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91.
92.
SAD‐B kinase regulates pre‐synaptic vesicular dynamics at hippocampal Schaffer collateral synapses and affects contextual fear memory
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93.
Akio Mori Toshitaka Iwamoto Umeyo Mori Afework Bekele 《Primates; journal of primatology》1999,40(2):365-381
A new population of gelada baboons isolated from other known gelada populations living on the opposite side of the Rift Valley
was found in 1989 in the Arsi region of Ethiopia (Mori &Belay, 1990). Subsequent observations were conducted on the new gelada population in three study periods of 16 to 55 days over
three consecutive years, 1994–1996. When we compare this population with other well studied northern populations, densities
were lower, band size was smaller and the ratio of juveniles to adult females was lower. Based onOhsawa andDunbar's (1984) criteria these results suggest that this population exploits the harshest environment among known gelada populations.
This may be due to the severe effect of the dry season at low altitude in the study site. Band size was small in the study
site. Association rates of units were low, and each unit behaved more independently than those of northern populations. Age-sex
composition of units changed drastically between consecutive study periods, indicating unstable unit structure. Moreover,
there seems to be a tendency in this population whereby several adult males easily invade and are incorporated into a unit
but the unit is expected to thereafter divide. The phenomenon can be explained by two factors: (1) Each unit fed rather independently
in this area, where units fed intensively on both plateau and the slope of the cliff; and (2) Males may be incorporated in
a unit for defense against leopards. As the units were vary small in size and unstable as compared with the Semien gelada
units, the traditional concept of a stable gelada unit formed by blood related females, does not seem to fit this population. 相似文献
94.
The mechanism of infection by Vibrio sp. P11 promoting the ice-ice disease in Kappaphycus alvarezii was investigated in vitro.
Its intensity of infection differs from that of another ice-ice promoter (Cytophaga sp. P25) by promoting the disease much
faster. However, when secondary infection by other bacteria starts, its ability to compete with these bacteria gradually diminishes,
whereas, infection by P25, although not displaying such drastic effects as P11, shows consistent competitive ability against
other bacteria. Time-series infection experiments with application of polyclonal antibodies to specifically detect Vibrio
sp. P11 revealed that this bacterium has a high affinity for the seaweed especially when the latter is stressed. It promotes
the disease after a rapid increase in cell density of up to 107 g−1 (wet wt.) in the first 24 h. This bacterial cell build-up may take only 1–2 h on stressed thalli, but takes about 24 h on
non-stressed thalli. Build-up is not sustainable in non-stressed thalli as high density is usually followed by a sudden decline
in cell number believed to result from an algal defence against potential pathogens. Inoculation of the bacterium on thalli
incubated in continuous culture system extends the time of bacterial attachment due to laminar flow and, possibly, competition
by existing bacteria on the seaweed surface and in ambient seawater medium. Motility-driven cell attachment by this bacterium
is suggested as an important factor for infection.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
95.
Effects of lactoferrin and lactoperoxidase‐containing food on the oral microbiota of older individuals
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Manabu Nakano Hiroyuki Wakabayashi Hirosuke Sugahara Toshitaka Odamaki Koji Yamauchi Fumiaki Abe Jin‐Zhong Xiao Kohji Murakami Kentaro Ishikawa Shouji Hironaka 《Microbiology and immunology》2017,61(10):416-426
96.
Toshio Takahashi Osamu Koizumi Eisuke Hayakawa Sumiko Minobe Rinako Suetsugu Yoshitaka Kobayakawa Thomas C. G. Bosch Charles N. David Toshitaka Fujisawa 《Development genes and evolution》2009,219(3):119-129
From an evolutionary point of view, Hydra has one of the most primitive nervous systems among metazoans. Two different groups of peptides that affect neuron differentiation
were identified in a systematic screening of peptide signaling molecules in Hydra. Within the first group of peptides, a neuropeptide, Hym-355, was previously shown to positively regulate neuron differentiation.
The second group of peptides encompasses the PW family of peptides that negatively regulate neuron differentiation. In this
study, we identified the gene encoding PW peptide preprohormone. Moreover, we made the antibody that specifically recognizes
LPW. In situ hybridization and immunohistochemical analyses showed that the PW peptides and the gene encoding them were expressed
in ectodermal epithelial cells throughout the body except for the basal disk. The PW peptides are produced by epithelial cells
and are therefore termed “epitheliopeptides.” Together with Hym-355, the PW family peptides mediate communication between
neurons and epithelial cells and thereby maintain a specific density of neurons in Hydra.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Toshio Takahashi, Osamu Koizumi equally contributed to this study. 相似文献
97.
