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1.
Summary Cytoplasmic male sterility (cms) was found in plants derived from the F2 progeny of fertile, normal cytoplasm plants of the inbred R181 pollinated with a genetic stock carrying the recessive nuclear gene, iojap. The male sterile plants were maintained by back-crossing with the inbred W182BN which maintains all known sources of cytoplasmic male sterility. The new male sterile progeny were found to exhibit stable male sterility under field conditions in two environments. However, they were partially fertile in the hot, dry summer of 1983 at Aurora, NY. It was found that these lines were restored by lines that characteristically restore cms S group cytoplasms. Pollen phenotype studies indicated that the restoration was gametophytic in nature, also characteristic of the cms S group. Agarose gel electrophoresis of undigested mitochondrial DNA (mtDNA) from these steriles indicated that these lines have the S-1 and S-2 episomes characteristic of the cms S group. Restriction endonuclease digest patterns of mtDNA from these sterile lines digested with BamH I indicated that these steriles fit into the CA subgroup of the cms S group. The new source of cms has been designated cms Ij-1.  相似文献   

2.
The leaves of mistletoe (Viscum album L.) contain three galactose- and N-acetylgalactosamine-specific isolectin groups (ML I, II, III). The groups ML I and ML III showed strong cryoprotective activity during freezing and thawing of isolated spinach (Spinacia oleracea L.) thylakoid membranes, while ML II showed no such activity. The cryoprotective efficiency of the proteins was correlated with their relative hydrophobicity, as determined by a fluorescence titration assay. We found that the frost hardiness of mistletoe leaves was seasonally regulated under natural conditions. While leaves harvested in winter were not damaged by freezing to −20 °C, leaves harvested in July had already suffered 70% electrolyte leakage after freezing to −5 °C. Likewise, the amount of ML I and ML III varied during the year, with the highest amounts of these cryoprotective lectins in winter and early spring and the lowest amounts during the summer months. There was no comparable change in the amount of ML II. These data suggest that some lectins may play a role in the stabilization of cellular membranes under environmental stress conditions. Received: 18 December 1996 / Accepted: 29 March 1997  相似文献   

3.
Using behaviourally-defined adjectives, observers rated individuals in a colony of rhesus monkeys on a seven-point scale. Principal component analysis of the ratings produced three main components: CI and CII were stable over three years, and CIII arose from the introduction of new items in the third year. Component I can be described as ranging fromConfident toFearful; and adult males scored higher on it than did adult females or one- to five-year olds. Component II ranged fromActive toSlow; and adult males scored higher on it than did adult females. Component III ranged fromSociable toSolitary; and adult males scored less on it than did adult females or one- to five-year olds. In addition, there was a positive correlation between scores of mothers and their one year olds on CI and CIII.  相似文献   

4.
辽东三块石天然次生林的排序   总被引:4,自引:0,他引:4       下载免费PDF全文
 利用主成份分析(PCA)和相互平均法(RA),把辽宁省新宾县三块石林场次生林划分为三个类型:Ⅰ蒙古栎林;Ⅱ胡桃楸-水曲柳林,Ⅲ杂木林。影响这些次生林排序的主导因子是海拔和坡向。Fisher判别分析验证了PCA对该地区次生林分类是正确的,同时还可以利用Y= 0.0383X1+0.0362X2+0.0944X3+0.0133X4+0.1191X5-0.0510X6,预测调查地区的次生林类型。  相似文献   

5.
Purified carbonic anhydrase isozymes I, II, and III (CA I, CA II, CA III) from various sources were treated with 2,3-butanedione and their bicarbonate dehydration reactions followed. The specific activities of human and bovine CA I and CA II and chicken CA III were not affected by the butanedione treatment, whereas the activities of human, gorilla, and bovine CA III were rapidly activated. These findings suggest that one, or both, of the two arginyl residues which appear to be unique to the active sites of the mammalian CA III isozymes are modified by butanedione.  相似文献   

6.
The composition of the essential oils of fifteen populations of Cistus salviifolius L. (Cistaceae) from Crete (Greece) and their interpopulation variability was investigated by GC-MS. 167 compounds were identified representing an average of 96–100% of the oil composition. Labdane diterpenes were detected and identified in the essential oils of Cistus salviifolius L., for the first time. The results obtained from GC-MS analysis of the oils were submitted to a Principal Component Analysis (PCA). Three main chemotypes (clusters) were differentiated. All the essential oils were tested for their antimicrobial activity against Gram-positive and Gram-negative bacteria. Only chemotype III having camphor as a major constituent was active against Gram-positive bacteria. Camphor, viridiflorol, longiborneol, phyllocladene, abietatriene and cis-feruginol are the main constituents, while the group of oxygenated sesquiterpenes has the highest percentage composition.  相似文献   

