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61.
A new leaf blight and mummy fruit disease caused by a species of Monilinia was first found on Rhododendron kaempferi at the lakeside of Shikotsu-ko, Hokkaido, northern Japan, in 2002. Studies on morphology, life cycle, cultural characters, and gene analyses of the causal fungus enabled us to conclude that it is a new species of the genus. It is named M. jezoensis. Rhododendron is a new host genus for Monilinia fungi in Japan. 相似文献
62.
The catalytic activity of heme-regulated phosphodiesterase from Escherichia coli (Ec DOS) on cyclic di-GMP is markedly enhanced upon binding of gas molecules, such as O2 and CO, to the heme iron complex in the sensor domain. Arg97 interacts directly with O2 bound to Fe(II) heme in the crystal structure of the isolated heme-bound sensor domain with the PAS structure (Ec DOS-PAS) and may thus be critical in ligand recognition. To establish the specific role of Arg97, we generated Arg97Ala, Arg97Glu, and Arg97Ile mutant Ec DOS-PAS proteins and examined binding to O2, CO, and cyanide, as well as redox potentials. The autoxidation rates of the Arg97Ala and Arg97Glu mutant proteins were up to 2000-fold higher, while the O2 dissociation rate constant for dissociation from the Fe(II)-O2 heme complex of the Arg97Ile mutant was 100-fold higher than that of the wild-type protein. In contrast, the redox potential values of the mutant proteins were only slightly different from that of the wild type (within 10 mV). Accordingly, we propose that Arg97 plays critical roles in recognition of the O2 molecule and redox switching by stabilizing the Fe(II)-O2 complex, thereby anchoring O2 to the heme iron and lowering the autoxidation rate to prevent formation of Fe(III) hemin species not regulated by gas molecules. Arg97 mutations significantly influenced interactions with the internal ligand Met95, during CO binding to the Fe(II) complex. Moreover, the binding behavior of cyanide to the Fe(III) complexes of the Arg mutant proteins was similar to that of O2, which is evident from the Kd values, suggestive of electrostatic interactions between cyanide and Arg97. 相似文献
63.
Embryonic, larval, and juvenile development of a Taiwanese cyprinid fish, Candidia barbatus, is described from laboratory-reared specimens. The eggs, measuring 1.8–2.1 mm in diameter, were demersal, almost spherical in shape, transparent and unpigmented, with a pale yellow yolk and no oil globule. Hatching occurred 56–69 h after fertilization, the newly hatched larvae measuring 4.9–5.3 mm in body length (BL) with 25–26 + 13–14 = 39–40 myomeres. The yolk was completely absorbed at 7.6 mm BL. Notochord flexion was initiated at 6.8 mm BL and finished at 7.6 mm BL. Aggregate numbers of all fin rays were completed at 12 mm BL. Barbels on the upper jaw appeared near the corner of the mouth at 17 mm BL. Eggs of the species closely resembled those of its related cyprinid genera, Opsariichthys and Zacco. Larvae and juveniles of C. barbatus were similar to those of O. uncirostris subspp., Z. platypus, and Z. pachycephalus, but differed from the latter in the process of disappearance of the adipose finfold (postflexion larval stage), barbels on upper jaw (juvenile stage), and pigmentation on the lateral body surface (postflexion larval and juvenile stages). Although C. barbatus also differed from the Z. temminckii species' group [Z. temminckii and Zacco sp. (sensu Hosoya, 2002)] in having barbels, larvae and juveniles of the former showed more similarity to the latter species group than to O. uncirostris subspp., Z. platypus, and Z. pachycephalus, from the aspect of head and body pigmentation. 相似文献
64.
65.
Yukako Ishigaki Hiroyuki Tanaka Hiroaki Akama Toshiki Ogara Koji Uwai Kiyotaka Tokuraku 《PloS one》2013,8(8)
The aggregation of amyloid β protein (Aβ) is a key step in the pathogenesis of Alzheimer’s disease (AD), and therefore inhibitory substances for Aβ aggregation may have preventive and/or therapeutic potential for AD. Here we report a novel microliter-scale high-throughput screening system for Aβ aggregation inhibitors based on fluorescence microscopy-imaging technology with quantum-dot Nanoprobes. This screening system could be analyzed with a 5-µl sample volume when a 1536-well plate was used, and the inhibitory activity could be estimated as half-maximal effective concentrations (EC50). We attempted to comprehensively screen Aβ aggregation inhibitors from 52 spices using this system to assess whether this novel screening system is actually useful for screening inhibitors. Screening results indicate that approximately 90% of the ethanolic extracts from the spices showed inhibitory activity for Aβ aggregation. Interestingly, spices belonging to the Lamiaceae, the mint family, showed significantly higher activity than the average of tested spices. Furthermore, we tried to isolate the main inhibitory compound from
Satureja
hortensis
, summer savory, a member of the Lamiaceae, using this system, and revealed that the main active compound was rosmarinic acid. These results demonstrate that this novel microliter-scale high-throughput screening system could be applied to the actual screening of Aβ aggregation inhibitors. Since this system can analyze at a microscopic scale, it is likely that further minimization of the system would easily be possible such as protein microarray technology. 相似文献
66.
