Contagious bovine Pleuropneumonia (CBPP) is an infectious and highly contagious respiratory disease of cattle and water buffalo, caused by the Mycoplasma mycoides subspecies mycoides. It induces significant economic l...Contagious bovine Pleuropneumonia (CBPP) is an infectious and highly contagious respiratory disease of cattle and water buffalo, caused by the Mycoplasma mycoides subspecies mycoides. It induces significant economic losses and leads to a severe livestock production problem, negatively influencing people’s livelihoods of affected countries. In Somalia, there is no updated data on the prevalence and distribution of the disease. Hence, a descriptive cross-sectional study was conducted from September 2022 to June 2023 in different villages under the Afgoye District of lower Shabelle region, Somalia. The main purpose of this study is to assess the sero-prevalence and identify the associated risk factors for the occurrence of the disease. In this study, villages, age, sex, breed, and body condition were considered as risk factors. A total of 90 blood samples were collected and tested in the laboratory using the Anti-CBPP Elisa kit test. Out of 90 serum samples from herd cattle, 32 were positive, resulting in an overall prevalence of 35.5%. In addition, we found a statistically significant variation between the prevalence of the disease and factors such as sex, age, body condition and breeds. In summary, the overall prevalence of Contagious bovine pleuropneumonia in this study area is worth to be considered because there is a low quality of health care and less awareness of the Contagious bovine Pleuropneumonia effects on herds, which warrants the official authorities to act and follow appropriate preventive and control measures to reduce the incidence of the disease and generate appropriate controlling and prevention measures in all regions of Somalia.展开更多
Bovine tuberculosis (bTB) is an endemic zoonosis significantly affects animal health in Burkina Faso. The primary causative agent is Mycobacterium tuberculosis (M. tuberculosis) complex, mainly M. bovis. Cattle are co...Bovine tuberculosis (bTB) is an endemic zoonosis significantly affects animal health in Burkina Faso. The primary causative agent is Mycobacterium tuberculosis (M. tuberculosis) complex, mainly M. bovis. Cattle are considered as natural reservoir of M. bovis. However, in Burkina Faso, the circulation of these strains remains poorly understood and documented. This study aimed to identify and characterize Mycobacterium strains from suspected carcasses during routine meat inspection at Bobo-Dioulasso refrigerated slaughterhouse. A prospective cross-sectional study was conducted from January 2021 to December 2022 on cases of seizures linked to suspected bovine tuberculosis. Microbiological and molecular analyzes were used for mycobacterial strain isolation and characterization. Out of 50 samples, 24% tested positive by microscopy and 12% by culture. Molecular analysis identified 6 strains of Mycobacteria, exclusively Mycobacterium bovis specifically the subspecies bovis (Mycobacterium bovis subsp bovis). In conclusion, M. bovis subsp bovis is the primary agent responsible for bovine tuberculosis in Bobo-Dioulasso. Continuous monitoring of mycobacterial strains is therefore necessary for the effective control of this pathology in the local cattle population.展开更多
Transmissible spongiform encephalopathies(TSEs)are a group of progressive and ultimately fatal neurologic diseases of man and animals,all resulting from the propagated misfolding of the host's normal cellular prio...Transmissible spongiform encephalopathies(TSEs)are a group of progressive and ultimately fatal neurologic diseases of man and animals,all resulting from the propagated misfolding of the host's normal cellular prion protein.These diseases can be spontaneous,heritable,anthropogenic/iatrogenic,or in some cases horizontally transmissible,and include such notable TSEs as bovine spongiform encephalopathy(BSE)of cattle and chronic wasting disease(CWD)of cervids.Although they are both unequivocally protein misfolding disorders,they differ markedly in their pathogenesis,transmissibility,and zoonotic potential.While the BSE epidemic has largely abated over the past three decades following global feed bans on ruminant meat and bone meal,CWD,which is readily transmitted through various forms of excreta,has rapidly expanded from its original endemic zone to encompass much of North America,along with recently identified foci in Scandinavia.Most importantly,although the classical form of BSE has proven transmissible to humans consuming contaminated beef or beef products,so far there have been no conclusive reports on the zoonotic transmission of cWD to humans.The underlying basis for these differences-whether host or agent directed-are not well understood,though may be due to inherent differences in the three-dimensional structure of the misfolded BSE or CWD prion proteins or the expression levels and tissue distribution of respective cellular prion proteins.With the uncontrolled geographic spread of CWD,it is imperative that we improve our understanding of the factors governing prion disease pathogenesis,transmission,and zoonotic potential.展开更多
Bovine coronavirus(BCoV)poses a significant threat to the global cattle industry,causing both respiratory and gastrointestinal infections in cattle populations.This necessitates the development of efficacious vaccines...Bovine coronavirus(BCoV)poses a significant threat to the global cattle industry,causing both respiratory and gastrointestinal infections in cattle populations.This necessitates the development of efficacious vaccines.While several inactivated and live BCoV vaccines exist,they are predominantly limited to calves.The immunization of adult cattle is imperative for BCoV infection control,as it curtails viral transmission to calves and ameliorates the impact of enteric and respiratory ailments across all age groups within the herd.This study presents an in silico methodology for devising a multiepitope vaccine targeting BCoV.The spike glycoprotein(S)and nucleocapsid(N)proteins,which are integral elements of the BCoV structure,play pivotal roles in the viral infection cycle and immune response.We constructed a remarkably effective multiepitope vaccine candidate specifically designed to combat the BCoV population.Using immunoinformatics technology,B-cell and T-cell epitopes were predicted and linked together using linkers and adjuvants to efficiently trigger both cellular and humoral immune responses in cattle.The in silico construct was characterized,and assessment of its physicochemical properties revealed the formation of a stable vaccine construct.After 3D modeling of the vaccine construct,molecular docking revealed a stable interaction with the bovine receptor bTLR4.Moreover,the viability of the vaccine’s high expression and simple purification was demonstrated by codon optimization and in silico cloning expression into the pET28a(+)vector.By applying immunoinformatics approaches,researchers aim to better understand the immune response to bovine coronavirus,discover potential targets for intervention,and facilitate the development of diagnostic tools and vaccines to mitigate the impact of this virus on cattle health and the livestock industry.We anticipate that the design will be useful as a preventive treatment for BCoV sickness in cattle,opening the door for further laboratory studies.展开更多
