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1.
《Comptes Rendus Palevol》2003,2(6-7):383-395
Vavilov’s dossier. Gould revived the memory of N.I. Vavilov, a victim of the Stalinian system and misjudged among occidental evolutionists. His contribution is impressive in applied research (phytogeography, his list of world-wide plant resources, a unique collection of germplasms intact and always available) as well as in theoretical research work on artificial selection, immunitary relationships between parasite and plant, the bases of his Law of homologous series in hereditary variations, and centers of origin of cultivated plants. Darwinian concept of natural selection were essential for him, but he considered that the evolutionary changes were not only produced by random variations, but by preset channels, recognising the internal constraints of heredity. His heritage has always been maintained in his Institutes. His Evolutionary theories are now confirmed by molecular genetics and systematics. S.J. Gould was the first to revive Vavilov’s memory and scientific importance. During his studies on the gastropod Cerion Gould recognised the balance between external and internal constraints in Evolution. To cite this article: M. Debrenne, F. Debrenne, C. R. Palevol 2 (2003).  相似文献   

2.
对国产青藤属3种植物作了补充和修订.报道短蕊青藤在广西和广东的新分布,大花青藤在四川的新分布;将小果青藤和柔毛青藤归入大花青藤,将绣毛青藤归入红花青藤。  相似文献   

3.
采用广义的马蓝属(Strobilanthes Blume)概念,提出3个新组合:匍匐半插花(S.primulifolia(Nees)Y.F.DengJ.R.I.Wood),直立半插花(S.cumingiana(Forst.)Y.F.DengJ.R.I.Wood)和狭叶马蓝(S.atropurpurea var.stenophylla(C.B.Clarke)Y.F.DengJ.R.I.Wood);描述了8新种:南岭马蓝(Strobilanthes austrosinensis Y.F.DengJ.R.I.Wood)、冯氏马蓝(S.fengiana Y.F.DengJ.R.I.Wood)、陶氏马蓝(S.taoana Y.F.DengJ.R.I.Wood)、启无马蓝(S.wangiana Y.F.DengJ.R.I.Wood)、景东马蓝(S.atroviridis Y.F.DengJ.R.I.Wood)、西畴马蓝(S.rostrata Y.F.DengJ.R.I.Wood)、黄连山马蓝(S.spiciformis Y.F.DengJ.R.I.Wood)和匍匐马蓝(S.procumbens Y.F.DengJ.R.I.Wood)。对南岭马蓝、黄连山马蓝、景东马蓝和匍匐马蓝的花粉形态进行了观察。  相似文献   

4.
E T Vasina-Popova 《Genetika》1987,23(11):2002-2006
N. I. Vavilov had been greatly interested in the problems of animal industry, genetics, breeding, origin and evolution of domestic animals. Due to his initiative and active participation in discussing these problems, important programmes were developed. The unique ideas of Nikolai Ivanovich had significant impact on a rise of animal genetics in the USSR.  相似文献   

5.
Symbiosis plays a fundamental role in contemporary biology, as well as in recent thinking in philosophy of biology. The discovery of the importance and universality of symbiotic associations has brought new light to old debates in the field, including issues about the concept of biological individuality. An important aspect of these debates has been the formulation of the hologenome concept of evolution, the notion that holobionts are units of natural selection in evolution. This review examines the philosophical assumptions that underlie recent proposal of the hologenome concept of evolution, and traces those debates back in time to their historical origins, to the moment when the connection between the topics of symbiosis and biological individuality first caught the attention of biologists. The review is divided in two parts. The first part explores the historical origins of the connection between the notion of symbiosis and the concept of biological individuality, and emphasizes the role of A. de Bary, R. Pound, A. Schneider and C. Merezhkowsky in framing the debate. The second part examines the hologenome concept of evolution and explores four parallelisms between contemporary debates and the debates presented in the first part of the essay, arguing that the different debates raised by the hologenome concept were already present in the literature. I suggest that the novelty of the hologenome concept of evolution lies in the wider appreciation of the importance of symbiosis for maintaining life on Earth as we know it. Finally, I conclude by suggesting the importance of exploring the connections among contemporary biology, philosophy of biology and history of biology in order to gain a better understanding of contemporary biology.  相似文献   

