An updated review of gastric cancer in the next-generation sequencing era:Insights from bench to bedside and vice versa

Gastric cancer(GC)is one of the most common malignancies and remains the second leading cause of cancer-related death worldwide.There is an increasing understanding of the roles that genetic and epigenetic alterations play in GCs.Recent studies using nextgeneration sequencing(NGS)have revealed a number of potential cancer-driving genes in GC.Whole-exome sequencing of GC has identified recurrent somatic mutations in the chromatin remodeling gene ARID1A and alterations in the cell adhesion gene FAT4,a member of the cadherin gene family.Mutations in chromatin remodeling genes(ARID1A,MLL3 and MLL)have been found in 47%of GCs.Whole-genome sequencing and whole-transcriptome sequencing analyses have also discovered novel alterations in GC.Recent studies of cancer epigenetics have revealed widespread alterations in genes involved in the epigenetic machinery,such as DNA methylation,histone modifications,nucleosome positioning,noncoding RNAs and microRNAs.Recent advances in molecular research on GC have resulted in the introduction of new diagnostic and therapeutic strategies into clinical settings.The antihuman epidermal growth receptor 2(HER2)antibody trastuzumab has led to an era of personalized therapy in GC.In addition,ramucirumab,a monoclonal antibody targeting vascular endothelial growth factor receptor(VEGFR)-2,is the first biological treatment that showed survival benefits as a single-agent therapy in patients with advanced GC who progressed after firstline chemotherapy.Using NGS to systematically identify gene alterations in GC is a promising approach with remarkable potential for investigating the pathogenesis of GC and identifying novel therapeutic targets,as well as useful biomarkers.In this review,we will summarize the recent advances in the understanding of the molecular pathogenesis of GC,focusing on the potential use of these genetic and epigenetic alterations as diagnostic biomarkers and novel therapeutic targets.

Impact of next-generation sequencing on antimicrobial treatment in immunocompromised adults with suspected infections

BACKGROUND:Prompt pathogen identification can have a substantial impact on the optimization of antimicrobial treatment.The objective of the study was to assess the diagnostic value of next-generation sequencing(NGS)for identifying pathogen and its clinical impact on antimicrobial intervention in immunocompromised patients with suspected infections.METHODS:This was a retrospective study.Between January and August 2020,47 adult immunocompromised patients underwent NGS testing under the following clinical conditions:1)prolonged fever and negative conventional cultures;2)new-onset fever despite empiric antimicrobial treatment;and 3)afebrile with suspected infections on imaging.Clinical data,including conventional microbial test results and antimicrobial treatment before and after NGS,were collected.Data were analyzed according to documented changes in antimicrobial treatment(escalated,no change,or deescalated)after the NGS results.RESULTS:The median time from hospitalization to NGS sampling was 19 d.Clinically relevant pathogens were detected via NGS in 61.7% of patients(29/47),more than half of whom suffered from fungemia(n=17),resulting in an antimicrobial escalation in 53.2% of patients(25/47)and antimicrobial de-escalation in 0.2% of patients(1/47).Antimicrobial changes were mostly due to the identification of fastidious organisms such as Legionella,Pneumocystis jirovecii,and Candida.In the remaining three cases,NGS detected clinically relevant pathogens also detected by conventional cultures a few days later.The antimicrobial treatment was subsequently adjusted according to the susceptibility test results.Overall,NGS changed antimicrobial management in 55.3%(26/47)of patients,and conventional culture detected clinically relevant pathogens in 14.9% of the patients(7/47).CONCLUSION:With its rapid identification and high sensitivity,NGS could be a promising tool for identifying relevant pathogens and enabling rapid appropriate treatment in immunocompromised patients with suspected infections.

Diagnostic Value of Targeted Next-generation Sequencing in Pulmonary Mycobacterial Infections

