Insights from avian influenza surveillance of chickens and ducks before and after exposure to live poultry markets

<正>Dear Editor,Live poultry markets are the major trading system of poultry in China and many other countries, and are also thought to be important for the generation and spread of avian influenza viruses and other avian pathogens (Zhang et al., 2013; Shi et al., 2017; Quan et al., 2018). Surveillance studies indicate that the H7 avian influenza viruses were maintained and circulated for years in the New York live poultry markets(Suarez et al., 1999). H9N2 and H5N1 influenza viruses have been detected in poultry in China since 1994 and 1996, respectively, and vaccines have been developed and used in poultry to control these two subtypes of viruses (MOA,     

FERM domain phosphorylation and endogenous 3'UTR are not essential for regulating the function and subcellular localization of polarity protein Crumbs

<正>In the past two decades,extensive studies have focused on a group of so-called polarity proteins that play conserved and essential functions in establishing and maintaining cell polarity in epithelial cells.Among them,Crumbs(Crb)is the only transmembrane polarity protein characterized to date(Tepass et al.,1990;Wodarz et al.,1995;Klebes and Knust,2000).Apical locali-     

Human evolution and human-influenced evolution of organisms in changing environments

Human evolution and human-influenced evolution of living organisms such as animals,plants,and microorganisms on our planet are among the most active and inspiring topics of scientific research.This is because the evolutionary processes influenced by humans can be detected within a quantifiable period of time,and the consequences of such evolutionary processes vary significantly in terms of their rates and diversification,compared to those under the conditions of no human influences (Hendry et al.,2008).For example,domesticated animals (e.g.,chicken and pig)and plant species (e.g.,rice and maize) have evolved relatively rapidly within the past 10 000 years,which has resulted in tremendous genetic diversity of these domesticates under human influences in different environments (Dorshorst et al.,2011;Huang et al.,2012;Rubin et al.,2012).However,the rapid evolution and changes in these organisms have had significant impacts on the environments that humans and these organisms inhabit.     

Lack of an Additive Effect between the Deletions of Klf5 and Nkx3-1 in Mouse Prostatic Tumorigenesis

Prostate cancer is one of the most common malignancies.The development and progression of prostate cancer are driven by a series of genetic and epigenetic events including gene amplification that activates oncogenes and chromosomal deletion that inactivates tumor suppressor genes.Whereas gene amplification occurs in human prostate cancer,gene deletion is more common,and a large number of chromosomal regions have been identified to have frequent deletion in prostate cancer,suggesting that tumor suppressor inactivation is more common than oncogene activation in prostatic carcinogenesis (Knuutila et al.,1998,1999;Dong,2001).Among the most frequently deleted chromosomal regions in prostate cancer,target genes such as NKX3-1 from 8p21,PTENfrom 10q23 andATBF1 from 16q22 have been identified by different approaches (He et al.,1997;Li et al.,1997;Sun et al.,2005),and deletion of these genes in mouse prostates has been demonstrated to induce and/or promote prostatic carcinogenesis.For example,knockout of Nkx3-1 in mice induces hyperplasia and dysplasia (Bhatia-Gaur et al.,1999;Abdulkadir et al.,2002) and promotes prostatic tumorigenesis (Abate-Shen et al.,2003),while knockout of Pten alone causes prostatic neoplasia (Wang et al.,2003).Therefore,gene deletion plays a causal role in prostatic carcinogenesis (Dong,2001).     