98.
Masafumi Tanaka Toshitaka Tanaka Shinya Ohta Toru Kawakami Hiroyuki Konno Kenichi Akaji Saburo Aimoto Hiroyuki Saito 《Journal of peptide science》2009,15(1):36-42
Although the N‐terminal region in human apolipoprotein (apo) A‐I is thought to stabilize the lipid‐free structure of the protein, its role in lipid binding is unknown. Using synthetic fragment peptides, we examined the lipid‐binding properties of the first 43 residues (1–43) of apoA‐I in comparison with residues 44–65 and 220–241, which have strong lipid affinity in the molecule. Circular dichroism measurements demonstrated that peptides corresponding to each segment have potential propensity to form α‐helical structure in trifluoroethanol. Spectroscopic and thermodynamic measurements revealed that apoA‐I (1–43) peptide has the strong ability to bind to lipid vesicles and to form α‐helical structure comparable to apoA‐I (220–241) peptide. Substitution of Tyr‐18 located at the center of the most hydrophobic region in residues 1–43 with a helix‐breaking proline resulted in the impaired lipid binding, indicating that the α‐helical structure in this region is required to trigger the lipid binding. In contrast, apoA‐I (44–65) peptide exhibited a lower propensity to form α‐helical structure upon binding to lipid, and apoA‐I (44–65/S55P) peptide exhibited diminished, but not completely impaired, lipid binding, suggesting that the central region of residues 44–65 is not pivotally involved in the formation of the α‐helical structure and lipid binding. These results indicate that the most N‐terminal region of apoA‐I molecule, residues 1–43, contributes to the lipid interaction of apoA‐I through the hydrophobic helical residues. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
99.
Koutaro Maeno 《Journal of insect physiology》2009,55(11):1021-1028
The role of juvenile hormone (JH) in the maternal regulation of progeny characteristics was examined in the desert locust, Schistocerca gregaria. Female adults of this species are known to produce smaller but more eggs when reared in isolation than do those reared in a group. Eggs laid by isolated females develop green hatchlings typical of solitarious forms, whereas those laid by the latter produce black hatchlings typical of gregarious forms. Topical application of a juvenile hormone analog (JHA), fenoxycarb, or implantation of corpora allata (CA) taken from the migratory locust, Locusta migratoria, caused crowded S. gregaria females to deposit smaller eggs, but did not have a significant effect on the number of eggs per egg pod except at high doses of JHA. The production of smaller eggs by treated and untreated crowded females was closely associated with earlier deposition of the egg pods and shorter oviposition intervals. However, neither JHA application nor CA implantation influenced the progeny characteristics in actively reproducing aged females under crowded conditions, while untreated control females started producing smaller and more eggs upon transfer to isolated conditions. These results may suggest that JH is not directly involved in the maternal regulation of phase-dependent progeny characteristics. 相似文献
100.
Brevican distinctively assembles extracellular components at the large diameter nodes of Ranvier in the CNS 总被引:1,自引:0,他引:1
Yoko Bekku Uwe Rauch† Yoshifumi Ninomiya Toshitaka Oohashi 《Journal of neurochemistry》2009,108(5):1266-1276
Brevican is known to be an abundant extracellular matrix component in the adult brain and a structural constituent of perineuronal nets. We herein show that brevican, tenascin-R (TN-R) and phosphacan are present at the nodes of Ranvier on myelinated axons with a particularly large diameter in the central nervous system. A brevican deficiency resulted in a reorganization of the nodal matrices, which was characterized by the shift of TN-R, and concomitantly phosphacan, from an axonal diameter-dependent association with nodes to an axonal diameter independent association. Supported by the co-immunoprecipitation results, these observations indicate that the presence of TN-R and phosphacan at nodes is normally brevican-dependent, while in the absence of brevican these molecules can also be recruited by versican V2. The versican V2 and Bral1 distribution was not affected, thus indicating a brevican-independent role of these two molecules for establishing hyaluronan-binding matrices at the nodes. Our results revealed that brevican plays a crucial role in determining the specialization of the hyaluronan-binding nodal matrix assemblies in large diameter nodes. 相似文献