7.
Cross-reactions among carbonic anhydrases (CAs) I, II, and III were studied using a variety of antisera: (1) a rabbit antiserum to bovine CA III, (2) mouse antisera to human CA I, CA II, and CA III; and (3) five monoclonal antibodies prepared by the hybridoma technique using splenocytes from a mouse immunized with human CAs I and II and bovine CA III. Cross-reactions between CAs were readily found by binding assays using these antisera. Human CA I, but not human CA II, inhibited the reaction of the rabbit anti-CA III with its homologous antigen. Mouse antisera to CA I or CA II bound the homologous I or II with nearly as great efficiency as the autologous isozyme and sometimes weakly bound CA III. Mouse antisera to CA III frequently bound CA I or II. These cross-reactions were confirmed by the first use of hybridoma-prepared, monoclonal antibodies to CAs. The mouse monoclonal antibodies to CA isozymes varied in the amount of cross-reactivity among I, II, and III: at one extreme, one monoclonal was highly specific for the autologous CA III; at the other extreme, one monoclonal weakly reacted with some examples of CAs I, II, and III.This work was supported by NIH Grant GM-24681 and a grant from the National Foundation-March of Dimes.  相似文献   

8.
The present study aimed to determine the serum trace elements (copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg)) along with erythrocyte carbonic anhydrase (CA) activity and effect of intervention with safe drinking water for 5 years in the school children of fluorosis endemic area. For this purpose, three categories of villages were selected based on drinking water fluoride (F): Category I (control, F?=?1.68 mg/L), category II (affected F?=?3.77 mg/L), and category III (intervention village) where initial drinking water F was 4.51 mg/L, and since the last 5 years, they were drinking water containing <?1.0 mg/L F. The results revealed that urinary F was significantly (P?<?0.05) higher in category II compared to categories I and III. A significant (P?<?0.05) increase in serum Cu and Mg was observed in category II compared to category I. Serum Zn and Ca was significantly (P?<?0.05) decreased in categories II and III compared to category I. The erythrocyte CA activity was decreased in the category II compared to category I. However, in the category III, erythrocyte CA activity was comparable to the control group. In conclusion, F exposure altered elemental homeostasis which has restored to some extent on intervention by safe drinking water for 5 years in school-going children.  相似文献   

9.
Mitochondrial DNA (mtDNA) from 13 cytoplasmic male-sterile (cms) lines from diverse sources were characterized by Southern blot hybridization to pearl millet and maize mtDNA probes. Hybridization patterns of mtDNA digested with PstI, BamHI, SmaI or XhoI and probed with 13.6-, 10.9-, 9.7- or 4.7-kb pearl millet mtDNA clones revealed similarities among the cms lines 5141 A and ICMA 1 (classified as the S-A1 type of cytoplasm based on fertility restoration patterns), PMC 30A and ICMA 2. The remaining cms lines formed a distinct group, within which three subgroups were evident. Among the maize mitochondiral gene clones used, the coxI probe revealed two distinct groups of cytoplasms similar to the pearl millet mtDNA clones. The atp9 probe differentiated the cms line 81 A4, derived from P. glaucum subsp. monodii, while the coxII gene probe did not detect any polymorphism among the cms lines studied. MtDNA digested with BamHI, PstI or XhoI and hybridized to the atp6 probe revealed distinct differences among the cms lines. The maize atp6 gene clone identified four distinct cytoplasmic groups and four subgroups within a main group. The mtDNA fragments hybridized to the atp6 gene probe with differing intensities, suggesting the presence of more than one copy of the gene in different stoichiometries. Rearrangements involving the coxI and/or rrn18-rrn5 genes (mapped within the pearl millet clones) probably resulted in the S-A1 type of sterility. Rearrangements involving the atp6 gene (probably resulting in chimeric form) may be responsible for male sterility in other cms lines of pearl millet.  相似文献   

