槭叶铁线莲(Clematis acerifolia Maxim.)群落物种生态位研究

槭叶铁线莲（Clematis acerifolia）为太行山特有植物,但数量稀少且分布零散,其生存状况受到学者和政府部门的高度关注。本文通过对河北省易县葫芦峪沟谷新发现的槭叶铁线莲群落的典型样地调查,以物种重要值作为生态位计量指标,对各物种生态位宽度、生态位重叠和生态位相似性进行了定量分析,对槭叶铁线莲的生存安全状况进行了评估。结果表明：在调查样地中共记录到14科15属17种植物,群落物种组成较为简单,槭叶铁线莲在大部分调查样地中的重要值最大,占据优势地位,其他物种重要值相对较低;群落内所有物种中,槭叶铁线莲的生态位宽度最大（B_i=6.264）,绒毛绣线菊（Spiraea dasyantha）次之（B_i=5.144）,其他种类较小;所有物种组成的136个种对中,生态位完全重叠（Q_ik=1）、重叠程度较高（0.5≤Q_ik<1）和重叠程度较低（Q_ik<0.5）的种对比例分别为8.09%、16.91%和75.00%,生态位完全相似（C_ik=1）、相似程度较高（0.5≤C_ik<1）和相似程度较低（C_ik<0.5）的种对比例分别为8.09%、5.88%和86.03%,大部分物种之间生态位重叠程度和相似性都处于较低水平;槭叶铁线莲与其他物种构成的16个种对中,62.50%的种对生态位重叠程度较低（Q_ik<0.5）,81.25%的种对生态位相似性程度较低（C_ik<0.5）,反映出群落内各物种间对资源和空间的竞争较为温和,群落较为稳定,槭叶铁线莲在其分布生境中生存状况相对安全;本文研究表明,利用生态位分析方法可以作为珍稀濒危物种生存状态和安全风险评估的一种方法。     

滇西北高原藏区小型兽类体表寄生蚤的生态位特征

为探讨云南西北高原藏区小型兽类体表寄生蚤的生态位特征,根据海拔和地形等自然环境特点,在德钦县选取42个调查样点,划分为5个垂直带,4种生境,采用铗夜法和笼日法捕获小兽,梳捡其体表寄生蚤,运用生态位宽度指数（B_i）和生态位重叠指数（NO）对其生态位特征进行分析。结果：共梳捡寄生蚤1275头,隶属4科9亚科17属33种,其中迪庆额蚤和云南栉眼蚤为优势种,常见种12种,稀有种19种。在海拔资源轴上,B_i值前三分别是特新蚤德钦亚种0.698、棕形额蚤0.690、斯氏新蚤川滇亚种0.667;生境资源轴上,B_i值前三分别是：无值大锥蚤0.630、特新蚤指名亚种0.57、特新蚤德钦亚种0.537;寄主资源轴上,B_i值前三为绒鼠怪蚤0.584、迪庆额蚤0.567、棕形额蚤0.553;多维生态位宽度来看,特新蚤德钦亚种和迪庆额蚤B_i值较大,分别为1.031、1.019。海拔、生境、寄主生态位重叠指数中,有意义的重叠种对分别占比35.6%、39.39%、9.28%;完全不重叠的种对分别占比26.89%、18.56%、51.14%;完全重叠的种对分别占比2.27%、13.26%和0.19%。三种生态因子中,优势种和常见种的生态位宽度值较大,对资源的利用能力和竞争能力较强。不同生态因子的生态位重叠指数格局不同,与资源轴本身有关。有意义的重叠和完全不重叠的种对占比较多,前者多为优势种、常见种、稀有种两两之间重叠,重叠指数越高,竞争关系越激烈;完全不重叠的种对多为稀有种之间,无资源利用竞争关系。总体来说,德钦县小兽体表寄生蚤种类丰富,生态位分化较为均匀,本研究可为该地蚤传疾病的监测防控提供生态学依据。     