Objective This study aimed to explore the diagnostic value of novel technique-targeted next-generation sequencing(tNGS)of bronchoalveolar lavage fluid(BALF)in pulmonary mycobacterial infections.Methods This retrospective study was conducted on patients who underwent bronchoscopy and tNGS,smear microscopy,and mycobacterial culture of BALF.Patients with positive Mycobacterium tuberculosis(MTB)culture or GeneXpert results were classified into the tuberculosis case group.Those diagnosed with nontuberculous mycobacteria(NTM)-pulmonary disease(NTM-PD)composed the case group of NTM-PD patients.The control group comprised patients without tuberculosis or NTM-PD.Sensitivity,specificity,and receiver operating characteristic(ROC)curves were used to evaluate the diagnostic performance.Results For tuberculosis patients with positive mycobacterial culture results,the areas under the ROC curves(AUCs)for tNGS,GeneXpert,and smear microscopy were 0.975(95%CI:0.935,1.000),0.925(95%CI:0.859,0.991),and 0.675(95%CI:0.563,0.787),respectively.For tuberculosis patients with positive GeneXpert results,the AUCs of tNGS,culture,and smear microscopy were 0.970(95%CI:0.931,1.000),0.850(95%CI:0.770,0.930),and 0.680(95%CI:0.579,0.781),respectively.For NTM-PD,the AUCs of tNGS,culture,and smear-positive but GeneXpert-negative results were 0.987(95%CI:0.967,1.000),0.750(95%CI:0.622,0.878),and 0.615(95%CI:0.479,0.752),respectively.The sensitivity and specificity of tNGS in NTM-PD patients were 100%and 97.5%,respectively.Conclusion tNGS demonstrated superior diagnostic efficacy in mycobacterial infection,indicating its potential for clinical application.

Bronchoalveolar lavage fluid metagenomic next-generation sequencing assay for identifying pathogens in lung cancer patients

Background:For patients with lung cancer,timely identification of new lung lesions as infectious or non-infectious,and accurate identification of pathogens is very important in improving OS of patients.As a new auxiliary examination,metagenomic next-generation sequencing(mNGS)is believed to be more accurate in diagnosing infectious diseases in patients without underlying diseases,compared with conventional microbial tests(CMTs).We designed this study tofind out whether mNGS has better performance in distinguishing infectious and non-infectious diseases in lung cancer patients using bronchoalveolar lavagefluid(BALF).Materials and Methods:This study was a real-world retrospective review based on electronic medical records of lung cancer patients with bronchoalveolar lavage(BAL)and BALF commercial mNGS testing as part of clinical care from 1 April 2019 through 30 April 2022 at The First Affiliated Hospital of Sun Yat-sen University.164 patients were included in this study.Patients were categorized into the pulmonary non-infectious disease(PNID)group(n=64)and the pulmonary infectious disease(PID)group(n=100)groups based onfinal diagnoses.Results:BALF mNGS increased the sensitivity rate by 60%compared to CMTs(81%vs.21%,p<0.05),whereas there was no significant difference in specificity(75%vs.98.4%,p>0.1).Among the patients with PID,bacteria were the most common cause of infection.Fungal infections occurred in 32%of patients,and Pneumocystis Yersini was most common.Patients with Tyrosine kinase inhibitors(TKIs)therapy possess longer overall survival(OS)than other anti-cancer agents,the difference between TKIs and immuno-checkpoint inhibitors(ICIs)was insignificant(median OS TKIs vs.ICIs vs.Anti-angiogenic vs.Chemo vs.Radiotherapy=76 vs.84 vs.61 vs.58 vs.60).Conclusions:our study indicates that BALF mNGS can add value by improving overall sensitivity in lung cancer patients with potential pulmonary infection,and was outstanding in identifying Pneumocystis infection.It could be able to help physicians adjust the follow-up treatment to avoid the abuse of antibiotics.

Brain abscess from oral microbiota approached by metagenomic next-generation sequencing: A case report and review of literature

BACKGROUND Brain abscess is a serious and potentially fatal disease caused primarily by microbial infection.Although progress has been made in the diagnosis and treatment of brain abscesses,the diagnostic timeliness of pathogens needs to be improved.CASE SUMMARY We report the case of a 54-year-old male with a brain abscess caused by oral bacteria.The patient recovered well after receiving a combination of metagenomic next-generation sequencing(mNGS)-assisted guided medication and surgery.CONCLUSION Therefore,mNGS may be widely applied to identify the pathogenic microor-ganisms of brain abscesses and guide precision medicine.

