Detection of hyper-conserved regions in hepatitis B virus X gene potentially useful for gene therapy

AIM To detect hyper-conserved regions in the hepatitis B virus(HBV) X gene(HBX) 5' region that could be candidates for gene therapy.METHODS The study included 27 chronic hepatitis B treatmentnaive patients in various clinical stages(from chronic infection to cirrhosis and hepatocellular carcinoma, both HBeA g-negative and HBeA g-positive), and infected with HBV genotypes A-F and H. In a serum sample from each patient with viremia > 3.5 log IU/m L, the HBX 5' end region [nucleotide(nt) 1255-1611] was PCRamplified and submitted to next-generation sequencing(NGS). We assessed genotype variants by phylogenetic analysis, and evaluated conservation of this region by calculating the information content of each nucleotide position in a multiple alignment of all unique sequences(haplotypes) obtained by NGS. Conservation at the HBx protein amino acid(aa) level was also analyzed.RESULTS NGS yielded 1333069 sequences from the 27 samples, with a median of 4578 sequences/sample(2487-9279, IQR 2817). In 14/27 patients(51.8%), phylogenetic analysis of viral nucleotide haplotypes showed a complex mixture of genotypic variants. Analysis of the information content in the haplotype multiple alignments detected 2 hyper-conserved nucleotide regions, one in the HBX upstream non-coding region(nt 1255-1286) and the other in the 5' end coding region(nt 1519-1603). This last region coded for a conserved amino acid region(aa 63-76) that partially overlaps a Kunitz-like domain.CONCLUSION Two hyper-conserved regions detected in the HBX 5' end may be of value for targeted gene therapy, regardless of the patients' clinical stage or HBV genotype.

肺泡灌洗液Gene X-pert MTB/RIF在肺结核诊断中的应用价值

目的探讨支气管肺泡灌洗液Gene X-pert MTB/RIF(简称X-pert)检查对成年人肺结核的诊断价值。方法收集2019年10月至2020年7月湖北省十堰市太和医院165例高度疑似肺结核患者的肺泡灌洗液,完善X-pert检查及BALF涂片检测,分别以病原学诊断和临床诊断为诊断金标准,分析X-pert诊断结核的阳性率,评估X-pert对BALF涂片阴性肺结核的诊断价值,并分析X-pert在成人肺结核中的诊断准确性。结果最终诊断结核81例,X-pert诊断结核阳性率为39.39%(65/165),BALF涂片的阳性率22.42%(37/165),X-pert诊断结核的阳性率明显高于BALF涂片,差异有统计学意义(P<0.05);在81例结核病例中,X-pert真阳性率为77.78%(63/81),分别以病原学诊断和临床诊断为诊断金标准,X-pert在病原学诊断结核中阳性率为82.00%(41/50),敏感度为82.00%,特异度为79.13%。在临床诊断结核中阳性率为70.97%(22/31),敏感度为70.97%,特异度为67.91%。在非结核组出现X-pert阳性2例,假阳性率为2.38%(2/84);以BALF涂片为金标准,在44例BALF涂片阴性的疑似病例中,X-pert检测出结核分枝杆菌阳性27例,检出率为61.36%(27/44)。结论支气管肺泡灌洗液Gene X-pert MTB/RIF在结核诊断中敏感性高,且在BALF涂片阴性时可快速检测出结核分枝杆菌,具有较高的临床实用价值。

Gene X-pert MTB/RIF检测对肺结核病的诊断价值研究

目的 研究分析肺结核病应用Gene X-pert MTB/RIF检测的诊断价值。方法 选取2022年3—10月在本院就诊的疑似肺结核病患者164例为研究对象,所有患者均给予结核分枝杆菌培养检查、痰涂片抗酸染色法诊断、Gene X-pert MTB/RIF检测,以结核分枝杆菌培养检查结果为金标准,比较痰涂片抗酸染色法诊断与Gene X-pert MTB/RIF检测的阳性率以及诊断准确性、灵敏度、特异度。结果 痰涂片抗酸染色法诊断阳性率为21.34%(35/164),Gene X-pert MTB/RIF检测阳性率为35.98%(59/164),Gene X-pert MTB/RIF检测明显高于痰涂片抗酸染色法诊断(P<0.05)。痰涂片抗酸染色法诊断的准确性为85.37%,灵敏度为59.65%,Gene X-pert MTB/RIF检测的准确性为95.12%,灵敏度为94.74%,Gene X-pert MTB/RIF检测明显高于痰涂片抗酸染色法诊断(P<0.05)。结论 在肺结核病诊断中,Gene X-pert MTB/RIF检测的阳性率更高,同时诊断准确率与灵敏度也更高,为肺结核病的诊断与治疗提供了可靠的指导依据。

