The present experiment was conducted to investigate the effects of Lactobacillus plantarum postbiotics on growth performance, immune status, and intestinal microflora of growing minks. A total of 80 minks (40 males and 40 females) were divided into four groups, each group contained 20 minks (10 males and 10 females). The minks in the four groups were fed a basal diet supplemented with 0, 0.15%, 0.3%, and 0.45% Lactobacillus plantarum postbiotics (PLP), respectively. After one week of adaptation, the experiment ran for eight weeks. The results showed that Lactobacillus plantarum postbiotics tended to have effects on average daily again (ADG) during the first 4 wk of the study (p < 0.1), and had effects on immune status (p < 0.05). Lactobacillus plantarum postbiotics also affected the abundance of intestinal bacteria at genus level (p < 0.05), but had no effects on α diversity of growing minks (p > 0.05). Compared to the minks in the control group, minks in 0.30% PLP group tended to have greater ADG, and IgA and IgM content in serum as well as SIgA content in jejunal mucosa (p < 0.05), and had less jejunal mucosal TNF-α and IL-8 levels, while minks in 0.45% PLP group had less IL-2 (p < 0.05). Compared to the control, Lactobacillus plantarum postbiotics decreased the relative abundances of Bacteroides_vulgatus and Luteimonas_sp. in male minks, and the relative abundances of Streptococcus_halotolerans in female minks (p < 0.05), respectively. Males grew faster and ate more associated with less F/G than females (p < 0.05). Males also had greater serum IgA and IgG content (p < 0.05), and males had less jejunal mucosal IL-1β, IL-8, IL-2, IL-6, IL-12, IL-10, TNF-α, and IFN-γ levels (p < 0.05). These results suggest that dietary supplementation of 0.3% postbiotics harvested from Lactobacillus plantarum could improve growth performance and immune status, and modulated the intestinal bacteria abundance of growing minks.
This study aimed to investigate the effects of different levels of autophagy induced by transient serum starvation on the metabolism, lipid metabolism, and differentiation of porcine skeletal muscle satellite cells (SMSCs) to preliminary elucidate the role and function of autophagy in the regulatory network of skeletal muscle development. Different levels of autophagy were induced by controlling the serum concentration in the culture system for 24 h. Apoptosis, membrane potential, reactive oxygen species (ROS), ATP, and myogenic and lipogenic differentiation markers were monitored to determine if autophagy affected the metabolism and differentiation of SMSCs. Autophagy was induced in SMSCs via serum starvation (5%, 15%), as evidenced by decreased p62 and mTOR phosphorylation levels and increased LC3B lipidation and AMPK phosphorylation levels. Transmission electron microscopy revealed the presence of autophagosomes, and the rates of morphologically abnormal nuclei and mitochondria gradually increased with the decrease in serum concentration, the number of autophagic lysosomes also increased, indicating that 5% serum starvation induced severe autophagy, while 15% serum starvation induced mild autophagy. Compared with the control group and 15% serum-starved SMSCs, SMSCs undergoing 5% serum starvation had the highest intracellular ATP and ROS levels, the highest percentage of apoptotic cells, and the lowest membrane potential. The 15% serum-starved SMSCs had the highest membrane potential, but the percentage of apoptotic cells did not change significantly compared with the control group. The levels of the myogenic markers MyoD1 and MHC were significantly higher in 15% serum-starved SMSCs than in serum-sufficient SMSCs and the lowest in the 5% serum-starved SMSCs. The lipid contents (measured by Oil Red O staining and quantification of triglycerides) and lipogenic markers Peroxisome Proliferators-activated Receptors γ and Lipoprotein Lipase were also significantly higher in SMSCs undergoing 15% serum starvation than in the control group, and the lowest in the 5% serum-starved SMSCs. Different levels of starvation stress induce different levels of autophagy. Mild autophagy induced by moderate serum starvation promotes the metabolism and differentiation of SMSCs, while severe autophagy renders SMSCs more apoptotic, abnormal metabolism and suppresses SMSC differentiation into adipocytes or myocytes, and reduces lipid metabolisms. Our study suggests that autophagy plays a role in skeletal muscle development and may help design strategies for improving meat production traits in domestic pigs.