Metagenomic next-generation sequencing may assist diagnosis of osteomyelitis caused by Mycobacterium houstonense:A case report

BACKGROUND Mycobacterium houstonense(M.houstonense)belongs to the nontuberculous mycobacterium group.Infection caused by M.houstonense is prone to recurrence.CASE SUMMARY We present a patient who was diagnosed with osteomyelitis caused by M.houstonense and treated with a combination of cefoxitin,and amikacin combined with linezolid.CONCLUSION The emergence of metagenomic next-generation sequencing(NGS)has brought new hope for the diagnosis and treatment of listeria meningitis.NGS can analyze a large number of nucleic acid sequences in a short time and quickly determine the pathogen species in the sample.Compared with traditional cerebrospinal fluid culture,NGS can greatly shorten the diagnosis time and provide strong support for the timely treatment of patients.Regarding treatment,NGS can also play an important role.Rapid and accurate diagnosis can enable patients to start targeted treatment as soon as possible and improve the treatment effect.At the same time,by monitoring the changes in pathogen resistance,the treatment plan can be adjusted in time to avoid treatment failure.

Diagnosis of Acute Q Fever in an Elderly Patient Using Metagenomic Next-Generation Sequencing:A Case Report

Query fever(Q fever)is a globally spread zoonotic disease caused by Coxiella burnetii,commonly found in natural foci but rarely seen in Hebei Province.The clinical manifestations of Q fever are diverse and nonspecific,which often leads to missed or incorrect diagnoses in clinical practice.This article reports a case of acute Q fever diagnosed in an elderly patient using metagenomic next-generation sequencing.

Spatial transcriptomics combined with single-nucleus RNA sequencing reveals glial cell heterogeneity in the human spinal cord

Glial cells play crucial roles in regulating physiological and pathological functions,including sensation,the response to infection and acute injury,and chronic neurodegenerative disorders.Glial cells include astrocytes,microglia,and oligodendrocytes in the central nervous system,and satellite glial cells and Schwann cells in the peripheral nervous system.Despite the greater understanding of glial cell types and functional heterogeneity achieved through single-cell and single-nucleus RNA sequencing in animal models,few studies have investigated the transcriptomic profiles of glial cells in the human spinal cord.Here,we used high-throughput single-nucleus RNA sequencing and spatial transcriptomics to map the cellular and molecular heterogeneity of astrocytes,microglia,and oligodendrocytes in the human spinal cord.To explore the conservation and divergence across species,we compared these findings with those from mice.In the human spinal cord,astrocytes,microglia,and oligodendrocytes were each divided into six distinct transcriptomic subclusters.In the mouse spinal cord,astrocytes,microglia,and oligodendrocytes were divided into five,four,and five distinct transcriptomic subclusters,respectively.The comparative results revealed substantial heterogeneity in all glial cell types between humans and mice.Additionally,we detected sex differences in gene expression in human spinal cord glial cells.Specifically,in all astrocyte subtypes,the levels of NEAT1 and CHI3L1 were higher in males than in females,whereas the levels of CST3 were lower in males than in females.In all microglial subtypes,all differentially expressed genes were located on the sex chromosomes.In addition to sex-specific gene differences,the levels of MT-ND4,MT2A,MT-ATP6,MT-CO3,MT-ND2,MT-ND3,and MT-CO_(2) in all spinal cord oligodendrocyte subtypes were higher in females than in males.Collectively,the present dataset extensively characterizes glial cell heterogeneity and offers a valuable resource for exploring the cellular basis of spinal cordrelated illnesses,including chronic pain,amyotrophic lateral sclerosis,and multiple sclerosis.

Application of next-generation sequencing technology to precision medicine in cancer: joint consensus of the Tumor Biomarker Committee of the Chinese Society of Clinical Oncology

Next-generation sequencing(NGS) technology is capable of sequencing millions or billions of DNA molecules simultaneously.Therefore, it represents a promising tool for the analysis of molecular targets for the initial diagnosis of disease, monitoring of disease progression, and identifying the mechanism of drug resistance. On behalf of the Tumor Biomarker Committee of the Chinese Society of Clinical Oncology(CSCO) and the China Actionable Genome Consortium(CAGC), the present expert group hereby proposes advisory guidelines on clinical applications of NGS technology for the analysis of cancer driver genes for precision cancer therapy. This group comprises an assembly of laboratory cancer geneticists, clinical oncologists, bioinformaticians,pathologists, and other professionals. After multiple rounds of discussions and revisions, the expert group has reached a preliminary consensus on the need of NGS in clinical diagnosis, its regulation, and compliance standards in clinical sample collection. Moreover, it has prepared NGS criteria, the sequencing standard operation procedure(SOP), data analysis, report, and NGS platform certification and validation.

