Genotyping of Mycoplasma mycoides subsp. mycoides SC by multilocus sequence analysis allows molecular epidemiology of contagious bovine pleuropneumonia     

Yaya A  Manso-Silván L  Blanchard A  Thiaucourt F 《Veterinary research》2008,39(2):14

Mycoplasma mycoides subsp. mycoides SC (MmmSC) is the etiological agent of contagious bovine pleuropneumonia (CBPP). Although eradicated in most developed countries, the disease reappeared in Europe in the 1990s. This reappearance may have been caused either by importation from sub-Saharan Africa, where CBPP is still endemic, or by the reemergence of virulent strains in Europe, as suggested by earlier studies. A multilocus sequence analysis scheme has been developed to address this issue and, most importantly, to be able to monitor new epidemics. The alignment of the full genome sequence of the reference strain PG1 and the partial genome sequence of a pathogenic strain allowed the identification of polymorphic sites. Nineteen initial loci were selected within housekeeping genes, genes of unknown function and non coding sequences. The suitability of these loci for genotyping MmmSC strains was first tested on six strains of diverse geographic origin. The analyses showed that the published PG1 sequence contained a number of specific polymorphisms that were therefore of no use for molecular typing. Among the eight informative polymorphic loci finally selected, only one (ftsY) was positioned within a housekeeping gene. Three main groups and 31 different allelic profiles were identified among 51 strains and strain variants examined. Cluster analysis confirmed that European strains from the 1990s did not originate from Africa. It also showed a genetic link between a European strain isolated in 1967 and those found in southern Africa and Australia. This was in agreement with historical data showing that CBPP was introduced in these regions during colonisation in the 19th century.  相似文献   

茶树新品种20-3-2选育研究报告     

闵彩云  贾尚智  金孝芳  陈勋  石亚亚  毛迎新 《茶叶》2010,36(4):208-209,212

以龙井43自然杂交后代为育种材料,采用单株选择,无性繁殖,品比试验育成茶树新品种20-3-2。经多年的观察和比较试验结果,20-3-2一芽一叶期、制茶品质与福鼎大白茶（CK）相仿;氨基酸含量4.1%;鲜叶产量比CK增产72%;抗性强。  相似文献   

Towards community-based in situ conservation strategies: a typological analysis of Borgou cattle herding systems in northeastern Benin     

Worogo  Hilaire S. S.  Idrissou  Rachidi  Assani  Alassan S.  Adjassin  Josias S.  Azalou  Maximilien  Assogba  Brice G. C.  Idrissou  Yaya  Alabi  Cham D. A.  Alkoiret  Ibrahim T. 《Tropical animal health and production》2020,52(3):1055-1064

A thorough knowledge of cattle herding systems is very important for planning sustainable genetic improvement and conservation strategies. This paper is initiated to characterize Benin native Borgou cattle farming systems in its department of origin by mean of survey including 180 cattle farmers owning at least one phenotype of that breed. Using multiple correspondence analysis and hierarchical ascending classification, four groups of Borgou cattle farms have been identified. The first group qualified as “semi-intensive purebred Borgou cattle farming” own high numbers (87.2 ± 3.95 heads) purchased and reared with the view to promote its genetic improvement, its production, and its conservation as Benin animal genetic resource. The second group (sedentary purebred Borgou cattle farming) is represented by Bariba ethnic group with small numbers (22.18 ± 0.71 heads) of purebred Borgou cattle used mainly for draught. Cattle farmers of the third group are “large transhumant of Zebu and Borgou crossbred cattle farmers” represented by Fulani and Gando ethnic groups whose herds are generally composed of high numbers (75.20 ± 3.43 heads) of cattle acquired by purchasing, inheriting, and fostering. The last one is the “small transhumant of Zebu and Borgou crossbred cattle farming” with an average herd size of 31.98 ± 0.72 heads. Cattle farming is their main activity and animals are used for the production of milk and cheese. These distinctions between Borgou cattle farmers can be an anchorage point for designing sustainable community-based in situ conservation strategies for safeguarding this local breed in its original cradle.

