Hybrid origin of SIV in chimpanzees     

Bailes E  Gao F  Bibollet-Ruche F  Courgnaud V  Peeters M  Marx PA  Hahn BH  Sharp PM 《Science (New York, N.Y.)》2003,300(5626):1713

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Single-molecule DNA sequencing of a viral genome   总被引：4，自引：0，他引：4  

Harris TD  Buzby PR  Babcock H  Beer E  Bowers J  Braslavsky I  Causey M  Colonell J  Dimeo J  Efcavitch JW  Giladi E  Gill J  Healy J  Jarosz M  Lapen D  Moulton K  Quake SR  Steinmann K  Thayer E  Tyurina A  Ward R  Weiss H  Xie Z 《Science (New York, N.Y.)》2008,320(5872):106-109

The full promise of human genomics will be realized only when the genomes of thousands of individuals can be sequenced for comparative analysis. A reference sequence enables the use of short read length. We report an amplification-free method for determining the nucleotide sequence of more than 280,000 individual DNA molecules simultaneously. A DNA polymerase adds labeled nucleotides to surface-immobilized primer-template duplexes in stepwise fashion, and the asynchronous growth of individual DNA molecules was monitored by fluorescence imaging. Read lengths of >25 bases and equivalent phred software program quality scores approaching 30 were achieved. We used this method to sequence the M13 virus to an average depth of >150x and with 100% coverage; thus, we resequenced the M13 genome with high-sensitivity mutation detection. This demonstrates a strategy for high-throughput low-cost resequencing.  相似文献   

Growth of prochlorococcus, a photosynthetic prokaryote, in the equatorial pacific ocean     

Vaulot D  Marie D  Olson RJ  Chisholm SW 《Science (New York, N.Y.)》1995,268(5216):1480-1482

The cell cycle of Prochlorococcus, a prokaryote that accounts for a sizable fraction of the photosynthetic biomass in the eastern equatorial Pacific, progressed in phase with the daily light cycle. DNA replication occurred in the afternoon and cell division occurred at night. Growth rates were maximal (about one doubling per day) at 30 meters and decreased toward the surface and the bottom of the ocean. Estimated Prochlorococcus production varied between 174 and 498 milligrams of carbon per square meter per day and accounted for 5 to 19 percent of total gross primary production at the equator. Because Prochlorococcus multiplies close to its maximum possible rate, it is probably not severely nutrient-limited in this region of the oceans.  相似文献   

Role of formins in actin assembly: nucleation and barbed-end association   总被引：2，自引：0，他引：2  

Pruyne D  Evangelista M  Yang C  Bi E  Zigmond S  Bretscher A  Boone C 《Science (New York, N.Y.)》2002,297(5581):612-615

Nucleation of branched actin filaments by the Arp2/3 complex is a conserved process in eukaryotic cells, yet the source of unbranched actin filaments has remained obscure. In yeast, formins stimulate assembly of actin cables independently of Arp2/3. Here, the conserved core of formin homology domains 1 and 2 of Bni1p (Bni1pFH1FH2) was found to nucleate unbranched actin filaments in vitro. Bni1pFH2 provided the minimal region sufficient for nucleation. Unique among actin nucleators, Bni1pFH1FH2 remained associated with the growing barbed ends of filaments. This combination of properties suggests a direct role for formins in regulating nucleation and polarization of unbranched filamentous actin structures.  相似文献   

The serine protease TMPRSS6 is required to sense iron deficiency   总被引：1，自引：0，他引：1  

Du X  She E  Gelbart T  Truksa J  Lee P  Xia Y  Khovananth K  Mudd S  Mann N  Moresco EM  Beutler E  Beutler B 《Science (New York, N.Y.)》2008,320(5879):1088-1092

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Technology. Electronic paper: a revolution about to unfold?     

Granmar M  Cho A 《Science (New York, N.Y.)》2005,308(5723):785-786

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A dual role for Hox genes in limb anterior-posterior asymmetry     

Zákány J  Kmita M  Duboule D 《Science (New York, N.Y.)》2004,304(5677):1669-1672

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Dual activation of the Drosophila toll pathway by two pattern recognition receptors     

Gobert V  Gottar M  Matskevich AA  Rutschmann S  Royet J  Belvin M  Hoffmann JA  Ferrandon D 《Science (New York, N.Y.)》2003,302(5653):2126-2130

The Toll-dependent defense against Gram-positive bacterial infections in Drosophila is mediated through the peptidoglycan recognition protein SA (PGRP-SA). A mutation termed osiris disrupts the Gram-negative binding protein 1 (GNBP1) gene and leads to compromised survival of mutant flies after Gram-positive infections, but not after fungal or Gram-negative bacterial challenge. Our results demonstrate that GNBP1 and PGRP-SA can jointly activate the Toll pathway. The potential for a combination of distinct proteins to mediate detection of infectious nonself in the fly will refine the concept of pattern recognition in insects.  相似文献   

Spatiotemporal normalized ratio methodology to evaluate the impact of field-scale variable rate application     

Katz  L.  Ben-Gal  A.  Litaor  M. I.  Naor  A.  Peres  M.  Bahat  I.  Netzer  Y.  Peeters  A.  Alchanatis  V.  Cohen  Y. 《Precision Agriculture》2022,23(4):1125-1152

Precision Agriculture - Wide assimilation of precision agriculture among farmers is currently dependent on the ability to demonstrate its efficiency at the field-scale. Yet, most experiments that...  相似文献   

Proximate Analysis and Some Antinutritional Factor Constituents in Selected Varieties of Jamaican Yams (<Emphasis Type="Italic">Dioscorea</Emphasis> and <Emphasis Type="Italic">Rajana</Emphasis> spp.)     

McAnuff MA  Omoruyi FO  Sotelo-López A  Asemota HN 《Plant foods for human nutrition (Dordrecht, Netherlands)》2005,60(2):93-98

Two wild (Dioscorea polygonoides and Rajana cordata) and seven cultivated varieties of Jamaican yams (Dioscorea spp.) were analyzed for their proximate composition and the levels of antinutritional factors. The protein level range was 47.8 ± 2.6 to 88.0 ± 2.5 g/kg dry weight. The lowest level was seen in D. cayenensis. The range for the dietary fiber content in the tubers was 16.3 ± 0.7 to 63.5 ± 0.4 g/kg dry weight. The wild yam varieties recorded higher levels. Saponins level was < 600 mg/kg dry weight in all the tubers analyzed except for bitter yam (2962.5 ± 60.5 mg/kg dry weight). Total phenol content ranged from 1.3 ± 0.1 to 79.3 ± 6.1 g/kg while total condensed tannin content ranged from 0.1 ± 0.0 to 26.7 ± 3.8 g/kg dry weight. Samples that showed high levels of phenols also had high levels of condensed tannins. All the samples analyzed contained low levels of lectins and no alkaloids were detected. The levels of antinutritional factors did not clearly delineate the wild varieties from the edible varieties.  相似文献