排序方式： 共有89条查询结果，搜索用时 703 毫秒
71.
Yu Kanaji Yoshiro Watanabe Tomohiko Kawamura Songguang Xie Yoh Yamashita Chiyuki Sassa Youichi Tsukamoto 《Fisheries Research》2009,95(2-3):139-145
The jack mackerel, Trachurus japonicus, has a prolonged spawning season and widely spread spawning grounds. The population in the coastal waters of Japan seems to be composed of several cohorts spawned seasonally from different waters. To understand its population structure along the Tsushima Warm Current, we analysed hatchdates and growth histories of fish from Kunda Bay, the southern, central and northern East China Sea (ECS), the southern Sea of Japan, and Maizuru Bay. Seven cohorts were detected from fish collected between June 2005 and June 2006 in Kunda Bay. Comparing hatchdate distributions and growth trajectories of the seven cohorts with those of the other five regional samples, we did not find that cohorts collected in Kunda Bay originated in the southern ECS. Therefore, these coastal waters of Japan appear to be significant spawning grounds for juvenile jack mackerel. 相似文献
72.
Lee DS Matsumoto S Matsumura Y Mori T 《Journal of agricultural and food chemistry》2002,50(25):7412-7419
To investigate the site specificity of two transglutaminases (TGases), that is, the enzymes from guinea pig liver (GTGase) and Streptoverticillium (MTGase), the acyl acceptor and donor sites in alpha-lactalbumin were determined. Alpha-lactalbumin was cross-linked in the presence of dithiothreitol by GTGase and MTGase for 15 and 30 min, respectively. Cross-linked alpha-lactalbumins by GTGase and MTGase were digested with lysylendopeptidase followed by the separation of the resulting peptides using reverse-phase HPLC. By the sequence analysis of the peptide fragments containing two N termini, which indicates the presence of cross-linked peptide, the lysine residues targeted by TGases were identified as follows: for GTGase, Lys16, Lys93, and Lys122; for MTGase, Lys5. These peptide fragments were further digested by V8 protease. Separation and sequence analyses of the resultant peptides were performed to identify glutamine residue involved in cross-linking. It was found that Gln54 was cross-linked to lysine residues by GTGase and MTGase in common. It is suggested that the difference in the numbers of lysine residues targeted by GTGase and MTGase may be responsible for the difference in the polymerization process of alpha-lactalbumin between GTGase- and MTGase-catalyzed systems. 相似文献
73.
Yoichiro Takanose Shinya Ishida Natsumi Kudo Tomohiko Kamitani 《Paddy and Water Environment》2013,11(1-4):45-58
Traditional weed management, such as tillage and irrigation, has led to an enhanced maintenance of wetland plant species in fallow paddy fields. Recent herbicide usage and improvements in irrigation and drainage systems however have caused habitat loss of these species, especially in fields on open lowlands. We conducted experiments in three fallow paddy fields situated on the alluvial Echigo Plain in central Japan with an aim to restore the habitat of native wetland plant species. The three experimental fields were managed under different irrigation regimes, (1) perennially flooded with water, (2) intermittent irrigation, and (3) temporary irrigation. Half the area of each experimental field was tilled before irrigation. Detrended correspondence analysis revealed obvious floristic differences between experimental and control fields with no irrigation. The proportion of wetland plant species in the experimental fields increased corresponding to the irrigation period, ranging 60–86%, and was relatively greater than that in control fields. In the experimental fields, differences in both tillage and irrigation affected the occurrence of plant species. Tillage restricted the occurrence of many non-wetland plant species, and had a positive effect on the establishment of several annual wetland plant species. In addition, a longer duration of irrigation is not necessarily suitable for the occurrence of all wetland plant species. We concluded that fallow paddy fields provide a possible habitat for the restoration of native wetland plant species through appropriate tillage and irrigation. 相似文献
74.
