Abstract:Objective MCM3, a component of the MCM complex (MCM2-MCM7 complex), plays a critical role in the initiation of DNA replication and is a marker overexpressed in most malignant tumors such as liver cancer.However, whether it is involved in the early development of zebrafish liver is largely unknown. Our current study addressed whether zygotic mcm3 contributes to the regulation of liver development in zebrafish. Methods Expression of zygotic mcm3 was examined using in situ hybridization. mcm3 was then knocked down by injecting a mcm3 MO, and the liver developmental phenotype was analyzed in transgenic line (fabp10: GFP) and wild type embryos. Results Being as azygotic gene, mcm3 was expressed ubiquitously before the bud stage, whereas it was highly restricted in somite, head andendoderm-related tissues from the somite stage. After mcm3 loss of function, the liver was smaller than that in the controlembryos, but no other distinct developmental defects were observed. In addition, mcm3 mRNA injection rescued the defectof liver development in the mcm3 morphants. Conclusion Zygotic mcm3 is involved in the regulation of early development of zebrafish lever.

Abstract:Objective To discover novel transcripts from RNA-seq data of rainbow trout under heat stress andoptimize the annotated gene structure. Methods Total RNA was extracted from the liver of rainbow trout and used toconstruct a cDNA library that was sequenced by the Illumina two-terminal sequencing Hiseq 2500 platform. Sequencing datawere assembled by Cufflinks software and aligned with the rainbow trout genome. Results Among 6555 new transcripts, 30were differentially expressed under heat stress ( P < 0. 05). A total of 3097 novel transcripts were annotated and blasted bythe GO database. There were 3617 new transcripts annotated in 284 metabolic pathways by KEGG database. The structure of19 424 annotated genes was optimized, and the 5′-ends of 14 719 genes and 3′-ends of 14 796 genes were extended.Conclusions Discovery and analysis of 6555 novel transcripts and 19 424 gene structure optimization provide a powerfulreference optimizing the genome annotation information of rainbow trout, and a more powerful theoretical basis for further understanding the mechanism of heat stress in rainbow trout.

Abstract:Objective To establish a mouse model of experimental autoimmune myasthenia gravis (EAMG) byimmunization with purified AchR extracted from the Narcine maculata electric organ, which meets the requirements ofinternational criteria of preclinical experiment. Methods Purified AchR protein was extracted from the electric organ ofNarcine maculata and validated by SDS-polyacrylamide gel electrophoresis. C57BL/6 mice were immunized with the proteinand complete Freund adjuvant (CFA) for the EAMG group or CFA alone for the control group three times at days 1, 30,and 60. After 70 days, the clinical assessments were determined according to body weight, serum anti-AchR antibody level,neostigmine text, and electromyography. Results Compared with control mice, the clinical scores of EAMG mice wereincreased significantly ( P < 0. 01). Body weight was significantly decreased ( P < 0. 01), neostigmine test was positive,and the percentage of decrement of the fifth wave of electromyography and levels of anti-AchR antibody were significantlyhigher ( P < 0. 01). Conclusions The C57BL/6 EAMG mouse model is successfully established by immunization withpurified AchR protein extracted from the Narcine maculata electric organ, which may provide a better research tool for studies of experimental autoimmune myasthenia gravis.

Abstract:Objective To investigate the effects of Panax notoginsenosides (PNSs) on primitive and definitivehematopoiesis of zebrafish embryos, and provide new insights into pharmacological application of PNSs. Methods PNSswere obtained by ethanol extraction from panax notoginseng powder. Zebrafish embryos were treated with 50 or 100 μg/ mLPNSs from the 75% epiboly stage until harvest to detect hematopoietic markers by in situ hybridization. Results Comparedwith the control larvae, the embryos treated with PNSs exhibited obviously reduced expression of primitive hematopoieticmarkers such as gata1 and hbbe3. Consistently, the formation of erythrocytes was also impaired in the PNSs-treated embryosat later stages. Furthermore, PNSs treatments disrupted the definitive hematopoiesis as indicated by decreased expression ofhematopoietic stem cell markers runx1 and cmyb and the T lymphocyte marker rag1. Interestingly, the inhibitory effects ofPNSs on the primitive and definitive hematopoiesis were concentration-dependent. Conclusions Our results indicate thatPNSs impair primitive and definitive hematopoiesis during zebrafish embryonic development, implying that PNSs should be used with caution during pregnancy.