Gene X-pert MTB/RIF检测对肺结核病诊断的价值

目的探讨Gene X-pert MTB/RIF检测对肺结核病诊断的价值。方法选取2020年5月—2021年10月期间在张家港市第一人民医院接受治疗的拟诊断为肺结核病患者113例为研究对象,所有患者均接受Gene Xpert MTB/RIF系统分子检测、结核分枝杆菌(MTB)培养和抗酸染色镜检诊断,以Gene X-pert MTB/RIF系统分子检测结果为观察组,以MTB培养检测结果为对照1组,以痰涂片抗酸染色镜检诊断结果为对照2组。对比3组诊断结果。结果结核病患者诊断结果中,以对照1组MTB培养检测结果为金标准,检测阳性39例(34.51%),观察组诊断阳性率(35.40%)高于对照2组(21.24%),差异有统计学意义(χ^(2)=12.250,P<0.05)。观察组诊断结果准确度、灵敏度高于对照2组,差异有统计学意义(P<0.05)。结论在对肺结核病诊断的诊断中,Gene X-pert MTB/RIF检测阳性率显著高于抗酸染色镜检诊断。

Characterization of hepatitis B virus X gene quasispecies complexity in mono-infection and hepatitis delta virus superinfection

Hepatitis delta virus(HDV) seems to strongly suppress hepatitis B virus(HBV)replication, although little is known about the mechanism of this interaction. Both these viruses show a dynamic distribution of mutants, resulting in viral quasispecies. Next-generation sequencing is a viable approach for analyzing the composition of these mutant spectra. As the regulatory hepatitis B X protein(HBx) is essential for HBV replication, determination of HBV X gene(HBX)quasispecies complexity in HBV/HDV infection compared to HBV monoinfection may provide information on the interactions between these two viruses.AIM To compare HBV quasispecies complexity in the HBX 5' region between chronic hepatitis delta(CHD) and chronic HBV mono-infected patients.METHODS Twenty-four untreated patients were included: 7/24(29.2%) with HBeAgnegative chronic HBV infection(CI, previously termed inactive carriers), 8/24(33.3%) with HBeAg-negative chronic hepatitis B(CHB) and 9/24(37.5%) with CHD. A serum sample from each patient was first tested for HBV DNA levels.The HBX 5' region [nucleotides(nt) 1255-1611] was then PCR-amplified for subsequent next-generation sequencing(MiSeq, Illumina, United States). HBV quasispecies complexity in the region analyzed was evaluated using incidencebased indices(number of haplotypes and number of mutations), abundancebased indices(Hill numbers of order 1 and 2), and functional indices(mutation frequency and nucleotide diversity). We also evaluated the pattern of nucleotide changes to investigate which of them could be the cause of the quasispecies complexity.RESULTS CHB patients showed higher median HBV-DNA levels [5.4 logIU/mL,interquartile range(IQR) 3.5-7.9] than CHD(3.4 logIU/mL, IQR 3-7.6)(P = n.s.)or CI(3.2 logIU/mL, IQR 2.3-3.5)(P < 0.01) patients. The incidence and abundance indices indicated that HBV quasispecies complexity was significantly greater in CI than CHB. A similar trend was observed in CHD patients, although only Hill numbers of order 2 showed statistically significant differences(CHB2.81, IQR 1.11-4.57 vs CHD 8.87, 6.56-11.18, P = 0.038). There were no significant differences in the functional indices, but CI and CHD patients also showed a trend towards greater complexity than CHB. No differences were found for any HBV quasispecies complexity indices between CHD and CI patients. G-to-A and C-to-T nucleotide changes, characteristic of APOBEC3 G, were higher in CHD and CI than in CHB in genotype A haplotypes, but not in genotype D. The proportion of nt G-to-A vs A-to-G changes and C-to-T vs T-to-C changes in genotype A and D haplotypes in CHD patients showed no significant differences. In CHB and CI the results of these comparisons were dependent on HBV genotype.CONCLUSION The lower-replication CHD and CI groups show a trend to higher quasispecies complexity than the higher-replication CHB group. The mechanisms associated with this greater complexity require elucidation.