Background Hesperidin is a citrus flavonoid with anti-inflammatory and antioxidant potential. However, its protective effects on bovine mammary epithelial cells(b MECs) exposed to oxidative stress have not been elucid...Background Hesperidin is a citrus flavonoid with anti-inflammatory and antioxidant potential. However, its protective effects on bovine mammary epithelial cells(b MECs) exposed to oxidative stress have not been elucidated.Results In this study, we investigated the effects of hesperidin on H_(2)O_(2)-induced oxidative stress in b MECs and the underlying molecular mechanism. We found that hesperidin attenuated H_(2)O_(2)-induced cell damage by reducing reactive oxygen species(ROS) and malondialdehyde(MDA) levels, increasing catalase(CAT) activity, and improving cell proliferation and mitochondrial membrane potential. Moreover, hesperidin activated the Keap1/Nrf2/ARE signaling pathway by inducing the nuclear translocation of Nrf2 and the expression of its downstream genes NQO1 and HO-1, which are antioxidant enzymes involved in ROS scavenging and cellular redox balance. The protective effects of hesperidin were blocked by the Nrf2 inhibitor ML385, indicating that they were Nrf2 dependent.Conclusions Our results suggest that hesperidin could protect b MECs from oxidative stress injury by activating the Nrf2 signaling pathway, suggesting that hesperidin as a natural antioxidant has positive potential as a feed additive or plant drug to promote the health benefits of bovine mammary.展开更多
Objective:To evaluate the therapeutic effect of recombinant bovine basic fibroblast growth factor(rbFGF)eye gel combined with tobramycin-dexamethasone(TOB-Dex)eye drops on dry eye syndrome(DES)after cataract surgery.M...Objective:To evaluate the therapeutic effect of recombinant bovine basic fibroblast growth factor(rbFGF)eye gel combined with tobramycin-dexamethasone(TOB-Dex)eye drops on dry eye syndrome(DES)after cataract surgery.Methods:86 patients with DES after cataract surgery,admitted from November 2021 to November 2023,were randomly divided into groups.The observation group included 43 patients treated with rbFGF eye gel combined with TOB-Dex eye drops.The reference group included 43 patients treated with TOB-Dex eye drops alone.Multiple indicators,including total effective rate and clinical symptom scores,were compared between the two groups.Results:The total effective rate in the observation group was higher than in the reference group(P<0.05).Before treatment,there were no differences in clinical symptom scores,serum factors,or disease severity scores between the two groups(P>0.05).Three weeks after treatment,the observation group had lower clinical symptom scores,serum factors,and disease severity scores compared to the reference group(P<0.05).The adverse reaction rate in the observation group was lower than in the reference group(P<0.05).Conclusion:rbFGF eye gel combined with TOB-Dex eye drops can improve the clinical efficacy for patients with DES after cataract surgery,alleviate disease symptoms,reduce inflammatory responses,and have fewer adverse reactions.展开更多
Background MicroRNAs(miRNAs)are small,single-stranded,non-coding RNA molecules of 22–24 nucleotides that regulate gene expression.In the last decade,miRNAs have been described in sperm of several mammals,including ca...Background MicroRNAs(miRNAs)are small,single-stranded,non-coding RNA molecules of 22–24 nucleotides that regulate gene expression.In the last decade,miRNAs have been described in sperm of several mammals,including cattle.It is known that miRNAs can act as key gene regulators of early embryogenesis in mice and humans;however,little is known about the content,expression,and function of sperm-borne miRNAs in early bovine embryo.In this study,total sperm RNA was isolated from 29 cryopreserved sperm samples(each coming from a separate bull)using a RNeasy kit and treatment with DNase I.RNA concentration and purity were determined through an Epoch spectrophotometer and an Agilent Bioanalyzer.The expression of 10 candidate miRNAs in bovine sperm(bta-miR-10a,bta-miR-10b,bta-miR-138,bta-miR-146b,bta-miR-19b,bta-miR-26a,bta-miR-34a,bta-miR-449a,bta-miR-495 and btamiR-7),previously identified in testis and/or epididymis,was evaluated with RT-qPCR.The cel-miR-39-3p was used as a spike-in exogenous control.Nonparametric Mann–Whitney tests were run to evaluate which miRNAs were differentially expressed between bulls with high fertility[HF;non-return rates(NRR)ranging from 39.5 to 43.5]and those with subfertility(SF;NRR ranging from 33.3 to 39.3).Several sperm functionality parameters(e.g.,viability,membrane stability or oxygen consumption,among others)were measured by multiplexing flow cytometry and oxygen sensing technologies.Results RNA concentration and purity(260/280 nm ratio)(mean±SD)from the 29 samples were 99.3±84.6 ng/μL and 1.97±0.72,respectively.Bioanalyzer results confirmed the lack of RNA from somatic cells.In terms of the presence or absence of miRNAs,and after applying the Livak method,8 out of 10 miRNAs(bta-miR-10b,-138,-146b,-19b,-26a,-449a,-495,-7)were consistently detected in bovine sperm,whereas the other two(bta-miR-10a,and-34a)were absent.Interestingly,the relative expression of one miRNA(bta-miR-138)in sperm was significantly lower in the SF than in the HF group(P=0.038).In addition to being associated to fertility potential,the presence of this miRNA was found to be negatively correlated with sperm oxygen consumption.The expression of three other miRNAs(bta-miR-19b,bta-miR-26a and bta-miR-7)was also correlated with sperm function variables.Conclusions In conclusion,although functional validation studies are required to confirm these results,this study suggests that sperm bta-miR-138 is involved in fertilization events and beyond,and supports its use as a fertility biomarker in cattle.展开更多
Awdal region is the most northwesterly province of Somaliland. The region is one of the agro-pastoral livelihood zones in Somaliland, where farming and agricultural production are the predominant livelihood sources. I...Awdal region is the most northwesterly province of Somaliland. The region is one of the agro-pastoral livelihood zones in Somaliland, where farming and agricultural production are the predominant livelihood sources. IGAD (Intergovernmental Authority on Development) Sheikh Technical University of Science (ISTUS) worked to study the prevalence of Bovine Tuberculosis (TB) among cattle in Awdal region of Somaliland. The aim was to inform public health and Veterinary experts on having one-health approach to infectious diseases among humans and animals. The serum that was stored at -20?C was transported to IGAD Sheikh Technical University of Science (ISTUS) for further analysis using BOVIGAM serological test (Sandwich ELISA). The results indicate that Bovine Tuberculosis is highly prevalent in the study area (10.1%). The high prevalence recorded in the current study could be due to the consumption of raw milk and lack of proper control strategies in place to control the transmission of the disease between animals, between animals and wildlife and between animals and humans. Hence, an awareness creation campaign should be created on bTB transmission and its public health significance to cattle owners, milk and meat consumers and people who are in close proximity to cattle. In addition, testing and eradication programme should be implemented where applicable.展开更多
