Abstract:
:Molting or ecdysis is the most fundamentally important process in arthropod life history, because shedding of the exoskeleton is an absolute prerequisite for growth and metamorphosis. Although the hormonal mechanisms driving ecdysis in insects have been studied extensively, nothing is known about these processes in crustaceans. During late premolt and during ecdysis in the crab Carcinus maenas, we observed a precise and reproducible surge in hemolymph hyperglycemic hormone (CHH) levels, which was over 100-fold greater than levels seen in intermolt animals. The source of this hormone surge was not from the eyestalk neurosecretory tissues but from previously undescribed endocrine cells (paraneurons), in defined areas of the foregut and hindgut. During premolt (the only time when CHH is expressed by these tissues), the gut is the largest endocrine tissue in the crab. The CHH surge, which is a result of an unusual, almost complete discharge of the contents of the gut endocrine cell, regulates water and ion uptake during molting, thus allowing the swelling necessary for successful ecdysis and the subsequent increase in size during postmolt. This study defines an endocrine brain/gut axis in the arthropods. We propose that the ionoregulatory process controlled by CHH may be common to arthropods, in that, for insects, a similar mechanism seems to be involved in antidiuresis. It also seems likely that a cascade of very precisely coordinated release of (neuro) hormones controls ecdysis.
journal_name
Proc Natl Acad Sci U S Aauthors
Chung JS,Dircksen H,Webster SGdoi
10.1073/pnas.96.23.13103keywords:
subject
Has Abstractpub_date
1999-11-09 00:00:00pages
13103-7issue
23eissn
0027-8424issn
1091-6490journal_volume
96pub_type
杂志文章abstract::We have previously described a gene delivery system based upon the receptor-mediated endocytosis of DNA complexed with transferrin-polycation conjugates. This delivery system has been found to be very effective for both the internalization and the expression of genetic material in cells that have many transferrin rece...
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.88.10.4255
更新日期:1991-05-15 00:00:00
abstract::We prove that the property of excision in algebraic K-theory is for a Q-algebra A equivalent to the H-unitality of the latter. Our excision theorem, in particular, implies Karoubi's conjecture on the equality of algebraic and topological K-theory groups of stable C*-algebras. It also allows us to identify the algebrai...
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.87.24.9582
更新日期:1990-12-15 00:00:00
abstract::For centuries, traditional agricultural systems have contributed to food and livelihood security throughout the world. Recognizing the ecological legacy in the traditional agricultural systems may help us develop novel sustainable agriculture. We examine how rice-fish coculture (RF), which has been designated a "globa...
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.1111043108
更新日期:2011-12-13 00:00:00
abstract::A 1H NMR study of the 79-residue globular domain of chicken erythrocyte histone H5 (GH5) is presented. Using a combination of two-dimensional NMR techniques to demonstrate through-bond and through-space (less than 5 A) connectivities, the resonances of GH5 are assigned in a sequential manner. From a qualitative interp...
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.83.20.7628
更新日期:1986-10-01 00:00:00
abstract::mRNA for the large subunit (LS) of ribulose-1,5-bisphosphate carboxylase [3-phospho-D-glycerate carboxylase (dimerizing), EC 4.1.1.39] of Zea mays is complementary to an uninterrupted 1600-base-pair-long chloroplast DNA sequence that has been mapped precisely within the 4350-base-pair-long chloroplast DNA fragment Bam...
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.77.4.1832
更新日期:1980-04-01 00:00:00
abstract::Sixteen hybridomas have been identified that secrete antibodies specific to horizontal cells in the carp retina. The hybridomas have been classified into three groups based on their antibody staining patterns: group I, staining associated with all horizontal cells; group II, staining associated with the most abundant ...
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.81.19.6255
更新日期:1984-10-01 00:00:00
abstract::CR1 is a short interspersed repetitive DNA element originally identified in the domestic chicken (Gallus gallus). However, unlike virtually all other such sequences described to date, CR1 is not confined to one or a few closely related species. It is probably a ubiquitous component of the avian genome, having been det...