10.
In order to obtain information of the gross-structure of glutelin, chemical and physicochemical properties of S-cyanoethyl glutelin were investigated. Glutelin remained at the origin in polyacrylamide gel electrophoresis, while S-cyanoethyl glutelin migrated in the gel and resolved into two components. The ion-exchange chromatography by carboxymethyl Sephadex C-50 gave further resolution of S-cyanoethyl glutelin into one neutral component corresponding to the anodic component and two basic components corresponding to the cathodic component in polyacrylamide gel electrophoresis at neutral pH. The amino-terminal residue of the neutral component (Component I) could not be detected by the fluorodinitrobenzene method, while both the basic components (Component II and III) had only glycine as the amino-termini. On the basis of dinitrophenyl-glycine found, the minimum molecular weights of Component II and III were calculated at about 35,000 and 43,000 respectively. The relative concentration of these three components was as follows; Component I: Component II: Component III=8:1:1. These facts obviously indicate that glutelin is a very large molecule composed from these three components polymerized by disulfide linkage, Component I being the major subunit.  相似文献   

11.
目的:探究血清癌胚抗原(carcinoembryonic antigen,CEA)、糖类抗原19-9、细胞角蛋白19片段(cytokeratin19 fragements,CYFRA21-1)与结直肠腺癌的病理相关性。方法:选择于我院接受治疗的80例结直肠腺癌患者为病例组,选择同期于我院接受治疗的50例良性结直肠病变患者为良性对照组,选择我院体格检查的50例健康个体为对照组,分别采集三组个体的血样并进行CEA、CA19-9以及CYFRA21-1水平的检测,并比对三组个体上述因子阳性表达率、因子水平,同时分析三种因子同结直肠腺癌患者TNM分期相关性,最后探究三种因子对结直肠腺癌的诊断价值。结果:(1)以CEA≥2.805μg/L、CA19-9≥39 U/m L、CYFR21-1≥3.3 ng/mL为临界值,结果显示病例组CEA阳性率51.25%,CA19-9阳性率31.25%,CYFR21-1阳性率40.00%,明显高于良性组的10.00%、20.00%和10.00%,高于对照组的8.00%、12.00%和2.00%(P<0.05);(2)比较显示病例组患者的CEA、CA19-9以及CYFR21-1水平明显高于良性对照组以及对照组(P<0.05),良性对照组CEA、CA19-9以及CYFR21-1水平明显高于对照组(P<0.05);(3)比较显示IV期结直肠腺癌患者CEA、CA19-9以及CYFRA21-1水平明显高于III期以及I+II期(P<0.05),III期三种因子水平明显高于I+II期(P<0.05);(4)CEA对结直肠腺癌诊断一致性71.25%,灵敏度65.00%,特异度90.00%;CA19-9诊断一致性46.25%,灵敏度35.00%,特异度80.00%;CYFRA21-1诊断一致性55.00%,灵敏度46.67%,特异度80.00%;联合诊断一致性95.00%,灵敏度95.00%,特异度95.00%。结论:血清CEA、CA19-9以及CYFRA21-1对结直肠腺癌具有较明确的诊断价值,不同病理分期患者中表达差异明显,可以考虑将联合诊断作为结直肠腺癌鉴别方式之一,推广于临床中。  相似文献   

12.
Three new linkage groups of enzyme loci are described usingPoeciliopsis monacha × P. viriosa-derived interspecific backcross hybrids. Comparison to known linkage groups of the confamilial genusXiphophorus shows homology betweenXiphophorus linkage group I andPoeciliopsis linkage group III,Xiphophorus linkage group II andPoeciliopsis linkage group I, andXiphophorus linkage group IV andPoeciliopsis linkage group IV. Comparison of the gene content of other fish, amphibians, and mammal syntenic groups suggests retention of plesiomorphic vertebrate gene arrangements in at least two poeciliid linkage groups. Expansion of thePoeciliopsis gene map should be of utility in the identification of tumor regulatory genes through demonstration of linkage to biochemical markers.This work was supported by NSF Grants BSR 19355 and BSR 16569 and NIH Grants CA 44303 and CA 39729 to R. S. Nairn and D.C.M. and NIEHS Grant EHS 1P50ES 0384801A1 to R.J.S.  相似文献   

13.
Allozyme genotypes of nine Populus maximowiczii clonal varieties originating in China and Japan were determined for 35 loci coding for 12 enzyme systems in root tips. The interclonal variability was controlled by 13 polymorphic loci. Seven unique multilocus genotypes were identified. The unique genotypes differed from each other on an average of 6.73 loci. Principal Component (PC) 1 from the Principal Component Analysis of the clonal allozyme genotype data separated the clones into two distinct groups; one consisting of clones of Chinese and another clones of Japanese origins. Japanese clones of different sources were further differentiated by the PC 2. Allozyme genotypes were found to be useful for identification of clones and differentiation of their geographic origins.  相似文献   

