长白猪×蓝塘猪及其杂种基因组甲基化片段克隆与分析

应用甲基化敏感扩增多态性(MSAP)技术对6头长白公猪和50头蓝塘母猪及5头长白×蓝塘杂交F1代3个群体基因组DNA胞嘧啶甲基化位点进行检测,旨在克隆和分析父母代猪及其杂种F1代之间基因组DNA共同甲基化片段和差异片段,并找到其同源基因.结果显示,从MSAP条带中分离、克隆得到18条3个群体共同的甲基化片段、10条母代独有的甲基化片段和9条杂交一代独有的甲基化片段,其中有1条3个群体共有的甲基化片段通过EST拼接和电子延伸后在NCBI数据库中找到同源基因,即猪类酪氨酸蛋白激酶Lyn基因(GeneID:LOC100152890,序列号:XM_001926250).结果表明,长蓝杂交F1代与其父母代之间的基因组甲基化存在异同,为通过MSAP技术克隆猪基因组DNA甲基化片段及寻找其对应的甲基化基因提供可能,也会为将来研究这些甲基化基因表达调控机制奠定基础.     

东乡野生稻耐冷渐渗系DNA甲基化水平和模式变化研究

根据水稻全基因组和特定位点的CpG岛序列设计引物,采用McrBC酶酶切DNA,以东乡野生稻耐冷渐渗系(IL5335和IL5423)及其双亲为试材,研究其基因组和特定位点的DNA甲基化水平和模式变化特征,探讨甲基化变异对野生优异基因渐渗的影响。结果显示:(1)在覆盖全基因组的83个CpG岛中,IL5335和IL5423的基因组甲基化频率分别为46.6%和53.8%,低于受体亲本协青早B的62.6%;大部分(75.9%~80.7%)受体亲本的甲基化模式在两耐冷渐渗中能稳定遗传,另外一些位点发生了甲基化模式的改变,主要表现为脱甲基化(13.3%~18.1%)和过甲基化(4.4%~6.0%)。(2)在耐冷QTLs区间,两耐冷渐渗系的甲基化水平为13.3%~26.7%,远低于受体亲本的61.4%;它们在该区域的甲基化模式变异主要为脱甲基化(33.3%~40.0%),高于全基因组的平均变异率。(3)分析逆转座子Houba和Osr14区域的51个CpG岛发现,耐冷渐渗系在该区域具有较高频率的甲基化修饰和较低的甲基化模式变异。研究表明,种间杂交渐渗诱发了受体亲本广泛的甲基化水平和模式变异,为野生优异基因的有效利用提供了新的机遇和挑战。     

高粱314A、13A与苏丹草杂种F1代的农艺特性及细胞学分析

分析了雄性不育系高粱314A、13A与3种苏丹草杂交组合F1代的生育、株高、穗型、分蘖性、产量、光合性能及细胞遗传学等特性.结果表明各杂交种F1植株高大,平均株高343～369 cm,穗型呈双亲中间型,种子活秆成熟,生育期130～137 d,分蘖性强,单株平均分蘖数6.3～9.0个,花粉可育率91%以上,自然结实率63.88%～67.79%;F1鲜草产量比各自父本苏丹草增加16.17%～32.73%,种子产量增加41.40%～52.97%,杂种超亲优势19.29%～48.68%,茎叶比3.05～3.66;F1净光合速率、气孔导度、胞间CO2浓度均明显超过其各自亲本,CO2固定能力强;F1代PMCMⅠ染色体均能正常配对,平均构型为2n=2x=20(10Ⅱ),但棒状二价体频率明显高于其双亲,原亲本间的遗传组成仍存在着一定的差异;试验证明母本314A、13A的雄不育发生在减数分裂后的小孢子形成期.     

RAPD及SRAP两种分子标记技术对苦瓜杂交种纯度的鉴定分析

以F1代苦瓜杂交种如玉11号及其亲本为材料,利用RAPD及SRAP两种分子标记技术对这3种苦瓜基因组DNA进行比较分析,以获得该杂交种及其亲本(或母本)差异目的基因片段。经过多次对该3种苦瓜叶片DNA提取,PCR扩增及其PCR产物的琼脂糖凝胶电泳分析,在供试的46个RAPD引物及121对SRAP引物中,筛选出1个RAPD引物及1对SRAP引物能区分该苦瓜杂交种及其母本种子,通过进一步验证分析,证明该两种分子标记的特异引物可作为如玉11号苦瓜杂交种子的纯度鉴定之用。     

