湖北推广小麦品种(系)高分子量麦谷蛋白亚基组成分析

应用SDS-PAGE技术分析了45份湖北推广小麦品种(系)籽粒的高分子量麦谷蛋白亚基组成。40份材料的高分子量麦谷蛋白亚基组成为同质,5份为异质。在Glu-1位点共检测到9种等位基因变异类型,其中Glu-A1位点有“1、2^ 、Null”3种变异类型,Glu-B1位点有“7、7 8、7 9、14 15”4种,Glu-D1位点有“2 12、5 10”2种。“Null、7 8、2 12”是主要亚基,它们的频率分别是62．5％、60％和72．5％。亚基组合类型有12种,其中(Null,7 8,2 12)亚基组合占30．0％,(1,7 8,2 12)、(1,14 15,2 12)、(Null,7 9,2 12)、(Null,7 8,5 10)4种组合的频率都在10％以上,这5种亚基组合占总组合的72．5％。供试小麦材料品质评分在5～10之间,平均评分为7．0。含5 10亚基的品种(系)所占比例低,是湖北小麦烘烤品质较差的部分原因。     

四川小麦地方品种AS1643中低分子量谷蛋白基因的克隆及其蛋白质的二级结构预测

根据小麦低分子量谷蛋白基因保守区序列设计引物P1/P2, 采用PCR法对四川小麦地方品种AS1643的基因组DNA进行扩增, 获得1条约900 bp的片段, 分离、纯化后连接到载体pMD18-T上, 对筛选阳性克隆测序, 获得1个低分子量谷蛋白基因LMW-AS1643(GenBank登录号: EF190322), 其编码区长度为909 bp, 可编码302个氨基酸残基组成的成熟蛋白。序列分析结果表明, LMW-AS1643具有典型的低分子量谷蛋白基因的基本结构, 其推导氨基酸序列与其它已知的LMW-GS相比, 最高相似性为93.40%。生物信息学分析表明, 在LMW-AS1643低分子量谷蛋白中, 无规则卷曲含量最高, 为67.90 %, 其次是a-螺旋, 占30.46 %, b-折叠含量最少, 为1.64 %。     

High-molecular-weight glutenin subunits in the Cylindropyrum and Vertebrata section of the Aegilops genus and identification of subunits related to those encoded by the Dx alleles of common wheat

The high-molecular-weight (HMW) glute-nin subunit composition of seven species from the Cylindropyrum and Vertebrata sections of the Aegilops genus was studied using SDS-PAGE and Western blot analysis. Two subunits were detected in Ae. caudata and three in Ae. cylindrica. In both species, subunits showing electrophoretic mobility similar to that of 1Dx2 were present. Western blot analysis using a monoclonal antibody (IFRN 1602) specific for the 1Ax and 1Dx subunits of bread wheat showed that the 1Dx-like subunit of Ae. caudata gave only a weak reaction. This indicates that Ae. caudata expresses subunits which are more distantly related to the 1Dx subunits. Two subunits were detected in each of the 60 accessions of Ae. tauschii, including several 1D^tx subunits showing different electrophoretic mobilities from those of the 1Dx subunits commonly found in bread wheat. All of the 1D^tx subunits reacted strongly with IFRN 1602, confirming their close relationship to the 1Dx subunits of bread wheat. Three subunits were found in Ae. crassa (6 x), four in Ae. ventricosa and Ae. juvenalis and five in Ae. vavilovii. In these four species, the subunits that showed electrophoretic mobility similar, or close, to that of 1Dx2 all reacted with IFRN 1602. In addition, Ae. ventricosa contained a subunit showing electrophoretic mobility slower than that of 1Dx2.2, which also reacted with IFRN 1602. These results suggest that the D-genome component in the multiploid Aegilops species express at least one HMW glutenin subunit that is structurally related to the 1Dx subunits of bread wheat. Received: 5 November 1999 / Accepted: 12 February 2000     