Epigenetic Variations in Plant Hybrids and Their Potential Roles in Heterosis

Heterosis,one of the most important biological phenomena,refers to the phenotypic superiority of a hybrid over its genetically diverse parents with respect to many traits such as biomass,growth rate and yield.Despite its successful application in breeding and agronomic production of many crop and animal varieties,the molecular basis of heterosis remains elusive.The classic genetic explanations for heterosis centered on three hypotheses:dominance (Davenport,1908;Bruce,1910;Keeble and Pellew,1910;Jones,1917),overdominance (East,1908;Shull,1908) and epistasis (Powers,1944;Yu et al.,1997).However,these hypotheses are largely conceptual and not connected to molecular principles,and are therefore insufficient to explain the molecular basis of heterosis (Birchler et al.,2003).Recently,many studies have explored the molecular mechanism of heterosis in plants at a genome-wide level.These studies suggest that global differential gene expression between hybrids and parental lines potentially contributes to heterosis in plants (e.g.,Swanson-Wagner et al.,2006;Zhang et al.,2008;Wei et al.,2009;Song et al.,2010).Research suggests that genetic components,including cis-acting elements and trans-acting factors,are critical regulators of differential gene expression in hybrids (Hochholdinger and Hoecker,2007;Springer and Stupar,2007;Zhang et al.,2008).However,other research indicates that epigenetic components,the regulators of chromatin states and genome activity,also have the potential to impact heterosis (e.g.,Ha et al.,2009;He et al.,2010;Groszmann et al.,2011;Barber et al.,2012;Chodavarapu et al.,2012;Greaves et al.,2012a;Shen et al.,2012).     

Expansion of the mutant monkey through cloning

正Non-human primates with gene-modifications have been considered as the ideal models for some complex human diseases that are extremely difficult to be recapitulated in other animal models, especially for neural disorders, due to the similarity between monkeys and human. Meanwhile,these models may substantially promote the development of therapeutic treatments of human diseases. However, for years, the low gene-editing efficiency and genetic variations in non-human primates greatly impede their biomedical applications. Recently, two research articles published in National Science Review (Qiu et al., 2019; Liu et al., 2019)     

Understanding the pathogenic evolution of Zika virus

正Unlike the previous circulating strains that were not associated with significant human pathology,recent circulating Zika virus(ZIKV)strains isolated during the 2015–2016Brazilian Outbreak are highly suspected to cause neuropathology,including disorders of fetal brain development and Guillain-Barrésyndrome(Broutet et al.,2016).Studies have revealed that recent ZIKV strains can be spread through maternal-fetal(Calvet et al.,2016)and sexual(Hills et al.,2016)transmission,in addition to the traditional route     

An urgent call on revisions to current genome annotation strategies

<正>Transposable elements(TEs) account for a large proportion of eukaryotic genomes and contribute to the evolution of novel genic sequences as well as regulatory elements(Long et al., 2003; Wang et al., 2019; Wang et al., 2016b). The questions of how and to what extent transposable elements may contribute to new functional genes remain largely unknown. In the current issue, Yang et al.(2023) revealed a very interesting phenomenon about the role that TEs may play during genome divergence. A...     

Fecal microbiota transplantation: standardization or diversification?

<正>Call for standardization of fecal microbiota transplantation(FMT)The gut microbiota plays an important role in human health and disease. Dysbiosis is often recognized in patients with diseases of the digestive and other systems(Blaser, 2019; Li et al., 2018 b; Qin et al., 2018). FMT refers to the administration of fecal material containing distal gut microbiota from a healthy person(donor) to a patient(recipient) to restore the gut microecology of the recipient(Kelly et al., 2015). Clinical guidelines have strongly recommended FMT for the     

Bayesian evolutionary analysis for emerging infectious disease: an exemplified application for H7N9 avian influenza viruses

正Dear Editor,Ever since the first human infection with H7N9 avian influenza virus(AIV)was reported in China in March 2013,there have been five H7N9 AIV pandemics in humans.Wave5 began earlier than the previous four waves,spread to more districts and counties in affected provinces,and had more confirmed cases(Wang et al.,2017).Human infections with     

Engrafted newborn neurons could functionally integrate into the host neuronal network

The limited capability to regenerate new neurons following injuries of the central neural system (CNS) still remains a major challenge for basic and clinical neuroscience.Neural stem cells (NSCs) could nearly have the potential to differentiate into all kinds of neural cells in vitro.Previous studies verified that exogenous transplanted NSCs are capable of differentiating into neurons and projecting onto the host neurons in the rat brain (Tabar et al.,2005;Dong JR et al.,2012),which could lead to behavioral recovery from neuronal damages such as spinal cord injury (McDonald et al.,1999),Parkinson's disease (Gonzalez et al.,2015;Kim et al.,2002;Lindvall,2001),and stroke (Zhang et al.,2016).     

