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1.
Phys Rev B ; 1012020.
Article in English | MEDLINE | ID: mdl-38855404

ABSTRACT

In this study, the inelastic neutron scattering probe of SIKA in ANSTO is employed to investigate the magnon dispersion curve in ferromagnetic SrRuO3 single crystal epitaxial films and to better understand the underlying mechanisms. This report presents the successful measurement of a magnon peak from the SrRuO3 films which contained an amount of material of only 0.9 mg. We reveal one significant magnon dispersion curve along [002] following the quadratic E ∝ Q 2 ) relation, which shows a magnon gap of 0.32 meV. We have discussed several possible mechanisms, such as the higher symmetry structure and the impurity levels, which may contribute to this smaller gap.

2.
Curr Oncol ; 26(1): e115-e118, 2019 02.
Article in English | MEDLINE | ID: mdl-30853818

ABSTRACT

Nivolumab, an anti-PD-1 antibody, is now considered an important therapeutic agent in several advanced malignancies. However, immune-related adverse events such as endocrinopathies have been reported with its use. Thyroid disorder and isolated adrenocorticotropic hormone deficiency have frequently been reported as nivolumab-induced immune-related adverse events. Another endocrinopathy is nivolumab-induced type 1 diabetes mellitus (t1dm), described as diabetes mellitus with rapid onset and complete insulin insufficiency, at times leading to fulminant t1dm. We report the case of a 68-year-old woman who developed pancreatic islet-related autoantibody-negative t1dm, possibly induced by nivolumab, under continuous glucocorticoid administration. She was treated with nivolumab for advanced malignant melanoma, concomitant with 10 mg prednisolone daily for thrombophlebitis tapered to 5 mg after 13 courses of nivolumab therapy. At approximately the 27th course of nivolumab therapy, she showed elevated plasma glucose levels despite preserved insulin secretion. A month later, she developed diabetic ketoacidosis. Her insulin secretion decreased and finally was exhausted. She was diagnosed with acute-onset rather than fulminant t1dm because of a rapidly progressive course to diabetic ketoacidosis during just more than 1 week. She is currently receiving insulin replacement. There has been no recurrence of the melanoma. Thus, nivolumab might induce autoimmune diabetes mellitus, with patients having t1dm-sensitive human leucocyte antigen being more susceptible even when receiving glucocorticoids. Physicians should be aware that nivolumab could potentially induce t1dm as a critical immune-related adverse event.


Subject(s)
Melanoma/chemically induced , Nivolumab/adverse effects , Aged , Diabetes Mellitus, Type 1/chemically induced , Female , Humans
3.
Phys Rev Lett ; 120(7): 077201, 2018 Feb 16.
Article in English | MEDLINE | ID: mdl-29542973

ABSTRACT

Fedotovite K_{2}Cu_{3}O(SO_{4})_{3} is a candidate of new quantum spin systems, in which the edge-shared tetrahedral (EST) spin clusters consisting of Cu^{2+} are connected by weak intercluster couplings forming a one-dimensional array. Comprehensive experimental studies by magnetic susceptibility, magnetization, heat capacity, and inelastic neutron scattering measurements reveal the presence of an effective S=1 Haldane state below T≅4 K. Rigorous theoretical studies provide an insight into the magnetic state of K_{2}Cu_{3}O(SO_{4})_{3}: an EST cluster makes a triplet in the ground state and a one-dimensional chain of the EST induces a cluster-based Haldane state. We predict that the cluster-based Haldane state emerges whenever the number of tetrahedra in the EST is even.

4.
Phys Rev Lett ; 120(8): 087201, 2018 Feb 23.
Article in English | MEDLINE | ID: mdl-29543015

ABSTRACT

We report on comprehensive results identifying the ground state of a triangular-lattice structured YbZnGaO_{4} as a spin glass, including no long-range magnetic order, prominent broad excitation continua, and the absence of magnetic thermal conductivity. More crucially, from the ultralow-temperature ac susceptibility measurements, we unambiguously observe frequency-dependent peaks around 0.1 K, indicating the spin-glass ground state. We suggest this conclusion holds also for its sister compound YbMgGaO_{4}, which is confirmed by the observation of spin freezing at low temperatures. We consider disorder and frustration to be the main driving force for the spin-glass phase.