Genomic characterization of esophageal squamous cellcarcinoma:insights from next-generation sequencing

Two major types of cancer occur in the esophagus: squamous cell carcinoma, which is associated with chronic smoking and alcohol consumption, and adenocarcinoma, which typically arises in gastric reflux-associated Barrett's esophagus. Although there is increasing incidence of esophageal adenocarcinoma in Western counties, esophageal squamous cell carcinoma(ESCC) accounts for most esophageal malignancies in East Asia, including China and Japan. Technological advances allowing for massively parallel, high-throughput next-generation sequencing(NGS) of DNA have enabled comprehensive characterization of somatic mutations in large numbers of tumor samples. Recently, several studies were published in which whole exome or whole genome sequencing was performed in ESCC tumors and compared with matched normal DNA. Mutations were validated in several genes, including in TP53, CDKN2 A, FAT1, NOTCH1, PIK3 CA, KMT2 D and NFE2L2, which had been previously implicated in ESCC. Several new recurrent alterations have also been identified in ESCC. Combining the clinicopathological characteristics of patients with information obtained from NGS studies may lead to the development of effective diagnostic and therapeutic approaches for ESCC. As this research becomes more prominent, it is important that gastroenterologist become familiar with the various NGS technologies and the results generated using these methods. In the present study, we describe recent research approaches using NGS in ESCC.

The next-generation sequencing technology and application

As one of the key technologies in biomedical research,DNA sequencing has not only improved its productivity with an exponential growth rate but also been applied to new areas of application over the past few years.This is largely due to the advent of newer generations of sequencing platforms,offering ever-faster and cheaper ways to analyze sequences.In our previous review,we looked into technical characteristics of the nextgeneration sequencers and provided prospective insights into their future development.In this article,we present a brief overview of the advantages and shortcomings of key commercially available platforms with a focus on their suitability for a broad range of applications.

Effects of viral infection and microbial diversity on patients with sepsis:A retrospective study based on metagenomic next-generation sequencing

BACKGROUND: The study aims to investigate the performance of a metagenomic next-generationsequencing (NGS)-based diagnostic technique for the identifi cation of potential bacterial and viral infectionsand eff ects of concomitant viral infection on the survival rate of intensive care unit (ICU) sepsis patients.METHODS: A total of 74 ICU patients with sepsis who were admitted to our institution from February1, 2018 to June 30, 2019 were enrolled. Separate blood samples were collected from patients for bloodcultures and metagenomic NGS when the patients’ body temperature was higher than 38 °C. Patients’demographic data, including gender, age, ICU duration, ICU scores, and laboratory results, were recorded.The correlations between pathogen types and sepsis severity and survival rate were evaluated.RESULTS: NGS produced higher positive results (105 of 118;88.98%) than blood cultures(18 of 118;15.25%) over the whole study period. Concomitant viral infection correlated closelywith sepsis severity and had the negative effect on the survival of patients with sepsis. However,correlation analysis indicated that the bacterial variety did not correlate with the severity of sepsis.CONCLUSIONS: Concurrent viral load correlates closely with the severity of sepsis and thesurvival rate of the ICU sepsis patients. This suggests that prophylactic administration of antiviraldrugs combined with antibiotics may be benefi cial to ICU sepsis patients.

Impact of the next-generation sequencing data depth on various biological result inferences

Next-generation sequencing(NGS) technologies have revolutionized the field of genomics and provided unprecedented opportunities for high-throughput analysis at the levels of genomics,transcriptomics and epigenetics.However,the cost of NGS is still prohibitive for many laboratories.It is imperative to address the trade-off between the sequencing depth and cost.In this review,we will discuss the effects of sequencing depth on the detection of genes,quantification of gene expression and discovering of gene structural variants.This will provide readers information on choosing appropriate sequencing depth that best meet the needs of their particular project.

Clinical applications of next-generation sequencing in colorectal cancers

Like other solid tumors,colorectal cancer(CRC) is a genomic disorder in which various types of genomic alterations,such as point mutations,genomic rearrangements,gene fusions,or chromosomal copy number alterations,can contribute to the initiation and progression of the disease. The advent of a new DNA sequencing technology known as next-generation sequencing(NGS) has revolutionized the speed and throughput of cataloguing such cancer-related genomic alterations. Now the challenge is how to exploit this advanced technology to better understand the underlying molecular mechanism of colorectal carcinogenesis and to identify clinically relevant genetic biomarkers for diagnosis and personalized therapeutics. In this review,we will introduce NGS-based cancer genomics studies focusing on those of CRC,including a recent large-scale report from the Cancer Genome Atlas. We will mainly discuss how NGS-based exome-,whole genome- and methylome-sequencing have extended our understanding of colorectal carcinogenesis. We will also introduce the unique genomic features of CRC discovered by NGS technologies,such as the relationship with bacterial pathogens and the massive genomic rearrangements of chromothripsis. Finally,we will discuss the necessary steps prior to development of a clinical application of NGS-related findings for the advanced management of patients with CRC.