  相似文献   

Saccharides of ectomycorrhizal fungal sclerotia as sources of forest soil polysaccharides     

Yuki Sugiura  Makiko Watanabe  Yaya Nonoyama  Nobuo Sakagami  Yong Guo 《Soil Science and Plant Nutrition》2013,59(5):426-433

ABSTRACT

The neutral monosaccharide composition of forest soils differs from that of non-forest soils suggesting there is an accumulation of microbial saccharides. Ectomycorrhizal (ECM) fungi can be responsible as the fungi are typical in forest soils. We investigated neutral saccharides of ECM fungal sclerotia to determine what part it might play in the origin of forest soil polysaccarides. Sclerotial grain (SG) was collected from the O, A1 and A2 horizons of a soil of subalpine forest of Mt. Ontake, central Japan. Neutral saccharides in soil and SG were analyzed by two step hydrolysis with sulfuric acid and gas-chromatography of alditol acetate derivatives. Saccharides accounted for 6.0?16% of the SG by carbon content. The SG contained predominantly easily hydrolysable (EH)-glucose, which accounted for 75–85% of the composition depending on grain size and the soil horizon, followed by mannose (7.7?15%), galactose (2.2?4.8%) and non-easily hydrolysable (NEH)-glucose (1.7?6.1%). The SG contained all of these sugars irrespective of its size. The SG collected from the A1 and A2 horizons contained all sugar components found in that from the O horizon, except for fucose in that from A2 horizon. The monosaccharide composition of SG indicates that accumulation of ECM fungal sclerotial polysaccharides might have been responsible for enlarging the molar ratios of (galactose + mannose) /(arabinose + xylose) and EH-glucose/NEH-glucose of forest soils. The proportions of SG saccharides relative to soil saccharides were 3.6, 1.2, and 0.83% for the O, A1 and A2 horizons, respectively. These levels of the proportion are considerable as ECM fugal sclerotia are the products of a limited species among hundreds and thousands of microbial species inhabiting forest soils. The sclerotia forming ECM fungal species such as Cenococcum geophilum may be key sources of forest soil polysaccharides.  相似文献   

日粮中添加植物多酚调控肉色稳定性的作用机制     

赵亚亚  常江  剧柠  罗玉龙 《畜牧兽医学报》2023,54(1):36-47

肉色是衡量肉品质的重要感官指标,直接影响消费者的购买意愿。植物多酚是天然的抗氧化剂,日粮添加植物多酚可通过影响肌红蛋白氧化还原状态、脂质氧化程度及肌纤维类型来改善肉色及其稳定性。为进一步明确日粮中添加植物多酚调控肉色的作用机制,本文对植物多酚介导肉色稳定性的信号途径进行了综述,以期为今后通过在日粮中补充植物多酚调控机体抗氧化能力、促进肌纤维类型转化进而改善肉色提供理论依据。  相似文献   

雨淋对不同泡桐品系木材颜色的影响     

许雅雅  常德龙  胡伟华  黄文豪  张云岭 《东北林业大学学报》2021,49(9):90-94

以白花泡桐(Paulownia fortunei)、毛泡桐(Paulownia tomentoda)、兰考泡桐(Paulownia elongata)、楸叶泡桐(Paulownia catalpifolia)、毛白33(Paulownia×'Tefu(TF)33')、豫林1号(Paulownia fortunei CL'YL01')6品系泡桐木材为研究对象,测量木材雨淋处理前后及自然老化过程中亮度(L?)、变红度(a?)、变黄度(b?)、总色差(ΔE)、白度(W)等色度指标,分析6品系泡桐材色差异、同种泡桐不同立地的材色、泡桐不同部位材色、泡桐材色随时间变化趋势、雨淋对泡桐材色的影响,探索主要泡桐栽培资源的木材颜色特点、雨淋对材色的优化效果、泡桐材色变化规律.结果表明:不同品系泡桐的材色具有显著性差异,其中白花泡桐木材的白度、亮度最高,分别比最低的毛泡桐木材高6.52、6.35;甘肃兰考泡桐木材与河南兰考县兰考泡桐木材的各色度指标均无显著性差异,其各色度指标相差均不超过1;泡桐木材不同部位材色差异很大,轴向的木材白度与亮度由大到小依次为顶部、中部、下部,径向的木材白度与亮度由大到小依次为心部、边部、中间部位;随着时间的变迁,材色有劣化趋势,半年过后材色趋于稳定呈缓慢下降趋势;雨淋后,材色更为均一,色差显著变小,白度和亮度明显升高,其中毛泡桐木材亮度和白度提升最高,分别提升9.00、7.44.  相似文献   

Analysis of cellular responses to Mycoplasma mycoides subsp. mycoides small colony biotype associated with control of contagious bovine pleuropneumonia     

Totté P  Rodrigues V  Yaya A  Hamadou B  Cisse O  Diallo M  Niang M  Thiaucourt F  Dedieu L 《Veterinary research》2008,39(1):8