旨在分析Hippo信号通路的效应基因YAP1在不同繁殖力湖羊子宫内膜中的表达模式及功能.本研究根据系谱档案和BMPR-1B基因多态性分析,将9只体况相近且健康的经产母羊分为3组(HBB、LBB以及LB+,n=3).提取不同繁殖力湖羊子宫内膜组织RNA,并反转录为cDNA,实时荧光定量PCR(RT-qPCR)分析Hippo信号通路中几个主效基因的表达模式.运用生物信息学方法分析YAP1在不同物种间的氨基酸同源性及其亲缘关系.体外分离湖羊子宫内膜基质细胞,利用RNA干扰和细胞转染技术体外干扰YAP1,采用实时荧光定量PCR(RT-qPCR)分析YAP 1基因对子宫容受性相关基因的影响.利用流式细胞术分析干扰YAP1对细胞凋亡的影响,同时利用RT-qPCR和Western blot检测干扰YAP 1后凋亡及线粒体相关基因的表达.结果显示,Hippo信号通路中YAP1、LATS1、MST1基因在不同繁殖力湖羊子宫内膜组织中的表达水平存在差异,其中YAP1基因在高繁殖力(HBB)湖羊子宫内膜中的表达量显著高于两组低繁殖力(LB+、LBB)湖羊;氨基酸同源性及系统进化树分析显示,绵羊YAP1蛋白与山羊和牛的同源性最高,亲缘关系最近;干扰YAP1基因后,子宫内膜基质细胞中容受性相关基因(FOXO1、PRL、VEGF、OPN、COX-2)的mRNA表达水平均发生了显著的变化.同时,子宫内膜基质细胞的凋亡率显著升高,凋亡相关基因Bax、BIM、p53、caspase3、caspase8、caspase9表达水平及Bax/Bcl-2的比值显著升高,Bcl-2表达水平显著下调.此外,线粒体功能相关基因(FIS1、DNM1L、MFN2、PPARGC1A、OPA1)mRNA表达水平也发生了显著变化.YAP1可能通过抑制细胞凋亡和稳定线粒体功能等途径建立良好的子宫内膜容受性.
There is no commercially diagnostic kits for swine acute diarrhea syndrome coronavirus （SADS-CoV）. To fill the gap， in this study， monoclonal antibodies （MAbs） against the SADS-CoV nucleocapsid （N） protein were prepared and the sequences of MAbs were analyzed. The N protein was expressed using prokaryotic expression system. The purified N protein was used as an antigen to immunize Balb/C mice. After cell fusion， screening， and subcloning， five stable secreting MAbs against N protein were obtained， and designated as 1C10， 4B10， 6G1， 6F3 and 6E8，respectively. The variable region gene sequences of MAbs were obtained by nested PCR. Indirect immunofluorescence assay （IFA） results showed that all MAbs could specifically recognize Huh7 infected with SADS-CoV. ELISA results showed that the five MAbs could react with the purified N protein， while only the MAb 6E8 could react with SADS-CoV. The results of western blot showed that the five MAbs specifically recognized with the purified N protein， as well as the native N protein in cells infected with SADS-CoV. Isotyping revealed that the MAbs 1C10， 4B10， 6G1， and 6F3 were of the IgG1 class， and 6E8 was of the IgG2a class， and which have a kappa light chain. Truncated expression analysis showed that the recognition region of N protein of the five MAbs was 1-142aa. Overall， the MAbs against SADS-CoV N protein were promising a useful tool for development of new immunodiagnostic methods and research N protein function and structure.