2017–2019年中国南方五省规模化养猪场副猪格拉菌血清型、耐药性及β-内酰胺类耐药基因bla-TEM分子特征分析

【目的】旨在分析当前规模化养殖场副猪格拉菌(Glaesserella parasuis)优势血清型、耐药特性、耐药基因与分子特征。【方法】对源自规模化养猪场21株副猪格拉菌临床分离株,采用PCR鉴定血清型;利用K-B纸片扩散法鉴定其对25种抗生素的耐药表型;采用PCR检测bla-_TEM、bla-_NDM和bla-_CTX等7种耐药基因,并采用Chi-square test和Fisher exact test分析耐药表型和耐药基因型的相关性;耐药基因目的条带测序,并应用CLC Sequence Viewer软件分析β-内酰胺类耐药基因(bla-_TEM)编码蛋白氨基酸关键位点差异与耐药性的关系。【结果】21株副猪格拉菌临床分离株的优势血清型为4和12型;对β-内酰胺类药物苯唑西林的耐药性较强,耐药菌占比达61.9%(13/21);多重耐药菌株占比高达90.5%(19/21);β-内酰胺类耐药基因bla-_TEM携带率较高(52.4%,11/21),且bla-_TEM与β-内酰胺类药物青霉素G、苯唑西林和头孢拉定的耐药性显著相关,部分bla-_TEM编码氨基酸存在可能与副猪格拉菌耐药能力有关的差异位点。【结论】本研究表明,规模化养猪场的副猪格拉菌多重耐药情况仍很严重,并明确了被调查区域β-内酰胺类药物耐药率高的主要原因是携带耐药基因bla-_TEM,为加强对规模化养猪场副猪格拉菌耐药性监测提供理论依据。     

哈密露天煤矿不同环境介质微生物群落特征分析

【背景】干旱区露天煤矿开采过程中产生的粉尘颗粒物加剧了土壤生态环境的恶化和矿区空气质量的下降,针对煤矿区土壤和粉尘颗粒物的微生物群落组成的研究鲜有报道。【目的】研究新疆哈密南湖乡露天煤矿土壤、粉尘及大气PM_2.5颗粒物中的微生物群落结构和多样性特征,并预测潜在的功能类群。【方法】采用高通量测序技术,对煤矿露天采坑区和电厂粉煤灰堆放区的土壤、粉尘及大气PM_2.5颗粒物的微生物真菌及细菌群落组成进行比对分析。【结果】矿区优势真菌类群来自子囊菌门(Ascomycota)和担子菌门(Basidiomycota),优势细菌类群来自变形菌门(Proteobacteria)和放线菌门(Actinobacteria)。真菌和细菌群落的丰富度及α多样性在整个矿区内无显著性差异,大气PM_2.5颗粒物的细菌群落生态位宽度显著大于露天采坑区和粉煤灰区。矿区内的土壤和PM_2.5颗粒物样本中均发现了一些丰度差异显著的功能类群,真菌特征功能类群为腐生营养型类群,细菌特征功能类群主要包括甲烷营养型类群、几丁质酶类细菌类群等。【结论】露天煤矿区粉尘可能对区域内土壤和PM_2.5颗粒物的微生物群落结构产生重要影响,具有煤组分降解功能的特定微生物类群可能是维持矿区土壤生态安全的重要微生物学机制之一。     

干扰方式对香蕉园入侵杂草群落种间关联的影响

【目的】探讨干扰方式对香蕉园入侵杂草群落种间关联的影响。【方法】在样方调查的基础上,运用方差比率法(V_R)、χ²检验、联结系数A_c、Ochiai指数I_O、Spearman秩相关分析法研究人工挖除、药剂除草、机械割除3种干扰方式下香蕉园入侵杂草的种间关联特征。【结果】白花鬼针草、阔叶丰花草、鹅肠菜为香蕉农田入侵杂草的主要建群种,入侵杂草群落总体方差比率V_R均大于1,3种杂草管理方式群落种间总体呈显著正联结趋势。χ²检验显示,人工挖除方式有3个种对显著联结,1个种对(香附子-两耳草)极显著联结;药剂除草方式有3个种对显著联结;机械割除方式有6个种对显著联结,3个种对(鹅肠菜-败酱叶菊芹、阔叶丰花草-败酱叶菊芹、阔叶丰花草-无刺含羞草)极显著联结。联结系数A_c、联结程度I_O分析得到的结果与χ²检验基本一致,达到显著和极显著联结的种对较少,大部分入侵杂草种间联结性较弱。Spearman相关性分析显示,人工挖除、药剂除草、机械割除3种干扰方式的入侵杂草显著相关的种对比例均较低,分别为18.2%、14.3%、13.6%。【结论】3种干扰方式的香蕉园入侵杂草种间关系均较松散,机械割除方式的杂草群落更趋于稳定。阔叶丰花草在不同干扰方式下与种间都有显著的关联性,对杂草群落稳定共存发挥重要作用,在香蕉园杂草生物防治中具有利用潜力。     

