemachilus genilepis, and Y. pulcherrimus clusters with Micronemacheilus cruciatus, indicating that Y. jinxiensis and Y. pulcherrimus belong to Paranemachilus and Micronemacheilus, respectively. Based on morphological data, Y. bailianensis and Y. longibarbatus are placed in Heminoemacheilus, while Y. jinxiensis and Y. pulcherrimus, are placed in Paranemachilus and Micronemacheilus, respectively. Yunnanilus niulanensis and Y. qujinensis are treated as junior synonyms of Eonemachilus caohaiensis. Eonemachilus, Micronemacheilus, and Yunnanilus are show short separation between anterior and posterior nostrils. The genera can be distinguished from each other by mouth structure, lateral line and cephalic lateral-line canals, and papillae on median part of both lips. The anterior and posterior nostrils of Heminoemacheilus and Paranemachilus are closely set. Paranemachilus and Micronemacheilus are distinguished by cheeks covered with scales and lips with papillae, respectively. Our phylogenetic tree and morphological characters support Traccatichthys as a valid genus, which can be distinguished from Micronemacheilus by anterior and posterior nostrils closely set (vs. clearly separated). Four species are placed in Traccatichthys.
Parabiosis is a surgical method of animal modeling with a long history. It has been widely used in medical research, particularly in the fields of aging, stem cells, neuroscience, and immunity in the past two decades. The protocols for parabiosis have been improved many times and are now widely accepted. However, researchers need to consider many details, from surgical operation to perioperative management, to reduce mortality and maintain the parabiosis union. Although parabiosis has certain inevitable limitations, it still has broad application prospects as an irreplaceable animal model in the medical research field.
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The water-to-land transition was a major step in vertebrate evolution and eventually gave rise to the tetrapods, including amphibians, reptiles, birds, and mammals. The first land invasion of our fish ancestors is considered to have occurred during the late Devonian period ~370 million years ago (Mya) (Daeschler et al., 2006). Many fossils from important transitional species, such as Tiktaalik, Acanthostega, and Ichthyostega, have helped to identify key morphological and anatomical structures crucial to vertebrate terrestrial adaptation (Coates, 1996; Johanson & Ahlberg, 2001; Shubin et al., 2006). However, homologous analyses of these body forms and structures in more ancient species have suggested that some of the morphologies related to vertebrate land dispersal were already present in early bony fish species. For instance, the presence of shoulder girdles on the articular surface of the endoskeleton in Late Lochkovian Psarolepis indicates that stem sarcopterygians already possessed an endoskeletal fin pattern similar to that of tetrapod stylopods (Zhu & Yu, 2009). In addition, primitive lungs, which originated from the respiratory pharynx and were located on the ventral side of the alimentary tracts, can be observed in several extant basal actinopterygians (bichirs, reedfish) and all extant sarcopterygians, as well as some fossils of coelacanths and salamanders (Cupello et al., 2017; Tissier et al., 2017) (Figure 1). This evidence suggests that, instead of relying on genetic innovations evolving after the first fish left their water habitat, this transition may have been accomplished by adopting physical traits and genetic components that already existed far earlier than when the transition occurred. Whether such an ancestral developmental regulatory network was present or not and how far this ancestral network can be traced in history are challenging questions for paleontologists. Three recent papers published in Cell provide new insights into this hypothesis. Wang et al. (2021) sequenced the giant genome of lungfish, the closest fish species to tetrapods, and Bi et al. (2021) sequenced the genomes of multiple early divergent ray-finned fish. Comparative genomic analyses from these two studies confirmed the presence of ancestral genetic regulatory networks that likely played essential roles in the development and evolution of various biological functions related to vertebrate land invasion. Although certain ancestral features have been lost in teleosts, the most derived fish lineage to evolve after whole-genome duplication (Sato & Nishida, 2010), they have been recreated in zebrafish by modifying their genetic makeup to reactivate the ancestral genetic network (Hawkins et al., 2021).