Simple and accurate early pregnancy diagnosis is an important means to reduce open cows， improve female fecundity and improve farm economic benefits. Although traditional pregnancy diagnoses methods such as rectal palpation， B-ultrasound examination， and progesterone detection have provided important technical support for breeding production， they have not yet achieved the earliest detection of cows after mating， and some farms still difficult to meet their high technical requirements or laboratory conditions. Pregnancy-associated proteins （PAGs） are pregnancy-specific proteins secreted by embryonic trophoblast cells， which play an important role in the pregnancy of dairy cows and are widely used in the diagnosis of early pregnancy in dairy cows. This article briefly summarizes the existing diagnostic methods for pregnancy， discusses the development process of PAGs diagnostic methods in detail， looks forward to the future development direction of pregnancy diagnostic technology， and makes important progress in "early"， "accurate" and "simple"， and provides relevant research information. an important reference.
鹿茸作为鹿科动物的一种骨质性器官,基于干细胞进行年周期性再生,独特的生物学特性使其逐渐成为生物学、医学等领域的理想模型.鹿茸的骨化与体内性激素水平变化密切相关:在鹿机体性激素水平低、肋骨骨质流失的生理环境下,鹿茸的生长速度高达2.7 cm·d-1,一边生长一边骨化;随后性激素水平上升,鹿茸便进入快速骨化期,3个月的时间可形成重达30 kg的骨质性组织.鹿茸能够在体骨骼骨质大规模流失且低水平性激素的内分泌条件下实现快速成骨的现象称之为鹿茸逆向成骨.本文从细胞分化、激素、成骨、破骨和细胞因子角度对鹿茸逆向成骨的研究现状和发生机制进行了综述,旨在探索鹿茸逆向成骨机制,为提高产茸量与动物福利健康提供借鉴与参考.
The purpose of this study was to identify Guyuan cattle as relatively independent beef cattle genetic resources， further describe their growth and development rules， and provide certain theoretical basis for the identification and breeding of germplasm resources for meat of Guyuan cattle. The evolutionary history of Guyuan cattle was analyzed through historical documents and investigation. The whole genome genetic variation data of 337 individuals of 13 breeds including Guyuan cattle were detected through GGP Bovine 100K gene chip and downloaded from public databases， and the genetic background of Guyuan cattle was analyzed by multidimensional scaling analysis and adjacent phylogenetic tree. Taking the Red Angus×Guyuan crossbred cattle as the control population， the phenotypic data such as body weight， body size， backfat thickness and loin eye area of Guyuan cattle at different growth stages were measured and collected， with reference to the phenotypic data of Qinchuan cattle and Mongolian cattle published in the Journal of Chinese Livestock and Poultry Genetic Resources， the population rule of relevant indicators of Guyuan cattle is excavated from the phenotypic description. The results showed that 1) Guyuan cattle is a unique population with the same shape and appearance after long-term breeding due to the mutual influence of Guyuan native cattle with neighboring Mongolian cattle and Qinchuan cattle; 2) The genetic structure of existing Guyuan cattle population is close to the neighboring Qinchuan cattle and Jinnan cattle， and it is a relatively independent resource population. 3) Compared with heifer of Guyuan cattle， somatic index of adult cow of Guyuan cattle was increased by 9.57%; 4) After crossbreeding with Red Angus cattle， brassiere index and somatic index of adult cow of crossbred Guyuan cattle were respectively increased by 11.59% and 12.70%， body length index and brassiere index of bull of crossbred Guyuan cattle were respectively increased by 15.15% and 19.26%; 5) Beef-purpose index of adult cow of Guyuan cattle was 2.65±0.46， Beef-purpose index of bull of Guyuan cattle was 2.87±0.35， and Guyuan cattle is draft cattle; 6) The backfat thickness of bull of Guyuan cattle was （5.29±1.41）mm， higher than the backfat thickness of bull of Mongolian cattle （4.00±1.00）mm; 7) The loin eye area of bull of Guyuan cattle was （62.17±8.51）cm 2 ， between the loin eye area of of Qinchuan cattle （79.80±9.70）cm 2 and Mongolian cattle （50.40±9.80）cm 2 . Guyuan cattle is a new genetic resource of beef cattle， which has good germplasm characteristics for meat. However， its body size indexes and beef-purpose index have not reached the standard of specialized beef cattle. In the later stage， strengthen breeding and the stock breeding and genetic improvement of Guyuan cattle are needed to further develop its germplasm resource characteristics.
