Identification of spontaneous age-related cataract in Microtus fortis. / ä¸œæ–¹ç”°é¼ è‡ªå‘æ€§å¹´é¾„ç›¸å ³æ€§ç™½å† éšœçš„é‰´å®š.

OBJECTIVES: Age-related cataract is the most common type of adult cataract and a leading cause of blindness. Currently, there are few reports on the establishment of animal models for age-related cataract. During the experimental breeding of Microtus fortis (M. fortis), we first observed that M. fortis aged 12 to 15 months could naturally develop cataracts. This study aims to explore the possibility of developing them as an animal model for age-related cataract via identifing and analyzing spontaneous cataract in M. fortis. METHODS: The 12-month-old healthy M. fortis were served as a control group and 12-month-old cataractous M. fortis were served as an experimental group. The lens transparency was observed using the slit-lamp biomicroscope. Hematoxylin and eosin staining was used to detect pathological changes in the lens. Biochemical detection methods were applied to detect blood routine, blood glucose levels, the serum activities of superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in both groups. Finally, real-time RT-PCR was used to detect the transcription levels of cataract-related genes in the lens of 2 groups. RESULTS: Compared with the control group, the lens of cataract M. fortis showed severely visible opacity, the structure of lens was destroyed seriously, and some pathological damage, such as swelling, degeneration/necrosis, calcification, hyperplasia, and fiber liquefaction were found in lens epithelial cells (LECs). The fibrous structure was disorganized and irregularly distributed with morgagnian globules (MGs) aggregated in the degenerated lens fibers. There was no statistically significant difference in blood glucose levels between the experimental and control groups (P>0.05). However, white blood cell (WBC) count (P<0.05), lymphocyte count (P<0.01), and lymphocyte ratio (P<0.05) were significantly decreased, while neutrophil percentage (P<0.05) and monocyte ratio (P<0.01) were significantly increased. The serum activities of SOD and GSH-Px (both P<0.05) were both reduced. The mRNAs of cataract-related genes, including CRYAA, CRYBA1, CRYBB3, Bsfp1, GJA3, CRYBA2, MIP, HspB1, DNase2B, and GJA8, were significantly downregultaed in the lenses of the experimental group (all P<0.05). CONCLUSIONS: There are significant differences in lens pathological changes, peroxidase levels, and cataract-related gene expression between cataract and healthy M. fortis. The developed cataract spontaneously in M. fortis is closely related to age, the cataract M. fortis might be an ideal animal model for the research of age-related cataract.

Paper mulberry leaves as a potential sterilant: evidence from Microtus fortis-a laboratory study.

Introduction: The Yangtze vole (Microtus fortis) is a small herbivorous rodent that usually causes damage to crops and forests in China. Various measures were used to control their population including chemical rodenticides. However, rodenticides may cause secondary damage to the environment and the ecosystem. Therefore, the development of new rodent sterilants is urgent. Considering that some compounds of paper mulberry leaves have been verified that can inhibit the biosynthesis of sexual hormone, we aimed to explore the antifertility effect of paper mulberry leaves on M. fortis. Methods: In this study, voles were divided into three groups including a male group, a female group, and a breeding group, and paper mulberry leaves were added into basal fodder of voles maintained in laboratory, of which the proportion of leaf weight was 50%. In each group, voles were fed with mixed fodder as treatment (BP) and voles were fed with basal fodder as contrast (CK). Results and discussion: After feeding for more than 1 month, the results indicated that paper mulberry leaves attracted voles to feed, but inhibited their growth and reproduction. Since the second week, food intakes of BP have been significantly higher than CK (p< 0.05). However, weights of voles in male and female groups were 72.283 ± 7.394 g and 49.717 ± 2.278 g in the fifth week, and both were significantly reduced compared with their original weight (p< 0.05). Meanwhile, testicular volumes of male voles fed with BP were significantly smaller than CK (former: 318.000 ± 44.654 mm3, latter: 459.339 ± 108.755 mm3); the testosterone level, sperm number, and vitality of BP were obviously weaker than CK. Female uteruses and oophoron of BP grew slower, and the organ coefficients of uterus and oophoron fed BP were both significantly lower than CK (p< 0.05). The first reproduction of BP couple voles spent 45 days, while CK spent only 21 days. These results suggest that paper mulberry leaves could be the potential resource to produce sterilants to control rodent populations by delaying their sexual growth and reproduction. If it was practical, the apparent advantages of paper mulberry are that it is an abundant resource and the inhibitory effect could be effective in both male and female individuals. Our conclusion also supports the transformation of rodent management from lethal management to fertility control, which would be more ecologically friendly to agriculture and the ecosystem.

