Abstract:
:Mutations arise in a single individual and at a single point in time and space. The geographic distribution of mutations reflects both historical population size and frequency of migration. We employ coalescence-based methods to coestimate effective population size, frequency of migration, and level of recombination compatible with observed genealogical relationships in sequence data from nine nuclear genes in wild barley (Hordeum vulgare ssp. spontaneum), a highly self-fertilizing grass species. In self-fertilizing plants, gamete dispersal is severely limited; dissemination occurs primarily through seed dispersal. Also, heterozygosity is greatly reduced, which renders recombination less effective at randomizing genetic variation and causes larger portions of the genome to trace a similar history. Despite these predicted effects of this mating system, the majority of loci show evidence of recombination. Levels of nucleotide variation and the patterns of geographic distribution of mutations in wild barley are highly heterogeneous across loci. Two of the nine sampled loci maintain highly diverged, geographic region-specific suites of mutations. Two additional loci include region-specific haplotypes with a much shallower coalescence. Despite inbreeding, sessile growth habit, and the observation of geographic structure at almost half of sampled loci, parametric estimates of migration suggest that seed dispersal is sufficient for migration across the approximately 3,500-km range of the species. Recurrent migration is also evident based on the geographic distribution of mutational variation at some loci. At one locus a single haplotype has spread rapidly enough to occur, unmodified by mutation, across the range of the species.
journal_name
Proc Natl Acad Sci U S Aauthors
Morrell PL,Lundy KE,Clegg MTdoi
10.1073/pnas.1633708100keywords:
subject
Has Abstractpub_date
2003-09-16 00:00:00pages
10812-7issue
19eissn
0027-8424issn
1091-6490pii
1633708100journal_volume
100pub_type
杂志文章abstract::Toward understanding their redundancies and interactions in hemostasis and thrombosis, we examined the roles of thrombin receptors (protease-activated receptors, PARs) and the ADP receptor P2RY12 (purinergic receptor P2Y G protein-coupled 12) in human and mouse platelets ex vivo and in mouse models. Par3(-/-) and Par4...
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.1013309107
更新日期:2010-10-26 00:00:00
abstract::The initial electron transfer steps in the photosynthetic reaction center of the purple bacterium Rhodobacter sphaeroides have been investigated by femtosecond time-resolved spectroscopy. The experimental data taken at various wavelengths demonstrate the existence of at least four intermediate states within the first ...
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.87.13.5168
更新日期:1990-07-01 00:00:00
abstract::Loquacious-PD (Loqs-PD) is required for biogenesis of many endogenous siRNAs in Drosophila In vitro, Loqs-PD enhances the rate of dsRNA cleavage by Dicer-2 and also enables processing of substrates normally refractory to cleavage. Using purified components, and Loqs-PD truncations, we provide a mechanistic basis for L...
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.1707063114
更新日期:2017-09-19 00:00:00
abstract::A fundamental aspect of climate change is the potential shifts in flowering phenology and pollen initiation associated with milder winters and warmer seasonal air temperature. Earlier floral anthesis has been suggested, in turn, to have a role in human disease by increasing time of exposure to pollen that causes aller...
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.1014107108
更新日期:2011-03-08 00:00:00
abstract::A study was made of the effects of di- and trivalent cations on homomeric rho 1-type gamma-aminobutyrate (GABA rho 1) receptors expressed in Xenopus oocytes after injection of mRNA coding for the GABA rho 1 subunit. GABA elicited large currents with a Kd approximately 1 microM. The properties of these GABA rho 1 recep...
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.91.26.12725
更新日期:1994-12-20 00:00:00
abstract::In order to study the mutagenic effects of site-specific, covalent modifications of biologically active DNA, we need host cells that are permissive for any type of mutation that might be produced in vivo from the modified DNA. Specifically, we require a general, in vivo complementation system for the bacteriophage phi...
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.75.2.774
更新日期:1978-02-01 00:00:00
abstract::The recent discovery of superconductivity with relatively high transition temperature (Tc) in the layered iron-based quaternary oxypnictides La[O(1-x)F(x)] FeAs by Kamihara et al. [Kamihara Y, Watanabe T, Hirano M, Hosono H (2008) Iron-based layered superconductor La[O1-xFx] FeAs (x = 0.05-0.12) with Tc = 26 K. J Am C...