African Swine Fever Virus （ASFV） pD205R protein is involved in virus gene transcription， which belongs to ASFV RNA polymerase， similar with RPB5 of eukaryotic RNA polymerase II. In this study， in order to further understand the structure， function of pD205R and interaction mechanism between virus and host， the sequence of D205R gene from different ASFV strains deposed in GenBank were analyzed by using DNAStar and Mega7.0 software. Physicochemical Properties and Structure of Protein were predicted by using ExPASy， GOR4 and AlphaFold software， and its prokaryotic expression and preparation of anti-pD205R protein polyclonal antibody were performed. Furthermore， the D205R gene was amplified and cloned into pET-28a vector， named as pET-28a-D205R. The results showed that the D205R gene was highly conserved among different genotypes of ASFV isolates. The physicochemical properties analysis showed that pD205R protein was hydrophilic with poor stability， its molecular formula was predicted as C 1088 H 1712 N 278 O 295 S 8 . The secondary structure and tertiary structure indicated that α helix was the main structural form， proportion for 35.12%. Furthermore， the pET-28a-D205R recombinant plasmids were constructed successfully using ASFV CN/SC/2019 strain genome as template and transformed into E. coli Rosetta （DE3） competent cells， the recombinant proteins were successfully induced and expressed by IPTG， with the size of 23.3 ku. Then the obtained protein was purified by nickel column affinity chromatography， which could react specifically with ASFV positive serum by Western blot identification. The titer of polyclonal antibody prepared by immunizing New Zealand white rabbits could reach to 1: 51 200， and could specially recognize the native pD205R protein expressed in ASFV-infected porcine alveolar macrophages （PAMs） by Western blot and IFA detection. It laid a foundation for further study the function of D205R gene and its role in host-pathogen interaction.
In order to solve the problem of how to optimize and innovate the existing methods to establish a new method for FMD antibody detection， this study aimed to optimize the method based on liquid phase blocking ELISA to achieve rapid and sensitive detection of FMD virus antibody. In this study， a novel liquid phase blocking ELISA method （SA-LPBE） was established by combining the purification of IgG labeled biotin （dolphin anti-foot-and-mouth disease） from guinea pig serum with HRP labeled streptavidin （HRP-SA）. Sa-lpbe has a high consistency rate in bovine and sheep serum samples. Combined with the actual situation， the optimized serum antibody titer of cattle and sheep was determined to be ≥128， and the serum sample of pigs was determined to be ≥64. The results were determined to be positive， which was consistent with the results of commercial detection kits. And after compliance analysis， it has a compliance rate of 92.3% with the original kit， and the intra-batch variation coefficient is less than 5%， and the inter-batch variation coefficient is less than 10%. This method changed the original route of preparing rabbit anti-guinea pig antiserum and labeling HRP， improved the efficiency of enzymatic reaction， guaranteed the original sensitivity of the method and improved the specificity of the method; Using the advantages of quick reaction between biotin-labeled antibody and HRP-SA， stable labeling raw material and detection background value， the operation time of liquid phase blocking ELISA kit was shortened from 2 days to 3 hours， which solved the problems of tedious， long time， operation fatigue， instability and error-prone of the original operation. It can be applied to FMDV antibody detection， providing a technical method for FMD epidemic and clinical detection.