De novo assembly and transcriptome characterization: Novel insights into the mechanisms of primary ovarian cancer in Microtus fortis.

The natural incidence of primary epithelial ovarian cancer (OVC) in adult female voles of some established strains of Microtus fortis is relatively high. M. fortis OVC has some pathological similarities to human epithelial OVC, therefore M. fortis represents the latest and most valuable animal model for studying human OVC. The lack of available genetic information for M. fortis limits the use of common immunological methods; thus, high­throughput sequencing technologies have been used to reveal the mechanisms of primary OVC in M. fortis. The individuals with cancer were diagnosed using histopathologic hematoxylin and eosin staining. The present study used RNA­sequencing (RNA­seq) technology to establish a de novo assembly of the M. fortis transcriptome produced 339,830 unigenes by the short reads assembly program Trinity. Comparisons were made between OVC and healthy ovarian tissue (OV) and between fallopian tube cancer (FTC) and healthy fallopian tube (FT) tissues using RNA­seq analysis. A total of 3,434 differentially expressed genes (DEGs) were identified in OVC tissue compared with OV tissue using RNA­Seq by Expectation­Maximization software, including 1,950 significantly upregulated and 1,484 significantly downregulated genes. There were 2,817 DEGs identified in the FTC tissues compared with the FT tissue, including 1,762 significantly upregulated and 1,055 significantly downregulated genes. Pathway enrichment analysis revealed that upregulated transcripts in the OVC vs. OV groups were involved in cell growth and proliferation­associated pathways, whereas the downregulated DEGS in the OVC vs. OV groups were enriched in steroid biosynthesis­related pathways. Furthermore, the tumor suppressor gene, p53, was downregulated in the FTC and OVC compared with the FT and OV groups, respectively; whereas, genes that promoted cell migration, such as Ras­related protein Rap­1b, Ras homolog family member A and RAC1, were upregulated. In summary, to the best of our knowledge, the present study characterized the M. fortis de novo transcriptome of OV and FT tissues and to perform RNA­seq quantification to analyze the differences in healthy and cancerous OV and FT tissues. These results identified pathways that differed between cancerous and healthy M. fortis tissues. Analysis of these pathways may help to reveal the pathogenesis of primary OVC in M. fortis in future work.

miR-181a regulates the host immune response against Schistosoma japonicum infection through the TLR4 receptor pathway.

BACKGROUND: Schistosomiasis japonica is a serious zoonotic parasitic disease. Preliminary studies have shown that the expression of microRNA-181a (miR-181a) in the liver, lung and spleen tissues of susceptible host BALB/c mice and resistant host reed vole (Microtus fortis) 10 days post-infection (dpi) with Schistosoma japonicum was significantly different from pre-infection levels. This difference suggests the possibility that miR-181a expression may be related to the regulation of the hosts' early immune response against S. japonicum infection and thereby affect the development and survival of parasites in their final hosts. METHODS: BALB/c mice, M. fortis, Toll-like receptor 4 (TLR4)-deficient mice and wild-type mice (C57BL/6) were infected with S. japonicum, and differences in miR-181a expression between BALB/c mice and M. fortis over different time points post-infection (0, 3, 7, 10 and 14 dpi) were compared. MiR-181a mimic, miR-181a inhibitor and irrelevant miRNA, as well as lipopolysaccharide (LPS), a TLR4 receptor ligand, were used to transfect mouse RAW264.7 macrophages. The expression levels of the TLR4 pathway-related cytokines interleukin (IL)-1ß, tumor necrosis factor α (TNF-α) and IL-6 were detected by quantitative PCR analysis. RESULTS: The expression of miR-181a was significantly upregulated in the serum and liver of mice infected with S. japonicum and downregulated in the serum and liver of M. fortis. T-helper cell (Th1)-type cytokines, such as TNF-α, IL-6 and IL-1ß, and Th2-type cytokines, such as IL-10 and IL-4, were differentially expressed in M. fortis and BALB/c mice in the early stage of infection. The expression level of miR-181a in the serum was threefold higher in TLR4-deficient mice than in wild-type mice 10 dpi with S. japonicum. The expression of IL-1ß, TNF-α and IL-6 decreased in RAW264.7 cells transfected with miR-181a mimic and increased in cells transfected with miR-181a inhibitor. miR-181a expression was downregulated and the expressions of TLR4 and three TLR4 pathway-related cytokines (IL-1ß, IL-6, and TNF-α) were upregulated in RAW264.7 macrophages stimulated with the TLR4 receptor ligand LPS. CONCLUSION: These results suggest the possibility of mutual regulation between miR-181a and the TLR4 signaling pathway during S. japonicum infection. miR-181a may regulate the expression of pro-inflammatory factors through the TLR4 receptor pathway and participate in the immunomodulatory effect of anti-S. japonicum infection.