5.
Cancer Gene Ther ; 24(2): 45-47, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28106046

ABSTRACT

We previously described the development of a highly-invasive, triple-negative breast cancer (TNBC) variant using serial orthotopic implantation of MDA-MB-231 human breast cancer in nude mice. The isolated variant is highly invasive in the mammary gland and metastasized to lymph nodes in 10 of 12 mice compared with 2 of 12 of the parental cell line. OBP-401 is a telomerase-dependent cancer-specific, green fluorescent protein (GFP)-expressing adenovirus. OBP-401 was used to infect parental MDA-MB-231P cells and high-metastatic MDA-MB-231H and MDA-MB-231HLN isolated from a lymph node metastasis and MDA-MB-231HLM isolated from a lung metastasis. Time-course imaging showed that OBP-401 labeled MDA-MB-231HP, MDA-MB-231HLN, and MDA-MB-231HLM cells more brightly than MDA-MB-231 parental cells. OBP-401 killed MDA-MB-231H, MDA-MB-231HLN, and MDA-MB-231HLM cells more efficiently than MDA-MB-231P parental cells. These results indicate that OBP-401 could infect, label and then kill high-metastatic MDA-MB-231 more efficiently than low-metastatic MDA-MB-231.


Subject(s)
Adenoviridae/genetics , Genetic Vectors/genetics , Green Fluorescent Proteins/genetics , Oncolytic Viruses/genetics , Telomerase/metabolism , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/pathology , Animals , Cell Line, Tumor , Cell Survival , Gene Expression , Genes, Reporter , Humans , Mice , Neoplasm Metastasis , Triple Negative Breast Neoplasms/therapy
6.
Bone Marrow Transplant ; 52(6): 818-824, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28112749

ABSTRACT

Clinical efficacy of allogeneic hematopoietic cell transplantation (HCT) using reduced-intensity conditioning (RIC) for younger patients remains unclear. We therefore performed a retrospective registry-based study to evaluate outcomes for patients with AML aged between 16 and 49 years who underwent RIC allogeneic HCT. Patients receiving RIC (N=125) showed significantly worse survival than those receiving myeloablative conditioning (MAC; N=1,554) (47.7% for RIC and 54.2% for MAC at 4 years, P=0.047). However, the difference became marginal after adjustment for patient characteristics (P=0.080), and inclusion in the multivariate analysis of the HCT comorbidity index or the propensity score for estimating the likelihood of choosing RIC or MAC further reduced statistical significance (P=0.371 and 0.206, respectively), indicating the existence of a selection bias against RIC. Nevertheless, outcomes for our patients receiving RIC were still acceptable, so that RIC constitutes a potential therapeutic option for younger AML patients who are deemed unsuitable for MAC. Subgroup analyses showed that patients aged between 40 and 49 years as well as those in first or second CR at the time of transplantation exhibited similar outcomes regardless of whether they were treated with RIC or MAC.


Subject(s)
Hematopoietic Stem Cell Transplantation , Leukemia, Myeloid, Acute/mortality , Leukemia, Myeloid, Acute/therapy , Registries , Transplantation Conditioning , Adolescent , Adult , Allografts , Disease-Free Survival , Female , Humans , Male , Middle Aged , Survival Rate
9.
Appl Radiat Isot ; 109: 325-329, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26701660

ABSTRACT

A 4π(ß(+)+γ) integral counting method using 4πß-4πγ detector configuration composed of a large well type NaI(Tl) scintillation detector and stacked plastic scintillators positioned in the center of the well and coupled with a slender PMT was adopted for activity measurement of (68)Ge-(68)Ga. Several source preparation schemes were studied to reduce the activity loss due to volatility. The possible contribution of EC events were rejected with pulse-height discrimination. Owing to the high counting efficiencies in both channels and the multiplicity of photons and ß-particles emitted, the 4π(ß(+)+γ) integral counting system gives a count rate very nearly equal to the positron emission rate. The activity can be determined simply from this value divided by the positron emission branching ratio. The remaining overall inefficiency was evaluated by the EGS5 code.