We recently identified a cynomolgus monkey with naturally occurring Parkinson’s disease (PD), indicating that PD may not be a uniquely human disease (Li et al, 2020). In our previous study, four lines of evidence, including typical PD clinical symptoms, pharmacological responses, pathological hallmarks, and genetic mutations, strongly supported the identification of a monkey with spontaneous PD (Figure 1). To the best of our knowledge, this is the first reported case of naturally developed PD in animals. This suggests that PD is not a disease restricted to humans, with its existence in a non-human primate providing a novel evolutionary angle for understanding PD. As a close relative to humans (Buffalo et al, 2019; Phillips et al, 2014; Yan et al, 2011), this rare case of PD in another primate species provides solid evidence that monkeys are ideal candidates for the development of a genuine “animal version of PD”, with conserved etiology and pathogenesis (Li et al, 2020). Furthermore, it allows us to compare similarities and differences in PD development between species and to understand PD pathogenesis from an evolutionary point of view.
Review
Secretory pore-forming proteins (PFPs) have been identified in organisms from all kingdoms of life. Our studies with the toad species Bombina maxima found an interaction network among aerolysin family PFPs (af-PFPs) and trefoil factors (TFFs). As a toad af-PFP, BmALP1 can be reversibly regulated between active and inactive forms, with its paralog BmALP3 acting as a negative regulator. BmALP1 interacts with BmTFF3 to form a cellular active complex called βγ-CAT. This PFP complex is characterized by acting on endocytic pathways and forming pores on endolysosomes, including stimulating cell macropinocytosis. In addition, cell exocytosis can be induced and/or modulated in the presence of βγ-CAT. Depending on cell contexts and surroundings, these effects can facilitate the toad in material uptake and vesicular transport, while maintaining mucosal barrier function as well as immune defense. Based on experimental evidence, we hereby propose a secretory endolysosome channel (SELC) pathway conducted by a secreted PFP in cell endocytic and exocytic systems, with βγ-CAT being the first example of a SELC protein. With essential roles in cell interactions and environmental adaptations, the proposed SELC protein pathway should be conserved in other living organisms.
Epithelial ovarian cancer (EOC) is the leading cause of gynecological cancer-related mortality in the developed world. EOC is a heterogeneous disease represented by several histological and molecular subtypes. Therefore, exploration of relevant preclinical animal models that consider the heterogenic nature of EOC is of great importance for the development of novel therapeutic strategies that can be translated clinically to combat this devastating disease. In this review, we discuss recent progress in the development of preclinical mouse models for EOC study as well as their advantages and limitations.
Article
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease 2019 (COVID-19) continue to impact countries worldwide. At present, inadequate diagnosis and unreliable evaluation systems hinder the implementation and development of effective prevention and treatment strategies. Here, we conducted a horizontal and longitudinal study comparing the detection rates of SARS-CoV-2 nucleic acid in different types of samples collected from COVID-19 patients and SARS-CoV-2-infected monkeys. We also detected anti-SARS-CoV-2 antibodies in the above clinical and animal model samples to identify a reliable approach for the accurate diagnosis of SARS-CoV-2 infection. Results showed that, regardless of clinical symptoms, the highest detection levels of viral nucleic acid were found in sputum and tracheal brush samples, resulting in a high and stable diagnosis rate. Anti-SARS-CoV-2 immunoglobulin M (IgM) and G (IgG) antibodies were not detected in 6.90% of COVID-19 patients. Furthermore, integration of nucleic acid detection results from the various sample types did not improve the diagnosis rate. Moreover, dynamic changes in SARS-CoV-2 viral load were more obvious in sputum and tracheal brushes than in nasal and throat swabs. Thus, SARS-CoV-2 nucleic acid detection in sputum and tracheal brushes was the least affected by infection route, disease progression, and individual differences. Therefore, SARS-CoV-2 nucleic acid detection using lower respiratory tract samples alone is reliable for COVID-19 diagnosis and study.
Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread rapidly worldwide with high rates of transmission and substantial mortality. To date, however, no effective treatments or enough vaccines for COVID-19 are available. The roles of angiotensin converting enzyme 2 (ACE2) and spike protein in the treatment of COVID-19 are major areas of research. In this study, we explored the potential of ACE2 and spike protein as targets for the development of antiviral agents against SARS-CoV-2. We analyzed clinical data, genetic data, and receptor binding capability. Clinical data revealed that COVID-19 patients with comorbidities related to an abnormal renin-angiotensin system exhibited more early symptoms and poorer prognoses. However, the relationship between ACE2 expression and COVID-19 progression is still not clear. Furthermore, if ACE2 is not a good targetable protein, it would not be applicable across a wide range of populations. The spike-S1 receptor-binding domain that interacts with ACE2 showed various amino acid mutations based on sequence analysis. We identified two spike-S1 point mutations (V354F and V470A) by receptor-ligand docking and binding enzyme-linked immunosorbent assays. These variants enhanced the binding of the spike protein to ACE2 receptors and were potentially associated with increased infectivity. Importantly, the number of patients infected with the V354F and V470A mutants has increased with the development of the SARS-CoV-2 pandemic. These results suggest that ACE2 and spike-S1 are likely not ideal targets for the design of peptide drugs to treat COVID-19 in different populations.