14.
Comparison of x-ray crystal structures of several legume lectins, co-crystallized with sugar molecules, showed a strong conservation of amino acid residues directly involved in ligand binding. For pea (Pisum sativum) lectin (PSL), these conserved amino acids can be classified into three groups: (I) D81 and N125, present in all legume lectins studied so far; (II) G99 and G216, conserved in almost all legume lectins; and (III) A217 and E218, which are only found in Vicieae lectins and are possibly determinants of sugar-binding specificity. Each of these amino acids in PSL was changed by site-directed mutagenesis, resulting in PSL molecules with single substitutions: for group I D81A, D81N, N125A; for group II G99R, G216L; and for group III A217L, E218Q, respectively. PSL double mutant Y124R; A126S was included as a control. The modified PSL molecules appeared not to be affected in their ability to form dimeric proteins, whereas the sugar-binding activity of each of the PSL mutants, with the exception of the control mutant (as shown by haemagglutination assays), was completely eliminated. These results confirm the model of the sugar-binding site of Vicieae lectins as deduced from X-ray analysis.  相似文献   

15.
Summary Mitochondrial (mt) and chloroplast (ct) DNAs from sugar beet carrying normal fertile and different cytoplasmic male sterile (cms) cytoplasms were compared by restriction analysis and for the occurrence of minicircles. One of the cms materials had the Owen cms cytoplasm currently used for hybrid production in sugar beet; the other three cms materials were derived from wild Beta beets. The mtDNAs from two of the latter cms types (C 7051, C 8640) differed from both the Owen and the fertile cytoplasms in fragment patterns seen after restriction enzyme analysis and in minicircle composition. The third cms type (C 8684) differed from the Owen cytoplasm in mini-circle composition, but restriction enzyme analysis revealed no differences. The presence of the different minicircles was confirmed by Southern hybridization using minicircle-specific clones. All bands hybridized as predicted by gel electrophoresis except a band in the cms type C 8640, which migrated in a similar manner as the c.c.c. form of the a minicircle. This band hybridized only faintly to a minicircle a-specific probe and could be removed by treatment with nuclease S1. In contrast to the large mtDNA variation, restriction analysis of ctDNA detected little variation between cytoplasms. The molecular characterization of the new sources of cms supports the results of previous crossings. Two of the cytoplasms are not only of independent origin, but are also most likely functionally different and thus may be of value in future production of hybrid sugar beet varieties.  相似文献   

16.
Four classes of Vibrio parahaemolyticus mutants defective in the phosphoenolpyruvate: glucose phosphotransferase system (PTS) are described. They were phenotypically different, and were defective in different PTS components. The components designated tentatively as II, I, III, and H were separated by gel filtration of a wild-type extract. Component II, which was specific for glucose and found in the particulate fraction, is probably membrane-bound, glucose-specific enzyme II. Both components I and H were soluble proteins, and the latter was relatively heat-stable. Component I was required for phosphorylation of glucose, trehalose, fructose, mannose, and mannitol. Component H was also required for phosphorylating all the above sugars except fructose. These and some additional findings strongly suggest that components I and H correspond to enzyme I and HPr, respectively. Component III, a soluble heat-stable protein, may be equivalent to the sugar-specific factor III found in other organisms, although it seems to participate in phosphorylating two sugars, glucose and trehalose. There were evidences that mutants defective in components I and III were deficient in cyclic adenosine 3',5'-monophosphate synthesis under certain conditions.  相似文献   

17.
Oral cancer is associated with high rates of recurrence, attributable to field cancerization. Early detection of advanced field changes that can potentially progress to carcinoma can facilitate timely intervention and can lead to improved prognosis. Previous in vivo studies have successfully detected advanced field effects in oral cancers. Raman exfoliative cytology has previously shown to differentiate normal, oral pre‐cancer and cancers. The present study explores Raman‐exfoliative‐cytology‐based detection of field effects. Exfoliated cells were collected from tumor (n = 16) and contralateral‐normal appearing mucosa (n = 16) of oral cancer patients, and healthy tobacco habitués (n = 20). After spectral acquisition, specimens were Pap‐stained for cytological evaluation. Data analysis, by Principal Component Analysis and Principal Component‐Linear Discriminant Analysis, indicate several spectral‐misclassifications between contralateral normal and tumor, which were investigated and correlated with spectral, cytological and clinical outcomes. A qualitative analysis by grouping patients with number of misclassifications with tumor (Group 1: 0, Group 2: 1 and Group 3: >1) was explored. Group 3 with highest misclassifications showed spectral and cytological similarity to tumor group — one patient was a case of early inoperable residual disease, despite clear margins on histopathology. Thus, these misclassifications could be indicative of cancer field changes, and can prospectively help to identify patients susceptible to recurrences .  相似文献   