Brucellosis is an infectious disease of worldwide distribution, which has a great economic impact due to the productive and reproductive losses that it causes, in addition to the serious public health problem. The aim...Brucellosis is an infectious disease of worldwide distribution, which has a great economic impact due to the productive and reproductive losses that it causes, in addition to the serious public health problem. The aim of this study is to estimate the economic losses, through financial analysis, caused by bovine brucellosis in the province of Carchi, over a one-year period. A random sampling was used to determine the prevalence in the study area, where 2976 animals were considered, and the Rose Bengal (RB) test was used as a screening test and the Fluorescence Polarized Assay (FPA) as a confirmatory test, obtaining a prevalence of 8.2% (244/2976). In addition, parameters associated to the losses caused by brucellosis in cattle were determined by literature review. To estimate costs, field information was collected through a survey of a total of 100 randomly selected farmers. The loss estimated due to calves lost as a result of abortions and neonatal death was USD. 79170.00. The loss due to death of 4 cows as a result of metritis was estimated at USD. 5000.00. The cost of examination and treatment of aborted cows was USD. 20100.00. The losses due to reduction in milk production from aborted and non-aborted seropositive cows were estimated at USD. 158114.21. The financial losses due to brucellosis in province of Carchi were estimated at USD. 262384.21.展开更多
Background Mammary gland(MG)infections(mastitis)are frequent diseases of dairy cows that affect milk quality,animal welfare and farming profitability.These infections are commonly associated with the bacteria Escheric...Background Mammary gland(MG)infections(mastitis)are frequent diseases of dairy cows that affect milk quality,animal welfare and farming profitability.These infections are commonly associated with the bacteria Escherichia coli and Staphylococcus aureus.Different in vitro models have been used to investigate the early response of the MG to bacteria,but the role of the teat in mastitis pathogenesis has received less attention.In this study,we used punch-excised teat tissue as an ex vivo model to study the immune mechanisms that arise early during infection when bacteria have entered the MG.Results Cytotoxicity and microscopic analyses showed that bovine teat sinus explants have their morphology and viability preserved after 24 h of culture and respond to ex vivo stimulation with TLR-agonists and bacteria.LPS and E.coli trigger stronger inflammatory response in teat when compared to LTA and S.aureus,leading to a higher produc-tion of IL-6 and IL-8,as well as to an up-regulation of proinflammatory genes.We also demonstrated that our ex vivo model can be applied to frozen-stored explants.Conclusions In compliance with the 3Rs principle(replacement,reduction and refinement)in animal experimenta-tion,ex vivo explant analyses proved to be a simple and affordable approach to study MG immune response to infec-tion.This model,which better reproduces organ complexity than epithelial cell cultures or tissue slices,lends itself particularly well to studying the early phases of the MG immune response to infection.展开更多
Background:Capacitation is a set of physiological changes sperms undergo to acquire fertilizing capacity.In vivo,this process is directly associated with high calcium levels in sperm cytoplasm.Calcitriol,the vitamin D...Background:Capacitation is a set of physiological changes sperms undergo to acquire fertilizing capacity.In vivo,this process is directly associated with high calcium levels in sperm cytoplasm.Calcitriol,the vitamin D hypercalcemic metabolite,is related to human sperm motility,capacitation,and acrosome reaction.This work aimed to study the effect of calcitriol on bull sperm quality parameters and capacitation.Methods:One million freezethawed spermatozoa were obtained from different bulls and treated with 20 nM of calcitriol for 30 min.Untreated cells(negative control)and treated ones with calcitriol or heparin(100μg/mL,positive capacitation control)were evaluated for motility,viability,and functional parameters.Menadione(70μM,30 min)treatment was included as a reactive oxygen species(ROS)positive sperm agent.Results:The results elucidated that sperm exposed to 20 nM calcitriol showed higher viability,vigor,and capacitation than their positive and negative controls.The percentage of sperm with intact plasma and acrosome membranes,mitochondrial membrane potential(ΔΨm),and phosphatidylserine externalization was similar in all the conditions evaluated,while ROS production was higher with heparin and menadione-treated groups than the calcitriol group or negative control.Conclusion:Our results indicate that calcitriol induces the capacitation of thawed bull spermatozoa and maintains acceptable values of progressive motility,viability,and vigor without altering key biological parameters such as redox status,ΔΨm,and cell death.展开更多
Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and ass...Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and associated economic losses for the herd owner.This study was designed to investigate the relationship between milk and serum antibody tests for bTB in dairy cows using 85 cows with milk and corresponding blood samples.Totally 4,395 milk samples were used to assesse the apparent(test)prevalence and incidence of bTB using the milk antibody ELISA.The association between levels of bTB milk antibody and milk quality was also evaluated.Milk and serum antibody tests showed a good correlation with a 87.5%(95%CI:61.7%,98.4)positive agreement and 98.7%(95%CI:95.4,99.8)negative agreement.The animal level lactoprevalence ranged from 0.3%(95%CI:0,1.2)to 33.3%(95%CI:26.6,40.6)in different farms and the incidence rate ranged from 0 head/cow-month(95%CI:0,0.02)to 0.04 head/cow-month(95%CI:0.02,0.07).Twenty percent of sampled farms met the criteria for bTB control in China.The prevalence on large-scale farms was lower(p<0.001)than on small farms.The bTB milk antibody levels had a negative correlation with milk yield and a positive correlation with somatic cell count(SCC),milk protein percentage(MPP)and percentage of total solids(TS).According to this research,milk ELISA could be used as a supplement of blood samples to assist in the surveillance for bTB and for alerting control and eradication of bTB.展开更多
This study aimed to analyze and compare the differentially expressed whey proteins(DEWPs)of donkey and bovine colostrum using high-performance liquid chromatography with tandem mass spectrometry-based proteomics.A tot...This study aimed to analyze and compare the differentially expressed whey proteins(DEWPs)of donkey and bovine colostrum using high-performance liquid chromatography with tandem mass spectrometry-based proteomics.A total of 620 and 696 whey proteins were characterized in the donkey and bovine colostrum,respectively,including 383 common whey proteins.Among these common proteins,80 were identified as DEWPs,including 21 upregulated and 59 downregulated DEWPs in donkey colostrum compared to bovine colostrum.Gene Ontology analysis revealed that these DEWPs were mainly related to cellular components,such as extracellular exosome,plasma membrane,and mitochondrion;biological processes,such as oxidation-reduction process,cell-cell adhesion,and small guanosine triphosphate(GTP)ase-mediated signal transduction;and molecular functions,such as GTP binding,GTPase activity,and soluble N-ethylmaleimide-sensitive factor(NSF)attachment protein receptor activity.Metabolic pathway analysis suggested that the majority of the DEWPs were associated with soluble NSF factor attachment protein receptor interactions in vesicular transport,fatty acid biosynthesis,and estrogen signaling pathways.Our results provide a vital insight into the differences between donkey and bovine colostrum,along with important information on the significant components as nutritional and functional factors to be included in infant formula based on multiple milk sources.展开更多