Allactaginae is a subfamily of dipodids consisting of four- and five-toed jerboas (Allactaga, Allactodipus, Orientallactaga, Pygeretmus, Scarturus) found in open habitats of Asia and North Africa. Recent molecular phylogenies have upended our understanding of this group’s systematics across taxonomic scales. Here, I used cranial geometric morphometrics to examine variation across 219 specimens of 14 allactagine species (Allactaga major, A. severtzovi, Orientallactaga balikunica, O. bullata, O. sibirica, Pygeretmus platyurus, P. pumilio, P. shitkovi, Scarturus aralychensis, S. euphraticus, S. hotsoni, S. indicus, S. tetradactylus, S. williamsi) in light of their revised taxonomy. Results showed no significant sexual size or shape dimorphism. Species significantly differed in cranial size and shape both overall and as species pairs. Species identity had a strong effect on both cranial size and shape. Only a small part of cranial shape variation was allometric, with no evidence of unique species allometries, and most specimens fit closely to the common allometric regression vector. Allactaga was the largest, followed by Orientallactaga, Scarturus, and finally Pygeretmus. Principal component 1 (PC1) separated O. bullata+O. balikunica+S. hotsoni (with inflated bullae along with reduced zygomatic arches and rostra) from A. major+A. severtzovi+O. sibirica (with converse patterns), while PC2 differentiated Orientallactaga (with enlarged cranial bases and rostra along with reduced zygomatic arches and foramina magna) from Scarturus+Pygeretmus (with the opposite patterns). Clustering based on the unweighted pair group method with arithmetic mean (UPGMA) contained the four genera, but S. hotsoni clustered with O. bullata+O. balikunica and O. sibirica clustered with A. major+A. severtzovi, likely due to convergence and allometry, respectively.
Although widely thought to be aggressive, solitary, and potentially cannibalistic, some spider species have evolved group-living behaviors. The distinct transition provides the framework to uncover group-living evolution. Here, we conducted a comparative transcriptomic study and examined patterns of molecular evolution in two independently evolved group-living spiders and twelve solitary species. We report that positively selected genes among group-living spider lineages are significantly enriched in nutrient metabolism and autophagy pathways. We also show that nutrient-related genes of group-living spiders convergently experience amino acid substitutions and accelerated relative evolutionary rates. These results indicate adaptive convergence of nutrient metabolism that may ensure energy supply in group-living spiders. The decelerated evolutionary rate of autophagy-related genes in group-living lineages is consistent with an increased constraint on energy homeostasis as would be required in a group-living environment. Together, the results show that energy metabolic pathways play an important role in the transition to group-living in spiders.
Letters to the editor
Deforestation represents one of the greatest threats to tropical forest mammals, and the situation is greatly exacerbated by bushmeat hunting. To construct informed conservation plans, information must be gathered about responses to habitat degradation, regeneration, and hunting over a sufficiently long period to allow demographic responses. We quantified changes in the abundance of three commonly occurring ungulate species (i.e., bushbuck, Tragelaphus scriptus; red duiker, Cephalophus sp.; blue duiker, Cephalophus monticola) at eight sites in Kibale National Park, Uganda (old growth=3; logged=3; regenerating=2) for 23 years. Changes in abundance (363 surveys totaling 1 450 km) were considered in regard to the park’s management strategy, regional economic indicators, and estimates of illegal hunting. Bushbuck abundance increased in old-growth and logged forests from 1996 to 2009, and then oscillated around this level or declined. Duiker abundance demonstrated a similar pattern, but abundance in the old-growth forests showed a general increase from 1996 to present day. Duiker abundance in the logged forests exhibited an early increase, but subsequent oscillation. Poaching signs per patrol have remained stable over the last decade, despite increases in the size of the surrounding population, cost of living, and cost of schooling, thus reflecting successful efforts in conservation education and enforcement. Our study highlights the positive impact of park establishment, patrol, and conservation efforts on ungulate populations and shows the adaptability of forest mammal populations to different management schemes.