旨在通过对北京油鸡(BY)和"广明2号"白羽肉鸡B系(广明白鸡,GM)在热应激和正常饲养条件下的脾脏转录组进行分析,鉴定两鸡种在应对热应激时的差异表达基因和信号通路,解析不同鸡种耐热性能差异的分子调控机制.试验动物采用相同饲养条件下的25日龄北京油鸡和广明白鸡,测定异嗜性粒细胞与淋巴细胞的比值(H/L)、超氧化物歧化酶(SOD)和总抗氧化能力(T-AOC)等表型数据,采集脾脏组织进行转录组测序(RNA-Seq).基于RNA-Seq数据,结合表型进行加权基因共表达网络分析(WGCNA),筛选出与性状相关性较高的模块与基因.脾脏转录组测序结果表明,热应激组相比于对照组,北京油鸡中共鉴定到313个差异表达基因,其中169个上调表达,144个下调表达;广明白鸡中鉴定到235个差异表达基因,其中152个上调表达,83个下调表达.利用WGCNA分析,在北京油鸡中筛选出2个与H/L相关性较高的模块,在广明白鸡中筛选出4个与H/L和T-AOC强相关的模块.通过筛选模块中的Hub基因,发现两品种中均存在TRIM29基因,说明该基因可能在抗热应激方面发挥重要作用.本研究通过转录组分析,揭示了不同鸡种在热应激下基因的表达差异规律,并鉴定到与耐热相关的候选基因,为进一步研究鸡的耐热机制提供了新的思路和线索.
The purpose of this experiment was to evaluate the differences in carcass traits， meat quality， and flavor quality between Rongchang （RC） pigs and Duroc×Landrace×Yorkshire （DLY） pigs， in order to provide basic data for further interpretation of the flavor characteristics of Rongchang pigs. DLY pigs （117.75±7.19 kg） （n=8） and RC pigs （112.40±8.78 kg） （n=10） in good health， with similar weights at slaughtering time were selected for the study; each group consisting of half female and male. The volatile flavor substances in pork were determined using SPME-GC-MS technique. The Results showed that: 1) Compared with the DLY pigs， the straight length， oblique length， and eye muscle area of RC pigs decreased significantly （P＜0.05）， while the average back fat thickness significantly increased （P＜0.01）. 2) Compared with the DLY pigs， longissimus dorsi muscle a * 45 min， a * 24 h cohesion of RC pigs significantly increased （P＜0.05）; whereas L * 24 h dripping loss， shear force and hardness significantly reduced （P＜0.05）. 3) Electronic tongue analysis showed that the taste profile of the longissimus dorsi muscle of RC pigs were significantly different from that of DLY pigs， and the taste richness and saltiness response value of RC pigs significantly increased （P＜0.05）. 4) Electronic nose analysis showed that the odor profile of the longissimus dorsi muscle of RC pigs were significantly different from that of DLY pigs. The response value of W2S sensor， which mainly responded to alcohols， aldehydes and ketones， was significantly increased in RC pigs as well （P＜0.01）. 5) Based on HS-SPME-GC-MS technology， 76 volatile flavor compounds were identified in the longissimus dorsi muscle of RC pigs and DLY pigs. Among them， 16 keys volatile flavor compounds were significantly increased in RC pigs （VIP＞1 and P＜0.05）. RC pig has bright red color， and high quality of meat tenderness and water power. Sixteen volatile flavor substances， including hexanal， valeraldehyde， 2，3-octanedione， ethyl acetate， allyl butyrate， and 2-ethylfuran， may play an important role in the formation of flavor differences between RC pigs and DLY pigs. Overall， these findings provide basic data for promoting the development and utilization of RC pig germplasm resources.
昼夜节律系统是哺乳动物的内部计时系统,在大多数动物中,下丘脑视交叉神经上核(suprachiasmatic nu-cleus,SCN)是主要的昼夜节律时钟,通过协调动物机体各个组织的时钟使内部节律与环境周期一致.SCN核心区细胞能够直接从内在光敏视网膜神经节细胞(intrinsically photosensitive retinal ganglion cell,ipRGCs)接收光信号,其内源性振荡决定了整个动物的行为和生理节律.雌激素能够调节哺乳动物的多个生理过程,包括但不限于发情周期的节律行为,雌激素通过和SCN协同调节GnRH分泌、LH峰以及排卵,最终影响哺乳动物的生殖过程.本文综述了哺乳动物雌激素分泌和昼夜节律、雌激素和昼夜节律之间的分子联系以及二者对雌性哺乳动物繁殖调控机制3个方面的最新研究进展,以期为深入探究雌性哺乳动物繁殖的节律和激素调控机制提供参考.