6.
The concept of ADHD has evolved gradually and still carries some traces of its origins. The idea of uncontrolled behaviour as a medical problem arose in eighteenth and nineteenth century accounts. It raised cultural issues about how far control was expected of children. This article traces the development of ideas with particular references to Hoffman's "Struwwelpeter", Frederick Still's "Disorders of Moral Control", minimal brain damage, and the hyperkinetic syndrome.  相似文献   

7.
Ischemia-reperfusion (I/R) lung injury is characterized by increased pulmonary endothelial permeability and edema, but the genetic basis for this injury is unknown. We utilized an in vivo mouse preparation of unilateral lung I/R to evaluate the genetic determinants of I/R lung injury. An index of pulmonary vascular protein permeability was measured by the ratio of left-to-right lung Evans blue dye of eight inbred mouse strains after 30 min of left lung ischemia and 150 min of reperfusion. The order of strain-specific sensitivity to I/R lung injury was BALB/c < SJL/J < CBA/J < C57BL/6J < 129/J < A/J < C3H/H3J < SWR/J. The reciprocal F1 offspring of the BALB/c and SWR/J progenitor strains had intermediate phenotypes but a differing variance. A similar pattern of right lung Evans blue dye content suggested the presence of contralateral injury because baseline vascular permeability was not different. Lung I/R injury was attenuated by NADPH oxidase inhibition, indicating a role for NADPH oxidase-derived reactive oxygen species (ROS). There was no strain-dependent difference in lung NADPH oxidase expression. Strain-related differences in zymosan-stimulated neutrophil ROS production did not correlate with I/R lung injury in that neutrophil ROS production in SWR/J mice was greater than C57BL/6J but not different from BALB/c mice. These data indicate the presence of a genetic sensitivity to lung I/R injury that involves multiple genes including a maternal-related factor. Although neutrophil-derived ROS production is also modulated by genetic factors, the pattern did not explain the genetic sensitivity to lung I/R injury.  相似文献   

8.
Phosphorylation of the R domain is required for cystic fibrosis transmembrane conductance regulator (CFTR) channel gating, and cAMP/protein kinase A (PKA) simulation can also elicit insertion of CFTR into the plasma membrane from intracellular compartments (Bertrand, C. A., and Frizzell, R. A. (2003) Am. J. Physiol. 285, C1-C18). We evaluated the structural basis of regulated CFTR trafficking by determining agonist-evoked increases in plasma membrane capacitance (Cm) of Xenopus oocytes expressing CFTR deletion mutants. Expression of CFTR as a split construct that omitted the R domain (Deltaamino acids 635-834) produced a channel with elevated basal current (Im) and no DeltaIm or trafficking response (DeltaCm) upon cAMP/PKA stimulation, indicating that the structure(s) required for regulated CFTR trafficking are contained within the R domain. Additional deletions showed that removal of amino acids 817-838, a 22-amino acid conserved helical region having a net charge of -9, termed NEG2 (Xie, J., Adams, L. M., Zhao, J., Gerken, T. A., Davis, P. B., and Ma, J. (2002) J. Biol. Chem. 277, 23019-23027), produced a channel with regulated gating that lacked the agonist-induced increase in CFTR trafficking. Injection of NEG2 peptides into oocytes expressing split DeltaNEG2 CFTR prior to stimulation restored the agonist-evoked DeltaCm, consistent with the concept that this sequence mediates the regulated trafficking event. In support of this idea, DeltaNEG2 CFTR escaped from the inhibition of wild type CFTR trafficking produced by overexpression of syntaxin 1A. These observations suggest that the NEG2 region at the C terminus of the R domain allows stabilization of CFTR in a regulated intracellular compartment from which it traffics to the plasma membrane in response to cAMP/PKA stimulation.  相似文献   

9.
本文描述了国产铁线莲属2新种、1新变种,并对荔波铁线莲的形态进行了补充描述。  相似文献   

10.
A restriction map of the virulence plasmid pVYE439-80, isolated from Yersinia enterocolitica 439-80 (serogroup 9) was constructed for EcoRI, BamHI, SstII, and SmaI. The mapping was done after cloning of about two-thirds of the plasmid in Escherichia coli. The restriction pattern was compared to those obtained with plasmids isolated from Y. enterocolitica strains of serogroups 1, 3, and 5b. The restriction sites are particularly conserved in a region of about 25 kb. This region contains fragments that are also conserved in serogroup 8 strains [J. Heeseman, C. Keller, R. Morawa, N. Schmidt, H. J. Siemens, and R. Lauf (1983) J. Infect. Dis. 147, 107-115] and that were shown, in strains from this serogroup, to encode calcium dependency [D. A. Portnoy, H. Wolf-Watz, I. Bolin, A. B. Beeder, and S. Falkow, (1984) Infect. Immun. 43, 108-114].  相似文献   