Muntjac deer (Cervidae: Muntiacus) are often cited as an excellent model for the study of vertebrate evolution due to their fast rate of change in chromosome number among vertebrates. However, the phylogenetic relationships within Muntiacus generally, and the taxonomic status of Muntiacus gongshanensis specifically, remain unclear. Here, the phylogenetic relationships within Muntiacus were studied using mitochondrial genome (mitogenome) and cytochrome b (cyt b) segments. Our results recognize 12 species within Muntiacus and support the controversial species M. gongshanensis, M. putaoensis, and M. malabaricus. Furthermore, Bayesian inference (BI) and maximum-likelihood (ML) approaches revealed M. gongshanensis and M. crinifrons to be closely related species, with M. feae as their sister species, and M. putaoensis and M. truongsonensis to be closely related, with M. rooseveltorum as their sister species. The distribution range of M. gongshanensis was also confirmed in southwest China (Namdapha, Modong, Zayu and Gongshan) and northern Myanmar (Putao). The results of this study provide insight into the evolution of Muntiacus and further provide a molecular basis for the taxonomic evaluation of the genus in the future and fundamental data for the conservation of M. gongshanensis.
Recent studies have examined the cost of raising parasitic cuckoos and highlighted the importance of “no extra cost” in explaining the low levels of defense in hosts. To clarify the reasons for parasitization in typical hosts, we present a simple model to explore the immediate and future costs of parasitism in shaping the evolution of defense behavior in hosts. Our results suggest that any cost of parasitization is maladaptive to the host and learned egg recognition is always favored to overcome these costs. Furthermore, although facing a potential cost of mis-imprinting, learned nestling recognition may still evolve when there is a non-zero immediate cost from raising a parasitic nestling. Therefore, we contend that “no extra cost” does not provide sufficient evidence to explain the low levels of defense behavior in hosts per se.
Parents may adjust their breeding time to optimize reproductive output and reduce reproductive costs associated with unpredictable climatic conditions, especially in the context of global warming. The breeding performance of tropical bird species in response to local climate change is relatively understudied compared with that of temperate bird species. Here, based on data from 361 white-rumped munia (Lonchura striata) nests, we determined that breeding season onset, which varied from 15 February to 22 June, was delayed by drought and high temperatures. Clutch size (4.52±0.75) and daily survival rate but not egg mass (0.95±0.10 g) were negatively affected by frequent rainfall. Daily nest survival during the rainy breeding season in 2018 (0.95±0.04) was lower than that in 2017 (0.98±0.01) and 2019 (0.97±0.00). The overall nesting cycle was 40.37±2.69 days, including an incubation period of 13.10±1.18 days and nestling period of 23.22±2.40 days. The nestling period in 2018 (25.11±1.97 days) was longer than that in 2017 (22.90±2.22 days) and 2019 (22.00±2.48 days), possibly due to the cooler temperatures. Climate also affected the total number of successful fledglings, which was highest under moderate rainfall in 2017 (115 fledglings) and lowest during prolonged drought in 2019 (51 fledglings). Together, our results suggest that drought and frequent rainfall during the breeding season can decrease reproductive success. Thus, this study provides important insights into bird ecology and conservation in the context of global climate change.
We describe a new species of the genus Kurixalus, Kurixalus raoi sp. nov ., from Guizhou Province, China, based on morphological and molecular evidence. Phylogenetically, the new species is sister to K. idiootocus, but is distinguishable from all known congeners by a combination of the following characters: small body size (snout-vent length 28.2‒32.2 mm in males; 38.6 mm in female); snout rounded, with no prominence on tip; single internal vocal sac; dorsal surface brown, rough, scattered with several small warts; chin clouded with blackish marking; pair of large symmetrical dark blotches on chest; vomerine teeth present; iris brown; tibiotarsal articulation reaching center of eye; nuptial pad slight; flank rough; mandibular symphysis weak; throat skin granular; and toes moderately webbed, formula I2‒2II1.5‒3III2‒3IV3‒2V. The genetic distances between the new species and K. idiootocus were 2.9% and 5.4% for 16S rRNA and COI, respectively.