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.88.13.5814
更新日期:1991-07-01 00:00:00
abstract::We have shown previously that guanine nucleotide-binding protein (G protein) beta gamma complexes purified from bovine brain membranes are methyl esterified on a C-terminal cysteine residue of the gamma polypeptide. In the present study, 3H-methylated G beta gamma complexes cleaved to their constituent amino acids by ...
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.87.15.5868
更新日期:1990-08-01 00:00:00
abstract::The molecular basis of bacterial cell morphogenesis remains largely an open question. Here we discover a morphogenic protein, RodZ, which is widely conserved across the bacterial kingdom. In Caulobacter crescentus, RodZ is essential for viability and is involved in all aspects of this organism's complex morphology. De...
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.0810794106
更新日期:2009-01-27 00:00:00
abstract::To efficiently represent all of the possible rewards in the world, dopaminergic midbrain neurons dynamically adapt their coding range to the momentarily available rewards. Specifically, these neurons increase their activity for an outcome that is better than expected and decrease it for an outcome worse than expected,...
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.1119969109
更新日期:2012-03-13 00:00:00
abstract::The bidirectional self-assembly of tobacco mosaic virus (TMV, common or U1 strain) has been studied extensively in vitro. Foreign single-stranded RNA molecules containing the TMV origin-of-assembly sequence (OAS, 75-432 nt in length) are also packaged by TMV coat protein (CP) in vitro to form helical pseudovirus parti...
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.91.19.9067
更新日期:1994-09-13 00:00:00
abstract::The [A] allele of SNP rs965513 in 9q22 has been consistently shown to be highly associated with increased papillary thyroid cancer (PTC) risk with an odds ratio of ∼1.8 as determined by genome-wide association studies, yet the molecular mechanisms remain poorly understood. Previously, we noted that the expression of 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.1506255112
更新日期:2015-05-12 00:00:00
abstract::Kinesin is the canonical plus-end microtubule motor and has been the focus of intense study since its discovery in 1985. We previously demonstrated a time-dependent inactivation of kinesin in vitro that was fully reversible by the addition of purified casein kinase 2 (CK2) and showed that this inactivation/reactivatio...
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.1321419111
更新日期:2014-05-13 00:00:00
abstract::Cryopreservation is widely used to maintain backups of cells as it enables the semipermanent storage of cells. During the freezing process, ice crystals that are generated inside and outside the cells can lethally damage the cells. All conventional cryopreservation methods use at least one cryoprotective agent (CPA) 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.1808645116
更新日期:2019-04-16 00:00:00
abstract::Platelet-derived growth factor (PDGF) isoforms lead to mitogenic, survival, and chemotactic responses in a variety of mesenchymal cell types during development and in the adult. We have studied the importance of phosphatidylinositol-3' kinase (PI3K) signaling in these responses by mutating the PI3K-binding sites in 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.96.20.11410
更新日期:1999-09-28 00:00:00
abstract::Hepatitis C virus (HCV) is a major cause of liver disease, affecting over 2% of the world's population. The HCV envelope glycoproteins E1 and E2 mediate viral entry, with E2 being the main target of neutralizing antibody responses. Structural investigations of E2 have produced templates for vaccine design, including 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.1609780113
更新日期:2016-11-08 00:00:00
abstract::Host-encoded factors play an important role in virus multiplication, acting in concert with virus-encoded factors. However, information regarding the host factors involved in this process is limited. Here we report the map-based cloning of an Arabidopsis thaliana gene, TOM1, which is necessary for the efficient multip...
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.170295097
更新日期:2000-08-29 00:00:00
abstract::A 2.5-fold stimulation of cyclic AMP cellular content is measured 60 sec after addition of 100 nM synthetic ovine corticotropin-releasing factor (C-RF; corticoliberin) to rat anterior pituitary cells in culture. A maximal response of cyclic AMP content at 400% above control is observed between 2 and 30 min after addit...
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.79.11.3466
更新日期:1982-06-01 00:00:00
abstract::Regulatory mechanisms for tissue repair and regeneration within damaged tissue have been extensively studied. However, the systemic regulation of tissue repair remains poorly understood. To elucidate tissue nonautonomous control of repair process, it is essential to induce local damage, independent of genetic manipula...