蟒河猕猴国家级自然保护区蛾类群落生态位特征

为了解山西蟒河猕猴国家级自然保护区蛾类群落与环境资源的相互关系,采用Levins生态位宽度和Pianka生态位重叠指数对山西蟒河猕猴国家级自然保护区蛾类群落结构和生态位进行分析。结果表明:在本保护区内采集蛾类标本隶属24科,其中螟蛾科、夜蛾科、卷蛾科和尺蛾科为优势类群;该保护区内主要蛾类的时间生态位宽度高于空间生态位宽度,各类群间存在程度不同的生态位重叠现象,其中尺蛾科和螟蛾科的时间生态位重叠指数(0.913)和空间生态位重叠指数(0.852)均高于其他类群;天蛾科和舟蛾科时间生态位重叠指数(0.772)也较高,但其空间生态位重叠指数(0.218)却较低;除天蛾科与毒蛾科时间生态位相似性系数(0.247)、天蛾科与大蚕蛾科(0.258)和舟蛾科与天蛾科(0.226)空间生态位相似性系数较小外,大多蛾类类群间生态位相似性系数均较大。说明蟒河猕猴国家级自然保护区主要蛾类群落之间生态位竞争较激烈。     

同域分布中华鬣羚与中华斑羚时空生态位特征

为了解同域分布有蹄类在环境复杂的山地森林生境中以何种方式维持种间关系以实现稳定共存,基于物种分布模型与日活动模式分析了四川省岷山、邛崃、大相岭、小相岭和凉山五大山系同域分布中华鬣羚(Capricornis milneedwardsii)与中华斑羚(Naemorhedus griseus)的时空生态位特征。结果显示:(1)在四川省五大山系,中华鬣羚的适宜栖息地面积为28006.07 km²,占研究区总面积的26.18%,其中高适宜栖息地面积为10015.90 km²,中华斑羚的适宜栖息地面积为21073.32 km²,占研究区总面积的19.71%,其中高适宜栖息地面积为8396.22 km²;(2)中华鬣羚与中华斑羚在生境因子选择上相似性高、栖息地重叠面积大,其空间生态位重叠度指数D=0.776,I=0.949,其适宜栖息地的主要重叠区域位于岷山和邛崃山系;(3)中华鬣羚与中华斑羚的日活动节律重叠指数为0.812;(4)中华鬣羚与中华斑羚属于同域分布的资源利用型竞争物种,中华鬣羚的存在会显著影响中华斑羚的日活动节律(P=0.016);二者同域分布时都会增加其昼间活动强度,并增加活动高峰期的强度及持续时间。本研究初步分析了中华鬣羚与中华斑羚的时空生态位特征,揭示了二者在空间、时间生态位上种群共存及种间竞争的耦合关系。研究有利于深入理解同域分布动物时空生态位特征、近缘物种的共存机制及种间竞争关系,为有蹄类等珍稀野生动物种群及栖息地的保护提供科学参考。     

亏祖山秋季不同海拔土壤纤毛虫优势种生态位及其与环境因子的关系

为深入了解拉萨河流域亏祖山不同海拔梯度秋季土壤纤毛虫优势种生态位及其与环境因子的关系,于2015年10月在亏祖山共设置11个样点,用土壤采样器采用梅花五点式采集土样,同时记录相应的理化因子,土样在实验室自然风干后,采用"非淹没培养法"和"活体观察法"进行培养和形态学鉴定。亏祖山11个样点中,共鉴定到土壤纤毛虫132种,隶属3纲14目48科66属,其中14个优势种(Y＞0.02)。土壤纤毛虫优势种生态位宽度最大的是明显长颈虫(Dileptus conspicuus),生态位宽度最小的是卵圆前管虫(Prorodon ovum)和似肾形虫(Colpoda simulans)。土壤纤毛虫优势种生态位重叠值位于0.02-0.99之间,生态位重叠值最低的为似肾形虫(Colpoda simulans)和卵圆前管虫(Prorodon ovum),而生态位重叠值最高的为念珠角毛虫(Keronopsis monilata)和膨胀肾形虫(Colpoda inflata)。亏祖山14个优势种生态响应速率之和为负值,表明土壤纤毛虫优势种处于衰退阶段。土壤纤毛虫优势种与环境因子的典范对应分析(CCA)结果显示,轴1和轴2累计解释物种变异的37.8%,表明轴1和轴2能较好地反映优势种与环境因子的关系;总氮是显著解释变量,对优势种变异的解释率为17.6%。综上分析得出,明显长颈虫(Dileptus conspicuus)、点滴半眉虫(Hemiophrys pectinata)和前口瞬目虫(Glaucoma frontata)对土壤环境适应能力较强,具有广泛的生态适应幅度;土壤纤毛虫优势种生态位重叠值低,种间竞争比较弱;土壤纤毛虫优势种之间以及优势种和环境之间尚未达到相对的动态平衡,优势种正处衰退阶段;总氮是影响拉萨河流域土壤纤毛虫优势种分布和生态位的主要环境因子。     

