Composition,function,and timing:exploring the early‑life gut microbiota in piglets for probiotic interventions

Background The establishment of a robust gut microbiota in piglets during their early developmental stage holds the potential for long-term advantageous effects.However,the optimal timeframe for introducing probiotics to achieve this outcome remains uncertain.Results In the context of this investigation,we conducted a longitudinal assessment of the fecal microbiota of 63 piglets at three distinct pre-weaning time points.Simultaneously,we gathered vaginal and fecal samples from 23 sows.Employing 16S rRNA gene and metagenomic sequencing methodologies,we conducted a comprehensive analysis of the fluctuation patterns in microbial composition,functional capacity,interaction networks,and colonization resistance within the gut microbiota of piglets.As the piglets progressed in age,discernible modifications in intestinal microbial diversity,composition,and function were observed.A source-tracking analysis unveiled the pivotal role of fecal and vaginal microbiota derived from sows in populating the gut microbiota of neonatal piglets.By D21,the microbial interaction network displayed a more concise and efficient configuration,accompanied by enhanced colonization resistance relative to the other two time points.Moreover,we identified three strains of Ruminococcus sp.at D10 as potential candidates for improving piglets’weight gain during the weaning phase.Conclusions The findings of this study propose that D10 represents the most opportune juncture for the introduction of external probiotic interventions during the early stages of piglet development.This investigation augments our comprehension of the microbiota dynamics in early-life of piglets and offers valuable insights for guiding forthcoming probiotic interventions.

反离子聚合聚(3,4-乙烯二氧噻吩)薄膜的热电性能研究进展

反离子的选择对电化学聚合聚(3,4-乙烯二氧噻吩)(PEDOT)薄膜的结构和热电性能的影响备受关注,在已报道的聚合物薄膜中,PEDOT:聚(苯乙烯磺酸盐)(PSS)、PEDOT:甲苯磺酸盐(Tos)、PEDOT:高氯酸(ClO_(4))和PEDOT:三氟甲磺酸酯(OTf)等被广泛研究。文中综合分析了不同类型反离子对PEDOT薄膜热电性能的应用研究,重点阐述了PEDOT:PSS和PEDOT:Tos提高热电性能的工艺方法,PEDOT:PSS薄膜具有高电导率、可水处理和热稳定性高等特点,二次掺杂、化学去掺杂和连续处理工艺能有效提高其热电性能,但是PSS有亲水性的限制;而Tos具有疏水性,且PEDOT:Tos薄膜能够有效平衡赛贝克系数和电导率的关系;其它的PEDOT:ClO_(4)和PEDOT:OTf等薄膜对热电性能也起到了一定的促进作用。最后,展望了反离子聚合PEDOT薄膜作为柔性热电器件和可穿戴电子器件的开发和实际应用。对进一步研究新的反离子聚合具有一定的参考价值。

Improving the accuracy of genomic prediction for meat quality traits using whole genome sequence data in pigs

Background Pork quality can directly affect customer purchase tendency and meat quality traits have become valu-able in modern pork production.However,genetic improvement has been slow due to high phenotyping costs.In this study,whole genome sequence(WGS)data was used to evaluate the prediction accuracy of genomic best linear unbiased prediction(GBLUP)for meat quality in large-scale crossbred commercial pigs.Results We produced WGS data(18,695,907 SNPs and 2,106,902 INDELs exceed quality control)from 1,469 sequenced Duroc×(Landrace×Yorkshire)pigs and developed a reference panel for meat quality including meat color score,marbling score,L*(lightness),a*(redness),and b*(yellowness)of genomic prediction.The prediction accuracy was defined as the Pearson correlation coefficient between adjusted phenotypes and genomic estimated breeding values in the validation population.Using different marker density panels derived from WGS data,accuracy differed substantially among meat quality traits,varied from 0.08 to 0.47.Results showed that MultiBLUP outperform GBLUP and yielded accuracy increases ranging from 17.39%to 75%.We optimized the marker density and found medium-and high-density marker panels are beneficial for the estimation of heritability for meat quality.Moreover,we conducted genotype imputation from 50K chip to WGS level in the same population and found average concord-ance rate to exceed 95%and r^(2)=0.81.Conclusions Overall,estimation of heritability for meat quality traits can benefit from the use of WGS data.This study showed the superiority of using WGS data to genetically improve pork quality in genomic prediction.