Transcriptional profiling of Microtus fortis responses to S. japonicum: New sight into Mf-Hsp90α resistance mechanism.

AIMS: Schistosomiasis is a parasitic disease with a chronic debilitating character caused by parasitic flatworms of the genus Schistosoma. The main disease-causing species of Schistosoma in China is S. japonicum. M fortis has been proved to be a nonpermissive host of S. japonicum. Mf-HSP90α (Microtus fortis heat shock protein 90alpha), the homologue of HSP90α, display anti-schistosome effect in vitro and in vivo. In the current study, in order to investigate the mechanism of anti-schistosome effect of Mf-HSP90α, we conducted RNA-Seq to obtain the transcriptome profile of M. fortis liver infected with S. japonicum at different time points. METHODS AND RESULTS: By mapping the differential expressed genes (DEGs) to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), we found that the JAK2/STAT1 pathway was highly enriched with an elevated level of IL-10 and HSP90α. We then checked the IL-10-JAK2/STAT1-HSP90α pathway, and found that this pathway was activated in the infected mice with S. japonicum. The expression of the molecules in this pathway was elevated on the 10th day after infection and gradually decreased on the 20th day. CONCLUSIONS: The IL-10-JAK2/STAT1-HSP90α axis was associated with the anti-schistosome effect of Mf-HSP90α, and targeting IL-10-JAK2/STAT1-HSP90α axis might be a novel therapeutic strategy for developing resistance to S. japonicum infection.

Genome assembly and transcriptome analysis provide insights into the antischistosome mechanism of Microtus fortis.

Microtus fortis is the only mammalian host that exhibits intrinsic resistance against Schistosoma japonicum infection. However, the underlying molecular mechanisms of this resistance are not yet known. Here, we perform the first de novo genome assembly of M. fortis, comprehensive gene annotation analysis, and evolution analysis. Furthermore, we compare the recovery rate of schistosomes, pathological changes, and liver transcriptomes between M. fortis and mice at different time points after infection. We observe that the time and type of immune response in M. fortis are different from those in mice. M. fortis activates immune and inflammatory responses on the 10th day post infection, such as leukocyte extravasation, antibody activation, Fc-gamma receptor-mediated phagocytosis, and the interferon signaling cascade, which play important roles in preventing the development of schistosomes. In contrast, an intense immune response occurrs in mice at the late stages of infection and could not eliminate schistosomes. Infected mice suffer severe pathological injury and continuous decreases in cell cycle, lipid metabolism, and other functions. Our findings offer new insights into the intrinsic resistance mechanism of M. fortis against schistosome infection. The genome sequence also provides the basis for future studies of other important traits in M. fortis.

Comparative analysis of intestinal flora of Microtus fortis living under laboratory feeding and wild survival conditions / 中国实验动物学报

Objective To compare the differences of bacterial distribution of intestinal flora in Microtus fortis living under laboratory feeding and wild survival conditions. Methods The 16S rDNA-V4-V5 region of bacteria in the ileocecal contents from Microtus fortis raised in lab and captured in wild were measured by high-throughput sequencing. The number of operational taxonomic units(OTUs)were sorted and calculated,and the species abundance and distribution and difference were analyzed. Results The rarefaction curves indicated that adequate sampling was achieved. At the phylum level,the distribution of intestinal flora between two groups was similar. The experimental group had a unique phylum, Lentisphaerae. The wild type group had 3 unique phylums,Fusobacteria,Thaumarchaeota and an unclassified phylum. At the genus level, the kind of intestinal flora in the wild type group was more abundant than the experimental group. Ruminococcus is the largest differential genus. Conclusions The microbial community structure and differences of Microtus fortis living under different conditions are obtained. It may further enrich the basic biology data of Microtus fortis.