Next-generation sequencing technology for diagnosis and efficacy evaluation of a patient with visceral leishmaniasis: A case report

BACKGROUND Visceral leishmaniasis(VL)is a parasitic disease caused by Leishmania and transmitted by infected sand flies.VL has a low incidence in China,and its clinical presentation is complex and atypical.This disease is easily misdiagnosed and can become life-threatening within a short period of time.Therefore,early,rapid and accurate diagnosis and treatment of the disease are essential.CASE SUMMARY A 25-year-old male patient presented with the clinical manifestations of irregular fever,hepatosplenomegaly,increased polyclonal globulin,and pancytopenia.The first bone marrow puncture biopsy did not provide a clear diagnosis.In order to relieve the pressure and discomfort of the organs caused by the enlarged spleen and to confirm the diagnosis,splenectomy was performed,and hemophagocytic syndrome was diagnosed by pathological examination of the spleen biopsy.Following bone marrow and spleen pathological re-diagnosis and metagenomic next-generation sequencing(mNGS)technology detection,the patient was finally diagnosed with VL.After treatment with liposomal amphotericin B,the body temperature quickly returned to normal and the hemocytes recovered gradually.Post-treatment re-examination of the bone marrow puncture and mNGS data showed that Leishmania was not detected.CONCLUSION As a fast and accurate detection method,mNGS can diagnose and evaluate the efficacy of treatment in suspicious cases of leishmaniasis.

Next-generation sequencing in clinical virology: Discovery of new viruses

Viruses are a cause of significant health problem world-wide, especially in the developing nations. Due to different anthropological activities, human populations are exposed to different viral pathogens, many of which emerge as outbreaks. In such situations, discovery of novel viruses is utmost important for deciding prevention and treatment strategies. Since last century, a number of different virus discovery methods, based on cell culture inoculation, sequence-independent PCR have been used for identification of a variety of viruses. However, the recent emergence and commercial availability of nextgeneration sequencers(NGS) has entirely changed the field of virus discovery. These massively parallel sequencing platforms can sequence a mixture of genetic materials from a very heterogeneous mix, with high sensitivity. Moreover, these platforms work in a sequenceindependent manner, making them ideal tools for virus discovery. However, for their application in clinics, sample preparation or enrichment is necessary to detect low abundance virus populations. A number of techniques have also been developed for enrichment or viral nucleic acids. In this manuscript, we review the evolution of sequencing; NGS technologies available today as well as widely used virus enrichment technologies. We also discuss the challenges associated with their applications in the clinical virus discovery.

The Diagnostic Value of Metagenomic Next-Generation Sequencing in <i>Angiostrongylus cantonensis</i>Encephalitis/Meningitis

Objective: Angiostrongylus cantonensis (A. cantonensis) is an important parasite, which causes neurological infection in children, and is generally difficult to diagnose. We analyzed the significance of metagenomic next-generation sequencing in diagnosing A. cantonensis encephalitis/meningitis in children to provide a reference for clinical diagnosis. Methods: The case collection of A. cantonensis encephalitis/meningitis was from July 2018 to August 2020. The patients’ clinical characteristics and pathogen were described, and diagnostic sensitivity methods for A. cantonensis encephalitis/meningitis were compared and analyzed, including parasite antibody detection and metagenomic next-generation sequencing (mNGS) detection in different samples. Results: Eleven cases were diagnosed with A. cantonensis encephalitis/meningitis, including six males (54.5%) and five females (45.5%), and the age ranged from 1 to 13 years with a median of 21 months (IQR: 15.6, 96). All patients were undiagnosed upon admission, of which ten cases had neurological symptoms or signs, six cases (54.5%) had a history of definite or suspicious exposure to parasites, and eight cases (72.7%) had abnormal changes in cranial MRI. The results of A. cantonensis antibodies in the peripheral blood and cerebrospinal fluid (CSF) were compared with CSF’s metagenomic next-generation sequencing (mNGS). The antibody-positive rate of peripheral blood was 54.5%, CSF antibody-positive rate was 27.2%, and mNGS-positive rate of CSF was 81.8%, and the positive diagnostic rate of the latter was significantly higher than the former two (p = 0.035 < 0.05 and p = 0.030 < 0.05, respectively). Conclusion: Metagenomic next-generation sequencing has a higher positive rate for diagnosing infection and plays an important role in clarifying diagnosis and reducing misdiagnosis.

