首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 253 毫秒
1.
黑麦1R染色体的显微分离、体外扩增及扩增产物的鉴定   总被引:1,自引:0,他引:1  
借助Leitz显微操作器,在国产倒置显微镜下(400×)用玻璃针对处于有丝分裂中期的黑麦根尖细胞中的1R染色体成功地进行了分离。分离出来的1R染色体转入0.5 ml的Eppendorf管中,用蛋白酶K处理,把DNA释放出来;经Sau3A酶切,再与人工合成的Sau3A连接头连接;以连接头的一条链的核苷酸顺序片段为引物对DNA酶切片段进行了PCR扩增。琼脂糖凝胶电泳显示扩增产物的长度大约为300~1000 bp。以生物素分别标记的黑麦总体DNA和小麦rDNA为探针进行斑点杂交,结果表明PCR扩增产物确实来源于黑麦的1R染色体DNA。这个方法为构建黑麦1R染色体亚基因组文库和筛选1R染色体特异性探针奠定了基础。  相似文献   

2.
通过玻璃针分离法从大豆 (GlycinemaxL .)根尖细胞中期分裂相中显微分离出一条染色体 ,经Sau3A人工接头介导的两轮PCR后 ,将其第二轮扩增产物克隆到质粒载体上 ,构建了单染色体质粒文库。经分析 ,该微克隆文库包含约 2 0 0 0 0 0个重组子。随机挑选 1 78个重组子进行鉴定 ,证明该文库的插入片段主要介于 2 0 0~ 1 80 0bp之间 ,平均大小 830bp ;其中 ,中、高拷贝重复序列占 44% ,单、低拷贝序列占 56%。微分离染色体体外扩增产物的原位杂交分析表明它们来自于大豆基因组 ,然而却未能将其只标记在该条微分离的染色体上  相似文献   

3.
采用玻璃针分离法,通过显微操作系统成功地分离到内葵杂3号三交种和单交种的随体染色体,经两轮LA.PCR扩增得到250~1500bp的DNA片段。用各自的基因组DNA标记成探针,与随体染色体扩增产物进行Southern杂交,显示杂交信号,证明内葵杂3号三交种和单交种随体染色体DNA已被成功扩增。将第2轮PCR产物构建质粒文库,得到三交种和单交种克隆数分别约为2.26×10^5和2.57×10^5。各随机挑取30个重组子进行分析,发现插入片段大小分别为200-700bp和200~500bp,平均插入片段大小分别为535bp和480bp。这是染色体微分离与微克隆技术首次在向日葵上的应用。  相似文献   

4.
玉米单染色体的分离和体外扩增   总被引:25,自引:0,他引:25  
胡赞民  党本元 《遗传学报》1998,25(6):545-550
建立了玉米单染色体的分离及体外扩增的方法。取95%乙醇固定后经果胶酶和纤维酶酶解的根尖制备染色体标本,用自制的微细玻璃针在倒置显微镜下挑取目的染色体。染色体DNA经Sau3A酶切后与人工合成的Sau3A连接接头连接,经两次PCR扩增获得足以用于构建单染色体DNA文库的扩增产物。片段大小为0.3~5kb,多数为0.5~3.5kb.与前人研究方法相比,所需底物量少(只需1条染色体),扩增片段大,为植物中小型染色体分离、体外扩增进而进行单染色体DNA文库构建奠定了基础。  相似文献   

5.
水仙单染色体特异文库的构建   总被引:2,自引:0,他引:2  
采用玻璃针分离法,通过显微操作系统成功地分离到一个多花水仙(N arcissus tazetta L.,2n=22)品种的中着丝粒单染色体,将分离到的单染色体放入0.2 mL Eppendorf管中,经去蛋白、S au3A酶切,并在染色体DNA片段两端加上S au3A人工接头后,进行两轮PCR扩增,得到0.3~3.0 kb之间的DNA片段.用水仙基因组DNA标记作探针,与扩增产物进行Sou thern杂交,从而证明单染色体DNA确实已被成功地扩增.将第二轮PCR产物构建质粒文库,随机挑取90个重组子进行分析,发现插入片段主要在600~2 500 bp之间.  相似文献   