[Preparation of recombinant retrovirus pRevTRE-E77.43 and its protective effect in a mouse model of Schistosoma japonicum infection].

OBJECTIVE: To explore the biological functions of E77.43, a gene segment of Microtus fortis, in treating Schistosoma japonicum infection. METHODS: Recombinant retroviral vectors of pRevTRE-E77.43 was constructed, and recombinant retroviral vectors were transfected into PA317 cells, and the stable cell lines were obtained by hygromycin screening, followed by the packaging, concentration and purification of recombinant retrovirus. The virus was transferred to the mice infected by S. japonicum via intravenous or intraperitoneal injection, through which the express of target gene and the treatment function in vivo were observed. RESULTS: The experiment showed the recombinant virus injected mice could efficiently express E77.43 on the 7th day after the injection which lasted for forty-five days thereafter. A significant reduction in adult worms (31.0%) and a high reduction (35.0%) in liver eggs were induced by pRevTRE-E77.43, while the reduction in adult worms and that in liver eggs was 1.2% and 0.9% induced by pRevTRE respectively (t = 3.524, 9.485, both P＜0.01). CONCLUSIONS: pRevTRE-E77.43 could be used for the treatment of S. japonicum infection, indicating that E77.43 may involve in the natural resistance of M. fortis to S. japonicum infection.

Preparation of recombinant retrovirus pRevTRE-E77.43 and its protective effect in a mouse model of Schistosoma japonicum infection / 中国血吸虫病防治杂志

Objective To explore the biological functions of E77.43, a gene segment of Microtus fortis, in treating Schistoso-ma japonicum infection. Methods Recombinant retroviral vectors of pRevTRE-E77.43 was constructed, and recombinant retro-viral vectors were transfected into PA317 cells, and the stable cell lines were obtained by hygromycin screening, followed by the packaging, concentration and purification of recombinant retrovirus. The virus was transferred to the mice infected by S. japoni-cum via intravenous or intraperitoneal injection, through which the express of target gene and the treatment function in vivo were observed. Results The experiment showed the recombinant virus injected mice could efficiently express E77.43 on the 7th day after the injection which lasted for forty-five days thereafter. A significant reduction in adult worms (31.0％) and a high reduction (35.0％) in liver eggs were induced by pRevTRE-E77.43, while the reduction in adult worms and that in liver eggs was 1.2％and 0.9％induced by pRevTRE respectively (t=3.524, 9.485, both P<0.01). Conclusion pRevTRE-E77.43 could be used for the treatment of S. japonicum infection, indicating that E77.43 may involve in the natural resistance of M. fortis to S. japonicum infec-tion.

Reproductive characteristics of the Yangtze vole (Microtus fortis calamorum) under laboratory feeding conditions.

The reproductive characteristics of a laboratory population of the vole Microtus fortis calamorum were examined. Voles were allowed to breed under laboratory feeding conditions. Over a period of 3 months, 61.82% of the 110 vole pairs examined produced 3 or 4 litters. There were 1-9 voles in each litter and the mean litter size was 4.67±0.28 (mean±SE). Most litters included 3-7 young voles, accounting for 83.62% of all litters. The mean farrowing interval was 25.9 days (range from 19 to 95 days), and the most farrowing intervals were 20-25 days, accounting for 79.9% of the total. When based on litter size, the reproductive index was 6.23, but was 3.42 when based on pup survival. The survival rate of offspring to weaning was 55.03%. The high rate of infanticide that occurred after removal of males from cages indicates that, in the laboratory, both parents need to be present prior to weaning.

[Culture and characterization of spontaneous ascites cells isolated from Microtus fortis].

