Whales originated from aquatic artiodactyls in the Eocene epoch of India.

abstract：:Functional studies seem now to confirm, as first suggested by E. Geoffroy Saint-Hilaire in 1822, that there was an inversion of the dorsoventral axis during animal evolution. A conserved system of extracellular signals provides positional information for the allocation of embryonic cells to specific tissue types both ...

journal_title：Nature

authors： De Robertis EM,Sasai Y

更新日期：1996-03-07 00:00:00

abstract：:The recognition of foreign antigens by T lymphocytes is essential to most adaptive immune responses. It is driven by specific T-cell antigen receptors (TCRs) binding to antigenic peptide-major histocompatibility complex (pMHC) molecules on other cells. If productive, these interactions promote the formation of an immu...

journal_title：Nature

authors： Huppa JB,Axmann M,Mörtelmaier MA,Lillemeier BF,Newell EW,Brameshuber M,Klein LO,Schütz GJ,Davis MM

更新日期：2010-02-18 00:00:00

abstract：:The RNA polymerase elongation complex (EC) is both highly stable and processive, rapidly extending RNA chains for thousands of nucleotides. Understanding the mechanisms of elongation and its regulation requires detailed information about the structural organization of the EC. Here we report the 2.5-A resolution struct...

journal_title：Nature

authors： Vassylyev DG,Vassylyeva MN,Perederina A,Tahirov TH,Artsimovitch I

更新日期：2007-07-12 00:00:00

abstract：:We have investigated age-related reactivation of the X chromosome by devising a model in which reactivation of a single gene in one cell among many can be identified. We have used mice with an X-autosomal translocation giving consistent non-random inactivation of the normal X (as judged by biochemical and cytogenetic ...

journal_title：Nature

authors： Wareham KA,Lyon MF,Glenister PH,Williams ED

更新日期：1987-06-25 00:00:00

abstract：:Chromatin is traditionally viewed as a nuclear entity that regulates gene expression and silencing. However, we recently discovered the presence of cytoplasmic chromatin fragments that pinch off from intact nuclei of primary cells during senescence, a form of terminal cell-cycle arrest associated with pro-inflammatory...

journal_title：Nature

authors： Dou Z,Ghosh K,Vizioli MG,Zhu J,Sen P,Wangensteen KJ,Simithy J,Lan Y,Lin Y,Zhou Z,Capell BC,Xu C,Xu M,Kieckhaefer JE,Jiang T,Shoshkes-Carmel M,Tanim KMAA,Barber GN,Seykora JT,Millar SE,Kaestner KH,Garcia BA,Ada

更新日期：2017-10-19 00:00:00

abstract：:T cells recognize foreign proteins as peptides bound to self molecules encoded by the major histocompatibility complex (MHC). The kinetics of interaction between purified class II MHC molecules and peptides is unusual, in that the rate of association is very slow, but once formed, the complexes are extremely stable. T...

journal_title：Nature

authors： Adorini L,Appella E,Doria G,Cardinaux F,Nagy ZA

更新日期：1989-12-14 00:00:00

abstract：:Hypermethylation is associated with the silencing of tumour susceptibility genes in several forms of cancer; however, the mechanisms responsible for this aberrant methylation are poorly understood. The prototypic DNA methyltransferase, DNMT1, has been widely assumed to be responsible for most of the methylation of the...

journal_title：Nature

authors： Rhee I,Jair KW,Yen RW,Lengauer C,Herman JG,Kinzler KW,Vogelstein B,Baylin SB,Schuebel KE

更新日期：2000-04-27 00:00:00

abstract：:The E6 oncoprotein derived from tumour-associated human papillomaviruses (HPVs) binds to and induces the degradation of the cellular tumour-suppressor protein p53. A common polymorphism that occurs in the p53 amino-acid sequence results in the presence of either a proline or an arginine at position 72. The effect of t...

journal_title：Nature

authors： Storey A,Thomas M,Kalita A,Harwood C,Gardiol D,Mantovani F,Breuer J,Leigh IM,Matlashewski G,Banks L

更新日期：1998-05-21 00:00:00

abstract：:Macroscopic mechanical oscillators have been coaxed into a regime of quantum behaviour by direct refrigeration or a combination of refrigeration and laser-like cooling. This result supports the idea that mechanical oscillators may perform useful functions in the processing of quantum information with superconducting c...

journal_title：Nature

authors： Palomaki TA,Harlow JW,Teufel JD,Simmonds RW,Lehnert KW

更新日期：2013-03-14 00:00:00

abstract：:Dominant alleles at the agouti locus (A) cause an obesity syndrome in the mouse, as a consequence of ectopic expression of the agouti peptide. This peptide, normally only found in the skin, is a high-affinity antagonist of the melanocyte-stimulating hormone receptor (MC1-R), thus explaining the inhibitory effect of ag...