11.
Human lipocortin I is a 38.5-kDa phospholipase A2 inhibitor that has been produced in Escherichia coli in large quantities by recombinant DNA technology (Wallner, B.P., Mattaliano, R.J., Hession, C., Cate, R. L., Tizard, R., Sinclair, L.K., Foeller, C., Chow, E.P., Browning, J.L., Ramachandran, K.L., and Pepinsky, R.B. (1986) Nature 320, 77-80). To localize the region within the protein responsible for its inhibitory activity, we generated a series of fragments of the recombinant product by limited proteolysis with elastase and characterized their structure by sequencing and peptide mapping. Five active fragments have been analyzed in detail. The smallest is an 18-kDa fragment derived from the amino-terminal half of lipocortin. Three of the larger fragments contain this region. The fifth fragment is missing 83 amino acids from the amino terminus. A region common to all the active fragments (amino acid residues 97-178) is 70% homologous with the corresponding region from a second member of the lipocortin family which recently was cloned (Huang, K-S., Wallner, B.P., Mattaliano, R.J., Tizard, R., Burne, C., Frey, A., Hession, C., McGray, P., Sinclair, L.K., Chow, E.P., Browning, J.L., Ramachandran, K.L., Tang, J., Smart, J.E., and Pepinsky, R.B. (1986) Cell 46, 191-199) and thus presumably is important for activity. In addition to inhibitory fragments, we have isolated a 3-kDa proteolytic fragment from the amino terminus of lipocortin I that contains the known phosphorylation site for protein-tyrosine kinases. Because of sequence homology of the 3-kDa fragment with biologically active synthetic peptides from pp60v-src and middle T antigen, its release by proteases may represent an important part of the activity of lipocortin.  相似文献   

12.
王玉国  韦发南   《广西植物》2000,20(3):228-231+192
在扫描电镜下对药用植物苦丁茶 (Ilex kudingcha C.J.Tseng)与 4个近缘种的叶表皮微形态进行了观察。结果显示这些材料的叶表皮仅远轴面有气孔器存在 ,气孔圆形至椭圆形 ,气孔外拱盖表面多平滑 ,拱盖内缘近平滑 ,浅波状或波状 ,外缘角质膜在气孔周围呈环形包着气孔。但各种间叶表皮的微形态特征具有较为明显的差异 ,有一定的分类鉴定意义。本研究结果支持将五棱苦丁茶 (I.pentagona S.K.Chen,Y.X.Feng et C.F.L iang)从苦丁茶中独立出来建立一新种 ,但因苦丁茶具有 2种类型气孔器外缘角质膜排列 ,而不支持对扣树 (I.kaushue S.Y.Hu)与苦丁茶的合并  相似文献   

13.
An efficient method for the synthesis of 5'-O-monomethoxytrityl-2',3'-dideoxy-2'-fluoro-3'-thioarabinothymidine [(5'MMT)araF-T(3'SH), (5)] and its 3'-phosphoramidite derivative (6) suitable for automated incorporation into oligonucleotides, is demonstrated. A key step in the synthesis involves reaction of 5'-O-MMT-2,3'-O-anhydrothymidine (4) (Eleuteri, A.; Reese, C.B.; Song, Q. J. Chem. Soc. Perkin Trans. 1 1996, 2237 pp.) with sodium thioacetate to give (5'-MMT)araF-T(3'SAc) (5) (Elzagheid, M.I.; Mattila, K.; Oivanen, M.; Jones, B.C.N.M.; Cosstick, L?nnberg, H. Eur. J. Org. Chem. 2000, 1987-1991). This nucleoside was then converted to its corresponding phosphoramidite derivative, 6, as described previously ((a) Sun, S.; Yoshida, A.; Piccirilli, J.A. RNA, 1997, 3, 1352-1363; (b) Matulic-Adamic, J.; Beigelman, L. Helvetica Chemica Acta 1999, 82, 2141-2150: (c) Fettes, K.J.; O'Neil, I.; Roberts, S.M.; Cosstick, R. Nucleosides, Nucleotides and Nucl. Acids 2001, 20, 1351-1354).  相似文献   