Taking the qualified bovine placenta as the research object,a series of pure physical separation and extraction processes such as tissue fragmentation,ultrasound,freeze-thawed,centrifugation and filtration were used t...Taking the qualified bovine placenta as the research object,a series of pure physical separation and extraction processes such as tissue fragmentation,ultrasound,freeze-thawed,centrifugation and filtration were used to prepare the bovine placental bioactive proteins.The results of protein concentration showed that bovine placental bioactive proteins prepared in this study could reach(11.33±2.09)mg/mL under optimal experimental condition.The determination of specific components showed that there were abundant exosome like vesicles in the product with particle size ranging from 30 to 150 nm,pie structure under transmission electron microscope and expressing CD9,CD63 and TSG101 by western blot detection.The results of cell efficacy evaluation showed that bovine placental bioactive proteins could significantly promote the proliferation of human skin fibroblasts and had anti-inflammatory effect via down-regulating IL-6 and TNF-αexpressionin RAW264.7 cells.展开更多
Aim To study the reaction mechanism between gatifloxacin and bovine serumalbumin (BSA) at different pHs. Methods Fluorescence spectra and UV absorbance spectra were used.Results The binding constants were determined f...Aim To study the reaction mechanism between gatifloxacin and bovine serumalbumin (BSA) at different pHs. Methods Fluorescence spectra and UV absorbance spectra were used.Results The binding constants were determined from a double reciprocal Lineweaver-Burk curves atdifferent pHs. The binding distance r under normal physiological condition was obtained according toFoster theory of non-radiative energy transfer. The binding force between gatifloxacin and BSA wasinferred by thermody-namical coordination. Conclusion The interaction between gatifloxacin and BSAseems to be strong and the main binding force is electrostatic force.展开更多
[ Objective] To investigate the feasibility of the primary culture of bovine mammary epithelial cells in biochemical incubator. [ Method] In vitro, bovine mammary epithelial cells were isolated and cultured by the tis...[ Objective] To investigate the feasibility of the primary culture of bovine mammary epithelial cells in biochemical incubator. [ Method] In vitro, bovine mammary epithelial cells were isolated and cultured by the tissue explant method in order to investigate the optimal culture conditions. The morphology observation and identification of the cultured cells were performed by inverted microscope observation, Giemsa staining and cytokeratin immunohistochemistry. [ Result] Observed with inverted microscope, most of the bovine mammary epithelial cells were polygonal and displayed typical slabstone-like appearance. As it can be seen from cell staining results, the cell body was big and the nucleus was stained dark blue and was round or oval in shape, with clearly visible nucleoli, generally 2 -4 nucleoli. The tissue-specific expression of cytokeratin 14 and cytokeratin 18 genes in mammary epithelial cells was identified by cytokeratin immunohistochemistry. [ Conclusion] Primary bovine mammary epithelial cells were successfully cultured in biochemical incubator.展开更多
Objective] This study aimed to develop a reverse transcription loop-medi-ated isothermal amplification (RT-LAMP) method for detecting BVDV. [Method] Since gp48 gene of BVDV is among the most conserved regions, a set...Objective] This study aimed to develop a reverse transcription loop-medi-ated isothermal amplification (RT-LAMP) method for detecting BVDV. [Method] Since gp48 gene of BVDV is among the most conserved regions, a set of four primers was designed to amplify six target sequences at the gp48 gene region for the RT-LAMP assay. The optimization of the RT-LAMP reaction was performed by evaluat-ing reaction temperature and reaction time. [Result] The RT-LAMP aasay was suc-cessful y conducted at 56 ℃ within 40 min under isothermal conditions, and the re-sults could be detected as ladder-like bands using agarose gel electrophoresis. The RT-LAMP assay is highly sensitive and able to detect 3.74 ×100 copies/μl of BVDV RNA, as no cross-reaction was observed with other viruses. [Conclusion] Overal , the newly established RT-LAMP assay indicates the potential application in both clinical diagnosis and field surveil ance of BVDV.展开更多
The aim of this work was to improve the rate of conventionally blind enucleation for bovine somatic cell nuclear transfer. The cross section of a 0.5 ml Eppendorf tube was attached with a sheet of 400 mesh/inch2-cell ...The aim of this work was to improve the rate of conventionally blind enucleation for bovine somatic cell nuclear transfer. The cross section of a 0.5 ml Eppendorf tube was attached with a sheet of 400 mesh/inch2-cell screen after the bottom of the Eppendorf tube had been cut, and put into a 1 mL Eppendorf tube. In experiment 1, the oocytes in the metaphase Ⅱ stage were placed on the membrane in the Eppendorf tube, and centrifuged at 1,000, 2,000, or 3,000 r/min for 10 min, respectively. The oocytes were stained with Hoechst 33342 and then the relative position of the first polar body to the chromosomes, and the efficiency of enucleation were evaluated. In experiment 2, enucleated oocytes were fused with granulosa cells, following centrifugation and enucleation, and the potential development of the reconstituted embryos was estimated. The results indicated that the rate of enucleation in oocytes after centrifugation at 2,000 r/min for 10 min was 86.6% with an angle less then 20° between the first polar body and chromosomes. The rate of enucleation in cells spun at 2,000 r/min was higher than that of controls (87.4% vs. 64.4%, P 〈 0.05). Fur- thermore; centrifugation of recipient oocytes did not have a detrimental effect on the development of reconstituted embryos following nuclear transfer. In conclusion, centrifugation assisted enucleation may significantly improve the rate of bovine oocyte enucleation.展开更多
[Objective] This study aimed to construct a full-length bovine TLR2 expression plasmid pEGFP-N1-boTLR2 and express it in HEK293 cells. [Method] A fulllength coding sequence of bovine TLR2 was cloned by RT-PCR, and lig...[Objective] This study aimed to construct a full-length bovine TLR2 expression plasmid pEGFP-N1-boTLR2 and express it in HEK293 cells. [Method] A fulllength coding sequence of bovine TLR2 was cloned by RT-PCR, and ligated into the pMD18-T simple vector and then subcloned into the pEGFP-N1 vector. A recombinant eukaryotic expression plasmid containing the full-length CDS region of bovine TLR2 was constructed and transiently transfected into HEK293 cells. The transfection efficiency and the location of recombinant protein were examined by FCM and confocal microscopy. Then the bovine TLR2 mRNA expression in HEK293/boTLR2 was detected by qRT-PCR. Finally, we analyzed the biological activity through the response that lipoteichoic acid stimulates HEK293/boTLR2 cells. [Result] The full-length TLR2 gene was successfully cloned and ligated into eukaryotic expression vector. The recombinant expression vector expressed bovine TLR2 in HEK293 cells. HEK293/boTLR2 cells produced higher levels of IL-8 secretion than nontransfected HEK293 cells when stimulated with LTA from Staphylococcus aureus. [Conclusion] The established cell model can provide a fast, flexible and convenient means for screening TLR agonists and antagonists, and may also be useful for investigating the interaction between TLR agonists and TLRs.展开更多