10.
Oncogene ; 35(8): 952-64, 2016 Feb 25.
Article in English | MEDLINE | ID: mdl-26028032

ABSTRACT

Lipoma preferred partner (LPP) is a LIM domain protein, which has multiple functions as an actin-binding protein and a transcriptional coactivator, and it has been suggested that LPP has some roles in cell migration or invasion, however, its role in cancer cells remains to be elucidated. Here, we showed that LPP degraded N-cadherin in lung cancer, PC14PE6 cells via regulating the expression of matrix metalloproteinase 15 (MMP-15), and loss-of-LPP increases collective cell migration (CCM) and dissemination consequently. Knockdown of LPP and its functional partner, Etv5, markedly restores the full-length N-cadherin and increases cell-cell adhesion. We investigated the common target of LPP and Etv5, and found that MMP-15 is transcribed as their direct transcriptional target. Furthermore, MMP-15 could directly digest the N-cadherin extracellular domain. LPP knockdown in PC14PE6 cells increases N-cadherin-dependent CCM in the three-dimensional collagen gel invasion assays, and promoted the dissemination of cancer cells when they were orthotopically implanted in nude mice. Immunohistochemistry of lung adenocarcinoma specimens revealed the heterogeneity of LPP intensity and complementary expression of LPP and N-cadherin in the primary tumors. These findings suggest that loss-of-LPP, Etv5 or MMP-15 can be a prognostic marker of increasing malignancy.


Subject(s)
Cell Movement , Cytoskeletal Proteins/physiology , LIM Domain Proteins/physiology , Neoplasm Metastasis , Neoplasms/physiopathology , Adenocarcinoma/metabolism , Adenocarcinoma of Lung , Animals , Cadherins/antagonists & inhibitors , Cadherins/metabolism , Cytoskeletal Proteins/genetics , DNA-Binding Proteins/metabolism , Fibroblasts/metabolism , Gene Knockdown Techniques , Humans , LIM Domain Proteins/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/physiopathology , Male , Matrix Metalloproteinase 15/metabolism , Melanoma/metabolism , Melanoma/physiopathology , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Invasiveness , Neoplasm Transplantation , Neoplasms/metabolism , Transcription Factors/metabolism , Tumor Cells, Cultured
11.
Oncogene ; 35(27): 3587-97, 2016 07 07.
Article in English | MEDLINE | ID: mdl-26549034

ABSTRACT

Targeted therapies are effective in subsets of lung cancers with EGFR mutations and anaplastic lymphoma kinase (ALK) translocations. Large-scale genomics have recently expanded the lung cancer landscape with FGFR1 amplification found in 10-20% of squamous cell carcinomas (SCCs). However, the response rates have been low for biomarker-directed fibroblast growth factor receptor (FGFR) inhibitor therapy in SCC, which contrasts to the relatively high rates of response seen in EGFR mutant and ALK-translocated lung cancers treated with epidermal growth factor receptor (EGFR) inhibitors and ALK inhibitors, respectively. In order to better understand the low response rates of FGFR1-amplified lung cancers to FGFR inhibitors, relationships between gene copy number, mRNA expression and protein expression of FGFR1 were assessed in cell lines, tumor specimens and data from The Cancer Genome Atlas. The importance of these factors for the sensitivity to FGFR inhibitors was determined by analyzing drug screen data and conducting in vitro and in vivo experiments. We report that there was a discrepancy between FGFR1 amplification level and FGFR1 protein expression in a number of these cell lines, and the cancers with unexpectedly low FGFR1 expression were uniformly resistant to the different FGFR inhibitors. Further interrogation of the receptor tyrosine kinase activity in these discordant cell lines revealed co-activation of HER2 and platelet-derived growth factor receptor-α (PDGFRα) caused by gene amplification or ligand overexpression maintained phosphoinositide 3-kinase (PI3K) and MEK/ERK signaling even in the presence of FGFR inhibitor. Accordingly, co-inhibition of FGFR1 and HER2 or PDGFRα led to enhanced drug responses. In contrast, FGFR1-amplified high FGFR1 protein-expressing lung cancers are sensitive to FGFR inhibitor monotherapy by downregulating ERK signaling. Addition of a PI3K inhibitor to these high FGFR1 protein-expressing cancers further sensitized them to FGFR inhibitor. These data reveal that biomarker-directed trials for FGFR1-amplified SCC require assessment of FGFR1 protein expression and uncover novel therapeutic strategies for FGFR1-amplified SCC with low FGFR1 protein expression.


