Abstract：
:The detrimental effects of elevated intensities of mid-UV radiation (UVB), a result of stratospheric ozone depletion during the austral spring, on the primary producers of the Antarctic marine ecosystem have been well documented. Here we report that natural populations of Antarctic zooplankton also sustain significant DNA damage [measured as cyclobutane pyrimidine dimers (CPDs)] during periods of increased UVB flux. This is the first direct evidence that increased solar UVB may result in damage to marine organisms other than primary producers in Antarctica. The extent of DNA damage in pelagic icefish eggs correlated with daily incident UVB irradiance, reflecting the difference between acquisition and repair of CPDs. Patterns of DNA damage in fish larvae did not correlate with daily UVB flux, possibly due to different depth distributions and/or different capacities for DNA repair. Clearance of CPDs by Antarctic fish and krill was mediated primarily by the photoenzymatic repair system. Although repair rates were large for all species evaluated, they were apparently inadequate to prevent the transient accumulation of substantial CPD burdens. The capacity for DNA repair in Antarctic organisms was highest in those species whose early life history stages occupy the water column during periods of ozone depletion (austral spring) and lowest in fish species whose eggs and larvae are abundant during winter. Although the potential reduction in fitness of Antarctic zooplankton resulting from DNA damage is unknown, we suggest that increased solar UV may reduce recruitment and adversely affect trophic transfer of productivity by affecting heterotrophic species as well as primary producers.
journal_name
Proc Natl Acad Sci U S Aauthors
Malloy KD,Holman MA,Mitchell D,Detrich HW 3rddoi
10.1073/pnas.94.4.1258subject
Has Abstractpub_date
1997-02-18 00:00:00pages
1258-63issue
4eissn
0027-8424issn
1091-6490journal_volume
94pub_type
杂志文章abstract：:Heterosis is widely applied in agriculture; however, the underlying molecular mechanisms for superior performance are not well understood. Ethylene biosynthesis and signaling genes are shown to be down-regulated in Arabidopsis interspecific hybrids. Ethylene is a plant hormone that promotes fruit ripening and maturati...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1722068115
更新日期：2018-05-22 00:00:00
abstract：:Researchers have documented many cases in which individuals rationalize their regrettable actions. Four experiments examine situations in which people go beyond merely explaining away their misconduct to actively deceiving themselves. We find that those who exploit opportunities to cheat on tests are likely to engage ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1010658108
更新日期：2011-09-13 00:00:00
abstract：:Photosynthesis has recently gained considerable attention for its potential role in the development of renewable energy sources. Optimizing photosynthetic organisms for biomass or biofuel production will therefore require a systems understanding of photosynthetic processes. We reconstructed a high-quality genome-scale...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1117907109
更新日期：2012-02-14 00:00:00
abstract：:Mineralogical processes taking place close to equilibrium, or with very slow kinetics, are difficult to quantify precisely. The determination of ultraslow dissolution/precipitation rates would reveal characteristic timing associated with these processes that are important at geological scale. We have designed an advan...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1105233108
更新日期：2011-09-20 00:00:00
abstract：:We provide empirical evidence of immigrants' specialization in skill acquisition well before entering the US labor market. Nationally representative datasets enable studying the academic trajectories of immigrant children, with a focus on high-school course-taking patterns and college major choice. Immigrant children ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1812041116
更新日期：2019-01-08 00:00:00
abstract：:Human liver alkaline phosphatase [ortho-phosphoric monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1] was purified, and some of its physical and chemical properties were examined and compared to those of human placental alkaline phosphatase. The results indicated a different peptide structure for each, based u...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.73.7.2201
更新日期：1976-07-01 00:00:00
abstract：:Injury to the peripheral processes produces a profound cell loss (40-50%) in the dorsal root ganglion of newborn rats. Although division of central processes produces little or no cellular change in sensory ganglion of adult animals, no information has been available on the effect of dorsal root section in developing ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.81.19.6245