Abstract:Objective To generate a transgenic zebrafish line expressing growth hormone (GH) and evaluate theeffects of growth hormone (GH) overexpression on zebrafish caudal fin regeneration. Methods An expression plasmid(pDestTol2CG2; ubi:GH-polyA) was constructed by Gateway technology. After coinjection of the expression plasmid andtransposase-encoding mRNA at the one cell stage, GH-overexpressing transgenic zebrafish were screened by fluorescencemicroscopy and qPCR. The zebrafish were divided into wild type control and GH overexpression groups. After the zebrafishcaudal fin was transected, its regeneration process was recorded and analyzed. Results The heart of the transgeniczebrafish was labeled with green fluorescent protein. The real-time PCR showed that the expression level of GH wassignificantly higher than that in the wild type zebrafish ( P < 0. 05). After the zebrafish caudal fin was transected, theregeneration rate of the GH overexpression group was increased significantly ( P < 0. 05). Conclusions In this study, atransgenic zebrafish strain overexpressing GH is generated, and it demonstrates that GH overexpression promotes the regeneration of zebrafish caudal fin.

Abstract:Objective Through artificial infection with egg drop syndrome virus ( EDSV), to observe theproliferation and dynamic changes of the distribution of EDSV in vivo in different mouse strains, and to provide a theoreticalbasis and data support for construction of the virus vectors. Methods Three mouse strains with different immune status,BALB/ c (normal immunity), Nu (T-cell immunodeficiency) and NSG (high immunodeficiency) mice were used. Thirtytwo5-6 week old female mice per strain were grouped. The mice were infected by intraperitonealy injection of EDSV andserum samples were collected 1, 3, 5, 7, 14, 21, 28 and 35 days later. Antibodies were monitored by an indirect ELISA.Samples of the heart, lung, liver, spleen, kidney, small intestine, uterus, trachea, esophagus and brain were collectedfrom the mice at 1, 7, 14,21 and 28 days after infection. The viral load in each tissue was detected by quantitativefluorescence PCR and comparative Ct (2-ΔΔCT ) method. Results Antibodies were detected 3 days after infection in thesera of BALB/ c mice, reached the highest level at 14 days, and this level was maintained until 35 days. Antibodies weredetected in the Nu mice 3 days post-infection, (but at a lower level than that in BALB/ c mice), the levels were reducedafter 14 days of infection and maintained at a low level until 35 days post-infection. The antibody of NSG mice was negativeduring the whole process of infection monitoring. Relative quantification of nucleic acids showed that EDSV expression inthe liver tissue of BALB/ c mice reached 5. 45 orders of magnitude at 1 day after infection, followed by the spleen,esophagus, uterus, small intestine, lung, trachea, kidney and heart. EDSV content in the brain tissue was the lowest. Withthe extension of infection period, EDSV expression in each tissue was lower than that on the first day of infection, andEDSV expression in the liver and spleen remained high 28 days after infection. Nu mice and NSG mice showed the highestEDSV expression in the spleen 1 day after infection (3. 95 and 4. 05 orders of magnitude, respectively), followed by that inthe liver. Positive signals could be detected in the organs of Nu mice and NSG mice 28 days after infection. EDSVexpression in the liver and spleen remained high. Conclusions EDSV can stimulate immune response in mice, and thelevel of antibody expression in immunodeficient mice is low. EDSV exhibites hepatic and splenic tropism in mice in vivo.The present study provides reference data for development of EDSV vectors, as well as for their further application in laboratory animals.