焦化废水O/H/O生物处理工艺二级好氧生物反应器的微生物结构和功能

【背景】焦化废水O/H/O生物处理工艺的二级好氧生物反应器O₂具有剩余污染物矿化和完全硝化功能,对废水的达标排放有重要作用。【目的】阐明O₂生物反应器的微生物结构和功能。【方法】利用16S rRNA基因测序,研究O₂生物反应器的微生物多样性和组成并进行功能预测,揭示其共现性特征和环境影响因子。【结果】O₂的优势菌门以变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、绿菌门(Chlorobi)为主。主要菌属中红游动菌属(Rhodoplanes)、溶杆菌属(Lysobacter)、硫杆菌属(Thiobacillus)等参与化学需氧量(chemical oxygen demand,COD)、酚类(phenols)和硫氰酸盐(thiocyanate,SCN^-)等剩余污染物的去除,亚硝化弧菌属(Nitrosovibrio)和硝化螺菌属(Nitrospira)分别作为氨氧化细菌(ammonia-oxidizing bacteria,AOB)和主要的亚硝酸盐氧化细菌(nitrite-oxidizing bacteria,NOB)。功能预测结果显示苯甲酸酯降解、氨基苯甲酸酯降解、氯烷烃和氯烯烃的降解、氟代苯甲酸酯降解和硝基甲苯降解是外源物质生物降解和代谢的前五大通路,广泛分布在主要菌属中,验证了微生物降解剩余污染物的作用。基因pmoA/B/C-amoA/B/C、hao和nxrA/B编码相关的酶,组成了完整的硝化途径。共现网络结果揭示溶杆菌属、Candidatus Solibacter和红游动菌属在O₂生态中的重要地位。通过冗余分析(redundancy analysis,RDA)表明COD和NH₃是影响O₂微生物群落的主要因素。【结论】红游动菌属和溶杆菌属是O₂中最核心的功能菌属,在污染物矿化和维持群落生态稳定上有重要作用。亚硝化弧菌属和硝化螺菌属是硝化作用的核心菌属。O₂中的代谢通路以剩余污染物矿化和完全硝化为主,微生物群落主要受COD和NH₃的影响。本研究阐明了O₂的微生物结构与功能,为焦化废水O/H/O生物处理工艺的改进提供了微生物学上的依据。     

舟山长白海域主要游泳动物生态位及其分化研究

基于2016年10月（秋季）和2017年4月（春季）舟山长白海域的渔业资源调查数据,运用生态位宽度、生态位重叠及冗余分析等方法,研究了主要游泳动物的生态位,种间生态关系及生态位分化。结果显示：春、秋季主要游泳动物分别11种与8种,两季生态位宽度值差异均较大,其中春季广生态位种、中生态位种均为3种,而秋季均为2种,窄生态位种分别为5种与4种。相对重要性指数（IRI）与生态位宽度值（B_i）之间呈显著正相关。生态位重叠程度不均衡,秋季主要游泳动物的生态位重叠程度较高,O_ik > 0.6的种对数占总种对数的42.86%;春季的重叠程度较低,仅占总种对数的21.82%。RDA分析得出温度、盐度为影响主要游泳动物分布的直接因素,而溶解氧、悬浮物和pH等则为重要因素,主要游泳动物在这些资源维上存在生态分化现象。综上,分布在毗邻杭州湾口且位于著名的岱衢洋的主要游泳动物种类总体营养级较低却生态宽度值较大,大黄鱼（Larimichthys crocea）、黄姑鱼（Nibea albiflora）等一些传统的高营养级、典型特色经济种类却沦为生态位宽度极小的一般种或少有种,群落种类显著减少,资源量下降,群落结构与功能退化,稳定性下降。因此,加强游泳动物资源修复、保护与管理十分迫切且具有重要意义。     