Subject(s)
Carcinoma, Squamous Cell/drug therapy , Lung Neoplasms/drug therapy , Protein Kinase Inhibitors/pharmacology , Receptor, Fibroblast Growth Factor, Type 1/genetics , Receptors, Fibroblast Growth Factor/antagonists & inhibitors , Xenograft Model Antitumor Assays , Antineoplastic Agents/pharmacology , Benzamides/pharmacology , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/metabolism , Cell Line , Cell Line, Tumor , Gene Amplification , Gene Dosage , Gene Expression Regulation, Neoplastic , Humans , Imatinib Mesylate/pharmacology , Immunoblotting , In Situ Hybridization, Fluorescence , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Phenylurea Compounds/pharmacology , Piperazines/pharmacology , Pyrazoles/pharmacology , Pyrimidines/pharmacology , Receptor, ErbB-2/antagonists & inhibitors , Receptor, ErbB-2/genetics , Receptor, ErbB-2/metabolism , Receptor, Fibroblast Growth Factor, Type 1/metabolism , Receptor, Platelet-Derived Growth Factor alpha/antagonists & inhibitors , Receptor, Platelet-Derived Growth Factor alpha/genetics , Receptor, Platelet-Derived Growth Factor alpha/metabolism , Receptors, Fibroblast Growth Factor/genetics , Receptors, Fibroblast Growth Factor/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/drug effects , Signal Transduction/genetics
13.
Bone Marrow Transplant ; 50(10): 1299-305, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26168068

ABSTRACT

Allogeneic stem cell transplantation (allo-SCT) is a curative option for patients with relapsed follicular lymphoma (FL). Prospective studies of reduced-intensity conditioning (RIC) have revealed that chemosensitivity at allo-SCT is the most reliable predictor of outcome; however, limited data are available for progressive/refractory disease. We report here a retrospective analysis of RIC allo-SCT for patients with FL. The purpose of this study was to elucidate the role of allo-SCT for patients with relapsed/refractory FL. We analyzed 46 patients-11 (24%) transplanted in CR, 6 (13%) transplanted in PR and 29 (63%) with progressive/refractory disease. The estimated 5-year overall survival rate was 71.6% (95% confidence interval (CI), 51.5-84.5%). According to the disease status at transplantation, the 5-year survival rate was 80.7% (95% CI, 37.7-95.4%) in the patients with CR or PR and 66.1% (95% CI, 41.5-82.3%) in those with progressive/refractory disease (P=0.29). There were no differences in relapse/progression and non-relapse mortality between the patients with chemosensitive disease and progressive/refractory disease. Allo-SCT may be a valuable treatment option, even for patients with progressive/refractory FL.