Abstract:Objective To verify the quality as well as in vitro and in vivo development potentiality of mousedormant embryos after freezing and thawing, and provide a reference for the production and application of embryonicdormancy technology. Methods Normally incubated and dormant embryos were frozen by conventional freezing method,followed by in vitro resuscitation culture and embryo transfer experiments. Subsequently, the cells of dormant and normallyhatched embryos before and after freezing and thawing were counted by double immunofluorescence staining, and thequalities of the two embryo types before and after freezing and thawing were observed. Results The recovery rate fromfreezing and thawing and the development rate of dormant embryos were significantly higher than those of hatched embryos(72. 1% vs 50. 2%, P < 0. 01; 94. 2% vs 73. 9%, P < 0. 01). The pregnancy rate of dormant embryos was significantlyhigher than that of hatched embryos (40. 8% vs 30. 1%, P < 0. 05). The number of cells in the inner cell mass of thedormant embryo was significantly higher than that in the hatched stage (27. 83 vs 19. 53, P < 0. 05), while the differencein the number of trophoblasts was not significant. The number of inner cell clusters in the dormant embryos after freezingand thawing was significantly higher than that in the hatched embryos (25. 18 vs 14. 68, P < 0. 05; 114. 09 vs 73. 88, P <0. 05). Conclusions The embryo quality as well as in vitro and in vivo development potential of mouse dormant embryos after freezing and thawing are better than those of normally hatched embryos.

Abstract:Objective To study the degrees of adrenocortical inhibition after the action of glucocorticoid drugs,and the differences in its drug-induced syndromes in five mouse strains. Methods ICR, BALB/ c, C57BL/6J, KM andnude mice were selected. Prednisolone was used as the drug for intervention. There were 16 mice of each strain, eight-eachin the normal control group and prednisolone group. Prednisolone (0. 5 mg/ kg·d) was administered for 14 consecutive daysin the prednisolone group. The body weight of mice was recorded every day, and TCM diagnostic information were detectedby the experimental methodology of syndrome differentiation and treatment in mice on the 14th day. Mice was sacrificed andtheir spleen and thymus were weighed, and the organ indexes were calculated. Serum levels of corticosterone andadrenocorticotropic hormone (ACTH) were measured by ELISA. Gene expression of Star(steroidogenic acute regulatoryprotein), Cyp11a1(cytochromes P450 11A1), Cyp21a1(cytochromes P450 21A1), Cyp11b1(cytochromes P450 11B1)and Cyp11b2(cytochromes P450 11B2) in the adrenal glands were detected by real-time fluorescent quantitative PCR.Protein expression of LDLR(low-density lipoprotein receptor), SRBI(scavenger receptor class B member 1) and StAR(steroidogenic acute regulatory protein)was detected by Western blot. Results Compared with the control group of therespective strains, the body weight of ICR mice decreased significantly 7 days after prednisolone administration ( P <0. 01), BALB/ c mice decreased significantly 13 days after prednisolone administration ( P < 0. 01), C57BL/6J micedecreased significantly 5 days after prednisolone administration ( P < 0. 01), and nude mice decreased significantly 13 daysafter prednisolone administration ( P < 0. 05). Prednisolone administration resulted in a significant decrease in the gripstrength and a significant decrease in the mean temperature of the body trunk of ICR mice ( P < 0. 05). Prednisoloneresulted in a significant decrease in the spleen weight of ICR mice and nude mice ( P < 0. 01) and a decrease in the splenicindex of nude mice ( P < 0. 05), whereas prednisolone administration resulted in a significant decrease in the thymic weightand thymic index of ICR, C57BL/6J and KM mice ( P < 0. 01). Prednisolone administration significantly decreased theserum corticosterone level in BALB/ c and KM mice ( P < 0. 05), and serum level of ACTH in BALB/ c mice ( P < 0. 01).Prednisolone significantly downregulated the Cyp21a1 expression in ICR mice ( P < 0. 05),Star expression in C57BL/6Jmice ( P < 0. 01), Cyp11a1 and Cyp21a1 expression in KM mice ( P < 0. 01), and Star and Cyp21a1 expression in nudemice ( P < 0. 05). In addition, prednisolone inhibited expression of LDLR and StAR in the ICR and KM mice. ConclusionsThe prednisolone-induced deficiency syndrome in mice is mainly characterized by “qi deficiency”, which is involved in the“kidney state” and “ spleen state”. The basis of this deficiency syndrome is primarily inhibition of expression ofadrenocortical steroid synthase and function of the pituitary-adrenocortical axis. ICR mice is suggested to be used for studies of glucocorticoid-induced asthenia.