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.0807325105
更新日期:2008-09-23 00:00:00
abstract::Contact-dependent growth inhibition (CDI) is a mechanism by which bacteria exchange toxins via direct cell-to-cell contact. CDI systems are distributed widely among Gram-negative pathogens and are thought to mediate interstrain competition. Here, we describe tsf mutations that alter the coiled-coil domain of elongatio...
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.1619273114
更新日期:2017-03-07 00:00:00
abstract::A hypothetical gene with similarity to the ispD gene of Escherichia coli was cloned from Arabidopsis thaliana cDNA. The ORF of 909 bp specifies a protein of 302 amino acid residues. The cognate chromosomal gene consists of 2,071 bp and comprises 11 introns with a size range of 78-202 bp. A fragment comprising amino ac...
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.97.12.6451
更新日期:2000-06-06 00:00:00
abstract::Single strands of DNA serve, in rare instances, as promoters for transcription; duplex DNA promoters with individual strands that also have a promoter capacityfunction have not been described. We show that the nontranscribed strand of the Saccharomyces cerevisiae U6 snRNA gene directs transcription initiation factor I...
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.242735699
更新日期:2003-02-04 00:00:00
abstract::Oxidants, such as those generated by metabolically activated phagocytes in inflammation, have been implicated in the metabolic activation of carcinogens, and in this study we demonstrate that the interaction of (+/-)-trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP 7,8-dihydrodiol) with phorbol ester-stimulated polym...
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.82.15.5194
更新日期:1985-08-01 00:00:00
abstract::BCL6 encodes a transcriptional repressor that is essential for the germinal center (GC) reaction and important in lymphomagenesis. Although its promoter has been well studied, little is known concerning its possible regulation by more distal elements. To gain such information, we mapped critical histone modifications ...
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.1004962107
更新日期:2010-06-29 00:00:00
abstract::Several Bradyrhizobium species nodulate the leguminous plant Aeschynomene indica in a type III secretion system-dependent manner, independently of Nod factors. To date, the underlying molecular determinants involved in this symbiotic process remain unknown. To identify the rhizobial effectors involved in nodulation, w...
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.1904456116
更新日期:2019-10-22 00:00:00
abstract::Sensitization of defensive gill and siphon withdrawal reflexes in Aplysia results, in part, from presynaptic facilitation of transmitter release from mechanoreceptor sensory neurons that innervate the siphon skin and synapse with interneurons and motor neurons. Presynaptic facilitation also can be elicited by applicat...
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.83.22.8794
更新日期:1986-11-01 00:00:00
abstract::In contrast to mechanisms mediating uptake of intracellular bacterial pathogens, bacterial egress and cell-to-cell transmission are poorly understood. Previously, we showed that the transmission of pathogenic mycobacteria between phagocytic cells also depends on nonlytic ejection through an F-actin based structure, ca...
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.1423318112
更新日期:2015-02-17 00:00:00
abstract::Although the polysialyltransferase ST8Sia IV is expressed in both primary and secondary human lymphoid organs, its product, polysialic acid (polySia), has been largely overlooked by immunologists. In contrast, polySia expression and function in the nervous system has been well characterized. In this context, polySia m...
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.0905188106
更新日期:2009-07-21 00:00:00
abstract::mRNA coding for mouse major transplantation antigens of the d haplotype was partially purified, copied into double-stranded cDNA, and cloned in Escherichia coli. Clones were selected by their ability to hybridize specifically with mRNA coding for H-2K, D, or L antigens. One of these clones, pH-2d-1, carries a 1200-bas...
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.78.5.2772
更新日期:1981-05-01 00:00:00
abstract::Integrin alphanubeta3 is found on a subset of tumor blood vessels where it is associated with angiogenesis and malignant tumor growth. We designed an alphanubeta3-targeted nanoparticle (NP) encapsulating the cytotoxic drug doxorubicin (Dox) for targeted drug delivery to the alphanubeta3-expressing tumor vasculature. W...