Silencing of HMW glutenins in transgenic wheat expressing extra HMW subunits

Wheat HMW glutenin subunit genes 1Ax1 and 1Dx5 were introduced, and either expressed or overexpressed, into a commercial wheat cultivar that already expresses five subunits. Six independent transgenic events were obtained and characterized by SDS-PAGE and Southern analysis. The 1Dx5 gene was overexpressed in two events without changes in the other endosperm proteins. Overexpression of 1Dx5 increased the contribution of HMW glutenin subunits to total protein up to 22%. Two events express the 1Ax1 subunit transgene with associated silencing of the 1Ax2* endogenous subunit. In the SDS-PAGE one of them shows a new HMW glutenin band of an apparent M_r lower than that of the 1Dx5 subunit. Southern analysis of the four events confirmed transformation and suggest that the transgenes are present in a low copy number. Silencing of all the HMW glutenin subunits was observed in two different events of transgenic wheat expressing the 1Ax1 subunit transgene and overexpressing the Dx5 gene. Transgenes and expression patterns were stably transmitted to the progenies in all the events except one where in some of the segregating T₂ seeds the silencing of all HMW glutenin subunits was reverted associated with a drastic lost of transgenes from a high to a low copy number. The revertant T₂ seeds expressed the five endogenous subunits plus the 1Ax1 transgene. Received: 16 June 1999 / Accepted: 29 July 1999     

四川小麦地方品种Gli-1、Gli-2和Glu-1位点的遗传多样性(英文)

运用APAGE和SDS_PAGE方法 ,研究了 89个四川小麦 (TriticumaestivumL .)地方品种Gli_1、Gli_2和Glu_1位点的遗传多样性。在这些地方品种中 ,总共发现 32种醇溶蛋白带型和 3种高分子谷蛋白带型。在Gli_1、Gli_2和Glu_1位点上 ,分别检测出 14、15和 5个等位基因。在每一个位点上 ,出现频率最高的等位基因分别为Gli_A1a(89% ) ,Gli_B1h (46 % ) ,Gli_D1a (6 5 % ) ,Gli_A2a (6 4% ) ,Gli_B2j (45 % ) ,Gli_D2a (48% ) ,Glu_A1c (99% ) ,Glu_B1b (99% )和Glu_D1a (10 0 % )。四川小麦地方品种的Nei’s遗传变异系数平均为 0 .370 6 ,变幅为 0到 0 .70 87;其中Gli_B2位点的遗传多样性最高 ,而Glu_D1位点最低。同时 ,Gli位点的遗传多样性高于Glu_1位点的遗传多样性 ,但又低于现代品种Gli位点的遗传多样性。这些结果说明四川地方小麦品种的遗传基础狭窄。在研究中 ,“成都光头”与“中国春”的醇溶蛋白和高分子谷蛋白的带型完全一致 ,进一步证实“中国春”是“成都光头”的一个选系。     

Genetic Diversity of Gli-1，Gli-2 and Glu-1 Alleles Among Chinese Endemic Wheats

Genetic diversity at Gli-1, Gli-2 and Glu-1 loci was investigated in 32 accessions of Chinese endemic wheat by using acid polyacrylamide gel electrophoresis (APAGE) and sodium dodecyl sulfate (SDS)-PAGE. There were 8 gliadin and 3 high-molecular-weight (HMW)-glutenin patterns in 14 Yunnan hulled wheat ( Triticum aestivum ssp. yunnanese King) accessions, 9 gliadin and 4 HMW-glutenin patterns in 9 Tibetan weedrace ( T. aestivum ssp. tibetanum Shao ) accessions, and 9 gliadin and 5 HMW-glutenin patterns in 9 Xinjiang rice wheat ( T. petropavlovskyi Udacz. et Migusch.) accessions. One accession (i.e. Daomai 2) carried new subunits 2.1+10.1 encoded by Glu-D1 . Among the three Chinese endemic wheat groups, a total of 10, 14 and 11 alleles at Gli-1 locus; 11, 14 and 12 alleles at Gli-2 locus; and 5, 6 and 8 alleles at Glu-1 locus were identified, respectively. Among Yunnan hulled wheat, Tibetan weedrace and Xinjiang rice wheat, the Nei's genetic variation indexes were 0.3798, 0.5625 and 0.5693, respectively. These results suggested that Tibetan weedrace and Xinjiang rice wheat had higher genetic diversity than Yunnan hulled wheat.     