Identification of a novel strain of influenza A (H9N2) virus in chicken

<正>Dear Editor,Avian Influenza virus(AIV)H9N2 subtype viruses circulate widely in domestic fowl,and usually cause mild clinical signs in poultry(Li et al.,2005).Occasionally,avian H9N2 can infect humans and cause mild clinical symptoms(Peiris et al.,1999;Lin et al.,2000).Genetic analysis indicates that the H9N2 genotype viruses exist in major poultry species(such as duck and chicken)and in minor poultry species(such as quail,partridge,chukar,pheasant,and guinea fowl)(Guan et al.,2000;Li et al.,2005).Meanwhile,frequent reassortment events among     

A new record of the capped langur (Trachypithecus pileatus) in China

DEAR EDITOR, The distribution of the capped langur (Trachypithecus pileatus)in China has become controversial since Shortridge's langur (Trachypithecus shortridgei) was upgraded to a full species.The capped langur is considered to be distributed in northeast India,Bangladesh,Bhutan,and northwest Myanmar only (Brandon-Jones et al.,2004;Choudhury,2008,2014;Das et al.,2008;Groves,2001).In our field survey,however,we obtained photos of the capped langur,demonstrating its existence in China. Following the species promotion of Shortridge's langur (Brandon-Jones et al.,2004;Groves,2001) and the delimiting of its distribution range to northwestern Yunnan in China and northeastern Myanmar (Brandon-Jones et al.,2004;Cui et al.,2016;Das et al.,2008;Groves,2001;Htun et al.,2008),with a new record in southeastern Tibet (Wu et al.,2016),the capped langur has been deleted from the checklist of mammals in China (Jiang et al.,2015).Despite this,Dr.George Schaller has suggested that capped langurs might exist in the northeastern section of the Yarlung-Zangbo River (Choudhury,2008).     

Genetic and Molecular Characterization of H9N2 Avian Influenza Viruses Isolated from Live Poultry Markets in Hubei Province,Central China, 2013–2017

H9N2 subtype avian influenza virus(AIV) is an influenza A virus that is widely spread throughout Asia, where it jeopardizes the poultry industry and provides genetic material for emerging human pathogens. To better understand the epidemicity and genetics of H9 subtype AIVs, we conducted active surveillance in live poultry markets(LPMs) in Hubei Province from 2013 to 2017. A total of 4798 samples were collected from apparent healthy poultry and environment. Realtime RT-PCR revealed that the positivity rate of influenza A was 26.6%(1275/4798), of which the H9 subtype accounted for 50.3%(641/1275) of the positive samples. Of the 132 H9N2 viral strains isolated, 48 representative strains were subjected to evolutionary analysis and genotyping. Phylogenetic analysis revealed that all H9N2 viral genes had 91.1%–100% nucleotide homology, clustered with genotype 57, and had high homology with human H9N2 viruses isolated from2013 to 2017 in China. Using a nucleotide divergence cutoff of 95%, we identified ten distinct H9N2 genotypes that continued to change over time. Molecular analysis demonstrated that six H9N2 isolates had additional potential glycosylation sites at position 218 in the hemagglutinin protein, and all isolates had I155 T and Q226 L mutations. Moreover, 44 strains had A558 V mutations in the PB2 protein and four had E627 V mutations, along with H9N2 human infection strains A/Beijing/1/2016 and A/Beijing/1/2017. These results emphasize that the H9N2 influenza virus in Hubei continues to mutate and undergo mammalian adaptation changes, indicating the necessity of strengthening the surveillance of the AIV H9N2 subtype in LPMs.     

A custom-designed panel sequencing study in 201 Chinese patients with craniosynostosis revealed novel variants and distinct mutation spectra

正Craniosynostosis is a rare disease in which one or more of the cranial sutures in an infant skull prematurely fuses by turning into bone,with a prevalence of 1 in 2,000—2,500 individuals from reports in Western countries (Wilkie et al., 2017). It may restrict the growth of the brain, leading to some degree of morphological and functional abnormalities, and may affect the neurocognitive function of infants(Lattanzi et al., 2017). Genetic variants underlying craniosynostosis have been identified in cohort studies in Western populations,     

A novel human mAb (MERS-GD27) provides prophylactic and postexposure efficacy in MERS-CoV susceptible mice

正Dear Editor,Since September 2012, the Middle East respiratory syndrome coronavirus (MERS-CoV) cases have been reported in more than 27 countries, and more than 2,000 cases have been confirmed in the laboratory (http://www.who.int/emergencies/mers-cov/en/). MERS-CoV causes an acute and severe respiratory illness with a high mortality rate(~35%) in humans (Shi et al., 2017, Zaki et al., 2012).Neutralizing antibodies targeting the spike of MERS-CoV have been shown to be a therapeutic option for treatment of lethal disease (Agrawal et al., 2016, Ying et al., 2014).     