反刍动物瘤胃微生物对瘤胃发育、营养物质消化和宿主生理健康有重要意义.瘤胃微生物移植(rumen microbiota transplantation,RMT)是将特定供体的瘤胃微生物及其代谢物移植到受体中,通过操纵瘤胃微生物群落进行菌群重塑或微生物组修复,改善宿主机能状态、生产效率、产品质量等,并可预防或治疗部分胃肠道疾病的措施.本文就RMT的发展历程、应用、安全性及潜在作用机制等进行了综述,重点阐述了 RMT在揭示瘤胃微生物组特性或功能、调节宿主新陈代谢、提高生长性能、调控微生物区系平衡、疾病治疗等方面的作用,为RMT的研究与应用提供技术参考.
This study aimed to explore the correlation among growth traits in Ujumqin sheep and the optimal regression equation of body size to body weight was established, and analyze the effect of TRHDE gene polymorphism on the growth traits of Ujumqin sheep. In this study, 336 well-developed Ujumqin sheep（176 males and 160 females） were selected as research objects, and growth traits were collected at 4-month-old and 6-month-old. Genotypes of SNPs in the TRHDE gene were detected using the sheep Illumina OvineSNP600 BeadChip in a population of 336 Ujumqin sheep. SPSS 26.0 software was used for correlation and regression analysis among growth traits and association analysis between TRHDE gene polymorphism and growth traits. The results showed that the optimal regression equations of 4-month-old and 6-month-old male and female Ujumqin sheep were as follows: Y 1 =-53.66+0.77X 1 +0.39X 2 , Y 2 =-47.83+0.63X 1 +0.45X 2 , Y 3 =-47.01+0.42X 1 +0.13X 2 +2.82X 3 +0.19X 4 +0.28X 5 , Y 4 =-61.32+0.25X 1 +0.40X 2 +3.15X 3 +0.39X 4 . The results of the association of TRHDE gene SNPs with growth traits in Ujumqin sheep showed that rs404402551A＞G locus was significantly or extremely significantly associated with body weight and chest circumference at 4-month-old and body weight, chest circumference and chest width at 6-month-old（P＜0.05; P＜0.01）. The rs415608385C＞A locus was significantly or extremely significantly associated with body weight at 4-month-old and body weight, body height, body length and chest width at 6-month-old（P＜0.05; P＜0.01）. The rs426657887G＞A locus was not significantly associated with each growth trait in Ujumqin sheep（P＞0.05）. And the rs404402551A＞G and rs426657887G＞A loci were in strong linkage disequilibrium in the Ujumqin sheep. In conclusion, the greater potential for selection of body weight in Ujumqin sheep and chest circumference can be used as an important indicator for assessing body weight in Ujumqin sheep. The rs404402551A＞G and rs415608385C＞A loci of the TRHDE gene can be used as potential molecular markers for growth and development in Ujumqin sheep, which can provide reference for molecular marker-assisted selection for breeding in Ujumqin sheep.
