Allopatric distributions of tetraploid and hexaploid forms of Aegilops neglecta Req. ex Bertol.     

Shoji Ohta  Yoshiki Nosaka  Hidekazu Yamagata 《Genetic Resources and Crop Evolution》2016,63(2):193-197

The genus Aegilops L. comprises 22 annual wild species that are closely related to wheat (Hammer in Kulturpflanze 28: 33–180, 1980). Aegilops neglecta Req. ex Bertol. is a member of the Aegilops section of this genus and is distributed from Morocco and Spain in the west to Transcaucasia and western Iran in the east. This species includes tetraploid (2n = 28, genome UUMM) and hexaploid forms (2n = 42, UUMMNN). However, the geographical distributions of the two cytological forms remain unclear. Clarifying the distribution of the two cytological forms is essential for a better understanding of the diffusion of Ae. neglecta and its tetraploid and hexaploid forms. In the present study, chromosome numbers were determined for accessions of Ae. neglecta from a total of 137 populations, located in the western area of the species distribution from the Aegean Islands to Morocco. Taken together with previous studies, the present data reveal a difference in the geographical distribution of tetraploid and hexaploid forms: tetraploid form is distributed in the eastern part of the species area and hexaploid form predominantly occurs in the western part with their border on the western margin of the Aegean Sea. Near the border, tetraploid and mixed populations are sporadically found among hexaploid populations in the Balkan and Peloponnesus Peninsulas, while a few hexaploid and mixed populations are found among tetraploid populations in the East Aegean Islands and West Anatolia.  相似文献   

General Chemical Properties of Brown Forest Soils Developed from Different Parent Materials in the Submontane Zone of the Kanto and Chubu Districts, Japan   总被引：1，自引：0，他引：1  

Akihiro Imaya  Seiichi Ohta  Nagaharu Tanaka  Yoshiyuki Inagaki 《Soil Science and Plant Nutrition》2005,51(6):873-884

It is essential to analyze chemical properties including the amount of various materials and the soil colloid characteristics in forest soils to forecast wood production and the distribution of and variations in the environmental functions of forest soils, such as conservation of stream water and carbon sequestration. Approximately 70% of the forest soils in Japan consists of Brown Forest Soils (BFS), which are considered to be typical zonal soils under the humid-temperate and warm-temperate regime of Japan. BFS were subclassifled into several groups according to the soil moisture environment along the slope and morphological properties. However, even the same type of soil may display different properties depending on the climatic conditions, parent materials and vegetation types. In the present study, the variations in the carbon content, nitrogen content, cation exchange capacity and some properties depending on the parent materials, were clarified by using 34 sola of BFS, and 3 sola of black soils (BLS) for comparison, which were distributed in the submontane zone of the Kanto and Chubu districts in central Japan under the same climatic conditions. We observed differences in the pH, cation exchange capacity, base saturation and clay content among BFS samples derived from various parent materials. The BFS derived from volcanic ash contained obviously larger amounts of carbon and nitrogen than the BFS derived from other parent materials. However, the BFS derived from volcanic ash differed from the BLS derived from volcanic ash in the vertical distribution pattern of carbon and nitrogen. Thus, even in the submontane zone of the Kanto and Chubu districts, the chemical properties of BFS varied considerably with the parent materials. It was concluded that the classification of BFS by the parent materials was useful for evaluating the ability of the BFS, that cover 70% of the forests in Japan, to store various materials.  相似文献   

Metabolism of polychlorinated dibenzo-p-dioxins (PCDDs) by human cytochrome P450-dependent monooxygenase systems     

Inouye K  Shinkyo R  Takita T  Ohta M  Sakaki T 《Journal of agricultural and food chemistry》2002,50(19):5496-5502