We report on a new amphibian species of the genus Micryletta from Hainan Island, China, based on morphological and molecular analyses. The new species, Micryletta immaculata sp. nov. , is diagnosed by a combination of the following morphological characters: medium-sized within genus (SVL 23.3–24.8 mm in males, n=3; 27.7–30.1 mm in females, n=2); dorsum bronze brown to reddish brown in life; dark brown spots and stripes on dorsum and flank absent; flanks largely pigmented with silver white; throat in adult males dark brown; undersides without dark patterns; outer metatarsal tubercle absent; supratympanic fold distinct; webbing between toes basal and poorly developed; tibiotarsal articulation adpressed limb reaching level of tympanum. The new species is divergent from all other congeners based on 16S rRNA gene sequences (3.0%–7.7%). Data on the natural history and male advertisement calls of the new species are provided. Following the IUCN Red List Categories and Criteria, we propose the new species to be listed as Vulnerable B1ab (iii).
A new loach species (Cypriniformes: Nemacheilidae: Yunnanilini), Yunnanilus chuanheensis sp. nov. , was caught from Chuanhe in the upper reaches of the Lixianjiang River, a tributary of the Red River in Nanjian County, Yunnan Province, China. This species is a member of the traditional Y. pleurotaenia species group based on the presence of a lateral line and cephalic lateral-line canals. It can be distinguished from other species in the Y. pleurotaenia species group by the following characters: lips without papillae, anterior and posterior nostrils separated, whole body scaled, eye diameter smaller than interorbital width, outer gill raker absent on first gill arch, eye diameter greater than 18% of head length, 10–11 inner gill rakers on first gill arch, and lateral line not extending to vertical through dorsal fin insertion. To the best of our knowledge, this is the first Yunnanilus species recorded from the Red River drainage.
Somatic mutations are a large category of genetic variations, which play an essential role in tumorigenesis. Detection of somatic single nucleotide variants (SNVs) could facilitate downstream analysis of tumorigenesis. Many computational methods have been developed to detect SNVs, but most require normal matched samples to differentiate somatic SNVs from the normal state, which can be difficult to obtain. Therefore, developing new approaches for detecting somatic SNVs without matched samples are crucial. In this work, we detected somatic mutations from individual tumor samples based on a novel machine learning approach, svmSomatic, using next-generation sequencing (NGS) data. In addition, as somatic SNV detection can be impacted by multiple mutations, with germline mutations and co-occurrence of copy number variations (CNVs) common in organisms, we used the novel approach to distinguish somatic and germline mutations based on the NGS data from individual tumor samples. In summary, svmSomatic: (1) considers the influence of CNV co-occurrence in detecting somatic mutations; and (2) trains a support vector machine algorithm to distinguish between somatic and germline mutations, without requiring normal matched samples. We further tested and compared svmSomatic with other common methods. Results showed that svmSomatic performance, as measured by F1-score, was significantly better than that of others using both simulation and real NGS data.
Erratum
Following the publication of our paper (Zhang et al., 2020), it has come to our attention that we erroneously listed two funding sources unrelated to this study in the “ACKNOWLEDGEMENTS” section. Hereby, we wish to update the “ACKNOWLEDGEMENTS” section as a correction:
After the publication of Wang et al. (2020), we realized that there were some inappropriate statements in the content. Hereby, we correct them and apologize for any confusion this may have caused.
The Dianchi golden-line barbel, Sinocyclocheilus grahami (Regan, 1904), is one of the “Four Famous Fishes” of Yunnan Province, China. Given its economic value, this species has been artificially bred successfully since 2007, with a nationally selected breed (“S. grahami, Bayou No. 1”) certified in 2018. For the future utilization of this species, its growth rate, disease resistance, and wild adaptability need to be improved, which could be achieved with the help of molecular marker-assisted selection (MAS). In the current study, we constructed the first chromosome-level genome of S. grahami, assembled 48 pseudo-chromosomes, and obtained a genome assembly of 1.49 Gb. We also performed QTL-seq analysis of S. grahami using the highest and lowest bulks (i.e., largest and smallest size) in both a sibling and random population. We screened two quantitative trait loci (QTLs) (Chr3, 14.9–39.1 Mb and Chr17, 4.1–27.4 Mb) as the major growth-related locations. Several candidate genes (e.g., map2k5, stat1, phf21a, sox6, and smad6) were also identified, with functions related to growth, such as cell differentiation, neuronal development, skeletal muscle development, chondrogenesis, and immunity. These results built a solid foundation for in-depth MAS studies on the growth traits of S. grahami.