文摘Contagious bovine Pleuropneumonia (CBPP) is an infectious and highly contagious respiratory disease of cattle and water buffalo, caused by the Mycoplasma mycoides subspecies mycoides. It induces significant economic losses and leads to a severe livestock production problem, negatively influencing people’s livelihoods of affected countries. In Somalia, there is no updated data on the prevalence and distribution of the disease. Hence, a descriptive cross-sectional study was conducted from September 2022 to June 2023 in different villages under the Afgoye District of lower Shabelle region, Somalia. The main purpose of this study is to assess the sero-prevalence and identify the associated risk factors for the occurrence of the disease. In this study, villages, age, sex, breed, and body condition were considered as risk factors. A total of 90 blood samples were collected and tested in the laboratory using the Anti-CBPP Elisa kit test. Out of 90 serum samples from herd cattle, 32 were positive, resulting in an overall prevalence of 35.5%. In addition, we found a statistically significant variation between the prevalence of the disease and factors such as sex, age, body condition and breeds. In summary, the overall prevalence of Contagious bovine pleuropneumonia in this study area is worth to be considered because there is a low quality of health care and less awareness of the Contagious bovine Pleuropneumonia effects on herds, which warrants the official authorities to act and follow appropriate preventive and control measures to reduce the incidence of the disease and generate appropriate controlling and prevention measures in all regions of Somalia.
文摘Bovine tuberculosis (bTB) is an endemic zoonosis significantly affects animal health in Burkina Faso. The primary causative agent is Mycobacterium tuberculosis (M. tuberculosis) complex, mainly M. bovis. Cattle are considered as natural reservoir of M. bovis. However, in Burkina Faso, the circulation of these strains remains poorly understood and documented. This study aimed to identify and characterize Mycobacterium strains from suspected carcasses during routine meat inspection at Bobo-Dioulasso refrigerated slaughterhouse. A prospective cross-sectional study was conducted from January 2021 to December 2022 on cases of seizures linked to suspected bovine tuberculosis. Microbiological and molecular analyzes were used for mycobacterial strain isolation and characterization. Out of 50 samples, 24% tested positive by microscopy and 12% by culture. Molecular analysis identified 6 strains of Mycobacteria, exclusively Mycobacterium bovis specifically the subspecies bovis (Mycobacterium bovis subsp bovis). In conclusion, M. bovis subsp bovis is the primary agent responsible for bovine tuberculosis in Bobo-Dioulasso. Continuous monitoring of mycobacterial strains is therefore necessary for the effective control of this pathology in the local cattle population.
基金funded in part by the Center on Emerging and Zoonotic Infectious Diseases(CEZID)of the National Institutes of General Medical Sciences underaward number P20GM130448.
文摘Transmissible spongiform encephalopathies(TSEs)are a group of progressive and ultimately fatal neurologic diseases of man and animals,all resulting from the propagated misfolding of the host's normal cellular prion protein.These diseases can be spontaneous,heritable,anthropogenic/iatrogenic,or in some cases horizontally transmissible,and include such notable TSEs as bovine spongiform encephalopathy(BSE)of cattle and chronic wasting disease(CWD)of cervids.Although they are both unequivocally protein misfolding disorders,they differ markedly in their pathogenesis,transmissibility,and zoonotic potential.While the BSE epidemic has largely abated over the past three decades following global feed bans on ruminant meat and bone meal,CWD,which is readily transmitted through various forms of excreta,has rapidly expanded from its original endemic zone to encompass much of North America,along with recently identified foci in Scandinavia.Most importantly,although the classical form of BSE has proven transmissible to humans consuming contaminated beef or beef products,so far there have been no conclusive reports on the zoonotic transmission of cWD to humans.The underlying basis for these differences-whether host or agent directed-are not well understood,though may be due to inherent differences in the three-dimensional structure of the misfolded BSE or CWD prion proteins or the expression levels and tissue distribution of respective cellular prion proteins.With the uncontrolled geographic spread of CWD,it is imperative that we improve our understanding of the factors governing prion disease pathogenesis,transmission,and zoonotic potential.
文摘Bovine coronavirus(BCoV)poses a significant threat to the global cattle industry,causing both respiratory and gastrointestinal infections in cattle populations.This necessitates the development of efficacious vaccines.While several inactivated and live BCoV vaccines exist,they are predominantly limited to calves.The immunization of adult cattle is imperative for BCoV infection control,as it curtails viral transmission to calves and ameliorates the impact of enteric and respiratory ailments across all age groups within the herd.This study presents an in silico methodology for devising a multiepitope vaccine targeting BCoV.The spike glycoprotein(S)and nucleocapsid(N)proteins,which are integral elements of the BCoV structure,play pivotal roles in the viral infection cycle and immune response.We constructed a remarkably effective multiepitope vaccine candidate specifically designed to combat the BCoV population.Using immunoinformatics technology,B-cell and T-cell epitopes were predicted and linked together using linkers and adjuvants to efficiently trigger both cellular and humoral immune responses in cattle.The in silico construct was characterized,and assessment of its physicochemical properties revealed the formation of a stable vaccine construct.After 3D modeling of the vaccine construct,molecular docking revealed a stable interaction with the bovine receptor bTLR4.Moreover,the viability of the vaccine’s high expression and simple purification was demonstrated by codon optimization and in silico cloning expression into the pET28a(+)vector.By applying immunoinformatics approaches,researchers aim to better understand the immune response to bovine coronavirus,discover potential targets for intervention,and facilitate the development of diagnostic tools and vaccines to mitigate the impact of this virus on cattle health and the livestock industry.We anticipate that the design will be useful as a preventive treatment for BCoV sickness in cattle,opening the door for further laboratory studies.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA26040304)。
文摘Background Hesperidin is a citrus flavonoid with anti-inflammatory and antioxidant potential. However, its protective effects on bovine mammary epithelial cells(b MECs) exposed to oxidative stress have not been elucidated.Results In this study, we investigated the effects of hesperidin on H_(2)O_(2)-induced oxidative stress in b MECs and the underlying molecular mechanism. We found that hesperidin attenuated H_(2)O_(2)-induced cell damage by reducing reactive oxygen species(ROS) and malondialdehyde(MDA) levels, increasing catalase(CAT) activity, and improving cell proliferation and mitochondrial membrane potential. Moreover, hesperidin activated the Keap1/Nrf2/ARE signaling pathway by inducing the nuclear translocation of Nrf2 and the expression of its downstream genes NQO1 and HO-1, which are antioxidant enzymes involved in ROS scavenging and cellular redox balance. The protective effects of hesperidin were blocked by the Nrf2 inhibitor ML385, indicating that they were Nrf2 dependent.Conclusions Our results suggest that hesperidin could protect b MECs from oxidative stress injury by activating the Nrf2 signaling pathway, suggesting that hesperidin as a natural antioxidant has positive potential as a feed additive or plant drug to promote the health benefits of bovine mammary.