Metabolism of polychlorinated dibenzo-p-dioxins (PCDDs) by monooxygenase systems dependent on 12 forms of human cytochrome P450 (CYP) was examined with the recombinant yeast microsomes containing each of the human CYP. The metabolites of PCDDs were analyzed by HPLC and GC-MS. Remarkable metabolism by the multiple CYP forms was observed toward dibenzo-p-dioxin (DD) and mono-, di-, and trichloroDDs. The metabolism contained multiple reactions such as hydroxylation at an unsubstituted position, hydroxylation with migration of a chloride substituent, and hydroxylation with elimination of a chloride substituent. Although major CYPs in human liver such as CYP2C8, CYP2C9, and CYP3A4 showed no significant metabolism toward the PCDDs, CYP1A1 and CYP1A2 showed high catalytic activity toward DD and mono-, di-, and trichloroDDs. The kinetic parameters K(m)(app) and V(max) of the CYP1A1-dependent 8-hydroxylation activity of 2,3,7-trichloro-DD (2,3,7-triCDD) were estimated to be 0.30 microM and 51 (mol/min/mol of P450), respectively, suggesting that 2,3,7-triCDD was a good substrate for CYP1A1. However, none of the CYPs showed any detectable activity [<0.01 mol/min/mol of P450)] toward 2,3,7,8-tetraCDD. Substrate-induced absorption spectrum and inhibition studies indicated that CYP1A1 could bind 2,3,7,8-tetraCDD with considerably high affinity. It was strongly suggested that the long half-life (7.1 years) of 2,3,7,8-tetraCDD in humans was due to an extremely low activity of CYPs toward 2,3,7,8-tetraCDD in addition to its chemical stability.  相似文献   

Clinical characteristics of dogs with food-responsive protein-losing enteropathy     

Noriyuki Nagata  Hiroshi Ohta  Nozomu Yokoyama  Yong Bin Teoh  Khoirun Nisa  Noboru Sasaki  Tatsuyuki Osuga  Keitaro Morishita  Mitsuyoshi Takiguchi 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(2):659-668

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Cryopreservation diluents for spermatozoa of Sakhalin taimen <Emphasis Type="Italic">Hucho perryi</Emphasis>     

Satoshi?KusudaEmail author  Nobuhisa?Koide  Hiloshi?Kawamula  Tetsuo?Teranishi  Jun?-Ichiro?Nakajima  Etsuro?Yamaha  Katsutoshi?Arai  Hiromi?Ohta 《Fisheries Science》2005,71(2):293-298

To develop a suitable cryopreservation diluent for spermatozoa of the endangered Sakhalin taimen Hucho perryi, all possible combinations of cryoprotectants (glycerol, dimethyl sulfoxide [DMSO], methanol) and extenders (fetal bovine serum [FBS], 300 mM glucose solution [GS], artificial seminal plasma for masu salmon) were examined by observing sperm motility 10 s after thawing. Spermatozoa cryopreserved with diluents such as mixtures of 10% glycerol plus 90% FBS, 10% DMSO plus 90% FBS, and 10% methanol plus 90% GS showed the highest motility. The maximal post-thaw motility was observed at 10% among all concentrations (0, 5, 10, 15 and 20%) of these three cryoprotectants. No significant difference among three diluents was observed in motility at 10 s. Mixtures of 10% glycerol plus 90% FBS, 10% DMSO plus 90% FBS, and 10% methanol plus 90% GS are suitable cryopreservation diluents for Sakhalin taimen spermatozoa.  相似文献   

Evaluation of end-check propagation based on mode I fracture toughness of sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>)     

Ken Watanabe  Satoshi Shida  Masamitsu Ohta 《Journal of Wood Science》2011,57(5):371-376

The relation between crack propagation based on fracture mechanics and end-check propagation during drying was evaluated in this study. Corresponding to the direction of end-check propagation, the mode I fracture toughness of air-dried sugi specimens in TR, TL, and intermediate systems was examined by single-edge-notched bending tests. The occurrence and propagation of end checks on sugi (Cryptomeria japonica D. Don) blocks during drying were observed at the scale of the annual rings. It was found that the critical stress intensity factor (K _IC) decreased as the crack propagation changed from TL to TR. The value of K _IC in the TR system was significantly lower than that in the TL system. As a measure of fracture energy, the area under the load-crack opening displacement curve in the TR system was more than twice that in the TL and intermediate systems. These results indicate that cracks perpendicular to the tangential direction initiate radially with ease, and then crack arrest occurs to prevent growing. This finding provides a consistent interpretation of the end-check propagation observed during drying as follows: tiny end checks, as an analog of TR cracks, occur easily and selectively in latewood or transition wood and propagate toward the pith during drying. When there is no corresponding secondary check in the forward latewood, the checks are arrested and do not propagate further.  相似文献   

Quinone profiling of bacterial populations developed in the surface layer of volcanic mudflow deposits from Mt. Pinatubo (the Philippines)     

Hiroyuki Ohta  Kazuya OgiwaraEri Murakami  Hiroshi TakahashiMasaru Sekiguchi  Kiyokazu KoshidaTakashi Someya  Wataru MorishimaJose D Rondal  Rogelio N ConcepcionMasao Yoshida  Makiko Watanabe 《Soil biology & biochemistry》2003,35(8):1155-1158