journal_title：Nature

authors： Fan W,Boston BA,Kesterson RA,Hruby VJ,Cone RD

更新日期：1997-01-09 00:00:00

abstract：:Prostaglandins have wide-ranging effects in the body and are thought to be important mediators of inflammation. Cyclooxygenase (COX) plays a key regulatory role in prostaglandin synthesis, and occurs in both constitutive (COX-1) and inducible (COX-2) isoforms. COX-1 is thought to provide cytoprotective effects, wherea...

journal_title：Nature

authors： Dinchuk JE,Car BD,Focht RJ,Johnston JJ,Jaffee BD,Covington MB,Contel NR,Eng VM,Collins RJ,Czerniak PM

更新日期：1995-11-23 00:00:00

abstract：:Remodelling its shape, or morphogenesis, is a fundamental property of living tissue. It underlies much of embryonic development and numerous pathologies. Convergent extension (CE) of the axial mesoderm of vertebrates is an intensively studied model for morphogenetic processes that rely on cell rearrangement. It involv...

journal_title：Nature

authors： Ninomiya H,Elinson RP,Winklbauer R

更新日期：2004-07-15 00:00:00

abstract：:Gut microbes supply the human body with energy from dietary polysaccharides through carbohydrate active enzymes, or CAZymes, which are absent in the human genome. These enzymes target polysaccharides from terrestrial plants that dominated diet throughout human evolution. The array of CAZymes in gut microbes is highly ...

journal_title：Nature

authors： Hehemann JH,Correc G,Barbeyron T,Helbert W,Czjzek M,Michel G

更新日期：2010-04-08 00:00:00

abstract：:The RAD3 gene of Saccharomyces cerevisiae is required for excision repair of ultraviolet-damaged DNA and is essential for cell viability. The RAD3-encoded protein shares a high degree of homology with the human ERCC2(XPD) gene product. Mutations in XPD, besides causing the cancer-prone syndrome xeroderma pigmentosum, ...

journal_title：Nature

authors： Guzder SN,Qiu H,Sommers CH,Sung P,Prakash L,Prakash S

更新日期：1994-01-06 00:00:00

abstract：:Crystal structures of insulin have been determined in various distinct forms, the relevance of which to receptor recognition has long been the subject of speculation. Recently the crystal structure of an inactive insulin analogue has been determined and, surprisingly, found to have a conformation identical to native i...

journal_title：Nature

authors： Hua QX,Shoelson SE,Kochoyan M,Weiss MA

更新日期：1991-11-21 00:00:00

abstract：:The mammalian microbiome has many important roles in health and disease, and genetic engineering is enabling the development of microbial therapeutics and diagnostics. A key determinant of the activity of both natural and engineered microorganisms in vivo is their location within the host organism. However, existing m...

journal_title：Nature

authors： Bourdeau RW,Lee-Gosselin A,Lakshmanan A,Farhadi A,Kumar SR,Nety SP,Shapiro MG

更新日期：2018-01-03 00:00:00

abstract：:The toxicity of misfolded proteins and mitochondrial dysfunction are pivotal factors that promote age-associated functional neuronal decline and neurodegenerative disease. Accordingly, neurons invest considerable cellular resources in chaperones, protein degradation, autophagy and mitophagy to maintain proteostasis an...

journal_title：Nature

authors： Melentijevic I,Toth ML,Arnold ML,Guasp RJ,Harinath G,Nguyen KC,Taub D,Parker JA,Neri C,Gabel CV,Hall DH,Driscoll M

更新日期：2017-02-16 00:00:00

abstract：:The average air temperature at the Earth's surface has increased by 0.06 degrees C per decade during the 20th century, and by 0.19 degrees C per decade from 1979 to 1998. Climate models generally predict amplified warming in polar regions, as observed in Antarctica's peninsula region over the second half of the 20th c...

journal_title：Nature

authors： Doran PT,Priscu JC,Lyons WB,Walsh JE,Fountain AG,McKnight DM,Moorhead DL,Virginia RA,Wall DH,Clow GD,Fritsen CH,McKay CP,Parsons AN

更新日期：2002-01-31 00:00:00

abstract：:The evolutionary biologist "studies the steps by which the miraculous adaptations so characteristic of every aspect of the organic world have evolved". But the general nature of such adaptive steps is still unclear. Evolution is often thought to be random and dependent on unpredictable events. In this light, one might...