植物人工异源多倍体的遗传及后遗传变化

据估计,70%以上的显花植物在其生活史上至少发生过一次以上的多倍化。传统的有关多倍性的观点认为,多倍体基因组应是其双亲基因组的积加。但是,有些合成异源多倍体的基因组发生了广泛的遗传及后遗传变化。这些变化包括亲本DNA序列丢失、核仁显性、DNA甲基化模式改变、基因沉默、反转座子激活等。亲本序列丢失可能与部分同源序列间重组有关,而亲本基因沉默可能与同源性依赖的基因沉默及RNA干涉等有关。     

菊黄东方鲀、暗纹东方鲀及其杂交F1代肌肉营养成分的比较分析

为了了解菊黄东方鲀(Takifugu flavidus)、暗纹东方鲀(T.obscurus)及其杂交F1代的肌肉营养特征,利用生物化学方法,从每类实验样本中取9尾对其肌肉中的粗蛋白、粗脂肪、水分、粗灰分和氨基酸成分进行了测定和分析。结果显示:(1)杂交F1代在生长方面具有明显的杂交优势,与亲本之间存在着显著差异(P0.05),杂交F1代的体重为其亲本的1.48~1.77倍;(2)杂交F1代肌肉水分含量与其母本含量相近,但粗脂肪含量均较亲本少(P0.05),粗蛋白含量则与亲本差异不显著(P0.05);(3)除色氨酸和胱氨酸外,16种氨基酸均在肌肉样本中被检测到,除甲硫氨酸外,其余15种氨基酸间含量均存在着显著性差异(P0.05)。菊黄东方鲀(♀)×暗纹东方鲀(♂)杂交F1代的总氨基酸含量最高,而暗纹东方鲀(♀)×菊黄东方鲀(♂)F1代总氨基酸含量则介于两亲本之间。对其必需氨基酸总量进行分析发现,菊黄东方鲀与其正反杂交F1代之间均存在显著性差异(P0.05),而暗纹东方鲀与其正反杂交F1代之间差异不显著(P0.05);(4)肌肉营养品质评价结果表明,菊黄东方鲀(♀)×暗纹东方鲀(♂)杂交F1代的鲜味氨基酸含量为26.68%,明显高于双亲样本(菊黄东方鲀22.28%、暗纹东方鲀25.20%),而暗纹东方鲀(♀)×菊黄东方鲀(♂)F1代的鲜味氨基酸总量(23.30%)较其父本偏高,但低于其母本。研究结果表明,杂交东方鲀的肌肉营养综合了双亲的优良特性,特别是是菊黄东方鲀(♀)×暗纹东方鲀(♂)杂交F1代,拥有最高的鲜味氨基酸含量,具有推广价值。     

泰国玉米生产和遗传改良研究

玉米是泰国一种重要的谷类作物。2000年种植面积估计为1.30百万公顷,籽粒产量约4.48百万吨。杂交种种植面积占到玉米总面积的85?08％,以单交种类型为主,占到杂交种各种类型的74％,其次为三交种。玉米生产主要限制因素为病害(高粱霜霉、南方锈、茎腐、大斑、小斑病)、虫害(亚洲玉米螟)和干旱胁迫。玉米种质发展和品种遗传改良开始于1950年,主要从事单位为农业部农业厅和大学部肯色萨大学。先后育成Suwan 1、Suwan 2、Suwan 3,Nakhon Sawan 1,Suwan 5等改良群体和Suwan Complex、KS 23 broadbase syn.。并从中提取出Ki21、45、Ni1等几十个优良系,组配出Suwan 2301、3851、Nakhon Sawan 72等十多个优良杂交种。分别应用10个群体双列杂交法、顶交法和优良适应品种与外引种质杂交法等,确定了如下几个杂种优势模式：(Suwan 1,Suwan 3)×(Caripeno DMR,KS6);(Suwan 1,Suwan 3,KS6选育系)×(Ki21,Mo17衍生系);[KS 23(S)C2,Suwan 5(S)C3]×[Suwan 1(S)C11]。 Abstract：Maize is one of major cereal crops in Thailand.In the year 2000,it was estimated that the planted area is of 1.30 million hectares and produces about 4.48 million tons.The amount of hybrid seed was 17.76 thousand tons with acquiring 85.08％ of total planted area.Production constraints main were biotic and abiotic factors,involving diseases of sorghum Downy Mildew,Southern rust,Southern corn leaf blight,Northern corn leaf blight and Charcoal stalk rot and inset of the Asian corn borer,and drought stress.The maize research for germplasm development and varietal genetic improvement in Thailand was initiated by the Department of Agriculture in 1950 and Kasetsart University in 1958.Several elite populations of Suwan 1,Suwan 2,Suwan 3, Suwan 5,KS6,KS23,and Suwan-Complex were developed.The superior lines of Ki21,Ki 45,Ni1 etc and elite hybrids of Suwan 2301,Suwan 3851,Nakhon Sawan72＃ etc. were bred.In order to search for heterotic partners,diallel crosses of elite populations with differing in genetic background were performed by the breeding program.The several heterotic partners were determined.i.e.(Suwan 1,Suwan3)×(Caripeno DMR,KS6);(Inbred lines from Suwan 1,Suwan 3,KS6)×(Ki21,a Mol7 derivative line) and [KS 23(S)C2,Suwan 5(S)C3]×[Suwan 1(S)C11].     