Subject(s)
Hematopoietic Stem Cell Transplantation/methods , Lymphoma, Follicular/therapy , Transplantation Conditioning/methods , Transplantation, Homologous/methods , Adult , Aged , Female , Humans , Lymphoma, Follicular/mortality , Male , Middle Aged , Retrospective Studies
14.
Cancer Gene Ther ; 22(7): 344-50, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26088297

ABSTRACT

Precise fluorescence-guided surgery (FGS) for pancreatic cancer has the potential to greatly improve the outcome in this recalcitrant disease. To achieve this goal, we have used genetic reporters to color code cancer and stroma cells in a patient-derived orthotopic xenograft (PDOX) model. The telomerase-dependent green fluorescent protein (GFP)-containing adenovirus OBP-401 was used to label the cancer cells of a pancreatic cancer PDOX. The PDOX was previously grown in a red fluorescent protein (RFP) transgenic mouse that stably labeled the PDOX stroma cells bright red. The color-coded PDOX model enabled FGS to completely resect the pancreatic tumors including stroma. Dual-colored FGS significantly prevented local recurrence, which bright-light surgery or single-color FGS could not. FGS, with color-coded cancer and stroma cells has important potential for improving the outcome of recalcitrant-cancer surgery.


Subject(s)
Neoplasm Recurrence, Local/prevention & control , Pancreatic Neoplasms/surgery , Surgery, Computer-Assisted , Animals , Genes, Reporter , Green Fluorescent Proteins/biosynthesis , Green Fluorescent Proteins/genetics , Luminescent Proteins/biosynthesis , Luminescent Proteins/genetics , Mice, Nude , Mice, Transgenic , Neoplasm Transplantation , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , Red Fluorescent Protein
15.
Bone Marrow Transplant ; 50(5): 727-33, 2015 May.
Article in English | MEDLINE | ID: mdl-25730191

ABSTRACT

This prospective study aimed to investigate the influence of pretransplant serum ferritin levels on the outcomes of allogeneic hematopoietic SCT (HSCT). In total, 190 patients with acute leukemia or myelodysplastic syndrome were consecutively enrolled. The patients were divided into two groups: low-ferritin group (<1000 ng/mL) and high-ferritin group (⩾1000 ng/mL). The primary end point was the cumulative incidence of infection within 100 days after HSCT, which was similar between the two groups: bloodstream infection, 35 vs 38%, P=0.65; bacterial infection, 44 vs 41%, P=0.68; and fungal infection, 6 vs 8%, P=0.71. The 1-year adjusted probability of OS of the high-ferritin group was significantly lower than that of the low-ferritin group (76 vs 63%, P=0.017). Using receiver operating characteristic curve, the threshold of pretransplant serum ferritin levels for bloodstream infection was 1400 ng/mL; the threshold for OS, EFS and non-relapse mortality was 1349 ng/mL. In conclusion, pretransplant serum ferritin levels of ⩾1000 ng/mL did not influence the incidence of infection but adversely affected OS after HSCT. A higher threshold of pretransplant serum ferritin levels may predict HSCT outcomes.


Subject(s)
Bacterial Infections , Ferritins/blood , Hematologic Neoplasms , Hematopoietic Stem Cell Transplantation , Mycoses , Preoperative Period , Adult , Aged , Allografts , Bacterial Infections/blood , Bacterial Infections/mortality , Disease-Free Survival , Female , Follow-Up Studies , Hematologic Neoplasms/blood , Hematologic Neoplasms/mortality , Hematologic Neoplasms/therapy , Humans , Incidence , Male , Middle Aged , Mycoses/blood , Mycoses/mortality , Prospective Studies , Survival Rate
16.
Curr Mol Med ; 15(2): 168-75, 2015.
Article in English | MEDLINE | ID: mdl-25732148

