Abstract：
:Over the past 50 y, behavioral experiments have produced a large body of evidence for the existence of a magnetic sense in a wide range of animals. However, the underlying sensory physiology remains poorly understood due to the elusiveness of the magnetosensory structures. Here we present an effective method for isolating and characterizing potential magnetite-based magnetoreceptor cells. In essence, a rotating magnetic field is employed to visually identify, within a dissociated tissue preparation, cells that contain magnetic material by their rotational behavior. As a tissue of choice, we selected trout olfactory epithelium that has been previously suggested to host candidate magnetoreceptor cells. We were able to reproducibly detect magnetic cells and to determine their magnetic dipole moment. The obtained values (4 to 100 fAm(2)) greatly exceed previous estimates (0.5 fAm(2)). The magnetism of the cells is due to a μm-sized intracellular structure of iron-rich crystals, most likely single-domain magnetite. In confocal reflectance imaging, these produce bright reflective spots close to the cell membrane. The magnetic inclusions are found to be firmly coupled to the cell membrane, enabling a direct transduction of mechanical stress produced by magnetic torque acting on the cellular dipole in situ. Our results show that the magnetically identified cells clearly meet the physical requirements for a magnetoreceptor capable of rapidly detecting small changes in the external magnetic field. This would also explain interference of ac powerline magnetic fields with magnetoreception, as reported in cattle.
journal_name
Proc Natl Acad Sci U S Aauthors
Eder SH,Cadiou H,Muhamad A,McNaughton PA,Kirschvink JL,Winklhofer Mdoi
10.1073/pnas.1205653109subject
Has Abstractpub_date
2012-07-24 00:00:00pages
12022-7issue
30eissn
0027-8424issn
1091-6490pii
1205653109journal_volume
109pub_type
杂志文章abstract：:Cyclic AMP levels increase abruptly in the secondary palatal shelf (mesenchyme plus a two- to three-cell-layered epithelium) between day 15 and 16 of gestation in the rat embryo. The addition of dibutyryl cyclic AMP to the media in which immature palatal shelves (day 14) are cultured causes a precocious decrease in DN...
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.72.3.874
更新日期：1975-03-01 00:00:00
abstract：:The BTB domain (also known as the POZ domain) is an evolutionarily conserved protein-protein interaction motif found at the N terminus of 5-10% of C2H2-type zinc-finger transcription factors, as well as in some actin-associated proteins bearing the kelch motif. Many BTB proteins are transcriptional regulators that med...
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.95.21.12123
更新日期：1998-10-13 00:00:00
abstract：:The importance of dystrophin and its associated proteins in normal muscle function is now well established. Many of these proteins are expressed in nonmuscle tissues, particularly the brain. Here we describe the characterization of beta-dystrobrevin, a dystrophin-related protein that is abundantly expressed in brain 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.95.1.241
更新日期：1998-01-06 00:00:00
abstract：:Sodium influx is an important early signal during the onset of mitogenesis in many types of cells. From this observation, one would predict that a decrease in extracellular Na+ concentration might retard cell proliferation. We tested this prediction by exposing sets of cultures of monkey kidney epithelial cells (BSC-1...
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.83.13.4764
更新日期：1986-07-01 00:00:00
abstract：:Optical spectra of biological polymers contain important information about their structure and function in living organisms. This information can be accessed by extracting an optical interaction of monomers, i.e., their exciton coupling, from experimental data. This coupling is sensitive to molecular structure, geomet...
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.0808513106
更新日期：2009-01-27 00:00:00
abstract：:gamma-Aminobutyric acid type A (GABA-A) receptors are a major mediator of inhibitory neurotransmission in the mammalian central nervous system, and the site of action of a number of clinically important drugs. These receptors exist as a family of subtypes with distinct temporal and spatial patterns of expression and d...