Gene X-pert Mtb/RIF检测技术与抗酸染色和BD960培养、药敏的比对研究

目的：评价Gene X-pert Mtb/RIF检测痰标本诊断结核病和结核菌对利福平耐药的效能。方法：采用2014年10月-2015年7月太原市第四人民医院收集的确诊结核病患者的痰标本进行涂片、BD960培养、BD960药敏试验及Gene Xpert Mtb/RIF检测,应用统计学方法对Gene Xpert Mtb/RIF与不同检测方法进行敏感度分析。结果：Gene X-pert Mtb/RIF检测技术敏感度均高于涂片和BD960培养（P〈0.05）,利福平耐药与BD960利福平耐药无统计学差异（P〉0.05）。结论：Gene Xpert Mtb/RIF检测技术是一种快速、自动化程度高、操作简便的结核病分子生物学诊断技术,为临床快速诊断结核病及是否对利福平耐药提供了有力的实验室佐证。

Construction of eukaryotic expression vector of HBV x gene

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A Multiplex PCR-Based Next-Generation Sequencing Approach Has Detected a Common Large Deletion in STS Gene in a Patient with X-Linked Ichthyosis

Several nuclear genes have been found to be linked to ichthyosis, and Next Generation Sequencing approach on panels of targeted genes has turned out to be particularly useful in analyzing diseases characterized by significant genetic and phenotypic heterogeneity. We developed a panel of 26 genes to be screened with the Ion Personal Genome Machine (PGM) for causative mutations relating to ichthyosis. Sequencing runs were obtained from a patient with ichthyosis using the Ion Torrent PGM and then processed with Ion Torrent Suite, Variant Caller, Coverage Analysis and wANNOVER tools. No causative mutations were found using Variant Caller and wANNOVER softwares, whereas the “Coverage Analysis” tool revealed a common large deletion in STS gene in a patient with X-linked ichthyosis. Identification of indels in Next Generation Sequencing (NGS) data is a veritable challenge. This study demonstrates the efficacy and effectiveness of using NGS approach to detect large deletions without resorting to specific algorithms for “indel” detection. Our results indicate that the NGS panel is a useful, rapid and cost-effective screening test for patients whose features are suggestive of a genetic etiology involving one of the genes embedded in the panel. It is an excellent alternative to Sanger sequencing as for costs, ease of analysis, and turnaround time.

HBV X Gene Transfection Upregulates IL-1β and IL-6 Gene Expression and Induces Rat Glomerular Mesangial Cell Proliferation

The X gene of HBV encodes a 17-kD protein, termed HBx, which has been shown to function as a transcriptional trans-activator of a variety of viral and cellular promoter/enhancer elements. The aim of this study was to investigate the effect of HBx on gene expression of interleukin （IL）-1β and IL-6, and proliferation of rat mesangial cells in vitro. The X gene of HBV was amplified by PCR assay, and inserted into the eukaryotic expression vector pCI-neo. The structure of recombinant pCI-neo-X plasmid was proved by restrict endonuclease digestion and sequencing analysis. pCI-neo-X was transfected into cultured rat mesangial cell line in vitro via liposome. HBx expression in transfected mesangial cells was detected by Western blot. The IL-1β and IL-6 mRNA expression in those cells was assayed by semiquantitative RT-PCR. Mesangial cell proliferation was tested by MTT. The results showed that HBx was obviously expressed in cultured mesangial cell line at 36th and 48th h after transfection. The expression of IL-1β and IL-6 mRNA was simultaneously increased. The cell proliferation was also obvious at the same time. It was concluded that HBx gene transfection could induce IL-1β and IL-6 gene expression and mesangial cell proliferation. HBx may play a critical role in mesangial cell proliferation through upregulation of the IL-1β and IL-6 gene expression.

STS Gene in a Pedigree with X-linked Ichthyosis

To investigate the gene mutation in a pedigree with X-linked iehthyosis （XLI） and to explore the relationship between the mutation and its clinical manifestations, genomic DNA of affected members, the normal member of the pedigree and 50 unrelated normal members was extracted with a whole blood genomie DNA extraction kit and the DNA was used as a template for the polymerase chain reaction （PCR） mediated amplification of exon 1 and exon 10 of the STS gene. hHb6 （human hair basic keratin） gene was used as the internal control. Our results showed that the STS gene was deleted in affected members in the pedigree with X-linked ichthyosis. The normal member of the pedigree and 50 unrelated normal members had no such deletion. The proband and his mother had products in the internal control after PCR amplification. The blank control had no product. It is concluded that deletion of the STS gene existed in this pedigree with X-linked iehthyosis, and it is responsible for the unique skin lesions of X-linked ichthyosis.