14.
Troponin I (TnI) is the inhibitory component of troponin, the ternary complex that regulates skeletal and cardiac muscle contraction. Previous work showed that the C-terminal region of TnI, when linked to the "inhibitory region" (residues 98-116), possesses the major regulatory functions of the molecule (Farah, C. S., Miyamoto, C. A., Ramos, C. H. I., Silva, A. C. R., Quaggio, R. B., Fujimori, K., Smillie, L. B., and Reinach, F. C. (1994) J. Biol. Chem. 269, 5230-5240). To investigate these functions in more detail, serial deletion mutants of the C-terminal region of TnI were constructed. These experiments showed that longer C-terminal deletions result in lower inhibition of the actomyosin ATPase activity and weaken the interaction with the N-terminal domain of troponin C (TnC), consistent with the antiparallel model for the interaction between these two proteins. The conclusion is that the whole C-terminal region of TnI is necessary for its full regulatory activity. The region between residues 137 and 144, which was shown to have homology with residues 108-115 in the inhibitory region (Farah, C. S., and Reinach, F. C. (1995) FASEB J. 9, 755-767), is involved in the binding to TnC. The region between residues 98 and 129 is involved in modulating the affinity of TnC for calcium. The C-terminal residues 166-182 are involved in the binding of TnI to thin filament. A model for the function of TnI is discussed.  相似文献   

15.
A species-level review of the genus Clinopodium in Bolivia is presented. Characters used to distinguish taxa are discussed and evaluated with emphasis being given to nutlet characteristics for the first time. Nine species are described, seven from Bolivia, one of which, C. pilosum J. R. I. Wood is described as new. Bystropogon uniflorus Rusby ex Briq. is treated as subsp. uniflorum (Rusby ex Briq.) J. R. I. Wood of C. axillare (Rusby) Harley and its typification is discussed. Three subspecies of C. bolivianum are recognised, one of which subsp. diffusum J. R. I. Wood is described as new. Notes on salient characteristics of each taxon, on intermediate forms and on the distribution of each species are provided, as well as a key to species, maps and illustrations.  相似文献   

16.
I describe here my recollection of the story of the discovery of the nature of ferredoxin in photosystems that began in 1965: this story involved the EPR measurements by a young physicist J.H.M. Thornley, using samples provided by J.F. Gibson and D. Hall, and in collaboration with F.R. Whatley.  相似文献   

17.
《The Journal of cell biology》1989,109(4):1807-1815
The integrin VLA-3 is a cell surface receptor, which binds to fibronectin, laminin, collagen type I and VI (Takada, Y., E. A. Wayner, W. G. Carter, and M. E. Hemler. 1988. J. Cell. Biochem. 37:385-393) and is highly expressed in substrate adherent cultures of almost all human cell types. The ligand specificity of VLA-3 and the inhibition of cell adhesion by anti-VLA-3 monoclonal antibodies suggest its involvement in cell-substrate interaction. In normal tissues, VLA-3 is restricted to few cell types, notably the kidney glomeruli and basal cells of the epidermis. In the epidermis, VLA-3 is generally strongly expressed on the entire plasma membrane of basal cells and is not polarized towards the basement membrane (Klein, C. E., C. Cardon-Cardo, R. Soehnchen, R. J. Cote, H. F. Oettgen, M. Eisinger, and L. J. Old. 1987. J. Invest. Dermatol. 89:500-507). Based on this finding we speculated that, in addition to a role of VLA-3 for adhesion of cells to substrate, it could also be relevant for cell-cell interaction. To investigate this, we ultrastructurally localized VLA-3 on the surface of cultured cells by immunoelectron microscopy. In accordance with our concept, we found VLA-3 strongly associated with intercellular contact sites. Interestingly, very little immunoreactivity was detected at the under- surface of cells which had been cultured for 18-32 h. This observation was unexpected but is consistent with previous findings (Kantor, R. R. S., M. J. Mattes, K. D. Lloyd, L. J. Old, and A. P. Albino. 1987. J. Biol. Chem. 262:15158-15165) which suggest that the association of VLA- 3 with the basal surface of substrate adherent tumor cells is a late event occurring after days of culture under confluent conditions. However, we cannot formally rule out VLA-3 expression at the undersurface of cells under our experimental conditions, since VLA-3 molecules at this location could be inaccessible for in situ labeling of unfixed cells because of spatial interferences. In conclusion, our results demonstrate the expression of VLA-3 at intercellular contact sites of cultured cells supporting the concept that it may be relevant for intercellular interactions also.  相似文献   