6.
小麦6B染色体微切割及其不同片段的DNA文库构建   总被引:2,自引:0,他引:2  
用Nd∶YAG激光微束将处于有丝分裂中期的小麦(Triticum aestivum L.)6B染色体微切割为四段,并用微细玻璃针将每个片段分别回收。将分离的染色体片段DNA用Sau3A接头介导的多聚酶链式反应(LA-PCR)分别扩增。Southern杂交证明4个特定区域的DNA确实来自于小麦基因组。用一系列(42对引物)位于6B染色体和其他染色体上的微卫星序列对微切割的染色体片段的PCR产物进行了验证。结果表明,获得的染色体片段的PCR产物来自于小麦6B染色体。将6B染色体4个片段的第二轮PCR产物克隆到pGEMT-vector中,建立了4个染色体特定区域的基因组文库,命名为R1、R2、R3和R4,分别包含2.1×10~5、2.74×10~5、2.45×10~5和2.93×10~5个重组子克隆。每个文库均随机挑选150个克隆进行质粒的小量制备和酶切验证。结果显示:插入片段大小在300~1800 bp之间,平均大小为820~870 bp,其中43%~48%的克隆为低/单拷贝序列,42%~47%为中/高拷贝序列。本研究为详细分析植物单染色体的不同片段的分子遗传学研究提供了基础。  相似文献   

7.
用Nd:YAG激光微束将处于丝分裂中期的小麦(Triticum aestivum L.)6B染色体微切割为四段,并用微细玻璃针将每个片段分别回收.将分离的染色体片段DNA用Sau3A接头介导的多聚酶链式反应(LA-PCR)分别扩增.Southem杂交证明4个特定区域的DNA确实来自于小麦基因组.用一系列(42对引物)位于6B染色体上的微卫星序列对微切割的染色体片段的PCR产物进行了验证.结果表明,获得的染色体片段的PCR产物来自于小麦6B染色体.将6B染色体4个片段的第二轮PCR产物克隆到pGET-vector中,建立了4个染色体特定区域的基因组文库,命名为R1、R2、R3和R4,分别包含2.1×105、2.74×105和2.93×105个重组子克隆.每个文库均随机挑选150个克隆进行质粒的小量制备和酶切验证.结果显示;插入片段大小在300~1800之间,平均大小为820~870bp,其中43%~48%的克隆为低/单拷贝序列,42%~47%为中/高拷贝序列.本研究为详细分析植物单染色体的不同片段的分子遗传学研究提供了基础.  相似文献   

8.
显微分离出黑麦(SecalecerealeL.)1R染色体,用CohesiveadapterssingleprimerPCR(CASPPCR)方法进行体外扩增,以DIG11dUTP标记扩增产物为探针,进行Southern分子杂交,结果表明扩增产物来自黑麦1R染色体。用1/10体积的连接物转化E.coliDH5α,获得10000多个重组菌落。经酶切分析,克隆子的插入片段为250~500bp,为进一步筛选1R染色体的分子标记打下了基础  相似文献   

9.
首先对显微分离出的黑麦(SecalecerealeL.)1R染色体进行了两轮Sau3A连接接头介导的PCR扩增(LA_PCR)。经Southern杂交证实这些染色体扩增片段来源于基因组DNA之后,再利用1R染色体的第二轮扩增产物、黑麦基因组DNA、rDNA基因为探针,与其根尖细胞中期分裂相进行染色体原位杂交,发现微分离的1R染色体体外扩增产物中包含大量的非该染色体特异性重复序列,而其信息量却较黑麦总基因组少;当以适量的黑麦基因组DNA进行封阻时,微分离染色体的体外扩增产物成功地被重新定位在中期分裂相的一对1R染色体上,说明微分离1R染色体的PCR扩增产物中的确包含了该染色体特异性的片段。此外,以从1R染色体微克隆文库中筛选出的一单、低拷贝序列和一高度重复序列分别为探针,染色体原位杂交检测发现,这一高度重复序列可能为端粒相关序列;而单、低拷贝序列却未检测到杂交信号。这些结果从不同侧面反映出染色体着染技术是证实微分离、微切割染色体的真实来源及筛选染色体特异性探针的有利工具。建立了可供参考的植物染色体着染实验体系,为染色体微克隆技术在植物中的进一步应用提供了便利。  相似文献   

10.
首先对显微分离出的黑麦(Secalecereale.L.)1R染色体进行了两轮Sau3A连接接头介导的PCR扩增(LAPCR)经Southern杂交证实这些染色体扩增片段来源于基因组DNA之后,再利用IR染色体的第二轮扩增产物,黑麦基因组DNA,rDNA基因为探针,与其根尖细胞中期分裂相进行染色体原位杂交,发现微分离的IR当色体体我扩增产物中包含大量的非该染色体特异性重复序列,而其信息量却较黑麦总  相似文献   