PIK-75 promotes homology-directed DNA repair

Homo!ogy-directed repair(HDR)is one of two major DNA repair pathways to mend the double-strand breaks(DSBs)formed in the genome(Liang et al.,1998;Pardo et al.,2009).Although less efficient compared with another DNA repair pathway,nonhomologous end joining(NHEJ),HDR is a type of precise repair to restore DNA damage and sustain genomic stability(Pardo et al.,2009;Ceccaldi et al.,2016).By contrast,NHEJ usually introduces mutations into the repaired site,thus probably harming the genomic integrity(Lieber et al.,2003).The error-free property enables HDR to be harnessed to correct a faulty mutation for therapeutic purpose in cells or in the body(Wu et al.,2013).In add让ion,HDR possesses great potential in the generation of genome-edited animals with precise genetic modifications,such as point mutation,DNA replacement,and DNA insertion in a specific genomic site(Wang et al.,2013).However,the low repair frequency mediated by HDR significantly limits让s application for efficient gene correction or establishment of various genetically modified animal models.Currently,multiple site-specific endonucleases have emerged as highly efficient tools to create targeted DSBs and markedly promote subsequent DNA repair either via HDR or NHEJ(Gaj et al.,2013).Nonetheless,the HDR-mediated modifications following the cleavage of engineering nucleases are still inefficient,usually with an efficiency less than 20%in cultured mammalian cells and embryos(Mali et al..2013;Wang et al.,2013;Yang et al.,2013).     

The effect of clinical-grade retinal pigment epithelium derived from human embryonic stem cells using different transplantation strategies

Dear Editor, Many forms of sight-threatening diseases, including retinitis pigmentosa (RP) and age-related macular degeneration (AMD), are caused by the dysfunction, degeneration and loss of the retinal pigment epithelium (RPE)(Strauss, 2005). RPE cell transplantation may potentially recover or halt disease progression, in which human embryonic stem cells (hESCs) could serve as an unlimited donor source for RPE differentiation, and a few clinical trials have shown the safety and effective of transplantation of hESCs-derived RPE (hESC-RPE) for AMD patients (Schwartz et al., 2012;Schwartz etal., 2015;Song etal., 2015;da Cruz et al., 2018;Kashani et al., 2018;Liu et al., 2018).     

Demonstrating mate choice copying in spiders requires further research

Mate choice copying-when individuals learn to prefer mates or mate types that have been chosen by others-can influence trait evo-lution and speciation(Varela et al.2018;Dion et al.2019).Most examples of mate choice copying are from fish,birds,and mammals including humans(Varela et al.2018).However,2 invertebrate examples-fruit flies and wolf spiders-have been used to argue that the phenomenon may be phylogenetically widespread,and perhaps the rule rather than the exception in nature(Varela et al.2018).Here,we revisit the evidence for mate choice copying in wolf spiders(Fowler-Fimn et al.2015)in light of new data(Gilman et al.2018).Then,we discuss why mate choice copying is a phenomenon that is likely to occur in wolf spiders,and why this deserves attention.     

New prevalence estimate of Torque Teno virus(TTV) infection in healthy population and patients with chronic viral hepatitis in Jiujiang,China

<正>Dear Editor,Torque Teno virus(TTV)is a nonenveloped human DNA virus that was isolated from the serum of a patient with transfusion-transmitted hepatitis with unknown etiology in 1997(Nishizawa et al.,1997).TTV is the first human virus with a single-stranded circular DNA genome to be identified,and is recently classified as the Alphatorquevirus genus of the Anelloviridae family by the International Committee on Taxonomy of Viruses(ICTV)(King et al.,2011).TTV shows very high genetic