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.96.17.9891
更新日期：1999-08-17 00:00:00
abstract：:We have used a membrane-leak mass spectrometer to follow the time courses of H2 evolution and substrate reduction by nitrogenase [reduced ferredoxin:dinitrogen oxidoreductase (ATP-hydrolyzing), EC 1.18.6.1]. In the absence of added substrates, dinitrogenase passes all of its electrons to protons to form H2, but when 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.85.24.9446
更新日期：1988-12-01 00:00:00
abstract：:The assembly and composition of human excision nuclease were investigated by electrophoretic mobility shift assay and DNase I footprinting. Individual repair factors or any combination of up to four repair factors failed to form DNA-protein complexes of high specificity and stability. A stable complex of high specific...
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.95.12.6669
更新日期：1998-06-09 00:00:00
abstract：:In vitro tests for predicting the response of tumors to chemotherapeutic agents might be improved if they were modified to take into account tumor-cell heterogeneity. We have studied the heterogeneity of cellular growth rate and drug response in mouse fibroblast NIH 3T3 cells and in NIH 3T3 cells transformed with 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.84.13.4490
更新日期：1987-07-01 00:00:00
abstract：:Insect damage on fossil leaves from the Central Rocky Mountains, United States, documents the response of herbivores to changing regional climates and vegetation during the late Paleocene (humid, warm temperate to subtropical, predominantly deciduous), early Eocene (humid subtropical, mixed deciduous and evergreen), 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.111069498
更新日期：2001-05-22 00:00:00
abstract：:We report a method for introducing mtDNA mutations into the mouse female germ line by means of embryonic stem (ES) cell cybrids. Mitochondria were recovered from the brain of a NZB mouse by fusion of synaptosomes to a mtDNA-deficient (rho degrees ) cell line. These cybrids were enucleated and the cytoplasts were elect...
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.250491597
更新日期：2000-12-19 00:00:00
abstract：:Fibronectin (FN) forms the primitive fibrillar matrix in both embryos and healing wounds. To study the matrix in living cell cultures, we have constructed a cell line that secretes FN molecules chimeric with green fluorescent protein. These FN-green fluorescent protein molecules were assembled into a typical matrix 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.96.5.2153
更新日期：1999-03-02 00:00:00
abstract：:We have reported previously that murine bone marrow-derived dendritic cells (DC) pulsed with whole tumor lysates can mediate potent antitumor immune responses both in vitro and in vivo. Because successful therapy was dependent on host immune T cells, we have now evaluated whether the systemic administration of the T 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.96.5.2268
更新日期：1999-03-02 00:00:00
abstract：:Two endocytic receptors, the low density lipoprotein (LDL) receptor (LDLR) and the LDLR-related protein (LRP), are thought to act in concert in the hepatic uptake of partially metabolized dietary lipoproteins, the chylomicron remnants. We have evaluated the role of these two receptors in the hepatic metabolism of chyl...
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.92.10.4611
更新日期：1995-05-09 00:00:00
abstract：:The Miocene is characterized by a series of key climatic events that led to the founding of the late Cenozoic icehouse mode and the dawn of modern biota. The processes that caused these developments, and particularly the role of atmospheric CO2 as a forcing factor, are poorly understood. Here we present a CO2 record b...
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.0708588105
更新日期：2008-01-15 00:00:00
abstract：:Intracisternal A-particles were isolated from three different myeloma lines in BALB/c mice and from cultured neuroblastoma cells of A/J origin. All preparations contained a major structural protein with an apparent molecular weight near 70,000 as estimated by electrophoretic mobility in sodium dodecyl sulfate-containi...
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.69.1.218
更新日期：1972-01-01 00:00:00
abstract：:The oxidative capacity of cat skeletal muscles (soleus, gracilis, and gracilis chronically stimulated for 28 days) was derived from the total mitochondrial content in the muscle, the surface area of mitochondrial inner membranes, and respiratory activities of isolated mitochondria. Mitochondrial content was estimated ...
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.86.5.1583
更新日期：1989-03-01 00:00:00
abstract：:The transcription initiation site of the human ribosomal RNA gene (rDNA) was located by using the single-strand specific nuclease protection method and by determining the first nucleotide of the in vitro capped 45S preribosomal RNA. The sequence of 1,211 nucleotides surrounding the initiation site was determined. 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.79.10.3092
更新日期：1982-05-01 00:00:00
abstract：:Duchenne muscular dystrophy (DMD) is a lethal genetic disorder caused by an absence of the dystrophin protein in bodywide muscles, including the heart. Cardiomyopathy is a leading cause of death in DMD. Exon skipping via synthetic phosphorodiamidate morpholino oligomers (PMOs) represents one of the most promising ther...