67.
Makaoto Goto Osamu Imamura Junro Kuromitsu Takehisa Matsumoto Yukako Yamabe Yoshiki Tokutake Noriyuki Suzuki Brian Mason Dennis Drayna Minoru Sugawara Masanobu Sugimoto Y. Furuichi 《Human genetics》1997,99(2):191-193
The profile of helicase gene mutations was studied in 89 Japanese Werner’s syndrome (WRN) patients by examining the previously
described mutations 1– 4 as well as a new mutation found during this study, designated mutation 5. Of 178 chromosomes (89
patients), 89 chromosomes (50%) had mutation 4, 11 (6.2%) chromosomes had mutation 1, and two chromosomes (1.1%) contained
mutation 5. Mutations 2 and 3 were not observed in this patient population. The remaining 76 (42.7%) chromosomes had none
of these mutations. A significant fraction of all patients (22 total patients, 24.7%) appear to be compound heterozygotes,
including those carrying mutations of both types 1 and 4. The genotype analysis of the markers surrounding the WRN helicase gene strongly suggests that most of the chromosomes carrying either mutation 1 or 4 were derived from two single
founders.
Received: 25 July 1996 / Revised: 20 September 1996 相似文献
68.
M C McCann M Bush D Milioni P Sado N J Stacey G Catchpole M Defernez N C Carpita H Hofte P Ulvskov R H Wilson K Roberts 《Phytochemistry》2001,57(6):811-821
Cell wall polysaccharides are some of the most complex biopolymers known, and yet their functions remain largely mysterious. Advances in imaging methods permit direct visualisation of the molecular architecture of cell walls and the modifications that occur to polymers during growth and development. To address the structural and functional relationships of individual cell wall components, we need to better characterise a broad range of structural and architectural alterations in cell walls, appearing as a consequence of developmental regulation, environmental adaptation or genetic modification. We have developed a rapid method to screen large numbers of plants for a broad range of cell wall phenotypes using Fourier transform infrared microspectroscopy and Principal Component Analysis. We are using model systems to uncover the genes that encode some of the cell-wall-related biosynthetic and hydrolytic enzymes, and structural proteins. 相似文献
69.
The lens capsule is a specialized thickened basement membrane that completely surrounds the lens and provides anchoring sites for zonules, the filamentous bodies that suspend the lens. Like other basement membranes, the lens capsule contains collagen IV, which is a family of six polypeptides, subunits alpha1(IV)-alpha6(IV), each of which is encoded by a distinct gene. We have investigated the presence of collagen IV subunits in the developing lens capsule by using confocal immunohistochemistry and antibodies against each of the six collagen IV subunits. In murine embryos, subunits alpha1(IV), alpha2(IV), alpha5(IV) and alpha6(IV) were detected in the basement membrane surrounding the lens vesicle, and they persisted in the capsule until adulthood. In contrast, neither collagen alpha3(IV) nor alpha4(IV) was detected in the lens capsule until 2 weeks postnatal. Similarly, we detected no collagen alpha3(IV) or alpha4(IV) in lens capsules of 54-day human embryos, while collagen alpha3(IV) and alpha4(IV) were detected in adult humans. Thus, in the lens capsule, there is a developmental shift in detectable collagen IV subunits; early in development we observed subunits alpha1(IV), alpha2(IV), alpha5(IV) and alpha6(IV), which is consistent with the presence of fibrillar [alpha1alpha1alpha2] and elastic [alpha5alpha5alpha6] protomers, but later in development components of the more cross-linked [alpha3alpha4alpha5] protomer appear. An elastic lens capsule may be necessary in order to accommodate rapid lens growth in early development, whereas later in development a stronger, more cross-linked capsule may be necessary in order to tolerate the stress caused by postnatal accommodation and disaccommodation of the lens. 相似文献
70.