Abstract:Objective To establish a rapid duplex polymerase chain reaction (PCR) assay for simultaneousdetection of Rat coronavirus and Sendai virus. Methods Specific primers were designed based on the N gene of Ratcoronavirus and L gene of Sendai virus. A duplex PCR system was established by optimizing the concentration of primersand annealing temperature, and testing the specificity and sensitivity of this system. This was followed by screening DNAsamples of artificial infections and tissues of experimental animals through our PCR system and comparing it with the ELISAmethod. Results Duplex PCR amplification of Rat coronavirus (168 bp) and Sendai virus (262 bp) was done. Theresults of sequencing of the PCR amplification products were compared with homologous sequences using BLAST functions.The homology of the Sendai virus and Rat coronavirus was 100% and 99%, respectively. The lower limit of detection for Ratcoronavirus and Sendai virus was 1. 56×102 copies/ μL. Specific detection of mouse hepatitis virus amplification resulted ina fragment size that similar to the Rat coronavirus product. The established duplex PCR system was used to detect the DNAsamples of artificially infected Sendai virus, and 30 positive DNA samples were detected. At the same time, in order toverify the applicability of the system, 94 experimental animal lung tissue samples were detected and the results werenegative. Conclusions A rapid PCR assay for simultaneous detection of Rat coronavirus and Sendai virus is successfullyestablished. This duplex PCR assay is specific, sensitive, simple and rapid, and can be used for rapid detection of Sendai virus and Rat coronavirus simultaneously in laboratory animals.

Abstract:Objective To observe and identify the skin alterations of aged TC mice with systemic lupuserythematosus (SLE), and to explore if they can be used as an animal model for studying cutaneous lupus erythematosus.Methods To determine the age of TC mice when skin changes start to occur, and to compare the skin alterations betweenC57BL/6 and TC mice at the same age. Serum levels of anti-double-stranded (ds) DNA antibodies and anti-nuclearantibodies (ANAs) were detected by ELISA. Pathological changes in the mouse skin were detected by hematoxylin andeosin (HE) staining. Results Two-thirds of TC mice developed hair loss and skin ulceration. The lesions first occurred at40 weeks of age. Serum titers of anti-dsDNA and anti-ANA antibodies in TC mice with skin lesions were significantly higherthan those of C57BL/6 mice ( P < 0. 05).Pathological examination observed loss of stratum corneum, interruption in theepithelial layer, and extensive lymphocyte infiltration in the dermid of SLE mice. Conclusion Skin lesions occur in SLEprone TC mice after 40 weeks of age, suggesting that aged TC mice may serve as a useful animal model for studies of chronic cutaneous lupus erythematosus.

Abstract:Objective To observe the expression and explore the significance of thrombomodulin(TM) in theformation and regression of deep vein thrombosis (DVT) in rats. Methods Sprague-Dawley rats were divided randomly intotwo groups: model (n = 60) and control (n = 6) groups. A DVT model was established by stenosis (“stenosis method”)in the model group and a sham operation was performed in the control group. The rats were killed at 1, 4, 6, 12, 24 h aswell as 3, 7, 14, 21 and 28 days after modeling. The weight:length ratio of thrombi, plasma concentration of solubleTM, expression of TM mRNA in the thrombi and inferior vena cava (IVC) endothelium were measured. Results The weight:length ratio of thrombi was low in the early stage of modeling (1, 4, 6, 12 h), showing no significant differenceamong the four subgroups ( P > 0. 05). The model was stable at a higher level 24 h, 3 days and 7 days after modeling ( P >0. 05). It began to decrease 14 days after modeling, but there was no significant difference among the results at 14, 21 or28 days ( P > 0. 05). The ELISA showed that the concentration of soluble TM was significantly higher than that in thecontrol group ( P < 0. 01), and that the level of soluble TM in plasma increased gradually. The real-time fluorescencequantitative polymerase chain reaction showed that the mRNA expression of TM in thrombi increased gradually over time.Expression of TM mRNA in IVC endothelium was significantly higher at 1, 4, 6 and 12 h than that in the control group ( P < 0. 01) and significantly lower than that in the control group at 24 h, 3 days and 7 days ( P < 0. 01). There was nosignificant difference in expression of TM mRNA at 14, 21, or 28 days compared with that in the control group ( P >0. 05). A negative correlation between the weight:length ratio of thrombi and expression of TM mRNA in the IVCendothelium was determined (r = - 0. 92, P < 0. 01). However, expression of TM mRNA in thrombi was positivelycorrelated with the levels of soluble TM in plasma (r= 0. 96, P < 0. 01). Conclusions Our findings suggest that TM isinvolved in the entire process of the formation and regression of thromb, and the changes in endothelial TM expression mayreflect the occurrence and development of deep vein thrombosis,and is of a good prognostic significance.