Recent years, techniques for in vitro embryo production（IVP） have advanced significantly, especially the ovum pick-up（OPU） technology grows widely. OPU is a new technology developed in the 1990 s that can obtain oocytes from excellent breeding heifers, which has a broad application prospect in the research of the mechanism of animal embryo production and development and in the clinical practice of human assisted reproductive technology. It can improve the resource protection efficiency of breeding females and precious wild animals, and the genetic potential of excellent females, and provide the necessary supporting technology for the development of cattle biotechnology. The quality of oocytes is the key to the success of the IVP system, and the in vitro maturation（IVM） process of the oocytes is critical for successful fertilization and embryo development. Oocyte IVM completes the cytoplasmic and nuclear maturation of the oocyte, preparing all necessary components for development to the activation of the embryonic genome. Developmental ability of oocytes matured in vitro is lower than that of oocytes matured in vivo, non-synchronization of oocyte meiosis and nucleocytoplasmic maturation, oxidative stress damage, et al are important for successful fertilization and embryo development. Therefore, it is necessary to further improve the in vitro maturation ability of oocytes to improve the bovine IVP system. In this paper, the problems of in vitro maturation of oocytes such as non-synchronization of nucleocytoplasmic maturation and oxidative stress were summarized, as well as the improvement effects of C-type natriuretic peptide, melatonin, FLI and other substances on oocytes IVM were discussed in order to improve the bovine IVP system.
Biomineralization technology can enhance the heat resistance of foot-and-mouth disease（FMD） virus-like particles（VLPs）, but there is no experimental data to support the feasibility of mineralized FMD VLPs for clinical use. The aim of this study was to evaluate the immunogenicity of the mineralized FMD VLPs vaccine in cattle and pigs. The pigs were immunized with VLPs and mineralized VLPs, and the specific antibody titers in the serum of the immunized pigs were detected by liquid-phase blocking ELISA（LPBE）. The specific IFN-γ secreted by peripheral blood lymphocytes（PBLs） after stimulation in vitro was detected by enzyme-linked immunospot assay（ELISpot）. Cattle were immunized with mineralized type A VLPs, mineralized type O VLPs, and mineralized type A and type O bivalent VLPs, respectively. The serum specific antibody, neutralizing antibody, IL-4 and IFN-γ contents were detected by LPBE, neutralization test and sandwich ELISA. The results showed that there was no significant difference in serum antibody level between VLPs and mineralized VLPs immunized pigs.Compared with VLPs, the level of IFN-γ secreted by PBLs of mineralized VLPs immunized pigs was higher than that of VLPs immunized pigs（P＜0.05）. The serum of cattle immunized with the three vaccines contained more IL-4 and IFN-γ（P＜0.05）, and there were no significant differences in the titers of serum specific antibodies and neutralizing antibodies between the mineralized bivalent vaccine and the corresponding mineralized monovalent vaccine. In conclusion, mineralized VLPs have good immunogenicity for both cattle and pigs, mineralized VLPs of different serotypes can be used in combination, and mineralized shells can enhance the ability of VLPs to induce cellular immune response.
Ocular and nasal swabs were collected from cats with upper respiratory tract infections in a cattery in Harbin, and the initial diagnosis was a mixed infection of feline herpesvirus-1（FHV-1） and feline calicivirus（FCV） by PCR. CRFK cells were used to isolate viruses from the swabs of infected cats. Nucleic acid assay of the first two generations of cell cultures showed that FHV-1 and FCV were both positive, and only FCV was isolated from the third generation. FHV-1 was isolated by serum neutralization using the prepared mouse-derived polyclonal antibody of the isolated FCV, which named HRB2019 strain. HRB2019 was identified by morphological observation of viral particles, indirect immunofluorescence assay（IFA） and gene sequence analysis. And the growth kinetics in vitro of HRB2019 was studied. The results showed that HRB2019 could produce typical cytopathic effect on CRFK cells and viral titer of the fourth generation of virus culture reached 1×10 8.43 TCID 50 ·mL -1 . Electron microscopy examination showed spherical virus particles with vesicle membrane, and its diameter was about 200 nm. IFA results showed that HRB2019 could bind to FHV-1 positive serum and appeared specific fluorescence. The gD gene of the isolate was amplified and the nucleic acid sequence analysis showed that the isolate was highly homologous with the domestic and foreign prevalent strains. The one-step growth curve of the virus showed that the virus began to replicate and proliferate from 12 h after inoculation, and the rapid proliferation period was from 12 to 36 h. The viral titers peaked at 48 to 72 h and began to decline at 84 h. In this study, FHV-1 was successfully isolated for the first time from samples infected with a mixture of FCV and FHV-1, which provided important data for epidemiological investigation and pathogenetic study of FHV-1 and provided methodological basis for isolation of growth-vulnerable strains in mixed infection.