文摘Objective:To evaluate the therapeutic effect of recombinant bovine basic fibroblast growth factor(rbFGF)eye gel combined with tobramycin-dexamethasone(TOB-Dex)eye drops on dry eye syndrome(DES)after cataract surgery.Methods:86 patients with DES after cataract surgery,admitted from November 2021 to November 2023,were randomly divided into groups.The observation group included 43 patients treated with rbFGF eye gel combined with TOB-Dex eye drops.The reference group included 43 patients treated with TOB-Dex eye drops alone.Multiple indicators,including total effective rate and clinical symptom scores,were compared between the two groups.Results:The total effective rate in the observation group was higher than in the reference group(P<0.05).Before treatment,there were no differences in clinical symptom scores,serum factors,or disease severity scores between the two groups(P>0.05).Three weeks after treatment,the observation group had lower clinical symptom scores,serum factors,and disease severity scores compared to the reference group(P<0.05).The adverse reaction rate in the observation group was lower than in the reference group(P<0.05).Conclusion:rbFGF eye gel combined with TOB-Dex eye drops can improve the clinical efficacy for patients with DES after cataract surgery,alleviate disease symptoms,reduce inflammatory responses,and have fewer adverse reactions.
基金the Ministry of Science and Innovation,Spain(IJC2019-039615-I and PID2020-113320RB-I00)the European Union’s Horizon 2020 research and innovation scheme under the Marie Sklodowska-Curie grant agreement No.801342(Techniospring INDUSTRY+2 种基金TECSPR-19-1-0003)the Regional Government of Catalonia(2017-SGR-1229 and 2021-SGR-00900)the Catalan Institution for Research and Advanced Studies(ICREA).
文摘Background MicroRNAs(miRNAs)are small,single-stranded,non-coding RNA molecules of 22–24 nucleotides that regulate gene expression.In the last decade,miRNAs have been described in sperm of several mammals,including cattle.It is known that miRNAs can act as key gene regulators of early embryogenesis in mice and humans;however,little is known about the content,expression,and function of sperm-borne miRNAs in early bovine embryo.In this study,total sperm RNA was isolated from 29 cryopreserved sperm samples(each coming from a separate bull)using a RNeasy kit and treatment with DNase I.RNA concentration and purity were determined through an Epoch spectrophotometer and an Agilent Bioanalyzer.The expression of 10 candidate miRNAs in bovine sperm(bta-miR-10a,bta-miR-10b,bta-miR-138,bta-miR-146b,bta-miR-19b,bta-miR-26a,bta-miR-34a,bta-miR-449a,bta-miR-495 and btamiR-7),previously identified in testis and/or epididymis,was evaluated with RT-qPCR.The cel-miR-39-3p was used as a spike-in exogenous control.Nonparametric Mann–Whitney tests were run to evaluate which miRNAs were differentially expressed between bulls with high fertility[HF;non-return rates(NRR)ranging from 39.5 to 43.5]and those with subfertility(SF;NRR ranging from 33.3 to 39.3).Several sperm functionality parameters(e.g.,viability,membrane stability or oxygen consumption,among others)were measured by multiplexing flow cytometry and oxygen sensing technologies.Results RNA concentration and purity(260/280 nm ratio)(mean±SD)from the 29 samples were 99.3±84.6 ng/μL and 1.97±0.72,respectively.Bioanalyzer results confirmed the lack of RNA from somatic cells.In terms of the presence or absence of miRNAs,and after applying the Livak method,8 out of 10 miRNAs(bta-miR-10b,-138,-146b,-19b,-26a,-449a,-495,-7)were consistently detected in bovine sperm,whereas the other two(bta-miR-10a,and-34a)were absent.Interestingly,the relative expression of one miRNA(bta-miR-138)in sperm was significantly lower in the SF than in the HF group(P=0.038).In addition to being associated to fertility potential,the presence of this miRNA was found to be negatively correlated with sperm oxygen consumption.The expression of three other miRNAs(bta-miR-19b,bta-miR-26a and bta-miR-7)was also correlated with sperm function variables.Conclusions In conclusion,although functional validation studies are required to confirm these results,this study suggests that sperm bta-miR-138 is involved in fertilization events and beyond,and supports its use as a fertility biomarker in cattle.
文摘Awdal region is the most northwesterly province of Somaliland. The region is one of the agro-pastoral livelihood zones in Somaliland, where farming and agricultural production are the predominant livelihood sources. IGAD (Intergovernmental Authority on Development) Sheikh Technical University of Science (ISTUS) worked to study the prevalence of Bovine Tuberculosis (TB) among cattle in Awdal region of Somaliland. The aim was to inform public health and Veterinary experts on having one-health approach to infectious diseases among humans and animals. The serum that was stored at -20?C was transported to IGAD Sheikh Technical University of Science (ISTUS) for further analysis using BOVIGAM serological test (Sandwich ELISA). The results indicate that Bovine Tuberculosis is highly prevalent in the study area (10.1%). The high prevalence recorded in the current study could be due to the consumption of raw milk and lack of proper control strategies in place to control the transmission of the disease between animals, between animals and wildlife and between animals and humans. Hence, an awareness creation campaign should be created on bTB transmission and its public health significance to cattle owners, milk and meat consumers and people who are in close proximity to cattle. In addition, testing and eradication programme should be implemented where applicable.