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.1523681113
更新日期:2016-02-16 00:00:00
abstract::Injection of 3':5'-cyclic AMP (cAMP) into larvae of the fly Sarcophaga bullata 3-4 hr before the beginning of puparium formation (red-spiracle stage) greatly accelerates the onset of tanning without affecting initiation of puparium formation (anterior retraction). Accelerated tanning resembles real tanning in two impo...
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.74.5.2182
更新日期:1977-05-01 00:00:00
abstract::Interbacterial interaction pathways play an important role in defining the structure and complexity of bacterial associations. A quantitative description of such pathways offers promise for understanding the forces that contribute to community composition. We developed time-lapse fluorescence microscopy methods for qu...
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.1213963109
更新日期:2012-11-27 00:00:00
abstract::T cell-dependent B-cell responses decline with age, suggesting defective CD4 T-cell function. CD4 memory T cells from individuals older than 65 y displayed increased and sustained transcription of the dual-specific phosphatase 4 (DUSP4) that shortened expression of CD40-ligand (CD40L) and inducible T-cell costimulator...
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.1109797109
更新日期:2012-04-10 00:00:00
abstract::The C4B isotype of the fourth component of human complement (C4) displays 3- to 4-fold greater hemolytic activity than does its other isotype C4A. This correlates with differences in their covalent binding efficiencies to erythrocytes coated with antibody and complement C1. C4A binds to a greater extent when C1 is on ...
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.87.17.6868
更新日期:1990-09-01 00:00:00
abstract::The error frequency of in vitro DNA synthesis using a natural DNA template has been measured with a biological assay for nucleotide substitutions. phiX174 DNA containing an amber mutation was copied in vitro by Escherichia coli DNA polymerase I, and the reversion frequency of the progeny DNA was determined by transfec...
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.75.4.1924
更新日期:1978-04-01 00:00:00
abstract::The transmembrane precursor of tumor necrosis factor-alpha (TNF) exits the trans-Golgi network (TGN) in tubular carriers for subsequent trafficking and delivery to the cell surface; however, the molecular machinery responsible for Golgi export is unknown. We previously reported that members of the TGN golgin family ar...
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.0800137105
更新日期:2008-03-04 00:00:00
abstract::Long-term depression (LTD) at cerebellar parallel fiber (PF)-Purkinje cell synapses must be balanced by long-term potentiation (LTP) to prevent saturation and allow reversal of motor learning. The only previously analyzed form of cerebellar LTP is induced by 4-8 Hz PF stimulation and requires cAMP but not nitric oxide...
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.122206399
更新日期:2002-06-11 00:00:00
abstract::A remarkable property of Ca2+ fluxes through the inositol 1,4,5-trisphosphate (InsP3)-gated Ca2+ channel is that successive increments of InsP3 induce repeated transient release of accumulated Ca2+. The initial aim of this study was to propose a model, based on hypotheses compatible with the current description of thi...
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.91.21.10074
更新日期:1994-10-11 00:00:00
abstract::Understanding how changes in antibiotic consumption affect the prevalence of antibiotic resistance in bacterial pathogens is important for public health. In a number of bacterial species, including Streptococcus pneumoniae, the prevalence of resistance has remained relatively stable despite prolonged selection pressur...
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.1617849114
更新日期:2017-01-31 00:00:00
abstract::Neuronal specificity in retinal ganglion cells of Xenopus subserves the orderly connections of the optic nerve fibers in the tectum. This specificity derives from positional information acquired by the developing retina at embryonic stages 28-31. Here we report that ganglion cells of embryonic stage 28 eyes can acquir...
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.69.4.780
更新日期:1972-04-01 00:00:00
abstract::The effects of the thymic polypeptide thymopoietin (Tpo) on the properties of the nicotinic acetylcholine receptor (AcChoR) were investigated by patch clamp techniques on mouse C2 myotubes and by biochemical assays on AcChoR-rich membrane fragments purified from the Torpedo marmorata electric organ. At high concentrat...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,收录出版
doi:10.1073/pnas.84.10.3477
更新日期:1987-05-01 00:00:00