Impact of next-generation sequencing on molecular diagnosis of inherited non-syndromic hearing loss

Hearing loss is one of the most common birth defects,with inherited genetic defects play an important role,contributing to about 60%of deafness occurring in infants.However,hearing impairment is genetically heterogeneous,with both common and rare forms occurring due to mutations in estimated 500 genes.Due to the large number and presumably low mutation frequencies of those genes,it would be highly expensive and time-consuming to address this issue by conventional gene-by-gene Sanger sequencing.Next-generation sequencing is a revolutionary technology that allows the simultaneous screening of mutations in a large number of genes.It is cost effective compared to classical strategies of linkage analysis and direct sequencing when the number or size of genes is large,and thus has become a highly efficient strategy for identifying novel causative genes and mutations involved in heritable disease.In this review, we describe major NGS methodologies currently used for genetic disorders and highlight applications of these technologies in studies of molecular diagnosis and the discovery of genes implicated in non-syndromic hearing loss.

Gene mutations in stool from gastric and colorectal neoplasia patients by next-generation sequencing

AIM To study cancer hotspot mutations by next-generation sequencing(NGS) in stool DNA from patients with different gastrointestinal tract(GIT) neoplasms. METHODS Stool samples were collected from 87 Finnish patients diagnosed with various gastric and colorectal neoplasms, including benign tumors, and from 14 healthy controls. DNA was isolated from stools by usingthe PSP~? Spin Stool DNA Plus Kit. For each sample, 20 ng of DNA was used to construct sequencing libraries using the Ion AmpliS eq Cancer Hotspot Panel v2 or Ion AmpliS eq Colon and Lung Cancer panel v2. Sequencing was performed on Ion PGM. Torrent Suite Software v.5.2.2 was used for variant calling and data analysis.RESULTS NGS was successful in assaying 72 GIT samples and 13 healthy controls, with success rates of the assay being78% for stomach neoplasia and 87% for colorectal tumors. In stool specimens from patients with gastric neoplasia, five hotspot mutations were found in APC,CDKN2 A and EGFR genes, in addition to seven novel mutations. From colorectal patients, 20 mutations were detected in AKT1, APC, ERBB2, FBXW7, KIT, KRAS,NRAS, SMARCB1, SMO, STK11 and TP53. Healthy controls did not exhibit any hotspot mutations, except for two novel ones. APC and TP53 were the most frequently mutated genes in colorectal neoplasms, with five mutations, followed by KRAS with two mutations.APC was the most commonly mutated gene in stools of patients with premalignant/benign GIT lesions.CONCLUSION Our results show that in addition to colorectal neoplasms,mutations can also be assayed from stool specimens of patients with gastric neoplasms.

Development and characterization of novel polymorphic microsatellite markers for the Korean freshwater snail Semisulcospira coreana and cross-species amplification using next-generation sequencing

Korean freshwater snails of the genus Semisulcospira are widely distributed across East Asia.It has been a very popular nutritional food in Korea,and is an ecologically important water quality indicator because it lives only in clean water.However,no microsatellite markers have been generated to study the population genetic diversity of this genus.In the present study,we developed and characterized 18 novel microsatellite loci from Semisulcospira coreana genomic DNA.The microsatellites were isolated using 454 GS-FLX titanium sequencing and 18 markers were used for genotyping in S.coreana.In addition,we also tested the cross-species transferability of the microsatellite markers in four additional Semisulcospira spp.We identified 18 polymorphic loci and the number of alleles per loci,and their polymorphism information content values ranged from 2 to 17 and 0.203 to 0.902,respectively.The observed and expected heterozygosities of the loci ranged from 0.063 to 0.924 and 0.226 to 0.924,respectively.According to the analysis of the cross-species transferability of these markers,four species,S.forticosta,S.gottschei,S.tegulata,and S.libertina,showed a very high transferability(80%–85%).These results show that this set of nuclear markers could be useful for population genetics studies of this species and closely related species.