A new species of the genus Atelopus, Atelopus fronterizo   sp. nov.  , from eastern Panama is described herein based on molecular, morphological, and bioacoustic evidence. The new species can be distinguished from its congeners occurring in the region by a combination of the following characters: (1) phalangeal reduction in thumb; (2) SVL (females only) (35.1–50.1; n=13), HW/SVL (0.23–0.34; n=59), EYND/HW (0.27–0.39; n=60), TIBL/SVL (0.41–0.56; n=58), and HAL/SVL (0.22–0.28; n=49); (3) dorsal color pattern with green or yellow background and extensive dark olive blotches forming transversal bands or mottling; (4) advertisement call duration 176–235 ms with 19–34 pulses, average pulse rate 131.69 pulses/s, and dominant frequency 2 422.50–2 606.50 Hz. The new species is nested within the Central American clade of Atelopus. The minimum Kimura‐2‐parameter (K2P) genetic divergence between Atelopus fronterizo   sp. nov.   and its most phylogenetically similar congeners (A. certus and A. glyphus) is >2.6% for 16S and >4.9% for COI (

Table 1

). The phylogenetic relationship is strongly supported by ultrafast bootstrap values for the maximum-likelihood trees of both genetic markers (16S, 96; COI, 100,

Figure 1A

). Bayesian analysis of the concatenated sequences resulted in a tree with similar topology and high posterior probability support (0.99; Supplementary Figure S1). In addition, haplotype networks inferred from COI and 16S (Supplementary Figure S2) showed a well-separated clade containing the new species (two for COI, four for 16S). The number of mutational steps between haplotypes for the new species samples is very low (1–4 in 16S; one in COI), and the minimum number of mutational steps from the nearest species is nine for 16S (distance to A. certus) and 28 for COI (distance to A. glyphus).