11.
Conclusion Even a cursory look at the ethnographic literature on other Northwest Coast societies reveals some striking similarities with the Tlingit way of conceptualizing aristocrats as special persons. Thus the Kwakiutl referred to their chiefs as real or complete people, who were heavier than commoners. The Coast Tsimshian called their highest aristocrats real or ripe persons, in contrast to the low-ranking ones, who were described as unhealed or green. The Coast Tshimshian also referred to their chiefs as strong, heavy, and solid like a rock. The neighboring Gitksan contrasted the chiefs, described as people who were good and clean and stayed put, with the commoners, who were said to be dirty, ignorant, and always moving around. Because spirits of the dead liked to return to persons who were clean and showed respect by giving away wealth and feasts, there was considerable moral and practical pressure on the aristocrats to remain pure, train knowledgeable and clean heirs, and continue potlatching. Finally, among the Haida, rank was tied to a wider system of symbolic classification, associating aspects of food, space, clothing, ritual pollution and the ethic of industry with attributes of seniority.While some of the symbolic associations of aristocratic status are culture specific, others are present in several, if not all, of the NWC cultures. What we need is a comparative symbology of aristocratic status, which would combine the reanalysis of the existing ethnographic data with the introduction of some new materials that can still be obtained in the field. Such work would be the best tribute to Irving Goldman himself and to our common illustrious ancestors—Franz Boas and Marcel Mauss.Sergei Kan is Professor of Anthropology at Dartmouth College.  相似文献   

12.
The role of -tocopherol uptake system in human erythrocyte in the uptake of plasma -tocopherol has been suggested. However no information is available on -tocopherol uptake activity of human erythrocytes in the presence of high levels of D-glucose which is known to lead to pathological alterations in different cells including human erythrocytes. Therefore, in order to examine the effect of D-glucose on the binding of -tocopherol to human erythrocytes, the binding characteristics of -tocopherol to these cells were established first. Binding of [3H]-tocopherol to human erythrocytes was both saturable and specific. Scatchard analysis of -tocopherol binding to these cells showed the presence of two independent classes of binding sites with widely different affinities. The high affinity binding sites had a dissociation constant (Kd1) of 90 nM with a binding capacity (n1) of 900 sites per cell, whereas the low affinity binding sites had a dissociation constant (Kd2) of 5.2 M and a binding capacity (n2) of 105,400 sites per cell. Trypsin treatment abolished all the -tocopherol binding activity. Competition for the binding of -tocopherol to human erythrocytes was effective with other homologues of -tocopherol (-tocopherol, -tocopherol and -tocopherol) and their potency was almost equal to -tocopherol itself. The order of preference was -tocopherol > -tocopherol -tocopherol -tocopherol. Incubation of human erythrocytes with various concentrations of D-glucose did not affect -tocopherol uptake activity. Our data demonstrate the presence of an -tocopherol uptake system in human erythrocytes and that the -tocopherol uptake activity is not modulated by the presence of D-glucose.  相似文献   

13.
用高效液相色谱法和酶解的方法检测了银杏叶片磷脂酰甘油(PG)脂肪酸的分子种组成和位置分布,确定银杏叶片PG主要分子种的脂肪酸组成(sn-1/sn-2)是18:3/16:1(3t),18:3/16:0,18:2/16:1(3t),18:2/16:0,18:1/16:1(3t),16:0/16:1(3t),18:1/18:1,18:/16:0和16:0和16:0/16:0。银杏叶片PC脂肪酸组成和位置分布的分析结果表明,C18脂肪酸主要位于sn-l位,16:1(3t)只分布于sn-2位,16:0在sn-1位和sn-2位上均有发现。sn-1位上的不饱和度∑u大于sn-2位上的∑u。  相似文献   