A better understanding of protective immune memory against contagious bovine pleuropneumonia (CBPP) is needed in order to facilitate the development of safer vaccines based on selected components of the pathogen. For this purpose, cells collected from lymph nodes draining the lungs of Mycoplasma mycoides subsp. mycoides small colony biotype (MmmSC)-infected cattle were stimulated with the pathogen in vitro and evaluated concurrently for proliferation (CFSE based method), expression of activation, memory markers and cytokine production. Direct evidence is presented for a major contribution of CD4+ T cells to the vigorous proliferative and T1 biased cytokine recall responses observed in cattle that have recovered from infection but not in animals developing the acute form of the disease. Two different phenotypes of MmmSC-specific memory CD4 were observed based on CD62L expression and proliferative capacities. Furthermore, recall proliferation of B cells also occurred but was strictly dependent on the presence of CD4. The information provided in this study will facilitate the search for MmmSC antigens that have potential for the development of subunit vaccines against CBPP.  相似文献   

成熟培养基对猪卵母细胞的影响     

郭云云  付博  马红  康雅雅  刘娣 《东北农业大学学报》2012,43(6):16-20

评估NCSU23和TCM199两种培养基对猪卵母细胞体外成熟、孤雌激活以及核移植重构胚发育的影响。分别以NCSU23和TCM199为基础培养基,向其中添加相同浓度的半胱氨酸、激素和生长因子,作为猪卵母细胞体外成熟培养液,培养44 h(5%CO2、39℃、饱和湿度),挑选第一极体;成熟后的卵母细胞进行孤雌激活和核移植重构胚操作,144 h后观察囊胚数。结果表明,NCSU23组与TCM199组对卵母细胞体外成熟(68.18%和67.55%)、孤雌囊胚率(38.40%和37.60%)与核移植囊胚率(23.79%和21.38%)无显著影响(P>0.05),但是两者对孤雌囊胚细胞数的影响差异显著(分别为38.4和37.6个细胞)(P<0.05)。NCSU23成熟培养基能够使胞质成熟完全,提高囊胚细胞数,有利于妊娠的发生。可见,以NCSU23为基础培养基的体外成熟液有利于猪卵母细胞体外发育。  相似文献   

不同水平有机锰(明微矿锰)对肉鸡生长、免疫力和抗氧化活性的影响   总被引：1，自引：0，他引：1  

马娅娅  Bun Sidoeun  刘丹  呙于明  曹宏  郭福存 《中国家禽》2011,33(13)

试验考察了不同剂量羟基蛋氨酸螯合锰--明微矿锰(Mintrex Mn)对0～3周龄肉鸡生长性能、免疫力以及抗氧化活性的影响。试验选用540只1日龄爱拔益加(AA)雄性肉仔鸡,随机分成5组,每组设9个重复,每个重复6只鸡。含27.86mg/kg锰的玉米-豆粕型基础日粮为负对照组,在基础日粮中添加60mg/kg硫酸锰为正对照组,添加30、60、90mg/kg有机锰为试验组,试验期为21d。结果表明,基础日粮中添加有机锰或无机锰对0～3周龄肉鸡体增重、采食量、料肉比没有显著影响,但与硫酸锰添加组相比,添加30、60、90mg/kg有机锰有提高肉鸡日增重的趋势,且随着有机锰添加量的增加肉鸡日增重也逐渐提高;饲料利用率和胫骨锰含量呈线性显著改善和增加(P≤0.05);有机锰能够显著提高0～3周龄肉鸡免疫力和抗氧化活性,添加60mg/kg、90mg/kg Mintrex Mn增加巨噬细胞吞噬指数和血清中谷胱甘肽过氧化物酶和肝脏中锰超氧化物歧化酶酶活,其效果显著高于无机硫酸锰添加组,而添加60mg/kgMintrex Mn能更好地促进肠道免疫球蛋白的分泌和降低肝脏脂质过氧化物的沉积。因此,从肉鸡的生长性能来看,添加使用有机...  相似文献   

Access to technical information and gendered NRM practices: Men and women in rural Senegal     

Keith M. Moore  Sarah Hamilton  Papa Sarr  Soukèye Thiongane 《Agriculture and Human Values》2001,18(1):95-105

Gender differences in knowledge of NRM practices have long been noted in Senegal and throughout Sub-Saharan Africa. An exploration of these differences among a sample of rural Senegalese men and women shows that these differences are, in part, a function of extension agent interventions. The level of knowledge of a set of NRM technologies is associated with contact with three key types of extension agent in rural Senegal: extension team leaders, forestry agents, and women's agents. Analysis of intra-household variation in levels of knowledge shows a degree of interdependence between the knowledge levels of husbands and wives for some practices. However, multi-variate analysis, controlling for personal and contextual factors, clearly demonstrates the independent impact of extension agents on gender differences in rural Senegalese NRM knowledge. It can be concluded that contact with extension agents increases knowledge of NRM practices. In particular, contact with the women's agent is a strong predictor of the level of women's NRM knowledge and, surprisingly, also contributes to the level of men's knowledge. Despite the small number of women's agents in the field, they appear to have significant positive impact on the dissemination of NRM knowledge among rural Senegalese women and men. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献