Fine-scale evolutionary genetic insights into Anopheles gambiae X-chromosome

Understanding the genetic architecture of indi-vidual taxa of medical importance is the first step for designing disease preventive strategies. To understand the genetic details and evolu-tionary perspective of the model malaria vector, Anopheles gambiae and to use the information in other species of local importance, we scanned the published X-chromosome se-quence for detail characterization and obtain evolutionary status of different genes. The te-locentric X-chromosome contains 106 genes of known functions and 982 novel genes. Majori-ties of both the known and novel genes are with introns. The known genes are strictly biased towards less number of introns;about half of the total known genes have only one or two in-trons. The extreme sized (either long or short) genes were found to be most prevalent (58% short and 23% large). Statistically significant positive correlations between gene length and intron length as well as with intron number and intron length were obtained signifying the role of introns in contributing to the overall size of the known genes of X-chromosome in An. gam-biae. We compared each individual gene of An. gambiae with 33 other taxa having whole ge-nome sequence information. In general, the mosquito Aedes aegypti was found to be ge-netically closest and the yeast Saccharomyces cerevisiae as most distant taxa to An. gambiae. Further, only about a quarter of the known genes of X-chromosome were unique to An. gambiae and majorities have orthologs in dif-ferent taxa. A phylogenetic tree was constructed based on a single gene found to be highly orthologous across all the 34 taxa. Evolutionary relationships among 13 different taxa were in-ferred which corroborate the previous and pre-sent findings on genetic relationships across various taxa.

Study of Hepatitis B Virus Genotypes and Mutation in 1762 &1764 Nucleotides of X Gene in Chronic HBV Patients from Golestan Province—Iran

Introduction: More than 350 million people are chronic carriers of HBV and many of them develop progressive diseases, including cirrhosis and hepatocellular carcinoma. Many of those infected develop persistent disease and a proportion goes on to develop liver failure and cancer. Researchers showed that double mutations of the x gene at position 1762 and 1764, have been found in chronic hepatitis B. These mutations were proposed to be associated with fulminant hepatitis B increasing risk of hepatocellular carcinoma. This project aimed to investigate mutation in the x gene region of HBV infected patients in Golestan province, Iran. Method: 100 patients were entered in this study. Hepatitis B viral DNA was extracted from plasma and PCR was performed using specific primers. Direct sequencing and alignment of x gene were applied using reference sequence from Gene Bank database (Okamoto, 1988;Accession number AB033559). Results: Among the chronic HBV patients 51% were male. The results showed that 49% of patients had A1762T, G1764A mutations changing AGG to stop codon TGA. 27% and 24% of cases were showed mutation only in A1762T and G1764A positions respectively. Conclusion: This study was shown presence of X gene mutation in HBV infected people in Golestan province, Iran. The rate of mutation in two positions 1762 and 1764 of HBV genotype D X gene was higher than the average rate of the world (34%).

Localization of X-gene translation product in human cholangiocarcinoma and its surrounding liver tissues

Intrahepatic cholangiocarcinoma is an uncommon type of primary hepatomaand its mechanism is still unknown.Twenty samples of the cancer and the surrounding tis-sues were all taken from the Xi’an area and examined for the presence of X-gene prod-uct(HBxAg)by the avidin-biotin-peroxidase complex method.It was found that 17 cases(85%)showed positive reaction,HBxAg was present in 15 cancer samples and 16non-tumor tissue samples.This result suggests that there is a close relationshipbetween human cholangiocarcinoma and HBV,and the HBxAg might play an importantrole in the pathogenesis of cholangiocarcinoma.

EXPRESSION OF X-GENE TRANSLATION PRODUCT IN HUMAN PRIMARY CHOLANGIOCARCINOMA AND ITS SURROUNDING NONTUMOROUS TISSUES

Intrahepatic cholangiocarcinoma is an uncommon type of primary hepatoma and its mechanism is still unknown. Twenty samples of the cancer and the tissues surrounding it were all taken from the Xi' an area and examined for the presence of X-gene product (HBxAg) by the avldin-biotin-peroxidase complex method. It was found that 17 cases (85%) showed positive reaction, HBxAg was present in 15 cancer samples and 16 non-tumor tissue samples. This result suggests that there is a close relationship between human choiangiocarcinoma and HBV, and the HBxAg might play an important role in the pathogenesis of cholanglocarcinoma.