14.
The geometrical structures of phenylthiosemicarbazone (HAPhTSC) conformers have been obtained by geometry optimizations using density functional theory (DFT) calculations at the B3LYP/6-31G(d) and B3LYP/6-311G(d,p) levels of theory. Six thioamino and 24 thioimino tautomers of HAPhTSC have been found. Six tautomerization reactions between thioamino and thioimino tautomers occurring via transition states and their corresponding activation energies have been obtained. Conformational pathways for tautomerizations and interconversions of HAPhTSC conformers have been presented. Tautomerization between the most stable species of thioamino (Atttcc) and its thioimino (Itttcct) tautomer is an endothermic reaction, H0=18.17 kcal mol–1 and its log K=–13.74, at 298.15 K. Thermodynamic quantities of tautomerizations, interconversions of HAPhTSC conformers and their equilibrium constants are reported. The geometry of the zinc complex with HAPhTSC, found as a Zn(HAPhTSC)2Cl2 structure, has been obtained using B3LYP/6-31G(d) calculations. Binding of the Zn(HAPhTSC)2Cl2 complex is an exothermic and spontaneous reaction.Figure Conformational notation defined as a name consisting of a letter A for a thioamino tautomer followed by c for cis or t for trans isomerism of five dihedral angles of (C4-C3-C2-N3), (C3-C2-N3-N2), (C2-N3-N2-C1), (N3-N2-C1-N1) and (N2-C1-N1-H2), serially, or a letter I for b thioimino tautomer followed by c for cis or t for trans isomerism of six dihedral angles of (C4-C3-C2-N3), (C3-C2-N3-N2), (C2-N3-N2-C1), (N3-N2-C1-N1), (N2-C1-N1-H2) and (N2-C1-S-H1), serially.Electronic Supplementary Material Supplementary material is available for this article at  相似文献   

15.
Distribution of Zearalenone-Producing Fusarium Species in Japan   总被引:2,自引:2,他引:0       下载免费PDF全文
One hundred sixty-six isolates of Fusarium spp. from domestic cereal grains, feed, and other sources were examined for their ability to produce zearalenone on autoclaved moist rice grains. They belonged to the following species (number of producers/number tested): F. roseum (9/28), F. roseum (Culmorum) (3/4), F. roseum (Gibbosum) (2/5), F. roseum (Avenaceum) (1/2), F. roseum (Scirpi) (0/1), F. tricinctum (1/4), F. tricinctum (Sporotrichiella) (0/7), F. lateritium (1/1), F. episphaeria (0/2), F. moniliforme (0/3), F. oxysporum (0/12), F. rigidiusculum (0/4), F. solani (0/4), F. splendens (0/1), F. nivale (0/2), and Fusarium spp. (15/86). Zearalenone was isolated from molded rice by ethanol extraction and purified by column chromatography. Selected isolates of F. roseum M-3-2 and F. roseum (Gibbosum) A-O-2 produced 50 to 100 mg of zearalenone per kg of rice. Increased yields (250 to 407 mg/kg of rice) were obtained by F. roseum M-3-2 when the substrate was supplemented with 1% peptone.  相似文献   

16.
Hyperglycemia has been linked to increased oxidative stress, a resultant endothelial cell dysfunction, and, ultimately, apoptosis. Heme oxygenases (HO-1/HO-2) and the products of their activity, biliverdin/bilirubin and carbon monoxide (CO), play a physiological role in the vascular system. The effects of heme-mediated HO-1 induction, CO, and biliverdin on urinary 8-epi-isoprostane PGF2 and endothelial cell sloughing were examined in an animal model of streptozotocin (STZ)-induced diabetes. Hyperglycemia itself did not affect HO-1 and HO-2 protein levels, but caused a net decrease in HO activity. Weekly heme administration induced HO-1 protein, as demonstrated by immunohistochemistry and Western blot analyses. Administration of biliverdin or the CO donor, CORM-3, decreased urinary 8-epi-isoprostane PGF2, P < 0.5 compared to diabetes. Hyperglycemia increased endothelial cell sloughing; 8.2 ± 0.8 cells/ml blood in control rats vs. 48 ± 4.8 cells/ml blood in diabetic rats (P < 0.05). Heme administration significantly increased endothelial cell sloughing in diabetic rats (98 ± 8.1 cells/ml blood, P < 0.0007) whereas biliverdin modestly decreased endothelial cell sloughing (26 ± 3.5 cells/ml blood, P < 0.003). Administration of CORM-3 to diabetic rats resulted in a significant decrease in endothelial cell sloughing to 21.3 ± 2.3 (P < 0.001). Administration of SnMP to CORM-3 diabetic rats only partially reversed the protective effects of CORM-3 on endothelial cell sloughing from 21.3 ± 2.3 to 29 ± 2.1 cells/ml, thus confirming a direct protective of CO, in addition to the ability of CORM-3 to induce HO-1 protein. These results demonstrate that exogenously administered CO or bilirubin can prevent endothelial cell sloughing in diabetic rats, likely via a decrease in oxidative stress, and thus represents a novel approach to prophylactic vascular protection in diabetes.  相似文献   