ABSTRACT

Imaging genetics is an integrated research method that uses neuroimaging and genetics to assess the impact of genetic variation on brain function and structure. Imaging genetics is both a tool for the discovery of risk genes for psychiatric disorders and a strategy for characterizing the neural systems affected by risk gene variants to elucidate quantitative and mechanistic aspects of brain function implicated in psychiatric disease. Early studies of imaging genetics included association analyses between brain morphology and single nucleotide polymorphisms whose function is well known, such as catechol-Omethyltransferase (COMT) and brain-derived neurotrophic factor (BDNF). GWAS of psychiatric disorders have identified genes with unknown functions, such as ZNF804A, and imaging genetics has been used to investigate clues of the biological function of these genes. The difficulty in replicating the findings of studies with small sample sizes has motivated the creation of largescale collaborative consortiums, such as ENIGMA, CHARGE and IMAGEN, to collect thousands of images. In a genome-wide association study, the ENIGMA consortium successfully identified common variants in the genome associated with hippocampal volume at 12q24, and the CHARGE consortium replicated this finding. The new era of imaging genetics has just begun, and the next challenge we face is the discovery of small effect size signals from large data sets obtained from genetics and neuroimaging. New methods and technologies for data reduction with appropriate statistical thresholds, such as polygenic analysis and parallel independent component analysis (ICA), are warranted. Future advances in imaging genetics will aid in the discovery of genes and provide mechanistic insight into psychiatric disorders.


Subject(s)
Bipolar Disorder/genetics , Genetics, Medical/methods , Hippocampus/metabolism , Neuroimaging/methods , Schizophrenia/genetics , Bipolar Disorder/diagnosis , Bipolar Disorder/pathology , Bipolar Disorder/physiopathology , Brain-Derived Neurotrophic Factor/genetics , Brain-Derived Neurotrophic Factor/metabolism , Catechol O-Methyltransferase/genetics , Catechol O-Methyltransferase/metabolism , Chromosomes, Human, Pair 12/chemistry , Chromosomes, Human, Pair 12/ultrastructure , Cooperative Behavior , Gene Expression , Genetics, Medical/instrumentation , Genome-Wide Association Study , Genotype , Hippocampus/pathology , Hippocampus/physiopathology , Humans , Kruppel-Like Transcription Factors/genetics , Kruppel-Like Transcription Factors/metabolism , Neuroimaging/instrumentation , Phenotype , Polymorphism, Single Nucleotide , Schizophrenia/diagnosis , Schizophrenia/pathology , Schizophrenia/physiopathology
17.
Bone Marrow Transplant ; 50(4): 559-65, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25531281

ABSTRACT

The impact of the conditioning intensity and TBI on acute GVHD (aGVHD) is still a matter of debate. We analyzed 6848 adult recipients who received allogeneic hematopoietic cell transplants (HCT) between 2006 and 2011 in Japan. The subjects were divided into groups who had received myeloablative conditioning (MAC) or reduced-intensity conditioning (RIC), either with or without TBI. There was a significant difference in the incidence of aGVHD 2-4 among the different conditioning types: 39% in TBI-MAC, 35% in TBI-RIC and 32% in both no-TBI MAC and no-TBI-RIC (P<0.001). In a multivariate analysis, TBI-MAC, but not no-TBI MAC, was significantly associated with an increased risk of aGVHD 2-4 (hazard ratio (HR) 1.33, P<0.01), whereas TBI-RIC was associated with an increased risk of GVHD 3-4 (HR 1.36, P=0.048). TBI-MAC and TBI-RIC were significantly associated with skin and gastrointestinal aGVHD. Subgroup analyses demonstrated that not only TBI-MAC, but also TBI-RIC, was significantly associated with aGVHD 2-4 in older patients. Furthermore, high-dose TBI only had an adverse impact on aGVHD 2-4 in HLA-matched HCT. Impacts of intensity and TBI on aGVHD differ by patient backgrounds, and this difference should be considered to establish a risk-adapted strategy for the prevention of aGVHD.


Subject(s)
Graft vs Host Disease/mortality , Hematopoietic Stem Cell Transplantation , Registries , Transplantation Conditioning , Acute Disease , Adolescent , Adult , Allografts , Female , Graft vs Host Disease/etiology , Hematologic Neoplasms/mortality , Hematologic Neoplasms/therapy , Humans , Male , Middle Aged , Risk Factors
18.
J Exp Biol ; 217(Pt 13): 2297-300, 2014 Jul 01.
Article in English | MEDLINE | ID: mdl-24737758