Removal of wastewater pathogen indicators in a constructed wetland in Leon, Spain

This paper studies the seasonal presence and removal of the pathogenous micro-organisms Escherichia coli, total coliforms (TC), Clostridium perfringens (Cp), faecal streptococci (FS), Giardia cysts, Cryptosporidium oocysts and helminth eggs, in a constructed wetland treatment system. The removal efficiency of this system with respect to the indicator micro-organisms achieved maximum values in spring and autumn at 99.9% for E. coli and TC, respectively, in winter at 97.0% for FS, in summer at 100% for Clostridium and throughout the year, also at 100%, in the case of Giardia cysts, Cryptosporidium oocysts and helminth eggs. In general, very low protozoan and helminth egg counts were found, and the system demonstrated efficient reduction of the wastewater indicator pathogens.     

Vermicomposting in the management of pig-waste in Hong Kong

The treatment and disposal of pig-waste in Hong Kong has received much attention in recent years but, following any of the presently used treatment processes, solids remain to be further stabilized. Vermicomposting is a waste stabilization technique which converts waste into potentially recyclable materials such as worm protein and worm casts. The earthworm, Pheretima asiatica, can stabilize most of the solids arising from the treatment of pig-waste, including raw pig manure, suggesting that vermicomposting has a high potential as a unit process in the management of pig-waste in Hong Kong.S.H. Wong is with the Environmental Protection Department, Hong Kong; and D.A. Griffiths is with the Department of Botany, University of Hong Kong, Hong Kong.     

Isolation of spore-forming bacilli from mosquitoes in natural breeding habitats in Iraq

New isolates of spore-forming bacilli from larvae and pupae of 3 species of mosquitoes are recorded in central Iraq.Bacillus sphaericus Meyer and Neide was isolated fromCulex pipiens (L.) larva.Bacillus carotarum Koch andBacillus cereus Frankland & Frankland were isolated fromTheobaldia longiareolata (Macquart) pupae.Bacillus laterosporus Laubach andBacillus thuringiensis (H 18) were isolated fromAedes caspius (Pallas) larvae. In addition, unidentifiedBacillus spp. were isolated fromCx. pipiens, T. longiareolata andAe. caspius larvae. Examination of soil samples collected from mosquito natural breeding habitats revealed isolates ofB. cereus, Bacillus thuringiensis H4a 4b; H 12 and H 16 and an unidentifiedBacillus sp.

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Résumé Des souches bactériennes sporogènes sont isolées de moustiques qui se trouvent dans la région centrale de l'Irak. Les résultats obtenus sont les suivants:Bacillus sphaericus Meyer & Neide [Culex pipiens (L.), larve],Bacillus carotarum Koch etBacillus cereus Frankland & Frankland [Theobaldia longiareolata (Macquart), nymphe],Bacillus laterosporus Laubach etBacillus thuringiensis (H 18) [Aedes caspius (Pallas), larvel]. L'examen des larves deCulex pipiens. T. longiareolata etAe. caspius, ainsi que l'analyse des échantillons du sol prélevés dans la région montrent la présence deBacillus cereus, Bacillus thuringiensis H4a 4b; H12 plus H16 et d'autresBacillus non identifiés.

     

Comparison between the allergenic airborne pollen in Trieste and at Lozzo di Cadore (Italy) in 1989

Summary A comparative study was carried out between aeroallergenic pollen spectra in Trieste and at Lozzo di Cadore. The two localities were found to be different on a five-day running mean basis as to the 8 pollen taxa monitored by the National Aerobiological Monitoring Network managed by the Italian Association of Aerobiology (AIA). In the zone of Lozzo the pollination curve of the spring flowering taxa showed a lag of about one month due to the colder climate. Lozzo di Cadore showed a poor airborne pollen content,Corylus and Graminaceae being prevailing. Trieste has a higher airborne pollen diversity and longer pollination times because of its higher floristic and vegetational complexity. In Trieste the allergenic pollen spectrum showed great quantities ofOstrya, Quercus, Oleaceae, Graminaceae and of ruderal taxa, widespread over the area, due to man's influence.     

Inbreeding in a french peasant population

Genealogical pedigrees were collected from 976 farming couples who lived in a canton of central France in the XIXth and XXth century. Several methods (genealogical, isonymic and probability of origin of genes) were used to appraise the evolution of the biological structure of this population, which has gone through two phases. The first phase from 1800 to the World War I, shows gene flows between the farming population of the canton and those of neighbouring rural districts which are linked to an increase in consanguineous marriages. The second phase, from 1920 onwards, shows important gene flow from distant areas. This trend implies a decrease in consanguineous marriages.     