更新日期：1984-10-01 00:00:00
abstract：:The dendritic building blocks with a focal pyrene unit self-organize into vesicles in aqueous phase. The in situ inclusion of the focal pyrene units into the cavity of beta- or gamma-cyclodextrin (CD) induces self-assembled organic nanotubes with an average outer diameter of approximately 45 nm and inner diameter of 2...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.0505364103
更新日期：2006-01-31 00:00:00
abstract：:The Alzheimer A beta amyloid peptide (A beta) is the principal proteinaceous component of amyloid associated with Alzheimer disease (AD). We have determined the relative abundance of A beta structural variants present in amyloid from brains of 10 individuals with sporadic AD, 2 individuals with familial AD carrying sp...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.91.18.8378
更新日期：1994-08-30 00:00:00
abstract：:The three-dimensional structure of a human monoclonal antibody (Fab), which binds specifically to a major epitope of the transmembrane protein gp41 of the human immunodeficiency virus type 1, has been determined by crystallographic methods to a resolution of 2.7 A. It has been previously determined that this antibody ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.89.15.7154
更新日期：1992-08-01 00:00:00
abstract：:The body-wall muscle cells of the nematode Caenorhabditis elegans produce thick filaments during embryonic, larval, and adult stages. These thick filaments contain two myosin isoforms, A and B, which assemble into different zones along the 10-microns lengths. Paramyosin, a protein homologous to myosin rods, forms a su...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.87.3.876
更新日期：1990-02-01 00:00:00
abstract：:The glucose transporter isoform GLUT4 is found only in cells that exhibit insulin-sensitive glucose transport. To investigate the function of this transporter, L6 myoblasts were stably transfected with GLUT4 cDNA. GLUT4 underwent insulin-dependent movement to the cell surface in myoblasts overexpressing the transporte...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.89.8.3493
更新日期：1992-04-15 00:00:00
abstract：:The existence and neuroanatomical locations of separate extrastriate visual pathways for object recognition and spatial localization were investigated in healthy young men. Regional cerebral blood flow was measured by positron emission tomography and bolus injections of H2(15)O, while subjects performed face matching,...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.88.5.1621
更新日期：1991-03-01 00:00:00
abstract：:In biosynthesis of the pancreatic cancer drug streptozotocin, the tridomain nonheme-iron oxygenase SznF hydroxylates Nδ and Nω' of Nω-methyl-l-arginine before oxidatively rearranging the triply modified guanidine to the N-methyl-N-nitrosourea pharmacophore. A previously published structure visualized the monoiron cofa...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.2015931118
更新日期：2021-01-26 00:00:00
abstract：:Inactivation of the p53 pathway represents the most common molecular defect of human cancer. But in the setting of melanoma, a highly aggressive and invariably fatal malignancy in its advanced disseminated form, mutation/deletion of p53 is relatively rare, whereas its positive regulator ARF is often lost. Here, we sho...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.0611638104
更新日期：2007-06-26 00:00:00
abstract：:The protein encoded by the GAL4 gene of the yeast Saccharomyces cerevisiae binds to DNA upstream of several genes and activates transcription. To try to understand these processes, we have undertaken a genetic analysis of GAL4. Here we report that nearly all missense mutations in GAL4, selected in vivo to lack functio...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.84.8.2401
更新日期：1987-04-01 00:00:00
abstract：:Speciation involves the origin of trait differences that limit or prevent gene exchange and ultimately results in daughter populations that form monophyletic or exclusive genetic groups. However, for recently diverged populations or species between which reproductive isolation is often incomplete, gene genealogies wil...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.0502054102
更新日期：2005-10-11 00:00:00
abstract：:In response to vascular injury, vascular smooth muscle cells (VSMCs) may switch from a contractile to a proliferative phenotype thereby contributing to neointima formation. Previous studies showed that the long noncoding RNA (lncRNA) NEAT1 is critical for paraspeckle formation and tumorigenesis by promoting cell proli...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1803725115
更新日期：2018-09-11 00:00:00
abstract：:DNA mismatch repair is central to the maintenance of genomic stability. It is initiated by the recognition of base-base mismatches and insertion/deletion loops by the family of MutS proteins. Subsequently, ATP induces a unique conformational change in the MutS-mismatch complex but not in the MutS-homoduplex complex th...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.2433654100