Abstract:Objective A monoclonal antibody (Mab) against transporter associated with antigen processing (TAP)was prepared to study the function of TAP protein in the immunogenetics of ducks. Methods BALB/ c mice were immunizedwith fused Escherichia coli expression products containing peptide-binding region of TAP protein of major histocompatibilitycomplex (MHC) haplotype SPF ducks. Specific monoclonal antibodies were screened by ELISA, and truncated expressionmethod was used to identify the antigenic epitope. An indirect immunofluorescence assay was used to compare the reactivity ofMab against the peripheral blood lymphocytes of ducks and chickens. Immunohistochemistry was used to identify thespecificity of the Mab was detected against SPF chickens, SPF ducks, SPF pigs, common quails and geese. Results A duckTAP-specific monoclonal antibody was obtained and named as “1A6”. The antigenic epitope against 1A6 was identifiedroughly at 297NARHQMLQQAVLDATAGTGMVVQEAI322 by a trimmed expressed fusion protein. Chicken and duck peripheralbloodlymphocytes were tested positive for 1A6 in this indirect immunofluorescence assay. Immunohistochemistry of theduodenum from SPF chickens, SPF ducks, SPF pigs, Corturnix and geese by 1A6 was undertaken. Specific strong signals inimmunohistochemistry assay were detected in the duodenum of chickens and ducks, but not detected in the pigs, quails,geese or negative-control jejunum. Conclusions A monoclonal antibody specific to the TAP protein of chickens and ducks is obtained. It provides a useful material for studies of avian diseases and immunology of poultry.

Abstract:Objective To investigate the protective effect of tetrahydroxystilbene glucoside (TSG) on cerebral ischemia/ reperfusion (I/ R) injury in mice. Methods One-hundred mice were divided randomly into five groups of 20mice each: sham, I/ R group, and low TSG (3 mg/ kg), medium TSG (6 mg/ kg) and high TSG (12 mg/ kg) groups. Themice underwent cerebral ischemia for 2 h by ligation of bilateral common carotid arteries, and were sacrificed 24 h afterreperfusion. Pathology of the brain tissues was assessed by hematoxylin and eosin (H&E) staining. Reactive oxygen species(ROS) levels in brain tissues were measured by dihydroethidium staining and electron spin resonance spectroscopy.Expression of the proteins of NADPH oxidase (NOX) 4 and cleaved caspase (CC)-3 and CC-9 in brain tissues weredetected by Western blot. Results Compared with the sham group, there was deformation and swelling of neurons,pyknosis and anachromasis of nuclei as well as shrunken cell bodies in the I/ R group. ROS levels were increasedsignificantly, and expression of NOX4, CC-3 and CC-9 was up-regulated significantly in the I/ R group. Compared with theI/ R group, TSG expression reduced markedly the pathological damages in brain tissues after cerebral I/ R. TSG downregulatedthe protein level of NOX4 significantly according to the Western blot. Dihydroethidium staining indicated that TSGdecreased ROS levels and inhibited the activity of CC-3 and CC-9 in the ischemic cortex after reperfusion. Conclusions TSG has neuroprotective effects on cerebral I/ R injury in mice. TSG may be associated with inhibiting expression of NOX4protein, thereby reducing ROS levels, and inhibiting overexpression of the apoptosis-related proteins CC-3 and CC-9.