OBJECTIVE: To isolate and culture the spontaneous ascites cells from Microtus fortis under artificial conditions, so as to investigate the molecular mechanism at the cell level. METHODS: The cells were isolated from spontaneous ascites of M. fortis artificially bred for 90 d, and were cultured and observed under a microscope. The differences of ascites cells among normal, spontaneous ascites and schistosomiasis infected samples of M. fortis were compared. The lesion of tissue was observed simultaneously. RESULTS: There were no obvious organ tissue lesions in M. fortis with spontaneous ascites, and the number and types of cells in peritoneal fluid were irregular and significantly changed. With the extension of culture time, the colonies appeared and there were a large number of vacuole-like cells in the cultured medium and sequentially presenting proliferation, deformation, disintegration and the fiber-like changes and could be passaged 3-4 d only. CONCLUSIONS: The cells from M. fortis with spontaneous ascites are similar to its abdominal cavity cells after infection of Schistosoma japonica.

Culture and characterization of spontaneous ascites cells isolated from Mi-crotus fortis / 中国血吸虫病防治杂志

Objective To isolate and culture the spontaneous ascites cells from Microtus fortis under artificial conditions, so as to investigate the molecular mechanism at the cell level. Methods The cells were isolated from spontaneous ascites of M. fortis artificially bred for 90 d,and were cultured and observed under a microscope. The differences of ascites cells among nor?mal,spontaneous ascites and schistosomiasis infected samples of M. fortis were compared. The lesion of tissue was observed si?multaneously. Results There were no obvious organ tissue lesions in M. fortis with spontaneous ascites,and the number and types of cells in peritoneal fluid were irregular and significantly changed. With the extension of culture time ,the colonies ap?peared and there were a large number of vacuole?like cells in the cultured medium and sequentially presenting proliferation ,de?formation,disintegration and the fiber?like changes and could be passaged 3-4 d only. Conclusion The cells from M. fortis with spontaneous ascites are similar to its abdominal cavity cells after infection of Schistosoma japonica.

Immunoproteomic analysis of Schistosoma japonicum schistosomulum proteins recognized by immunoglobulin G in the sera of susceptible and non-susceptible hosts.

The aim of this study was to search for immunogenic schistosomula proteins in the hope of identifying novel intervention targets. Schistosomula proteins were analyzed by immunoproteomic which the probes were sera derived from BALB/c mice (susceptible hosts) and Microtus fortis (resistant hosts). A total of 116 immunoreactive proteins recognized by 10 days post-infected BALB/c mice, M. fortis sera, and uninfected M. fortis sera were selected for further analysis. Finally, 95 protein spots were identified by mass spectrometry (MS) analysis. Bioinformatics analysis showed that the differentially identified immunogenic proteins participated mainly in cytoskeleton organization, cell motility, energy metabolism, responses to stimuli, and protein folding. Many of these proteins were the tegument or excretory-secretory products of schistosomes reported in previous studies. Among of them, Schistosoma japonicum DnaJ (Hsp40) homologue (SjDnaJ) was successfully expressed and the purified recombinant product was evaluated by immunoprotective experiment. After immunization of BALB/c mice with recombinant SjDnaJ, it could induce 34.5% and 48.9% reductions in the numbers of worms and eggs in the liver. These results contribute to a better understanding of the molecular mechanisms underlying the host-parasite relationship and provide a major dataset to facilitate the further development of new vaccine candidates and/or diagnostic markers for schistosomiasis. BIOLOGICAL SIGNIFICANCE: Schistosomiasis is caused by parasitic blood-dwelling flukes in tropical and subtropical areas, and it is one of the world's most prevalent tropical diseases. The lack of effective vaccine and reliable diagnostic methods make this disease difficult to control. In China, S. japonicum can infect more than 40 different susceptible mammals for this parasite. However, M. fortis is the only known mammal where the schistosome cannot develop and it exhibits no significant pathological effects. Many studies' results showed that native antibodies against S. japonicum are present in M. fortis that may have important anti-schistosomiasis roles during the infection process. The aim of this study was to search for immunogenic schistosomula proteins in the hope of identifying novel intervention targets. We present a comparative immunoproteomics analysis of the proteins recognized by susceptible and resistant host antibodies before and 10-days after infections. The results of this analysis will be helpful for identifying the key molecules required for the survival and development of schistosomes. At the same time, the study contributes to a better understanding of the molecular mechanisms underlying the host-parasite relationship associated with schistosomes and they also provide a major dataset to facilitate the further development of new diagnostic assays and/or vaccine candidates for schistosomiasis.