18.
X-ray quality crystals which diffract to high resolution (less than or equal to 1.9-2.1 A) have been grown of an anti-peptide Fab and its complex with a 9-residue peptide antigen. Both crystals are monoclinic P2(1), with unit cell dimensions a = 90.3 A, b = 82.9 A, c = 73.4 A, beta = 122.5 degrees for the native Fab and a = 63.9 A, b = 73.0 A, c = 49.1 A, beta = 120.6 degrees for the complex. The peptide sequence corresponds to residues 100-108 of all influenza virus hemagglutinins (HA1) of the H3 subtype (1968-1987). The peptide antigen has been well characterized immunologically (Wilson, I.A., Niman, H.L., Houghton, R.A., Cherenson, A.R., Connolly, M.L., and Lerner, R.A. (1984) Cell 37, 767-778; Wilson, I.A., Bergmann, K.F., and Stura, E.A. (1986) in Vaccines '86 (Channock, R.M., Lerner, R.A., and Brown, F., eds) pp. 33-37, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY), structurally, as a free peptide by NMR (Dyson, J.H., Cross, K.J., Houghton, R.A., Wilson, I.A., Wright, P.E., and Lerner, R.A. (1985) Nature 318, 480-483; Dyson, J.H., Lerner, R.A., and Wright, P.E., (1988) Annu. Rev. Biophys. Chem. 17, 305-324), as part of the intact antigen by x-ray crystallography (Wilson, I.A., Skehel, J.J., and Wiley, D. C. (1981) Nature 289, 366-373) and by binding studies to the HA molecule (White, J.M., and Wilson, I.A. (1987) J. Cell Biol. 105, 2887-2896). Knowledge of the three-dimensional structure of the complex will elucidate the details of how anti-peptide antibodies recognize a small peptide antigen and provide insights into the recognition of the same sequence in the intact protein antigen. As both native Fab and the peptide-Fab complex have been crystallized, we can also determine in addition whether changes in the structure of the antibody accompany antigen binding. The nucleotide sequence of the mRNA coding region of the anti-peptide Fab has been determined to provide the amino acid sequence ultimately required for the high resolution three-dimensional structure determination.  相似文献   

19.
Holmes EC 《Journal of virology》2011,85(11):5247-5251
Despite recent advances in our understanding of diverse aspects of virus evolution, particularly on the epidemiological scale, revealing the ultimate origins of viruses has proven to be a more intractable problem. Herein, I review some current ideas on the evolutionary origins of viruses and assess how well these theories accord with what we know about the evolution of contemporary viruses. I note the growing evidence for the theory that viruses arose before the last universal cellular ancestor (LUCA). This ancient origin theory is supported by the presence of capsid architectures that are conserved among diverse RNA and DNA viruses and by the strongly inverse relationship between genome size and mutation rate across all replication systems, such that pre-LUCA genomes were probably both small and highly error prone and hence RNA virus-like. I also highlight the advances that are needed to come to a better understanding of virus origins, most notably the ability to accurately infer deep evolutionary history from the phylogenetic analysis of conserved protein structures.  相似文献   

20.
The interaction of aldolase with the myofibrillar matrix of rabbit skeletal muscle has been investigated by means of its effect on kinetic parameters for the enzyme-catalyzed cleavage of fructose 1,6-bisphosphate. Involvement of the active site in the enzymic interaction with the thin filament of muscle is indicated, the association constant for competitive inhibition of catalysis (420,000 M-1) being in excellent agreement with the value of 410,000 M-1 obtained under the same conditions (pH 6.8, I 0.16) from partition equilibrium studies of the aldolase-myofibril interaction (Kuter, M.R., Masters, C.J. and Winzor, D.J. (1983) Arch. Biochem. Biophys. 225, 384-389). A second kinetic study, designed to take into greater account the inhibitory effects of substrate and other phosphate-containing metabolites on the interaction of enzyme with myofibrils, has substantiated further the concept of aldolase existing as an equilibrium mixture of cytoplasmic and filament-bound forms in muscle tissue.  相似文献   

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