Abstract:Objective To investigate the effect of silencing Wnt4 on renal interstitial fibrosis (RIF) and provide atheoretical basis for the treatment of chronic kidney disease. Methods A total of 128 Sprague-Dawley rats were dividedrandomly into four groups of 32 rats each: sham operation, model, negative control and Wnt4 silencing groups. The Wnt4siRNA lentiviral vector was transfected into the silencing group in vivo and divided into four subgroups of eight rats each,at3, 7, 10 and 14 days after transfection. Renal interstitial changes and expression of β-catenin, Wnt4 and α-smooth muscleactin (SMA) were examined by pathology using H&E staining and detected by reverse transcription-polymerase chainreaction. Results The pathological examination showed no renal interstitial changes at the four time points tested in thesham operation group; renal interstitial edema and a small amount of RIF occurred in the UUO group, negative silencing,and silencing groups at 3, 10 and 14 days after modeling. The number of diffuse macrophages and infiltration of lymphocyteswere increased. The negative silencing group showed similar alterations at the UUO group. The silencing group showeddifferent degrees of RIF at the four time points tested. Wnt4 expression was significantly correlated with the expression of β-catenin mRNA ( r =0. 886, P < 0. 001). There was a significant correlation between the mRNA expressions of Wnt4 and α-SMA ( r =0. 930, P < 0. 001). Correlation analysis of mRNA expression in the silencing group after Wnt4 silencing showedthat there was no significant correlation between the mRNA expressions of Wnt4 and β-catenin ( r = 0. 204, P = 0. 263).There was a significant correlation between the mRNA expressions of Wnt4 and α-SMA ( r = 0. 753, P < 0. 001).Conclusion Silencing Wnt4 can significantly inhibit RIF in rats, and may have therapeutic effects.

Abstract:Objective To study the protective effect of recombinant rat Club cell 16 (rCC16) protein on lunginjury and expressions of matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 in micesuffering from chronic obstructive pulmonary disease (COPD). Methods C57BL/6 mice (n =40) were randomly dividedinto four groups: blank, COPD model, rCC16 treatment 1, and rCC16 treatment 2 groups. The mice were exposed totobacco smoke for 3 months to create a COPD model. The blank-group mice were exposed to room air. When the model wasstable, mice in the blank and model groups were administered phosphate-buffered saline (PBS; i.n.), and mice in theother two groups were treated with rCC16 (1. 0 or 2. 5 μg/ g body weight, i.n., respectively). The mental state, diet, bodyweightchanges and urine of mice were observed. Histological changes in the lung tissues in different groups were observedwith hematoxylin and eosin staining. mRNA and protein levels of MMP-9 and TIMP-1 were analyzed by quantitative reversetranscription-polymerase chain reaction and immunohistochemistry. Results Body weights in the COPD group weredecreased compared with those in the blank group, which were increased with the feeding period. Body weights in therCC16 treatment 2 group were increased obviously, whereas the body weights in the rCC16 treatment 1 group increased moreslowly, and the differences were significant ( P < 0. 05). Lung structure in the COPD group was changed with widenedinteralveolar septa and development of emphysema. rCC16 treatment alleviated those pulmonary alterations and reduced theformation of pulmonary bullae. The expressions of MMP-9 and TIMP-1 were significantly higher than those in the blankgroup ( P < 0. 05). rCC16 treatment inhibited the expressions of MMP-9 and TIMP-1, which were overexpressed in theCOPD group, and the differences were significant ( P < 0. 05). Moreover, the rCC16’s regulation on MMP-9 expressionwas dose-dependent. Conclusions Intranasal administration of rCC16 reduces the pulmonary injury and expressions ofMMP-9 and TIMP-1 in lung tissues of COPD mice. Our results demonstrate that rCC16 has a promising therapeutic effect against COPD.

Abstract:Objective To study the diversity of intestinal flora in commonly used SPF mice and rats. MethodsThe cecum contents of C57BL/6, ICR, BALB/ c mice as well as Wistar and SD rats were collected from three experimentalanimal production units in the Guangdong area. The V4-V5 region was amplified using 16S rDNA primers and sequenced bythe Illumina Miseq 2x 300 bp sequencing platform. Microbial community analysis, alpha diversity analysis, and betadiversity analysis were carried out by bioinformatics. Results In OTU cluster analysis after sequence removal optimization,the dilution curve indicated that the data quantity of the sequencing was reasonable. The intestinal microflora of mice andrats were divided into eight phyla. Bacteroidetes and Firmicute phyla occupied the main position, mainly in the level ofBacteroides, followed by the genuses Hungatella and Parabacteroides and then Lactobacillus. Analysis of the differencesamong the samples showed that the flora composition of animals from the same facility, and that of the same strains from thesame facility was also similar. Alpha analysis showed that the species richness was similar in animals from the same facility,and beta analysis showed little difference in intestinal flora of the same origin animals. Moreover, the strain had an effect onthe difference of intestinal flora. Conclusions The origin is the main factor influencing the diversity of intestinal flora, and the strain has a certain influence on their diversity.