文摘Brucellosis is an infectious disease of worldwide distribution, which has a great economic impact due to the productive and reproductive losses that it causes, in addition to the serious public health problem. The aim of this study is to estimate the economic losses, through financial analysis, caused by bovine brucellosis in the province of Carchi, over a one-year period. A random sampling was used to determine the prevalence in the study area, where 2976 animals were considered, and the Rose Bengal (RB) test was used as a screening test and the Fluorescence Polarized Assay (FPA) as a confirmatory test, obtaining a prevalence of 8.2% (244/2976). In addition, parameters associated to the losses caused by brucellosis in cattle were determined by literature review. To estimate costs, field information was collected through a survey of a total of 100 randomly selected farmers. The loss estimated due to calves lost as a result of abortions and neonatal death was USD. 79170.00. The loss due to death of 4 cows as a result of metritis was estimated at USD. 5000.00. The cost of examination and treatment of aborted cows was USD. 20100.00. The losses due to reduction in milk production from aborted and non-aborted seropositive cows were estimated at USD. 158114.21. The financial losses due to brucellosis in province of Carchi were estimated at USD. 262384.21.
基金FEDER/Region Centre Val de Loire ANIMALT grant (FEDER convention number EX007516, Region Centre convention number 2019–00134936, research program number AE-2019–1850)a post-doc fellowship from INRAE–Département Santé Animale
文摘Background Mammary gland(MG)infections(mastitis)are frequent diseases of dairy cows that affect milk quality,animal welfare and farming profitability.These infections are commonly associated with the bacteria Escherichia coli and Staphylococcus aureus.Different in vitro models have been used to investigate the early response of the MG to bacteria,but the role of the teat in mastitis pathogenesis has received less attention.In this study,we used punch-excised teat tissue as an ex vivo model to study the immune mechanisms that arise early during infection when bacteria have entered the MG.Results Cytotoxicity and microscopic analyses showed that bovine teat sinus explants have their morphology and viability preserved after 24 h of culture and respond to ex vivo stimulation with TLR-agonists and bacteria.LPS and E.coli trigger stronger inflammatory response in teat when compared to LTA and S.aureus,leading to a higher produc-tion of IL-6 and IL-8,as well as to an up-regulation of proinflammatory genes.We also demonstrated that our ex vivo model can be applied to frozen-stored explants.Conclusions In compliance with the 3Rs principle(replacement,reduction and refinement)in animal experimenta-tion,ex vivo explant analyses proved to be a simple and affordable approach to study MG immune response to infec-tion.This model,which better reproduces organ complexity than epithelial cell cultures or tissue slices,lends itself particularly well to studying the early phases of the MG immune response to infection.
基金Research was funded by grants from National University of Río Cuarto(UNRC)through the Secretary of Science and Technology(SECYT,PPI 2020-2022,Res 083).
文摘Background:Capacitation is a set of physiological changes sperms undergo to acquire fertilizing capacity.In vivo,this process is directly associated with high calcium levels in sperm cytoplasm.Calcitriol,the vitamin D hypercalcemic metabolite,is related to human sperm motility,capacitation,and acrosome reaction.This work aimed to study the effect of calcitriol on bull sperm quality parameters and capacitation.Methods:One million freezethawed spermatozoa were obtained from different bulls and treated with 20 nM of calcitriol for 30 min.Untreated cells(negative control)and treated ones with calcitriol or heparin(100μg/mL,positive capacitation control)were evaluated for motility,viability,and functional parameters.Menadione(70μM,30 min)treatment was included as a reactive oxygen species(ROS)positive sperm agent.Results:The results elucidated that sperm exposed to 20 nM calcitriol showed higher viability,vigor,and capacitation than their positive and negative controls.The percentage of sperm with intact plasma and acrosome membranes,mitochondrial membrane potential(ΔΨm),and phosphatidylserine externalization was similar in all the conditions evaluated,while ROS production was higher with heparin and menadione-treated groups than the calcitriol group or negative control.Conclusion:Our results indicate that calcitriol induces the capacitation of thawed bull spermatozoa and maintains acceptable values of progressive motility,viability,and vigor without altering key biological parameters such as redox status,ΔΨm,and cell death.
基金the Natural Science Foundation of China(U21A20259)National Key Research and Development Program of Ningxia Hui Autonomous Region(2021BEF02028)+1 种基金the Natural Science Foundation of Hubei Province(2021CFA016)China Agriculture Research System of MOF and MARA and Basic and technical innovation team for prevention and control of bovine disease.
文摘Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and associated economic losses for the herd owner.This study was designed to investigate the relationship between milk and serum antibody tests for bTB in dairy cows using 85 cows with milk and corresponding blood samples.Totally 4,395 milk samples were used to assesse the apparent(test)prevalence and incidence of bTB using the milk antibody ELISA.The association between levels of bTB milk antibody and milk quality was also evaluated.Milk and serum antibody tests showed a good correlation with a 87.5%(95%CI:61.7%,98.4)positive agreement and 98.7%(95%CI:95.4,99.8)negative agreement.The animal level lactoprevalence ranged from 0.3%(95%CI:0,1.2)to 33.3%(95%CI:26.6,40.6)in different farms and the incidence rate ranged from 0 head/cow-month(95%CI:0,0.02)to 0.04 head/cow-month(95%CI:0.02,0.07).Twenty percent of sampled farms met the criteria for bTB control in China.The prevalence on large-scale farms was lower(p<0.001)than on small farms.The bTB milk antibody levels had a negative correlation with milk yield and a positive correlation with somatic cell count(SCC),milk protein percentage(MPP)and percentage of total solids(TS).According to this research,milk ELISA could be used as a supplement of blood samples to assist in the surveillance for bTB and for alerting control and eradication of bTB.
基金supported by the by National Key R&D Program of China(2018YFC1604302)“Twelfth Five Year”National Science and Technology Plan Project(2013BAD18B03)+2 种基金Chinese Scholarship Council(202008210391)Shenyang Technological Innovation Project(Y17-0-028)LiaoNing Revitalization Talents Project(XLYC1902083).
文摘This study aimed to analyze and compare the differentially expressed whey proteins(DEWPs)of donkey and bovine colostrum using high-performance liquid chromatography with tandem mass spectrometry-based proteomics.A total of 620 and 696 whey proteins were characterized in the donkey and bovine colostrum,respectively,including 383 common whey proteins.Among these common proteins,80 were identified as DEWPs,including 21 upregulated and 59 downregulated DEWPs in donkey colostrum compared to bovine colostrum.Gene Ontology analysis revealed that these DEWPs were mainly related to cellular components,such as extracellular exosome,plasma membrane,and mitochondrion;biological processes,such as oxidation-reduction process,cell-cell adhesion,and small guanosine triphosphate(GTP)ase-mediated signal transduction;and molecular functions,such as GTP binding,GTPase activity,and soluble N-ethylmaleimide-sensitive factor(NSF)attachment protein receptor activity.Metabolic pathway analysis suggested that the majority of the DEWPs were associated with soluble NSF factor attachment protein receptor interactions in vesicular transport,fatty acid biosynthesis,and estrogen signaling pathways.Our results provide a vital insight into the differences between donkey and bovine colostrum,along with important information on the significant components as nutritional and functional factors to be included in infant formula based on multiple milk sources.