吉林爆玉米遗传距离与杂种优势关系的研究

根据吉林省80个爆玉米自交系数量性状的表现,估算了它们之间的遗传距离。又估算了这80个自交系间随机组配的67个杂交组合F1代小区产量、爆粒率和膨胀倍数的杂种优势。相关和回归分析表明,F1代产量的对照优势与其双亲之间的遗传距离呈显著的二次曲线关系,而F1代品质特性爆粒率和膨胀倍数的对照优势与其双亲之间的遗传距离无确定性关系。因此,可以根据亲本间数量性状的综合遗传差异——遗传距离来预测吉林省爆玉米杂种一代的产量优势。 An experiment was conducted in 1990 to 1991 at the university,to study the relationships between genetic distance,cluster analysis and heterosis in popcorn(Zea mays var.everta).Results showed that there is no sense in cludtering parental lines for prediction of yield heterosis,but blood pedigree can beidentifed from cluster analysis.The relation between genetic divergence or distance and yield heterosis of F1 hybrids can be predicted from the genetic distances of their parental lines according to this model,but no definite relation could be found between parental genetic divergence and the quality heterosis of F1 hybrids.     

玉米根系水流导度差异的生理形态原因分析

在人工气候室水培条件下,研究了水分胁迫对不同基因型玉米杂交种及其亲本根系水流导度（Lpr）变化的影响,并从生理和形态角度对其差异进行了分析。结果表明：表型抗旱的杂交种F1代（户单四号）整株根系水流导度最高,具有根系水流导度上的杂种优势现象。对其差异的生理和形态因素分析表明,F1代水流导度高与其高脯氨酸含量、低MDA含量和低质膜透忡有关。同时表明,根系的形态特征对根系的水流导度也存在一定的影响。     

马铃薯杂种F1的SSR鉴定

为选育抗黑痣病、高产优质的马铃薯新品种,选用引进品种‘大西洋’分别与‘陇薯6号’、‘陇薯7号’杂交,获得了杂种F1代,利用SSR标记技术对‘大西洋’与‘陇薯6号’的42个杂种F1、‘大西洋’与‘陇薯7号’的9个杂种F1单株进行了鉴定。从59对SSR引物中筛选出2对在亲本间存在差异、扩增稳定、条带清晰的引物S184和STM1049,用于‘大西洋’ב陇薯6号’杂种F1、‘大西洋’ב陇薯7号’杂种F1及其亲本的基因组DNA扩增。SSR带型分析显示,杂种F1的SSR带型呈双亲互补型、缺失型、父本型和母本型4类,依据带型特征鉴定出供试的51个马铃薯杂种F1单株均为真杂种,表明SSR分子标记技术用于马铃薯杂种真实性鉴定是可行的。该研究可为进一步开展马铃薯杂交后代目标性状优异株系选育提供依据。     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Similar aerosol emission rates and viral loads in upper respiratory tracts for COVID-19 patients with Delta and Omicron variant infection

Highlights
1 Aerosol emission rates of Delta or Omicron patients were similar.
2 Viral loads in upper respiratory tract of Alpha, Delta and Omicron patients were similar.
3 Viral loads in upper respiratory tract of vaccinated or unvaccinated Delta patients had no difference.     

Recombinant human interferon-α1b inhibits SARS-CoV-2 better than interferon-α2b in vitro

Highlights
1) A comprehensive evaluation method for anti-SARS-CoV-2 drugs was established based on RT-qPCR, TCID₅₀ method, and immunofluorescence.
2) A significant antiviral effect of rHuIFN-α1b was shown with EC₅₀=0.12 IU/mL in Vero cells and EC₅₀=0.52 IU/mL in Calu-3 cells, which was better than rHuIFN-α2b (EC₅₀=0.25 IU/mL in Vero cells and EC₅₀=2.48 IU/mL in Calu-3 cells).
3) rHuIFN-α1b has a good potential in the application of anti-COVID-19 therapy.     

Continued antigenic variation of highly pathogenic avian influenza A (H7N9) virus in laying hens in China, 2020–2021

Highlights
1. 13 strains of H7N9 viruses from laying hens in 2020 and 2021 were identified.
2. H7N9 viruses in China comprised at least 11 genotypes.
3. H7N9 viruses are high pathogenic in chickens, not in ducks.
4. The most H7N9 viruses cross-reacted poorly with H7-Re3 antiserum.
5. The H7-Re3 vaccine was unable to prevent H7N9 infection.