369 research outputs found
Olfactory proteins mediating chemical communication in the navel orangeworm moth, Amyelois transitella.
BackgroundThe navel orangeworm, Amyelois transitella Walker (Lepidoptera: Pyralidae), is the most serious insect pest of almonds and pistachios in California for which environmentally friendly alternative methods of control--like pheromone-based approaches--are highly desirable. Some constituents of the sex pheromone are unstable and could be replaced with parapheromones, which may be designed on the basis of molecular interaction of pheromones and pheromone-detecting olfactory proteins.MethodologyBy analyzing extracts from olfactory and non-olfactory tissues, we identified putative olfactory proteins, obtained their N-terminal amino acid sequences by Edman degradation, and used degenerate primers to clone the corresponding cDNAs by SMART RACE. Additionally, we used degenerate primers based on conserved sequences of known proteins to fish out other candidate olfactory genes. We expressed the gene encoding a newly identified pheromone-binding protein, which was analyzed by circular dichroism, fluorescence, and nuclear magnetic resonance, and used in a binding assay to assess affinity to pheromone components.ConclusionWe have cloned nine cDNAs encoding olfactory proteins from the navel orangeworm, including two pheromone-binding proteins, two general odorant-binding proteins, one chemosensory protein, one glutathione S-transferase, one antennal binding protein X, one sensory neuron membrane protein, and one odorant receptor. Of these, AtraPBP1 is highly enriched in male antennae. Fluorescence, CD and NMR studies suggest a dramatic pH-dependent conformational change, with high affinity to pheromone constituents at neutral pH and no binding at low pH
Fundamental studies on the reproductive strategies of Quercus serrata - Pollination patterns in different flowering heights -
コナラは花の形質から風媒花とされているが、近年訪花昆虫が確認されており、その送粉様式は未解明である。そこで、送粉様式を解明するにあたり、次のような仮説を立てた。樹冠上部では、風媒の割合が下部より高く、下部では、虫媒の割合が上部より高いというものである。また、昆虫の訪花頻度は花のディスプレイサイズに影響を受けるため、コナラの花序数や花序長も考慮する必要がある。したがって、着花高度の違いによる送粉者の貢献度、着花高度と送粉者の違いによる結実への影響、着花高度と花のディスプレイサイズが訪花昆虫に与える影響を明らかにすることによってコナラの送粉様式を解明し、繁殖戦略を明らかにすることを目的とした。樹冠下部では、訪花昆虫を制限すると結実率が低下した。種子サイズは上部の方が大きかったが、ばらつきは上部と下部で変わらなかった。また、着花高度別の訪花昆虫については、下部の方が上部より個体数も種類も多かった。さらに、訪花昆虫は風速が一定以上に大きくなると訪花しなくなり、上部では訪花頻度が低下することが分かった。花のディスプレイサイズについては、上部の方が単位面積あたりの花序数が多いが花序は短く、下部では花序が長いものが多かった。昆虫の訪花頻度は風速だけでなく、花のディスプレイサイズにも影響を受け、それが花序数であるか花序長であるかは種によって異なった。以上のことから、送粉者である風と昆虫に対する依存度が着花高度によって異なることが示唆された。
皮膚創傷治療過程におけるIFN-γとTGF-βのシグナルクロストークの病態生理学的解析
取得学位 : 博士(医学), 学位授与番号 : 医博甲第1665号, 学位授与年月日 : 平成17年3月22日, 学位授与大学 : 金沢大
Training cessation and subsequent retraining of a world-class female Olympic sailor after Tokyo 2020: A case study
Olympic sailing is a complex sport where sailors are required to predict and interpret weather conditions while facing high physical and physiological demands. While it is essential for sailors to develop physical and physiological capabilities toward major competition, monitoring training status following the competition is equally important to minimize the magnitude of detraining and facilitate retraining. Despite its long history in the modern Olympics, reports on world-class sailors' training status and performance characteristics across different periodization phases are currently lacking. This case study aimed to determine the influence of training cessation and subsequent retraining on performance parameters in a world-class female sailor. A 31-year old female sailor, seventh in the Women's Sailing 470 medal race in Tokyo 2020, completely stopped training for 4 weeks following the Olympics, and resumed low-intensity training for 3 weeks. Over these 7 weeks, 12.7 and 5.3% reductions were observed in 6 s peak cycling power output and jump height, respectively, with a 4.7% decrease in maximal aerobic power output. Seven weeks of training cessation-retraining period induced clear reductions in explosive power production capacities but less prominent decreases in aerobic capacity. The current findings are likely attributed to the sailor's training characteristics during the retraining period.This study was part of Functional Development Project for Resilient Athlete Support commissioned by Japan Sports Agency
The estimated GFR, but not the stage of diabetic nephropathy graded by the urinary albumin excretion, is associated with the carotid intima-media thickness in patients with type 2 diabetes mellitus: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>To study the relationship between the intima-media thickness (IMT) of the carotid artery and the stage of chronic kidney disease (CKD) based on the estimated glomerular filtration rate (eGFR) and diabetic nephropathy graded by the urinary albumin excretion (UAE) in the patients with type 2 diabetes mellitus.</p> <p>Methods</p> <p>A cross-sectional study was performed in 338 patients with type 2 diabetes mellitus. The carotid IMT was measured using an ultrasonographic examination.</p> <p>Results</p> <p>The mean carotid IMT was 1.06 ± 0.27 mm, and 42% of the subjects showed IMT thickening (≥ 1.1 mm). Cerebrovascular disease and coronary heart disease were frequent in the patients with IMT thickening. The carotid IMT elevated significantly with the stage progression of CKD (0.87 ± 0.19 mm in stage 1, 1.02 ± 0.26 mm in stage 2, 1.11 ± 0.26 mm in stage 3, and 1.11 ± 0.27 mm in stage 4+5). However, the IMT was not significantly different among the various stages of diabetic nephropathy. The IMT was significantly greater in the diabetic patients with hypertension compared to those without hypertension. The IMT positively correlated with the age, the duration of diabetes mellitus, and the brachial-ankle pulse wave velocities (baPWV), and negatively correlated with the eGFR. In a stepwise multivariate regression analysis, the eGFR and the baPWV were independently associated with the carotid IMT.</p> <p>Conclusions</p> <p>Our study is the first report showing a relationship between the carotid IMT and the renal parameters including eGFR and the stages of diabetic nephropathy with a confirmed association between the IMT and diabetic macroangiopathy. Our study further confirms the importance of intensive examinations for the early detection of atherosclerosis and positive treatments for hypertension, dyslipidaemia, obesity, as well as hyperglycaemia are necessary when a reduced eGFR is found in diabetic patients.</p