18.
A soluble methane monooxygenase (sMMO: EC 1.14.13.25) was purified from a type II obligate methanotroph, Methylocystis sp. M. Ion exchange chromatography elution separated the sMMO into three components, I, II, and III. Components II and III were purified to homogeneity and were essential for the sMMO activity. Components II and III had molecular masses of approximately 233,000 and 39,000, respectively. Component II consisted of three subunits with molecular masses of 55,000, 44,000, and 21,000, which appeared to be present in stoichiometric amounts, suggesting a (αβγ)2 configuration in the native protein. Component II contained 1–4 mol of iron and was considered to be a hydroxylase. Component III was a flavoprotein, which contained 1 mol of FAD as well as 1–2mol of iron. It catalyzed the reduction of K3Fe(CN)6 and 2,6-dichloroindophenol by NADH. Component I, which was partially purified and not essential for sMMO activity, stimulated the activity by about 11-fold. Its stimulation could be replaced by addition of Fe2+. The molecular mass of the partially purified component I was estimated to be from 35,000 to 40,000 based on gel filtration, which suggested the presence of a new type of regulatory protein of sMMO.  相似文献   

19.
Fluorescence Lifetime Imaging (FLIM) is an attractive microscopy method in the life sciences, yielding information on the sample otherwise unavailable through intensity‐based techniques. A novel Noise‐Corrected Principal Component Analysis (NC‐PCA) method for time‐domain FLIM data is presented here. The presence and distribution of distinct microenvironments are identified at lower photon counts than previously reported, without requiring prior knowledge of their number or of the dye's decay kinetics. A noise correction based on the Poisson statistics inherent to Time‐Correlated Single Photon Counting is incorporated. The approach is validated using simulated data, and further applied to experimental FLIM data of HeLa cells stained with membrane dye di‐4‐ANEPPDHQ. Two distinct lipid phases were resolved in the cell membranes, and the modification of the order parameters of the plasma membrane during cholesterol depletion was also detected.

Noise‐corrected Principal Component Analysis of FLIM data resolves distinct microenvironments in cell membranes of live HeLa cells.  相似文献   


20.
Re-emergence of Rabies in the Guangxi Province of Southern China   总被引:1,自引:0,他引:1  

Background

Human rabies cases in the Guangxi province of China decreased from 839 in 1982 to 24 in 1995, but subsequently underwent a sharp increase, and has since maintained a high level.

Methodology/Principal Findings

3,040 brain samples from normal dogs and cats were collected from 14 districts of Guangxi and assessed by RT-PCR. The brain samples showed an average rabies virus (RV) positivity rate of 3.26%, but reached 4.71% for the period Apr 2002 to Dec 2003. A total of 30 isolates were obtained from normal dogs and 28 isolates from rabid animals by the mouse inoculation test (MIT). Six representative group I and II RV isolates showed an LD50 of 10−5.35/ml to 10−6.19/ml. The reactivity of monoclonal antibodies (MAbs) to group I and II RV isolates from the Guangxi major epidemic showed that eight anti-G MAbs showed strong reactivity with isolates of group I and II with titers of ≥10,000; however, the MAbs 9-6, 13-3 and 12-14 showed lower reactivity. Phylogenetic analysis based on the G gene demonstrated that the Guangxi RV isolates have similar topologies with strong bootstrap values and are closely bonded. Alignment of deduced amino acids revealed that the mature G protein has four substitutions A96S, L132F, N436S, and A447I specific to group I, and 13 substitutions T90M, Y168C, S204G, T249I, P253S, S289T, V332I, Q382H, V427I, L474P, R463K Q486H, and T487N specific to group II, coinciding with the phylogenetic analysis of the isolates.

Conclusions

Re-emergence of human rabies has mainly occurred in rural areas of Guangxi since 1996. The human rabies incidence rate increased is related with RV positive rate of normal dogs. The Guangxi isolates tested showed a similar pathogenicity and antigenicity. The results of phylogenetic analysis coincide with that of alignment of deduced amino acids.  相似文献   

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