OGG1 inhibition suppresses African swine fever virus replication

African swine fever virus(ASFV)is an important pathogen that causes a highly contagious and lethal disease in swine,for which neither a vaccine nor treatment is available.The DNA repair enzyme 8-oxoguanine DNA glycosylase 1(OGG1),which excises the oxidative base lesion 8-oxo-7,8-dihydroguanine(8-oxoG),has been linked to the pathogenesis of different diseases associated with viral infections.However,the role of OGG1-base excision repair(BER)in ASFV infection has been poorly investigated.Our study aimed to characterize the alteration of host reactive oxygen species(ROS)and OGG1 and to analyse the role of OGG1 in ASFV infection.We found that ASFV infection induced high levels and dynamic changes in ROS and 8-oxoG and consistently increased the expression of OGG1.Viral yield,transcription level,and protein synthesis were reduced in ASFV-infected primary alveolar macrophages(PAMs)treated by TH5487 or SU0268 inhibiting OGG1.The expression of BER pathway associated proteins of ASFV was also suppressed in OGG1-inhibited PAMs.Furthermore,OGG1 was found to negatively regulate interferonβ(IFN-β)production during ASFV infection and IFN-βcould be activated by OGG1 inhibition with TH5487 and SU0268,which blocked OGG1 binding to 8-oxoG.Additionally,the interaction of OGG1 with viral MGF360-14-L protein could disturb IFN-βproduction to further affect ASFV replication.These results suggest that OGG1 plays the crucial role in successful viral infection and OGG1 inhibitors SU0268 or TH5487 could be used as antiviral agents for ASFV infection.

非洲猪瘟病毒p35蛋白作为诊断抗原的抗原性比较

为了筛选出酶联免疫吸附测定(Enzyme linked immunosorbent assay,ELISA)反应性最佳的非洲猪瘟病毒(African swine fever virus,ASFV)诊断抗原,通过建立ELISA方法,以杆状病毒昆虫细胞表达系统表达的ASFV p30蛋白诊断抗原为参照,首次探讨原核表达系统表达的ASFVp35蛋白作为诊断抗原的抗原性和潜力。免疫印迹和免疫荧光结果表明,获得了40 kDa的重组p35蛋白和30 kDa的p30蛋白,两种蛋白与ASFV阳性血清均具有较好的免疫反应原性。采用重组p30和p35蛋白作为诊断抗原分别建立ELISA方法,并验证其敏感性、稳定性以及与进口试剂盒的符合率。结果显示,尽管p35-ELISA方法的检测敏感性稍低于p30-ELISA方法,但其敏感性仍可达95.8%,且p35-ELISA方法和p30-ELISA方法的批内和批间变异系数均小于10%。p35-ELISA方法与进口试剂盒比较,符合率达97.2%。结果表明建立的p35-ELISA方法敏感性高且稳定性好,可应用于ASFV感染血清的检测。

Recombinant Newcastle disease virus expressing African swine fever virus protein 72 is safe and immunogenic in mice

African swine fever(ASF) is a lethal hemorrhagic disease that affects wild and domestic swine. The etiological agent of ASF is African swine fever virus(ASFV). Since the first case was described in Kenya in 1921, the disease has spread to many other countries. No commercial vaccines are available to prevent ASF. In this study, we generated a recombinant Newcastle disease virus(r NDV) expressing ASFV protein 72(p72) by reverse genetics and evaluated its humoral and cellular immunogenicity in a mouse model. The recombinant virus, r NDV/p72, replicated well in embryonated chicken eggs and was safe to use in chicks and mice. The p72 gene in r NDV/p72 was stably maintained through ten passages. Mice immunized with r NDV/p72 developed high titers of ASFV p72 specific Ig G antibody, and had higher levels of Ig G1 than IgG2 a. Immunization also elicited T-cell proliferation and secretion of IFN-γ and IL-4. Taken together, these results indicate that r NDV expressing ASFV p72 might be a potential vaccine candidate for preventing ASF.

Efficient purification of cell culture-derived classical swine fever virus by ultrafiltration and size-exclusion chromatography

Large-scale production of cell culture-based classical swine fever virus(CSFV)vaccine is hampered by the adverse reactions caused by contaminants from host cell and culture medium.Hence,we have developed an efficient method for purifying CSFV from cell-culture medium.Pure viral particles were obtained with two steps of tangential-flow filtration(TFF)and size-exclusion chromatography(SEC),and were compared with particles from ultracentrifugation by transmission electron microscopy(TEM),infectivity and recovery test,and real time fluorescent quantitative PCR(FQ-PCR).TFF concentrated the virus particles effectively with a retention rate of 98.5%,and 86.2%of viral particles were obtained from the ultrafiltration retentate through a Sepharose 4 F F column on a biological liquid chromatography system.CSFV purified by TFF-SEC or ultracentrifugation were both biologically active from 1.0×10–4.25 TCID50·mL^(–1) to 3.0×10^(–6.25) TCID50·mL^(–1),but the combination of TFF and SEC produced more pure virus particles than by ultracentrifugation alone.In addition,pure CSFV particles with the expected diameter of 40–60 nm were roughly spherical without any visible contamination.Mice immunized with CSFV purified by TFF-SEC produced higher antibody levels compared with immunization with ultracentrifugation-purified CSFV(P<0.05).The purification procedures in this study are reliable technically and feasible for purification of large volumes of viruses.