Phylogenetic relationships in theCampanulales based onrbcL sequences

Phylogenetic relationships within the angiosperm orderCampanulales were investigated by comparative sequencing of the chloroplast generbcL. CompleterbcL sequences were obtained for ten species in six families within the order. These data were analyzed along with previously publishedrbcL sequences from other taxa (for a total of 117 species) within the subclassAsteridae and outgroups, producing 32 equally parsimonious trees. A subset consisting of 44 of these taxa was then chosen and more rigorous analyses performed, resulting in four equally parsimonious trees. Results indicate that two major clades roughly corresponding to traditionally circumscribedAsterales andCampanulales exist as sister taxa. In particular, therbcL trees indicate thatSphenoclea is not a member ofCampanulales orAsterales, thatPentaphragma is more closely allied toAsterales thanCampanulales, that theCyphiaceae are not monophyletic, thatCampanulaceae andLobeliaceae are not sister taxa, and thatStylidiaceae are correctly placed withinCampanulales.     

Lactic acid bacteria in fermented foods in Thailand

Traditional fermented foods (fish, meat and vegetable products), produced by many different processes, are eaten in many parts of Thailand. Lactic acid bacteria are responsible for the souring and ripening of these foods. Homofermentative strains of Lactobacillus pentosus, L. plantarum and Pediococcus pentosaceus are dominant in foods with low salt concentrations whereas P. halophilus strains are present in foods containing high salt. Strains of Lactobacillus sake, other Lactobacillus spp., P. acidilactici and P. urinaeequi are frequently found. Heterofermentative strains of L. brevis, L. confusus, L. fermentum, L. vaccinostercus, other Lactobacillus spp., and of Leuconostoc spp. are distributed as minor bacteria and strains of Staphylococcus, Enterococcus and Halobacterium are occasionally isolated.S. Tanasupawat is with the Department of Microbiology, Faculty of Pharmaceutical Sciences. Chulalongkorn University, Bangkok 10330, Thailand; K. Komagata is with the Department of Agricultural Chemistry, Tokyo University of Agriculture, Sakuragaoka 1-1-1, Setagaya-ku, Tokyo 156, Japan.     

Thioglycosides as glycosylating agents in oligosaccharide synthesis

A review is given of the use of thioglycosides as glycosyl donors in oligosaccharide synthesis. Both indirect use, by conversion of the thioglycoside into a glycosyl halide and direct use, by electrophilic activation of the thioglycoside, are discussed.Abbreviations DMTST dimethyl(methylthio)sulfonium trifluoromethanesulfonate - Bz benzoyl - Bn benzyl - pNBz p-nitrobenzoyl - Phth phthallyl - Ph phenyl     

Biosynthesis of glycoconjugates in mitochondrial outer membranes

The results reported in this paper show two distinct ways for the incorporation ofN-acetylglucosamine into mitochondrial outer membranes. The first one is the glycosylation of dolichol acceptors, which is indicated by the inhibition of the synthesis of these products by the inhibitors of the dolichol intermediates (tunicamycin and GDP). The second one is the incorporation ofN-acetylglucosamine into protein acceptors directly from UDP-N-acetylglucosamine. This second way of glycosylation is only localized in mitochondria outer membranes.The existence of a direct route forN-glycoprotein biosynthesis has been based on the following evidence. First, the synthesis of theN-acetylglucosaminylated protein acceptors was not inhibited by tunicamycin or GDP. Second, the addition of exogenous dolichol-phosphate did not change the rate of biosynthesis of glycosylated protein material. Third, the sequential incorporation ofN-acetylglucosamine and mannose from their nucleotide derivatives in the presence of GDP and tunicamycin led to the synthesis of glycosylated protein material which entirely bound to Concanavalin A-Sepharose. The oligosaccharide moiety of the glycosylated protein material resulting from the direct transfer of sugars from their nucleotide derivatives to the protein acceptor is of theN-glycan type. On sodium dodecylsulphate polyacrylamide gel electrophoresis, this glycosylated material migrated as a marker protein with a molecular weight between 45 000 and 63 000. HPLC chromatofocusing analysis revealed that the fraction studied was anionic. The oligosaccharide moiety of the glycoprotein material can only be elongated by the incorporation ofN-acetylglucosamine and galactose from their nucleotide derivatives.