17.
18.
The conformational properties of the oligosaccharide chain of GM1 ganglioside containingN-glycolyl-neuraminic acid, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer, were studied through NMR nuclear Overhauser effect investigations on the monomeric ganglioside in dimethylsulfoxide, and on mixed micelles of ganglioside and dodecylphosphocholine in water. Several interresidual contacts for the trisaccharide core--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-were found to fix the relative orientitation of the three saccharides, while the glycosidic linkage of the terminal -Gal-was found to be quite mobile as the -Gal-(1-3)--GalNAc-disaccharide exists in different conformations. These results are similar to those found for two GM1 gangliosides containingN-acetyl-neuraminic acid and neuraminic acid [1].Abbreviations Ganglioside nomenclature is in accordance with Svennerholm [23] and the IUPAC-IUB Recommendations [24] GM3(Neu5Ac) II3Neu5AcLacCer, -Neu5Ac-(2-3)--Gal-(1-4)--Glc-(1-1)-Cer - GM3(Neu5Gc) II3Neu5GcLacCer, -Neu5Gc-(2-3)--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu5Ac) II3Neu5AcGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu5Gc) II3Neu5GcGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu) II3NeuGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu-(2-3)]--Glc-(1-1)-Cer - GD1a IV3Neu5AcII3Neu5AcGgOse4Cer, -Neu5Ac-(2-3)--Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GalNAc-GD1a IV4GalNAcIV3Neu5AcII3Neu5AcGgOse4Cer, -GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - Neu neuraminic acid - Neu5Ac N-acetyl-neuraminic acid - Neu5Gc N-glycolyl-neuraminic acid - Cer ceramide  相似文献   

19.
Data are presented from a 10-year (1984 to 1993) study of a Salmo trutta population in the Afon Cwm, a small tributary of the Afon Dyfi, mid-Wales. The stream is a spawning and nursery area for sea trout. Growth of trout within the stream can be summarized by a von Bertalanffy growth coefficient ( K ) of 0·310, with asymptotic length (1∞) 21·6 cm and with length at age 1 of 7·6 cm. Mean population density in the whole stream varied from year to year between 0·05 and 0·60 0-group trout m−2 and between 0·05 and 0·70 older trout m−2. Mean biomass varied, between years, from 0·1 to 3·5 g m−2 for 0-group and from 1·3 to 10·4g m−2 for older trout. Loss between 3 and 5 months of age appeared to be proportionate at about 50 to 60% and instantaneous loss rate from 5 to 53 months of age varied from 0·04 to 0·10 month−1 and was positively correlated with cohort number at 3 months of age. Production between 3 and 53 months of age varied between cohorts from 3 to 8 g m −2 live weight.  相似文献   

20.
The activity of the phosphatidylcholine transfer protein from bovine liver toward phosphatidylcholine isomers carrying a long and a short fatty acyl chain on either the sn-1- or sn-2-position was determined by way of the monolayer-vesicle assay. In this assay equimolar mixtures of the isomers were spread at the air/water interface and their transfer measured to the vesicles in the subphase initiated by addition of the transfer protein. The following isomers were tested: 1-decanoyl-2-[3H]oleoyl-sn-glycero-3-phosphocholine (C10:0/[3H]C18:1-PC) and 1-oleoyl-2-decanoyl-sn-glycero-3-phospho[14C]choline (C18:1/C10:0-[14C]PC); 1-lauroyl-2-[3H]oleoyl-sn-glycero-3-phosphocholine (C12:0/[3H]C18:1-PC) and 1-oleoyl-2-[14C]lauroyl-sn-glycero-3-phosphocholine (C18:1/[14C]C12:0-PC); 1-myristoyl-2-[3H]oleoyl-sn-glycero-3-phosphocholine (C14:0/[3H]C18:1-PC) and 1-oleoyl,2-myristoyl-sn-glycero-3-phospho[14C]choline (C18:1/C14:0-[14C]PC). It was found that the protein transferred C10:0/[3H]C18:1-PC twice as fast as C18:1/C10:0-[14C]PC. Similar differences in rate were observed for C12:0/[3H]C18:1-Pc and C18:1/[14C]C12:0-PC but not for the isomers carrying myristic acid. We propose that the transfer protein can discriminate between PC isomers due to the presence of distinct binding sites for the sn-1- and sn-2-acyl chain (Berkhout et al. (1984) Biochemistry, 23, 1505-1513).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号