journal_title：Nature

authors： Gerrish P

更新日期：2001-09-20 00:00:00

abstract：:Prions are believed to be infectious, self-propagating polymers of otherwise soluble, host-encoded proteins. This concept is now strongly supported by the recent findings that amyloid fibrils of recombinant prion proteins from yeast, Podospora anserina and mammals can induce prion phenotypes in the corresponding hosts...

journal_title：Nature

authors： Ritter C,Maddelein ML,Siemer AB,Lührs T,Ernst M,Meier BH,Saupe SJ,Riek R

更新日期：2005-06-09 00:00:00

abstract：:A complex between HLA-DR3 and a fragment of invariant chain called CLIP was isolated from a human cell line defective in antigen presentation and its X-ray crystal structure determined. Previous data indicate that this complex is an intermediate in class II histocompatibility maturation, occurring between invariant ch...

journal_title：Nature

authors： Ghosh P,Amaya M,Mellins E,Wiley DC

更新日期：1995-11-30 00:00:00

abstract：:Why infer evolution when you can watch it happen in real time? This is the basic premise of using populations of fast-replicating microorganisms in test tubes to study evolution. The approach, known as experimental evolution, has provided a way of testing many of the key hypotheses that arose from the modern evolution...

journal_title：Nature

authors： Buckling A,Craig Maclean R,Brockhurst MA,Colegrave N

更新日期：2009-02-12 00:00:00

abstract：:Inositol-1,4,5-trisphosphate receptors (InsP(3)Rs) and ryanodine receptors (RyRs) are tetrameric intracellular Ca(2+) channels. In each of these receptor families, the pore, which is formed by carboxy-terminal transmembrane domains, is regulated by signals that are detected by large cytosolic structures. InsP(3)R gati...

journal_title：Nature

authors： Seo MD,Velamakanni S,Ishiyama N,Stathopulos PB,Rossi AM,Khan SA,Dale P,Li C,Ames JB,Ikura M,Taylor CW

更新日期：2012-01-29 00:00:00

abstract：:ATP, the principal energy currency of the cell, fuels most biosynthetic reactions in the cytoplasm by its hydrolysis into ADP and inorganic phosphate. Because resynthesis of ATP occurs in the mitochondrial matrix, ATP is exported into the cytoplasm while ADP is imported into the matrix. The exchange is accomplished by...

journal_title：Nature

authors： Pebay-Peyroula E,Dahout-Gonzalez C,Kahn R,Trézéguet V,Lauquin GJ,Brandolin G

更新日期：2003-11-06 00:00:00

abstract：:Current ideas about the dependence of neurons on target-derived growth factors were formulated on the basis of experiments involving neurons with projections to the periphery. Nerve growth factor (NGF) and recently identified members of the NGF family of neuronal growth factors, known as neurotrophins, are thought to ...

journal_title：Nature

authors： Yan Q,Elliott J,Snider WD

更新日期：1992-12-24 00:00:00

abstract：:Lord Rothschild presents his personal views about the terminology used to describe research and development. ...

journal_title：Nature

authors： Rothschild L

更新日期：1972-10-13 00:00:00

abstract：:The factors driving glacial changes in ocean overturning circulation are not well understood. On the basis of a comparison of 20 climate variables over the past four glacial cycles, the SPECMAP project proposed that summer insolation at high northern latitudes (that is, Milankovitch forcing) drives the same sequence o...

journal_title：Nature

authors： Lisiecki LE,Raymo ME,Curry WB

更新日期：2008-11-06 00:00:00

abstract：:Enzymes are the subset of proteins that catalyse the chemistry of life, transforming both macromolecular substrates and small molecules. The precise three-dimensional architecture of enzymes permits almost unerring selectivity in physical and chemical steps to impose remarkable rate accelerations and specificity in pr...

journal_title：Nature

authors： Walsh C

更新日期：2001-01-11 00:00:00

abstract：:The extent to which evolution is reversible has long fascinated biologists. Most previous work on the reversibility of morphological and life-history evolution has been indecisive, because of uncertainty and bias in the methods used to infer ancestral states for such characters. Further, despite theoretical work on th...

journal_title：Nature

authors： Bridgham JT,Ortlund EA,Thornton JW

更新日期：2009-09-24 00:00:00

abstract：:Galactose oxidase is an extracellular enzyme secreted by the fungus Dactylium dendroides. It is monomeric, with a relative molecular mass of 68,000, catalyses the stereospecific oxidation of a broad range of primary alcohol substrates and possesses a unique mononuclear copper site essential for catalysing a two-electr...

journal_title：Nature

authors： Ito N,Phillips SE,Stevens C,Ogel ZB,McPherson MJ,Keen JN,Yadav KD,Knowles PF

更新日期：1991-03-07 00:00:00