The diversity of bacterial populations developed in the surface layer (0-0.25 m depth) of volcanic mudflow deposits from the Mt. Pinatubo volcano (the Philippines) was investigated using quinone profiling. Samples were collected from sites (named N and S1) that had been hit repeatedly by mudflows during successive rainy seasons after the violent eruption of 1991 and also from sites (F1 and F3) covered by mudflow in 1991 but with no deposition in following years. The total microscopic count ranged from 10⁸ g⁻¹ (N and S1 sites) to 3.9×10⁹ g⁻¹(site F3). In the N sample only three quinone species were detected, while the quinone profiles of samples from sites S3 and F3 showed higher diversity. Tetrahydrogenated menaquinone with eight isoprenoid units [MK-8 (H₄)] was the predominant quinone species in the sample from site N, while MK-8, MK-8 (H₂), MK-8 (H₄), MK-9 (H₄) and MK-9 (H₈) were found as major quinones in the sample from site F3. Because these MK species are known to be the major respiratory quinones of the Actinobacteria, this bacterial group is expected to predominate in the land with primary vegetation recovery following the impact of the volcanic mudflow.  相似文献   

Expression and subcellular localization of apical junction proteins in canine duodenal and colonic mucosa     

Ohta H  Yamaguchi T  Rajapakshage BK  Murakami M  Sasaki N  Nakamura K  Hwang SJ  Yamasaki M  Takiguchi M 《American journal of veterinary research》2011,72(8):1046-1051

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Importance of bringing dogs in contact with children during their socialization period for better behavior     

Arai S  Ohtani N  Ohta M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(6):747-752

Much attention has been given to the role that dogs play in the social, physical, and psychological development of children. Furthermore, dogs are now playing a new important role in animal-assisted education (AAE). However, some dogs have difficulty getting along with children. The aim of this study was to demonstrate how dogs' contact with children during and after their socialization period influenced their responses toward children. In total, 31 pet dogs were divided into three groups. Group 1 dogs had been in contact with children during the canine socialization period (between 3 and 12 weeks of age); Group 2 dogs had been in contact with children after this socialization period; Group 3 dogs seldom had contact with children. As soon as a child entered the room, the dog was presented three stimuli by the child over the course of several intervals. The dogs' responses were evaluated by analyzing behavior and heart rates. The dogs that had been in contact with children during their socialization period did not show aggressive behavior or excited behavior toward the child in our test. Moreover, their heart rates were significantly decreased even during the last stimulus, which involved the child running around the dog while calling its name. This study suggested that the dogs having contact with children during socialization period might not show inappropriate responses toward children and could be suitable for taking part in AAE.  相似文献   

Effects of ovariectomy on bone metabolism and bone mineral density in spontaneously diabetic Torii-Lepr(fa) rats     

Kimura S  Sasase T  Ohta T  Matsushita M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(8):1025-1029

The Spontaneously Diabetic Torii-Lepr(fa) (SDT- fa/fa) rat is a new model of obese type 2 diabetes. The female SDT-fa/fa rat shows obesity, hyperglycemia and hyperlipidemia from a young age. However, it is not known whether diabetes and estrogen deficiency can lead to bone abnormalities in the female SDT-fa/fa rat. The objective of the present study was to investigate the effects of ovariectomy (OVX) on bone metabolism and bone mineral density (BMD) in the female SDT-fa/fa rat. Female Sprague-Dawley rats were used as control animals. The BMDs of the whole tibia and fifth lumbar (L5) vertebral body were analyzed at 30 weeks after OVX. Serum osteocalcin, a bone formation marker, and urine deoxypyridinoline (DPD), a bone resorption marker, were sequentially analyzed before and at 5, 15 and 30 weeks after OVX. Serum osteocalcin and urine DPD levels were lower in SDT-fa/fa rats than in control rats before OVX. Both serum osteocalcin and urine DPD levels were elevated in control rats 5-30 weeks after OVX, but only the urine DPD levels were elevated in SDT-fa/fa rats 5-30 weeks after OVX. SDT-fa/fa rats showed a decrease in the BMDs of the whole tibia and L5 vertebral body compared with control rats. OVX decreased the BMDs of the whole tibia and L5 vertebral body in control rats, but not in SDT-fa/fa rats. These data suggest that estrogen deficiency is not a risk factor for bone loss in type 2 diabetes mellitus.  相似文献