更新日期：2003-12-09 00:00:00
abstract：:Multituberculates were the longest-lived order of the Class Mammalia and, during the Mesozoic and early Cenozoic, were among the most diverse and abundant representatives of the class. However, until the recent discovery of two Cretaceous teeth, one from South America and one from Africa, they were known only from nor...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 历史文章,杂志文章
doi：10.1073/pnas.90.20.9379
更新日期：1993-10-15 00:00:00
abstract：:Clinical and epidemiological synergy exists between the globally important sexually transmitted infections, gonorrhea and HIV. Neisseria gonorrhoeae, which causes gonorrhea, is particularly adept at driving HIV-1 expression, but the molecular determinants of this relationship remain undefined. N. gonorrhoeae liberates...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1303738110
更新日期：2013-06-18 00:00:00
abstract：:It is well established that exposure to solar UVB (290-320 nm) gives rise to mutations in oncogenes and tumor suppressor genes that initiate the molecular cascade toward skin cancer. Although UVA (320-400 nm) has also been implicated in multistage photocarcinogenesis, its potential contribution to sunlight mutagenesis...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.92.6.2350
更新日期：1995-03-14 00:00:00
abstract：:There is an important medical need for new antifungal agents with novel mechanisms of action to treat the increasing number of patients with life-threatening systemic fungal disease and to overcome the growing problem of resistance to current therapies. F901318, the leading representative of a novel class of drug, the...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1608304113
更新日期：2016-11-08 00:00:00
abstract：:The polyomavirus enhancer is composed of multiple DNA sequence elements serving as binding sites for proteins present in mouse nuclear extracts that activate transcription and DNA replication. We have identified three such proteins and their binding sites and correlate them with enhancer function. Mutation of nucleoti...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.85.16.5839
更新日期：1988-08-01 00:00:00
abstract：:A double-antibody radioimmunoassay has been developed for the detection of Australia antigen and antibodies to Australia antigen in human sera. The assay is simple to perform, and can be completed in 18 hr. Based on parallel studies of human sera, it is approximately 2000 times more sensitive than agar gel diffusion a...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.68.5.1056
更新日期：1971-05-01 00:00:00
abstract：:A fundamental mystery of plant cell biology is the occurrence of "stromules," stroma-filled tubular extensions from plastids (such as chloroplasts) that are universally observed in plants but whose functions are, in effect, completely unknown. One prevalent hypothesis is that stromules exchange signals or metabolites ...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1511570112
更新日期：2015-08-11 00:00:00
abstract：:Sinorhizobium meliloti is an alpha-proteobacterium that forms agronomically important N(2)-fixing root nodules in legumes. We report here the complete sequence of the largest constituent of its genome, a 62.7% GC-rich 3,654,135-bp circular chromosome. Annotation allowed assignment of a function to 59% of the 3,341 pre...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.161294398
更新日期：2001-08-14 00:00:00
abstract：:Molecules of transfer RNA (tRNA) typically contain four stems composed of Watson-Crick (W-C) base pairs and infrequent mispairs such as G-U and A-C. The latter mispairs are fundamental units of RNA secondary structure found in nearly every class of RNA and are nearly isomorphic to W-C pairs. Therefore, they often subs...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.0600592103
更新日期：2006-03-21 00:00:00
abstract：:Adaptive radiation is the evolution of ecological and phenotypic diversity within a rapidly multiplying lineage. Recent studies have identified general patterns in adaptive radiation and inferred that resource competition is a primary factor driving phenotypic divergence. The role and importance of other processes, su...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.0601575103
更新日期：2006-06-13 00:00:00
abstract：:The medial prefrontal cortex (mPFC) plays an essential role in regulating emotion, including inhibiting fear when danger has passed. The extinction of fear, however, is labile and a number of factors, including stress, cause extinguished fear to relapse. Here we show that fear relapse in rats limits single-unit activi...
journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.1814278116
更新日期：2019-04-23 00:00:00