Prognostic significance of X-ray cross-complementing gene 1 expression in gastric cancer

Objective： The aim of this study is to identify the prognostic significance of X-ray cross-complementing gene 1 （XRCCI） in patients with gastric cancer undergoing surgery and platinum-based adjuvant chemotherapy. Methods： Immunohistochemistry （IHC） was used to evaluate XRCCI protein expression profiles on surgical specimens of 612 gastric cancer patients. The relationship between XRCC1 expression and existing prognostic factors, platinum-based adjuvant chemotherapy, disease-free survival （DFS） and overall survival （OS） were analyzed. Results： Among 612 patients staged II/III in our study, 182 （29.74%） were evaluated as XRCC1 IHC positive. XRCC1 expression was not significantly related to OS （P=0.347） or DFS （P=0.297）. Compared with surgery only, platinum-based adjuvant chemotherapy significantly improved the OS （P=0.031）. And the patients with negative XRCC1 expression benefited more from platinum-based adjuvant chemotherapy （P=0.049）. Multivariate analysis demonstrated that tumor size, T category, N category, vascular or nerve invasion and platinum-based chemotherapy were good prognostic factors for OS （P〈0.05）. Though XRCCI plays an important role in DNA repair pathways, no significant relationship is found in XRCCI expression and OS among gastric cancer in our study. Conclusions： XRCC1 might be an alternative prognostic marker for the patients of gastric cancer after radical resection. The patients with negative XRCC1 expression can benefit more from platinum-based adjuvant chemotherapy.

Four Cases of X-Linked Hypophosphatemic Rickets, Clinical Description and Genetic Testing

One of the major causes of congenital hypophosphatemic rickets is the X-linked hypophosphatemic rickets (XHR), due to a defect on PHEX gene. The XHR increases the renal elimination of phosphate, that condition leads a defective mineralization of bones and also affects the growth in children. Clinical diagnosis should be suspected in children with signs of rickets and hypophosphatemia with normal calcium levels. We describe clinical characteristics and genetic results of four patients diagnosed and treated in our Nephrology Section. All patients have a “de novo” XHR as none familiars are affected. Early diagnosis should be suspected before the bone deformities have been submitted and the growth would have been impaired.

DNA repair gene XRCC1 polymorphisms and susceptibility to childhood acute lymphoblastic leukemia: a meta-analysis

Objective： To estimate the relationship between genetic polymorphisms of X-ray repair cross- complementing group 1 （XRCC1） and the susceptibility to childhood acute lymphoblastic leukemia （ALL）. Methods： Relevant case-control studies were enrolled in the meta-analysis. We applied Rev Man 4.2 software to pool raw data and test studies＇ heterogeneity and to calculate the incorporated odds ratio （OR） and 95% confidence interval （95% CI）. Results： Our data showed that the OR for the Gln allele of the Arg399Gln polymorphism, compared with the Arg allele, was 1.35 （95% CI, 1.16-1.57; P〈0.0001） for childhood ALL patients. Similarly, the homozygous genotype Gln/Gln and heterozygous genotype Arg/Gln both significantly increased the risk of childhood ALL compared with the wild genotype Arg/Arg （OR =1.58; 95% CI, 1.13-2.21; P=0.008; OR =1.51; 95% CI, 1.21-1.87; P=0.0002）. The dominant model of Arg399Gln was associated with childhood ALL risk （OR =1.54; 95% CI, 1.25-1.89; P〈0.0001）. The ethnic subgroup analysis demonstrated that the Gln allele in all five ethnic groups was prone to be a risk factor for childhood ALL just with different degrees of correlation while Arg194Trp SNP showed a protective or risk factor or irrelevant thing in different races. Conclusions： XRCC1 399 polymorphism may increase the risk of childhood ALL. Different ethnic groups with some gene polymorphism have different disease risks.