Immunohistochemical Analysis of CXCR4 Expression in Fibrohistiocytic Tumors
Functional chemokine receptors are expressed in many malignant tumors. These receptors promote tumor growth and metastasis in response to endogenous chemokines. We analyzed the expression of CXCR4, CCR6 and CCR7 in fibrohistiocytic tumors, including dermatofibrosarcoma protuberance (DFSP), malignant fibrous histiocytoma (MFH), dermatofibroma (DF) using immunohistochemistry. We also investigated the relationship between CXCR4 and CD34, the latter of which is an immunohistochemical marker for DFSP. We observed a higher expression of CXCR4 in DFSP and MFH as compared with DF. Interestingly, a significantly higher expression of CXCR4 was detected in relapsed DFSP than in non-relapsed DFSP, but no significant differences were detected between non-relapsed DFSP and DFSP with CD34 immunostaining. Moreover, MFH had strong immunoreactivity for CXCR4, CCR6 and CCR7. These findings suggest that the assessment of CXCR4 immunoreactivity in fibrohistiocytic tumors is a useful tool for predicting tumor aggressiveness
A sacrificial millipede altruistically protects its swarm using a drone blood enzyme, mandelonitrile oxidase
A sacrificial millipede altruistically protects its swarm using a drone blood enzyme, mandelonitrile oxidase
Soldiers of some eusocial insects exhibit an altruistic self-destructive defense behavior in emergency situations when attacked by large enemies. The swarm-forming invasive millipede, Chamberlinius hualienensis, which is not classified as eusocial animal, exudes irritant chemicals such as benzoyl cyanide as a defensive secretion. Although it has been thought that this defensive chemical was converted from mandelonitrile, identification of the biocatalyst has remained unidentified for 40 years. Here, we identify the novel blood enzyme, mandelonitrile oxidase (ChuaMOX), which stoichiometrically catalyzes oxygen consumption and synthesis of benzoyl cyanide and hydrogen peroxide from mandelonitrile. Interestingly the enzymatic activity is suppressed at a blood pH of 7, and the enzyme is segregated by membranes of defensive sacs from mandelonitrile which has a pH of 4.6, the optimum pH for ChuaMOX activity. In addition, strong body muscle contractions are necessary for de novo synthesis of benzoyl cyanide. We propose that, to protect its swarm, the sacrificial millipede also applies a self-destructive defense strategy—the endogenous rupturing of the defensive sacs to mix ChuaMOX and mandelonitrile at an optimum pH. Further study of defensive systems in primitive arthropods will pave the way to elucidate the evolution of altruistic defenses in the animal kingdom
Structure of an Odorant-Binding Protein from the Mosquito Aedes aegypti Suggests a Binding Pocket Covered by a pH-Sensitive “Lid”
Background: The yellow fever mosquito, Aedes aegypti, is the primary vector for the viruses that cause yellow fever, mostly in tropical regions of Africa and in parts of South America, and human dengue, which infects 100 million people yearly in the tropics and subtropics. A better understanding of the structural biology of olfactory proteins may pave the way for the development of environmentally-friendly mosquito attractants and repellents, which may ultimately contribute to reduction of mosquito biting and disease transmission. Methodology: Previously, we isolated and cloned a major, female-enriched odorant-binding protein (OBP) from the yellow fever mosquito, AaegOBP1, which was later inadvertently renamed AaegOBP39. We prepared recombinant samples of AaegOBP1 by using an expression system that allows proper formation of disulfide bridges and generates functional OBPs, which are indistinguishable from native OBPs. We crystallized AaegOBP1 and determined its three-dimensional structure at 1.85 angstrom resolution by molecular replacement based on the structure of the malaria mosquito OBP, AgamOBP1, the only mosquito OBP structure known to date. Conclusion: The structure of AaegOBP1 (= AaegOBP39) shares the common fold of insect OBPs with six alpha-helices knitted by three disulfide bonds. A long molecule of polyethylene glycol (PEG) was built into the electron-density maps identified in a long tunnel formed by a crystallographic dimer of AaegOBP1. Circular dichroism analysis indicated that delipidated AaegOBP1 undergoes a pH-dependent conformational change, which may lead to release of odorant at low pH (as in the environment in the vicinity of odorant receptors). A C-terminal loop covers the binding cavity and this ""lid"" may be opened by disruption of an array of acid-labile hydrogen bonds thus explaining reduced or no binding affinity at low pH.National Science Foundation (NSF) [0918177]National Institutes of Health (NIH) NIAIDBrazilian National Institutes of Science and Technology: Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [573607/2008-7]Brazilian National Institutes of Science and Technology: FAPESP [08/57910-0
- …