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.0803728105
更新日期:2008-07-08 00:00:00
abstract::The hormone gibberellin (GA) is a key regulator of plant growth. Many of the components of the gibberellin signal transduction [e.g., GIBBERELLIN INSENSITIVE DWARF 1 (GID1) and DELLA], biosynthesis [e.g., GA 20-oxidase (GA20ox) and GA3ox], and deactivation pathways have been identified. Gibberellin binds its receptor,...
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.1113666109
更新日期:2012-05-08 00:00:00
abstract::We lack a clear understanding of the enzootic maintenance of the bacterium (Yersinia pestis) that causes plague and the sporadic epizootics that occur in its natural rodent hosts. A key to elucidating these epidemiological dynamics is determining the dominant transmission routes of plague. Plague can be acquired from ...
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.0510090103
更新日期:2006-04-18 00:00:00
abstract::In making sense of the visual world, the brain's processing is driven by two factors: the physical information provided by the eyes ("bottom-up" data) and the expectancies driven by past experience ("top-down" influences). We use degraded stimuli to tease apart the effects of bottom-up and top-down processes because t...
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.1111224109
更新日期:2012-05-15 00:00:00
abstract::Nonhuman primates possess a highly developed capacity for face recognition, which resembles the human capacity both cognitively and neurologically. Face recognition is typically tested by having subjects compare facial images, whereas there has been virtually no attention to how they connect these images to reality. C...
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.0912174106
更新日期:2009-12-22 00:00:00
abstract::The mature gag and pol proteins of human immunodeficiency virus (HIV) and all retroviruses derive from large gag and gag-pol polyprotein precursors by posttranslational cleavage. A highly specific, virally encoded protease is required for this essential proteolytic processing. In this study, the HIV protease gene prod...
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.84.24.8903
更新日期:1987-12-01 00:00:00
abstract::The heme-copper oxidases constitute a superfamily of terminal dioxygen-reducing enzymes located in the inner mitochondrial or in the bacterial cell membrane. The presence of a mechanistically important covalent bond between a histidine ligand of the copper ion (Cu(B)) in the active site and a generally conserved tyros...
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.0606254103
更新日期:2006-10-31 00:00:00
abstract::High molecular weight polypeptides (HMWPs) of 270,000 to 340,000 were found to be major components of intermediate filaments prepared by Triton X-100 extraction after spreading of rat glioma C6, HeLa, Chinese hamster ovary, and simian virus 40-transformed Chinese hamster lung cells. C6 HMWPs were shown to resemble hig...
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.77.8.4808
更新日期:1980-08-01 00:00:00
abstract::Defects in clearing apoptotic debris disrupt tissue and immunological homeostasis, leading to autoimmune and inflammatory diseases. Herein, we report that macrophages from lupus-prone MRL/lpr mice have impaired lysosomal maturation, resulting in heightened ROS production and attenuated lysosomal acidification. Impaire...
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.1513943113
更新日期:2016-04-12 00:00:00
abstract::The dauer larva state and the age-1 mutation, both of which extend life-span in Caenorhabditis elegans, were tested for hyperresistance to cellular damage that may be relevant to aging. The age-1 strain TJ401 displayed hyperresistance to oxidative stress relative to its parental strain. The activities of two enzymes t...
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.90.19.8905
更新日期:1993-10-01 00:00:00
abstract::Managing excess nutrients remains a major obstacle to improving ecosystem service benefits of urban waters. To inform more ecologically based landscape nutrient management, we compared watershed inputs, outputs, and retention for nitrogen (N) and phosphorus (P) in seven subwatersheds of the Mississippi River in St. Pa...
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.1618536114
更新日期:2017-04-18 00:00:00
abstract::We have studied a naturally occurring small-molecule antimitotic called diazonamide A. Diazonamide A is highly effective at blocking spindle assembly in mammalian cell culture and does so through a unique mechanism. A biotinylated form of diazonamide A affinity purifies ornithine delta-amino transferase (OAT), a mitoc...
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.0610832104
更新日期:2007-02-13 00:00:00
abstract::The study of specific trans-acting transcription factors in prokaryotes and lower eukaryotes has been greatly facilitated by genetic analysis of mutant strains deficient in such factors. We have developed such a system to study mammalian trans-acting factors that regulate the transcription of class II major histocompa...
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.85.23.8830
更新日期:1988-12-01 00:00:00