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.1613203114
更新日期：2017-04-18 00:00:00
abstract：:The results of physicochemical studies of mammalian metallothioneins are summarized and used to propose a model of the protein. The primary structures of all mammalian metallothioneins are very homologous; there are 38 invariant residues and 20 of them are cysteines. The results of UV and CD optical studies indicated ...
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.80.6.1501
更新日期：1983-03-01 00:00:00
abstract：:The regulatory photoreceptor phytochrome controls the transcription of its own phy genes in a negative feedback fashion. We have exploited microprojectile-mediated gene transfer to develop a rapid transient expression assay system for the study of DNA sequences involved in the phytochrome-regulated expression of these...
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.86.24.9692
更新日期：1989-12-01 00:00:00
abstract：:A murine monoclonal antibody (OKT9) raised against human leukemic cells binds to a wide variety of leukemia and tumor cell lines and to a minority of leukemia cells taken directly from patients. Fetal thymus and liver are strongly reactive as are some normal, immature hemopoietic cells and activated lymphocytes. React...
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.78.7.4515
更新日期：1981-07-01 00:00:00
abstract：:Cell adhesion molecules (CAMs) may act as regulators of morphogenesis by constraining cell motion, forming borders, and controlling intercellular communications that lead to embryonic induction. This postulated causal role of CAMs in inductive events was tested here in an in vitro system of feather induction. In the d...
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.83.21.8235
更新日期：1986-11-01 00:00:00
abstract：:Silencing of multiple cancer-related genes is associated with de novo methylation of linked CpG islands. Additionally, bivalent histone modification profiles characterized by the juxtaposition of active and inactive histone marks have been observed in genes that become hypermethylated in cancer. It is unknown how thes...
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.0810133105
更新日期：2008-12-16 00:00:00
abstract：:It is shown that, under certain standard assumptions, such as extended Riemann hypotheses, the scattering matrix varphi(s) for generic Gamma
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.82.11.3533
更新日期：1985-06-01 00:00:00
abstract：:We have identified a protein present only in erythroid cells that binds to two adjacent sites within an enhancer region of the chicken beta-globin locus. Mutation of the sites, so that binding by the factor can no longer be detected in vitro, leads to a loss of enhancing ability, assayed by transient expression in pri...
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.85.16.5976
更新日期：1988-08-01 00:00:00
abstract：:I reject the Darwinian assumption that larvae and their adults evolved from a single common ancestor. Rather I posit that, in animals that metamorphose, the basic types of larvae originated as adults of different lineages, i.e., larvae were transferred when, through hybridization, their genomes were acquired by distan...
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.0908357106
更新日期：2009-11-24 00:00:00
abstract：:In a previous study we demonstrated that vesicular stomatitis virus (VSV) can be used as a vector to express a soluble protein in mammalian cells. Here we have generated VSV recombinants that express four different membrane proteins: the cellular CD4 protein, a CD4-G hybrid protein containing the ectodomain of CD4 and...
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.93.21.11359
更新日期：1996-10-15 00:00:00
abstract：:Mouse interferon preparations inhibited the multiplication of mouse leukemia L 1210 cells cultivated under steady-state conditions in a chemostat. The use of this sensitive and controlled system led to the detection of a rapid inhibition in the incorporation of (3-H)thymidine into cellular acid-precipitable material 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.72.6.2265
更新日期：1975-06-01 00:00:00
abstract：:NRSF/REST is a protein that silences transcription of a number of genes that contain a DNA element called the neuron-restrictive silencer element (NRSE). During embryogenesis, REST is expressed ubiquitously in nonneural cells, but is down-regulated during differentiation of neural progenitors into neurons. REST is als...
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.050578797
更新日期：2000-02-29 00:00:00