Comparative analysis of microRNA in schistosomula isolated from non-permissive host and susceptible host.

The reed vole Microtus fortis is the only known mammal in which the schistosome is naturally prevented from maturing and schistosome infection does not cause significant pathogenesis. However, the mechanism behind this phenomenon remains unknown. In the present study, Solexa deep sequencing technology was used to carry out high-throughput sequencing and comparative analysis of microRNA (miRNA) between small RNA libraries isolated from 10 days oldschistosomula of M. fortis and BALB/c mice.In total, 10d schistosomula from M. fortis and BALB/c mice yielded 13.37 and 10.84 million reads, respectively, and nearly 39% and 40% of reads could be mapped to selected miRNAs in miRbase. Based on a bioinformatic analysis, we found that most of the miRNAs identified in Schistosoma japonicum were detected in our study. Further analysis revealed that 24 miRNAs were differentially expressed between the schistosomula from the two rodents, of which 21 were down-regulated and three were up-regulated in schistosomula from M. fortis. Also, six novel miRNAs were predicted and identified in this study. Target genes were mapped and filtered by correlating them with differentially expressed genes obtained from S. japonicum oligonucleotide microarray analyses performed in previous studies. miRNAs such as miR-10-3p, miR-10-5p, and miR-2b-5p may affect the growth, differentiation, and metabolism of worms via regulation of the expression of target genes such as enolase, aquaporin, TGF-beta-inducible nuclear protein, and paramyosin. Gene Ontology analysis of the predicted target genes of these six differentially expressed miRNAs revealed that some important biological pathways, such as metabolic processes,glycolysis, and catalytic activity, were involved. The results of this study highlight the function of miRNAs in the development and survival of the schistosome, and provide valuable information to increase our understanding of the regulatory function of miRNAs in schistosome development and host-parasite interactions in a differentially susceptible host environment.

Isolation and identification of macrophages from liver of Microtus fortis / 中国血吸虫病防治杂志

Objective To separate and purify intrahepatic macrophages from Microtus fortis Mf and identify its phagocy?tosis. Methods The intrahepatic macrophages from Mf were separated and purified by perfusion collagenase digestion and density gradient centrifugation. The function of the cells was identified by FACS analysis and ink phagocytosis activity. Results The macrophage cells from the liver of Mf were obtained. These cells were bright and circular and grew adhering to the wall. The proportion of the living cells was 95%. The binding rate of these cells from Mf with anti?mouse CD14 antibody Clone Sa2?8 was about 50%of the rate of macrophage from C57BL/6 mice with this monoclonal antibody. The result of ink?phagocytosis ex?periment of macrophage cells from the liver of Mf was positive. Conclusion The method above mentioned is useful to separate and purify macrophage from the liver of Mf. The study builds the foundation for further research on macrophages of Mf against Schistosoma japonicum.

Effect of population density on reproduction in Microtus fortis under laboratory conditions.

Between December 2011 and March 2012, the reproductive characteristics of Microtus fortis reared in the laboratory at different population densities were assessed. In all, 258 male and female voles were randomly divided into 4 groups and reared at densities of 2, 4, 6, and 8 animals per cage (sex ratio: 1:1). The results showed that the pregnancy rate (χ2 = 21.671, df = 3, P < 0.001) and first farrowing interval (F = 12.355, df = 3, P < 0.001) were significantly different among the different population density groups, but the mean litter size (mean ± SD) was not (F = 2.669, df = 3, P > 0.05). In particular, the reproductive index and sex hormone levels showed a significant difference among the different density groups studied.

Formulation of local standard of Microtus Fortis as a laboratory animal:formulation and related research / 中国实验动物学报

The principle, basis, necessity and significance of formulating the local standard of Microtu fortis as a laboratory animal were described in this paper, and the standard was compared with the relationship between this standard of Microtu fortis as laboratory animal and the existing laws, regulations of other standards of laboratory animals.The specific procedures and the degree of adoption of domestic standards and advanced foreign standards were introduced.Furthermore, the proposal and the reasons of recommendatory standards were presented.