Abstract:Objective To evaluate the effects of sampling parameters on electrocardiogram (ECG) waveforms inmice. Methods C57 mice were anesthetized with sodium pentobarbital and needle electrodes were placed subcutaneouslyin their limbs. ECG signals were sampled, recorded and analyzed with different sampling parameters using a RM6240BDmulti-channel physiological recording system. Results The sampling rate, low-pass filter, time constant, and notch filterhad different effects on ECG waveforms. Some parameters led to various deformation and distortion of the ECG signals.Conclusions Appropriate sampling parameters should be applied in ECG experiments in mice to obtain accurate results.An improved surgical technique is preferred to acquire stable ECG signals instead of filtering or digital smoothing.

Abstract:Vertebrate development begins with the patterning of the body axis, which is one of the most significantevents during early embryonic development. Previous genetic evidences suggest that Wnt, bone morphogenic protein(BMP), Nodal, and fibroblast growth factor (FGF) signaling networks act together to control the complex morphogeneticcell movements, development of the three germ layers, and establishment of dorsal-ventral, anterior-posterior, and left-rightaxes. In this review, we focus on the molecular nature of dorsal-ventral patterning in the zebrafish embryo, including a briefintroduction of the dorsal organizer, the molecular mechanisms of the Wnt/ β-catenin signaling pathway in dorsal organizerformation, and the molecular mechanisms of BMP signaling in establishment of the dorsal-ventral axis. Finally, we discuss the future directions of dorsal-ventral patterning research.

Abstract:Zebrafish has been widely used as an animal model for human disease research and drug screening.Bone disease models have been successfully established in zebrafish because of its highly conserved molecular mechanism of osteogenesis with mammals. Here, we introduce the processes and regulatory networks of zebrafish osteogenesis, and then summarize the classical method for zebrafish bone research and the research status of drug screening for bone diseases. This information will provide a reference for drug screening and basic research using zebrafish bone disease models.

Abstract:Influenza A viruses (IAVs) infect humans and animals, and pose continuous threats to public health.Animal models have pivotal roles in IAV research, and different animal models have different advantages and limitations.We focused on the advantages and disadvantages of the use of ferrets, and compared them with those of mice, guinea pigs,and non-human primate models. We highlighted the important role of ferrets in IAV research. This paper briefly reviews theresearch progress in use of ferret models in the studies of pathogenesis, transmission and evaluation of IAVs. As such, it provides references for the basic and applied research of IAVs.

Abstract:Zebrafish (Danio rerio) is a powerful model animal for studies on host-pathogen interactions. Because ofits optical transparency, the zebrafish larval infection model facilitates exploring the pathogenesis of Mycobacterium infectionin vivo in real time. In addition, the immune system of zebrafish larvae provides the conditions to explore the mechanisms ofimmune interactions between Mycobacterium marinum and the host. It is also popular because of its short developmentcycle, high reproductive yield, and low feeding conditions. Mycobacterium marinum is an alternative bacterium fortuberculosis research, because of its simple environmental requirements and high genetic similarity with Mycobacteriumtuberculosis. Therefore, the zebrafish-Mycobacterium marinum infection model has become one of the most effective research tools to reveal the pathogenesis of tuberculosis and develop drugs.

Abstract:Leukemia is often referred to as a “blood cancer”. The basic characteristic of the disease is thatleukemic cells become malignant and cause unrestricted proliferation in the bone marrow and other hematopoietic tissues.Then, these cells infiltrate all tissues and organs of the body causing various symptoms, and make patients prone to seriousinfections and life-threatening complications such as sepsis, hemorrhage, intestinal failure or hyperuricemia. Therefore,research on the treatment of leukemia using laboratory animal models is of great significance. For the study of leukemia,mice are similar to humans in terms of biology, genetics, and hematopoietic systems, and are, therefore, ideal models forleukemia research. This article reviews the mouse models of leukemia used commonly in studies both in China and abroad in the past 5 years.