Creating Wheat Germplasm for High Quality Breeding by Monosomic Backcrossing

By crossing bread wheat cultlvar GC8901 with the 1D monosonlc line of Xiaoyan No. 6 and backcrosslng the offsprlng with the Xlaoyan No. 6 1D monosonlc llne for 5 years, high-molecular-welght glutenin subunlts 1Dx5＋1Dy10 from GC8901 have been transferred Into wheat cultivar Xiaoyan No. 6. The BC5F1 offspring lines had been detected by using methods of cytology, marker, molecular marker and six elite single plants with high molecular-welght glutenin subunlts： lAx1, 1Bx14＋1 By15, 1Dx5＋1 Dy10 were Identified. Those lines have high-yleld potential with better agronomic characters and have been used In high quality wheat breeding processes as well.     

小麦-冰草多粒新种质的抗白粉病和高分子量麦谷蛋白亚基组成分析

穗粒数是决定小麦产量的三因素之一,因此通过远缘杂交创造多粒新种质,对于拓宽小麦育种的遗传基础和促进育种水平的持续提高具有重要意义。本研究以通过多年多点鉴定证明具有多粒特性(粒数/穗>80)的31份普通小麦-冰草(Agropyron cristatum,2n=4x=28,PPPP)衍生后代为材料,通过田间接种白粉病生理小种E09进行抗病性鉴定、采用SDS-PAGE方法进行高分子量麦谷蛋白亚基(HMW-GS)组成分析以及株高、有效分蘖等农艺性状调查,发现26份材料表现抗白粉病,12份材料具有优质高分子量麦谷蛋白亚基组合,亚基组成为(2*,7+8,5+10)或(1,7+8,5+10)。其中,8份材料的穗粒数大于80粒、株高小于75 cm、抗白粉病且具有优质高分子量麦谷蛋白亚基组合,这为未来培育兼具高产、优质、抗白粉病小麦新品种提供了重要的物质基础。此外,对多粒、抗白粉病和优质亚基的可能来源进行了讨论。     

CSPG4, a potential therapeutic target, facilitates malignant progression of melanoma

Chondroitin sulfate proteoglycan 4 (CSPG4), a transmembrane proteoglycan originally identified as a highly immunogenic tumor antigen on the surface of melanoma cells, is associated with melanoma tumor formation and poor prognosis in certain melanomas and several other tumor types. The complex mechanisms by which CSPG4 affects melanoma progression have started to be defined, in particular the association with other cell surface proteins and receptor tyrosine kinases (RTKs) and its central role in modulating the function of these proteins. CSPG4 is essential to the growth of melanoma tumors through its modulation of integrin function and enhanced growth factor receptor-regulated pathways including sustained activation of ERK 1,2. This activation of integrin, RTK, and ERK1,2 function by CSPG4 modulates numerous aspects of tumor progression. CSPG4 expression has further been correlated to resistance of melanoma to conventional chemotherapeutics. This review outlines recent advances in our understanding of CSPG4-associated cell signaling, describing the central role it plays in melanoma tumor cell growth, motility, and survival, and explores how modifying CSPG4 function and protein-protein interactions may provide us with novel combinatorial therapies for the treatment of advanced melanoma.     

Bacterial Protein N-Glycosylation: New Perspectives and Applications

Protein glycosylation is widespread throughout all three domains of life. Bacterial protein N-glycosylation and its application to engineering recombinant glycoproteins continue to be actively studied. Here, we focus on advances made in the last 2 years, including the characterization of novel bacterial N-glycosylation pathways, examination of pathway enzymes and evolution, biological roles of protein modification in the native host, and exploitation of the N-glycosylation pathways to create novel vaccines and diagnostics.