ABSTRACT

The two-spotted spider mite, Tetranychus urticae, usually lives in kin groups under common webs. Because only the first mating results in fertilisation in female T. urticae, adult males guard quiescent deutonymph females, those at the stage immediately before maturation, to ensure paternity. Therefore, the cost of precopulatory guarding time seems considerable for males. Moreover, the fitness indices of daughters from intra-population crosses were significantly lower than those of daughters from inter-population crosses, indicating that inbreeding depression exists in T. urticae. Therefore, we hypothesised that T. urticae males should be choosy in guarding familiar females to avoid inbreeding depression. Furthermore, webs should be a key element of the environment shared by familiar individuals. In this study, we demonstrated the inbreeding avoidance mechanism of T. urticae males in relation to webs produced by familiar females (known webs) or unfamiliar females (unknown webs). Regardless of surrounding webs (known or unknown), males preferred unfamiliar to familiar females. We further examined whether males detect unfamiliar females by their webs. When males had experienced a female's web without encountering that female, they subsequently preferred females that did not produce the surrounding webs in which the choice experiment was conducted. Results suggest that putative kin recognition for inbreeding avoidance in T. urticae males is based on the relationship between webs and females, and not on the discrimination of webs in shared environments.


Subject(s)
Sexual Behavior, Animal , Tetranychidae/physiology , Animals , Female , Inbreeding , Male , Reproduction
19.
Plant Biol (Stuttg) ; 16 Suppl 1: 91-6, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24148142

ABSTRACT

Cortical microtubules are involved in plant resistance to hypergravity, but their roles in resistance to 1 g gravity are still uncertain. To clarify this point, we cultivated an Arabidopsis α-tubulin 6 mutant (tua6) in the Cell Biology Experiment Facility on the Kibo Module of the International Space Station, and analyzed growth and cell wall mechanical properties of inflorescences. Growth of inflorescence stems was stimulated under microgravity conditions, as compared with ground and on-orbit 1 g conditions. The stems were 10-45% longer and their growth rate 15-55% higher under microgravity conditions than those under both 1 g conditions. The degree of growth stimulation tended to be higher in the tua6 mutant than the wild-type Columbia. Under microgravity conditions, the cell wall extensibility in elongating regions of inflorescences was significantly higher than the controls, suggesting that growth stimulation was caused by cell wall modifications. No clear differences were detected in any growth or cell wall property between ground and on-orbit 1 g controls. These results support the hypothesis that cortical microtubules generally play an important role in plant resistance to the gravitational force.


Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis/growth & development , Extraterrestrial Environment , Inflorescence/growth & development , Mutation/genetics , Tubulin/genetics , Weightlessness , Arabidopsis/cytology , Arabidopsis/genetics , Arabidopsis Proteins/metabolism , Biomechanical Phenomena , Cell Wall/metabolism , Gene Expression Regulation, Plant , Germination , Inflorescence/metabolism , Time Factors , Tubulin/metabolism
20.
Plant Biol (Stuttg) ; 16 Suppl 1: 43-9, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24128007

ABSTRACT

Gravitational force on Earth is one of the major environmental factors affecting plant growth and development. Spacecraft and the International Space Station (ISS), and a three-dimensional (3-D) clinostat have been available to clarify the effects of gravistimulation on plant growth and development in space and on ground conditions, respectively. Under a stimulus-free environment such as space conditions, plants show a growth and developmental habit designated as 'automorphosis' or 'automorphogenesis'. Recent studies in hormonal physiology, together with space and molecular biology, have demonstrated the close relationships between automorphosis and polar auxin transport. Reduced polar auxin transport in space conditions, or induced by the application of polar auxin transport inhibitors, substantially induced automorphosis or automorphosis-like growth and development, indicating that polar auxin transport is responsible for graviresponse in plants. This concise review covers graviresponse in plants and automorphosis observed in space conditions, and polar auxin transport related to graviresponse in etiolated Alaska and ageotropum pea seedlings. Molecular aspects of polar auxin transport clarified in recent studies are also described.


Subject(s)
Gravitropism/physiology , Indoleacetic Acids/metabolism , Plants/metabolism , Biological Transport , Extraterrestrial Environment , Plant Development
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