A Microtus fortis protein, serum albumin, is a novel inhibitor of Schistosoma japonicum schistosomula

Schistosomiasis is an endemic parasite disease and praziquantel is the only drug currently in use to control this disease. Experimental and epidemiological evidence strongly suggests that Microtus fortis ( Mf ) is a naturally resistant vertebrate host of Schistosoma japonicum . In the present study, we found that Mf serum albumin ( Mf -albumin) and the conditioned medium of pcDNA3.1- Mf -albumin caused 46.2% and 38.7% schistosomula death rates in 96 h, respectively, which were significantly higher than that of the negative control (p < 0.05). We also found that mice injected with Mf -albumin had a 43.5% reduction in worm burden and a 48.1% reduction in liver eggs per gram (p < 0.05) in comparison to the control animals. To characterise the mechanisms involved in clearance, schistosomula were incubated with fluorescein isothiocyanate-labelled Mf -albumin and fluorescent enrichment effects were found in the gut lumen of schistosomula after 48 h of incubation. Next, digestive tract excretions from schistosomula were collected and the sensitivity of Mf -albumin to digestive tract excretions was evaluated. The results indicated that schistosomula digestive tract excretions showed indigestibility of Mf -albumin. The death of schistosomula could be partially attributed to the lack of digestion of Mf -albumin by digestive tract excretions during the development of the schistosomula stage. Therefore, these data indicate the potential of Mf -albumin as one of the major selective forces for schistosomiasis.

Ecology survey of Microtus fortis in natural foci of plague in Dingbian town Shaanxi province in 2010 / 中国地方病学杂志

Objective To investigate the constitution,density changes and carrier rate about Yersinia pestis of rodents in plague foci,and to provide the scientific evidence for plague prevention.Methods According to the program of national monitoring plague,two survey procedures,namely quadrat of single-ha for 24 h and 5 m mouse jam,were used to monitor the host animals; culture and identification of Yersinia pestis in liver or spleen of the experimental animals was carried out by using self-made medium in the north of Beiyuanzi village in Dingbian town Shaanxi province.Results One hundred twelve rodents were captured using the first procedures and the rodent average density was 8.62 ind./hm2 and six species of rodents were found namely Meriones unguiculatus ( 100 individuals),Microtusfortis(5 individuals),Ochotona daurica(3 individuals),Meriones meridianus (2 individuals),Mus musculus Linnaeus (1 individual) and Cricetulus barabensis (1 individual).One hundred seventy-three field mouses were captured using the second procedures including Mus musculus Linnaeus (136 individuals),Cricetulus barabensis (36 individuals),and Microtus fortis ( 1 individual ).Among them,Microtus fortis was found in the salt marshes in the southern edge of Ordos Plateau steppe in plague area of Dingbian county.Yersinia pestis was not identified in all animals.Conclusions Microtus fortis is found in natural foci of plague in Shaanxi province for the first time,and a new geographic region was found.Its epidemiological significance needs further study.

Acquisition and Analysis of Three cDNA Full-Length Sequences from the Liver of Microtus fortis / 中国实验动物学报

Objective To obtain the full-length cDNA sequences of CYP2E1,CYP2D5,ECHS1,which may be related with non-alcoholic fatty liver disease,from Microtus fortis.Methods To construct Microtus fortis liver cDNA plasmid library using SMART technique,to get the purposed colonies through screening libraries by PCR,and to obtain their full-length cDNA sequences by sequencing with pBluescript II SK universal primers M13R.Results Three full-length cDNA sequences of Microtus fortis,CYP2E1,CYP2D5 and ECHS1 were obtained.The CYP2E1 cDNA was 1685 bp in length and contained a 1482 bp open reading frame(ORF) encoding a 494 amino acids.The CYP2D5 cDNA was 1690 bp in length,and contained a 1514 bp ORF encoding 504 amino acids.The ECHS1 cDNA was 1013 bp in length,and containsed an 873 bp ORF encoding 290 amino acids.Sequence analysis revealed that the identity of the three cDNA sequences and deduced amino acids among Microtus fortis,Homo sapiens,Mus musculus and Rattus norvegicus was high.Conclusion The full-length cDNA sequences of CYP2E1,CYP2D5,ECHS1 were obtained from Microtus forti,liver cDNA library.and the gene sequences have been deposited in GenBank (GQ507485,GQ507486,GQ845171),which may lay the foundation for researchies of pathogenesis of non-alcoholic fatty liver disease in Microtus fortis models.