Application of the back-error propagation artificial neural network(BPANN) on genetic variants in the PPAR-γ and RXR-α gene and risk of metabolic syndrome in a Chinese Han population

This study was aimed to explore the associations between the combined effects of several polymorphisms in the PPAR-γ and RXR-α gene and environmental factors with the risk of metabolic syndrome by back-error propaga- tion artificial neural network （BPANN）. We established the model based on data gathered from metabolic syndrome patients （n = 1012） and normal controls （n = 1069） by BPANN. Mean impact value （MIV） for each input variable was calculated and the sequence of factors was sorted according to their absolute MIVs. Generalized multifactor dimensionality reduction （GMDR） confirmed a joint effect of PPAR-9＂ and RXR-a based on the results from BPANN. By BPANN analysis, the sequences according to the importance of metabolic syndrome risk fac- tors were in the order of body mass index （BMI）, serum adiponectin, rs4240711, gender, rs4842194, family history of type 2 diabetes, rs2920502, physical activity, alcohol drinking, rs3856806, family history of hypertension, rs1045570, rs6537944, age, rs17817276, family history of hyperlipidemia, smoking, rs1801282 and rs3132291. However, no polymorphism was statistically significant in multiple logistic regression analysis. After controlling for environmental factors, A1, A2, B1 and B2 （rs4240711, rs4842194, rs2920502 and rs3856806） models were the best models （cross-validation consistency 10/10, P = 0.0107） with the GMDR method. In conclusion, the interaction of the PPAR-γ and RXR-α gene could play a role in susceptibility to metabolic syndrome. A more realistic model is obtained by using BPANN to screen out determinants of diseases of multiple etiologies like metabolic syndrome.

TGF-β2和geneX对BrdU标记骨髓间充质干细胞增殖与成骨分化的作用

目的研究TGF-β2和gene X对Brd U标记的骨髓间充质干细胞增殖与成骨分化作用的影响.方法采用全骨髓贴壁培养法分离骨髓间充质干细胞,传代并鉴定,设实验组和空白对照组,实验组分4组:A组:Brd U标记后的BMSCs组;B组:Brd U标记后的BMSCs+TGF-β2组;C组:Brd U标记后的BMSCs+gene X组;D组:Brd U标记后的BMSCs+gene X+TGF-β2组.空白对照组为Brd U标记后的单纯BMSCs加入基础培养基避光培养.诱导培养后观察骨髓间充质干细胞生长形态、检测生长动力学(methyl thiazolyl tetrazolium,MTT)、碱性磷酸酶(ALP)和钙定量、进行细胞Von-Kossa法染色,观察成骨分化作用.结果 (1)4组BMSCs吸光度值(OD)分析比较显示:细胞组间差异有统计学意义(P<0.05);(2)各组BMSCs成骨诱导后碱性磷酸酶(ALP)和钙定量检测结果显示:细胞组间差异有统计学意义(P<0.05);(3)进行细胞Von-Kossa法染色,D组可见大量钙结节;C组可见较多钙结节;B组可见部分钙结节;A组可见少量钙结节;空白对照组未见钙结节.结论 (1)TGF-β2可促进骨髓间充质干细胞的增殖和诱导其向成骨细胞分化;(2)gene X可促进骨髓间充质干细胞向成骨细胞分化,且在细胞因子TGF-β2联合作用下成骨分化作用更明显.

Expression and subcellular localization of a novel gene <i>Bm-X</i>of the silkworm, <i>Bombyx mori</i>

According to the large-scale sequencing of cDNA library from silkworm pupae, the cDNA of a novel gene with blank research background was identified and temporarily named Bm-X. The length of this cDNA is 778 bp. We obtained its ORF for further study by bioinformatics analysis. It is 444 bp and encodes 147 amino acid residues, with a predicted molecular weight (MW) of 16.4 kD and an isoelectric point (pI) of 3.69. In this study, we successfully constructed a recombinant plasmid pET-28a(+)-Bm-X and expressed it in Escherichia coli. We used the fusion protein rBm-X which purified by Niaffinity chromatography to produce polyclonal antibodies against Bm-X for Western blot analysis. The analysis revealed that Bm-X was expressed in the larval midgut, the epidermis and the silk gland. In addition, the subcellular localization analysis of silkworm ovary epithelial cells (BmN cells) showed that Bm-X protein was located both in cytoplasm and nucleus, and the signal was stronger in cytoplasm than in nucleus. Our findings indicate that Bm-X gene is a novel species-specificity gene and its expression product can be detected in tissues of the fifth silkworm instar larvae and BmN cells.