旨在探究感染早期宿主细胞的天然免疫应答和抗病毒反应,本研究将鸡传染性支气管炎病毒(infectious bronchitis virus,IBV)Beaudette株感染鸡巨噬细胞HD11,2 h后提取细胞总RNA反转录成cDNA,采用Illumina进行转录组高通量测序.结果显示,感染组筛选出1 363个上调基因,653个下调基因.通过对差异表达基因GO和KEGG分析发现,IBV感染HD11细胞早期,差异表达基因大多与免疫反应、抗病毒作用有关,富集到的信号通路主要集中在细胞因子和细胞因子受体之间的相互作用、病毒蛋白与细胞因子或细胞因子受体之间的相互作用、TNF信号通路、MAPK信号通路等.随机挑选10个与免疫反应、抗病毒相关基因进行RT-qPCR验证,结果与转录组测序分析一致.本研究为进一步探究IBV致病机制和感染早期宿主细胞免疫反应奠定了基础.
旨在探讨内质网应激在桔青霉素诱导肠道屏障功能障碍中的作用.试验选用24只初始体重为(27.8+1.5)g的7周龄昆明小鼠,随机分为4组,分别为对照组(5％乙醇)和桔青霉素低(1.25 mg·kg-1)、中(5 mg·kg-1)、高(20 mg·kg-1)剂量组.适应性饲养1周后,对照组按0.1 mL·10g-1体重灌胃5％乙醇,毒素处理组分别灌胃不同剂量桔青霉素,持续14 d.试验结束后,采血并分离血清,测量小肠长度并收集小鼠空肠样本.HE染色观察肠道病理变化;ELISA 检测血清中二胺氧化酶(diamine oxidase,DAO)、D-乳酸(D-lactic acid,D-LA)、内毒素(endotox-in,ET)的含量;检测空肠组织抗氧化酶的活性及活性氧(reactive oxygen species,ROS)的释放.为进一步探究内质网应激在桔青霉素诱导肠道损伤中的作用,选用32只昆明小鼠随机分为4组,分别为对照组(5％乙醇)、桔青霉素中剂量(5 mg·kg-1)组、内质网应激抑制剂4-苯基丁酸苯基丁酸(4-Phenylbutyric acid,4-PBA)(240 mg·kg-1)组和桔青霉素(5 mg·kg-1)+4-PBA(240 mg·kg-1)组.4-PBA经腹腔注射预处理小鼠1 h后,用桔青霉素对小鼠进行灌胃处理.14 d后,检测空肠组织病理损伤,氧化损伤,细胞凋亡情况及内质网应激相关蛋白表达,并用Spearman相关性分析确定内质网应激信号通路与肠道氧化应激、肠道屏障功能障碍之间的相关性.结果显示,不同剂量的桔青霉素会造成肠道组织损伤、氧化应激及屏障功能障碍.与桔青霉素中剂量组相比,4-PBA预处理能提高小鼠空肠总超氧化物歧化酶(total superoxide dismutase,T-SOD)、过氧化氢酶(catalase,CAT)的活性和总抗氧化能力(total antioxidant capacity,T-AOC),降低 ROS 和丙二醛(malondialdehyde,MDA)含量,抑制细胞凋亡及内质网应激,降低血清中DAO、D-LA和ET的含量,升高空肠组织中紧密连接蛋白ZO-1、Occludin和Claudin-1 mRNA表达,缓解桔青霉素诱导的空肠组织损伤,且内质网应激信号通路与肠道氧化应激及肠道屏障功能障碍之间存在显著相关性.综上表明,内质网应激在桔青霉素诱导的空肠屏障功能障碍中具有重要调控作用.