DNA studies of endangered or extinct species often rely on ancient or degraded remains. The majority of ancient DNA (aDNA) extraction protocols focus on skeletal elements, with skin and hair samples rarely explored. Similar to that found in bones and teeth, DNA extracted from historical or ancient skin and fur samples is also extremely fragmented with low endogenous content due to natural degradation processes. Thus, the development of effective DNA extraction methods is required for these materials. Here, we compared the performance of two DNA extraction protocols (commercial and custom laboratory aDNA methods) on hair and skin samples from decades-old museum specimens to Iron Age archaeological material. We found that apart from the impact sample-specific taphonomic and handling history has on the quantity and quality of DNA preservation, skin yielded more endogenous DNA than hair of the samples and protocols tested. While both methods recovered DNA from ancient soft tissue, the laboratory method performed better overall in terms of DNA yield and quality, which was primarily due to the poorer performance of the commercial binding buffer in recovering aDNA.
The Eremias multiocellata-przewalskii species complex is a viviparous group in the genus Eremias, and a well-known representative of taxonomically complicated taxa. Within this complex, a new species – E. dzungarica (Orlova et al., 2017) – has been described recently from western Mongolia and eastern Kazakhstan, with an apparent distribution gap in northwestern China. In this study, we used an integrative taxonomic framework to address whether E. dzungarica indeed occurs in China. Thirty specimens previously classified as E. multiocellata were collected in eastern Kazakhstan and the adjacent Altay region in China. The cytochrome c oxidase I (COI) barcodes were sequenced and compiled with those from Orlova et al. (2017) and analyzed with the standard and diverse barcoding techniques. We detected an absence of a barcoding gap in this complex, which indicates potential cryptic species in Eremias sp. 3 with high intraspecific diversity and multiple recently evolved species in Clade A. Both BIN and GMYC suggested an unrealistically large number of species (23 and 26, respectively), while ABGD, mPTP and BPP indicated a more conservative number of species (10, 12, and 15, respectively), largely concordant with the previously defined species-level lineages according to phylogenetic trees. Based on molecular phylogeny and morphological examination, all 30 individuals collected in this study were reliably identified as E. dzungarica – a distinct species – confirming the occurrence of this species in the Altay region, Xinjiang, China. Potentially owing to the larger sample size in this study, our morphological analyses revealed many inconsistencies with the original descriptions of E. dzungarica, which were primarily associated with sexual dimorphism and a broader range of values for various traits.
During a terrestrial vertebrate survey of the Dabie Mountains in Anhui Province, eastern China, we collected four Asian shrew mole specimens (hereafter, shrew moles). Based on published literature and comparison with previously collected materials, the four specimens were similar to shrew moles from the mountains of Southwest China; however, no species in this group has been previously recorded from the Dabie Mountains. The genetic and morphological characteristics of the specimens were analyzed, based upon which a new species of shrew mole is described, named Uropsilus dabieshanensis sp. nov.
As small heat shock proteins, α-crystallins function as molecular chaperones and inhibit the misfolding and aggregation of β/γ-crystallins. Genetic mutations of CRYAA are associated with protein aggregation and cataract occurrence. One possible process underlying cataract formation is that endoplasmic reticulum stress (ERS) induces the unfolded protein response (UPR), leading to apoptosis. However, the pathogenic mechanism related to this remains unexplored. Here, we successfully constructed a cataract-causing CRYAA (Y118D) mutant mouse model, in which the lenses of the CRYAA-Y118D mutant mice showed severe posterior rupture, abnormal morphological changes, and aberrant arrangement of crystallin fibers. Histological analysis was consistent with the clinical pathological characteristics. We also explored the pathogenic factors involved in cataract development through transcriptome analysis. In addition, based on key pathway analysis, up-regulated genes in CRYAA-Y118D mutant mice were implicated in the ERS-UPR pathway. This study showed that prolonged activation of the UPR pathway and severe stress response can cause proteotoxic and ERS-induced cell death in CRYAA-Y118D mutant mice.
The loach tribe Yunnanilini from China is reviewed here using morphological characters and complete mitochondrial genomes of select species. Molecular data suggest that the tribe Yunnanilini is not monophyletic and can be divided into three clades. Species of the Yunnanilus nigromaculatus group form an independent genus and are placed in Eonemachilus. In the phylogenetic tree, Y. jinxiensis clusters with Paranemachilus genilepis, and Y. pulcherrimus clusters with Micronemacheilus cruciatus, indicating that Y. jinxiensis and Y. pulcherrimus belong to Paranemachilus and Micronemacheilus, respectively. Based on morphological data, Y. bailianensis and Y. longibarbatus are placed in Heminoemacheilus, while Y. jinxiensis and Y. pulcherrimus, are placed in Paranemachilus and Micronemacheilus, respectively. Yunnanilus niulanensis and Y. qujinensis are treated as junior synonyms of Eonemachilus caohaiensis. Eonemachilus, Micronemacheilus, and Yunnanilus are show short separation between anterior and posterior nostrils. The genera can be distinguished from each other by mouth structure, lateral line and cephalic lateral-line canals, and papillae on median part of both lips. The anterior and posterior nostrils of Heminoemacheilus and Paranemachilus are closely set. Paranemachilus and Micronemacheilus are distinguished by cheeks covered with scales and lips with papillae, respectively. Our phylogenetic tree and morphological characters support Traccatichthys as a valid genus, which can be distinguished from Micronemacheilus by anterior and posterior nostrils closely set (vs. clearly separated). Four species are placed in Traccatichthys.
Parabiosis is a surgical method of animal modeling with a long history. It has been widely used in medical research, particularly in the fields of aging, stem cells, neuroscience, and immunity in the past two decades. The protocols for parabiosis have been improved many times and are now widely accepted. However, researchers need to consider many details, from surgical operation to perioperative management, to reduce mortality and maintain the parabiosis union. Although parabiosis has certain inevitable limitations, it still has broad application prospects as an irreplaceable animal model in the medical research field.

Vol 42, No 2 (18 March 2021)

Indexed by SCI-E

2019 Impact Factor 2.638

12/168 Zoology (Q1)

2020 Journal Citation Reports®

Bimonthly, Since 1980

Editor-in-Chief: Yong-Gang Yao

ISSN 2095-8137

CN 53-1229/Q

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