文摘Taking the qualified bovine placenta as the research object,a series of pure physical separation and extraction processes such as tissue fragmentation,ultrasound,freeze-thawed,centrifugation and filtration were used to prepare the bovine placental bioactive proteins.The results of protein concentration showed that bovine placental bioactive proteins prepared in this study could reach(11.33±2.09)mg/mL under optimal experimental condition.The determination of specific components showed that there were abundant exosome like vesicles in the product with particle size ranging from 30 to 150 nm,pie structure under transmission electron microscope and expressing CD9,CD63 and TSG101 by western blot detection.The results of cell efficacy evaluation showed that bovine placental bioactive proteins could significantly promote the proliferation of human skin fibroblasts and had anti-inflammatory effect via down-regulating IL-6 and TNF-αexpressionin RAW264.7 cells.
文摘Aim To study the reaction mechanism between gatifloxacin and bovine serumalbumin (BSA) at different pHs. Methods Fluorescence spectra and UV absorbance spectra were used.Results The binding constants were determined from a double reciprocal Lineweaver-Burk curves atdifferent pHs. The binding distance r under normal physiological condition was obtained according toFoster theory of non-radiative energy transfer. The binding force between gatifloxacin and BSA wasinferred by thermody-namical coordination. Conclusion The interaction between gatifloxacin and BSAseems to be strong and the main binding force is electrostatic force.
基金Supported by Natural Science Foundation of Inner Mongolia Autono-mous Region (200711020407)China Agricultural University and Inner Mongolia Agricultural University Cooperation Projects~~
文摘[ Objective] To investigate the feasibility of the primary culture of bovine mammary epithelial cells in biochemical incubator. [ Method] In vitro, bovine mammary epithelial cells were isolated and cultured by the tissue explant method in order to investigate the optimal culture conditions. The morphology observation and identification of the cultured cells were performed by inverted microscope observation, Giemsa staining and cytokeratin immunohistochemistry. [ Result] Observed with inverted microscope, most of the bovine mammary epithelial cells were polygonal and displayed typical slabstone-like appearance. As it can be seen from cell staining results, the cell body was big and the nucleus was stained dark blue and was round or oval in shape, with clearly visible nucleoli, generally 2 -4 nucleoli. The tissue-specific expression of cytokeratin 14 and cytokeratin 18 genes in mammary epithelial cells was identified by cytokeratin immunohistochemistry. [ Conclusion] Primary bovine mammary epithelial cells were successfully cultured in biochemical incubator.
文摘Objective] This study aimed to develop a reverse transcription loop-medi-ated isothermal amplification (RT-LAMP) method for detecting BVDV. [Method] Since gp48 gene of BVDV is among the most conserved regions, a set of four primers was designed to amplify six target sequences at the gp48 gene region for the RT-LAMP assay. The optimization of the RT-LAMP reaction was performed by evaluat-ing reaction temperature and reaction time. [Result] The RT-LAMP aasay was suc-cessful y conducted at 56 ℃ within 40 min under isothermal conditions, and the re-sults could be detected as ladder-like bands using agarose gel electrophoresis. The RT-LAMP assay is highly sensitive and able to detect 3.74 ×100 copies/μl of BVDV RNA, as no cross-reaction was observed with other viruses. [Conclusion] Overal , the newly established RT-LAMP assay indicates the potential application in both clinical diagnosis and field surveil ance of BVDV.
基金This work was supported by the National High Technology Research and Development Program of China(863 Program)(No.2001 AA213081).
文摘The aim of this work was to improve the rate of conventionally blind enucleation for bovine somatic cell nuclear transfer. The cross section of a 0.5 ml Eppendorf tube was attached with a sheet of 400 mesh/inch2-cell screen after the bottom of the Eppendorf tube had been cut, and put into a 1 mL Eppendorf tube. In experiment 1, the oocytes in the metaphase Ⅱ stage were placed on the membrane in the Eppendorf tube, and centrifuged at 1,000, 2,000, or 3,000 r/min for 10 min, respectively. The oocytes were stained with Hoechst 33342 and then the relative position of the first polar body to the chromosomes, and the efficiency of enucleation were evaluated. In experiment 2, enucleated oocytes were fused with granulosa cells, following centrifugation and enucleation, and the potential development of the reconstituted embryos was estimated. The results indicated that the rate of enucleation in oocytes after centrifugation at 2,000 r/min for 10 min was 86.6% with an angle less then 20° between the first polar body and chromosomes. The rate of enucleation in cells spun at 2,000 r/min was higher than that of controls (87.4% vs. 64.4%, P 〈 0.05). Fur- thermore; centrifugation of recipient oocytes did not have a detrimental effect on the development of reconstituted embryos following nuclear transfer. In conclusion, centrifugation assisted enucleation may significantly improve the rate of bovine oocyte enucleation.
文摘[Objective] This study aimed to construct a full-length bovine TLR2 expression plasmid pEGFP-N1-boTLR2 and express it in HEK293 cells. [Method] A fulllength coding sequence of bovine TLR2 was cloned by RT-PCR, and ligated into the pMD18-T simple vector and then subcloned into the pEGFP-N1 vector. A recombinant eukaryotic expression plasmid containing the full-length CDS region of bovine TLR2 was constructed and transiently transfected into HEK293 cells. The transfection efficiency and the location of recombinant protein were examined by FCM and confocal microscopy. Then the bovine TLR2 mRNA expression in HEK293/boTLR2 was detected by qRT-PCR. Finally, we analyzed the biological activity through the response that lipoteichoic acid stimulates HEK293/boTLR2 cells. [Result] The full-length TLR2 gene was successfully cloned and ligated into eukaryotic expression vector. The recombinant expression vector expressed bovine TLR2 in HEK293 cells. HEK293/boTLR2 cells produced higher levels of IL-8 secretion than nontransfected HEK293 cells when stimulated with LTA from Staphylococcus aureus. [Conclusion] The established cell model can provide a fast, flexible and convenient means for screening TLR agonists and antagonists, and may also be useful for investigating the interaction between TLR agonists and TLRs.