Yuya Umezu Toshihiro Onitsuka Tomohiko Kawamura Yoshiro Watanabe 《Fisheries Science》2017,83(2):221-233
To examine the feeding ecology of the sea urchin Strongylocentrotus intermedius, two types of macroalgal diet (kelp Saccharina longissima and red alga Ptilota filicina) and four types of benthic animal diet [barnacle Balanus glandula, limpet Lottia cassis, free-living Perinereis aibuhitensis and P. aibuhitensis attached to a stainless steel wire (wired polychaete)], were separately or simultaneously provided for urchins of 5- to 60-mm test diameter (TD). Sea urchins of even 3-mm TD could graze the kelp, and began to graze the red alga, the wired polychaete and limpet by 5-mm TD, the barnacle by 8-mm TD and the free-living polychaete by 15-mm TD, respectively. These results suggest that the variety of macroalgae and benthic animals which the urchin can graze increases with the ontogeny of their feeding organs, motility and ability to catch animals. Both juvenile and adult sea urchins preferred to eat the polychaete as well as the kelp fronds. Feed conversion efficiency and daily growth rate of the small sea urchins fed benthic animals like the polychaete were higher than those fed macroalgae. The sea urchins are likely to grow better when feeding on animals than on macroalgae, even in habitats where they can access adequate quantities of kelp. 相似文献
75.
Nam -Il Won Tomohiko Kawamura Toshihiro Onitsuka Jun Hayakawa Satoshi Watanabe Toyomitsu Horii Hideki Takami Yoshiro Watanabe 《Fisheries Science》2007,73(5):1123-1136
Abstract: The community and trophic structures of the subtidal habitat of the abalone Haliotis diversicolor were examined in Nagai, Sagami Bay, Japan. Conventional community indices showed no significant differences among three sampling stations. The overall continuum of stable isotope ratios was structured into three different trophic linkages: (i) brown algae-dependent benthic food chain; (ii) red algae-dependent benthic food chain; and (iii) planktonic food chain. Brown algae and red algae likely play different roles with respect to carbon sources in the habitat. Conventional fractionation values indicated that the abalone H. diversicolor (δ13 C = −12.4 ± 1.0‰, δ15 N = 9.3 ± 0.5‰) feeds on the lamina of Undaria pinnatifida during juvenile and adult stages (8.0–65.6 mm shell length). Stable isotope signatures suggested that the juveniles of other abalone species as well as some amphipods and a sea cucumber Holothuria decorata are competitors of H. diversicolor , whereas some Muricidae gastropods such as Thais bronni and Ergalatax contractus are predators. The isotopic differences among macroalgal species and the subsequent transfer to consumers indicate that stable isotopic analysis is an effective means of studying food webs in an open rocky shore community with little influence from external primary production such as terrestrial vegetation. 相似文献
76.
In order to clarify the effects of both the social and natural environment on the changes in landscape structure we analyzed
landscape elements using aerial photographs taken in different years in the primary and coppice forests in theFagus crenata forest region of central Japan. The present landscape diversity calculated by Shannon's diversity index (H′) appeared to be higher than that observed in photographs from the earlier year. The site with no residential areas and dominated
by primary forests had a lower level of landscape diversity than the site which included some residential areas and coppice
forests. These results show that the intensity of human activities contributes to changes in landscape diversity. The landscape
diversity on private land was higher than that in the national forest, and the changes in landscape structure in the national
forest were different from those seen on private land. This suggests that land ownership significantly affects the changes
in landscape structure. Topographic factors also affect the changes in landscape structure. Consequently, not only the natural
environment (topography), but also the social environment (intensity of human activity and land ownership) strongly influence
the changes in landscape structure. 相似文献
77.
We evaluated the contribution of seed dispersal by birds to the colonization of fleshy-fruited plants beneath plants that bear fleshy fruits and were used as perches by birds. Specifically, we investigated the composition of seeds and saplings sampled beneath nine fleshy-fruited perch plant species in a Pinus thunbergii stand on a coastal sand dune in central Japan. Both the numbers and the species numbers of bird-dispersed (pulpless) seeds differed significantly among the perch plant species. Nevertheless, the quantitative compositions of bird-dispersed seeds were similar among the perch plant species because of the significant positive interspecific correlations of species rank order in numbers of bird-dispersed seeds per species. Similar relationships were also found for saplings. For each perch plant species, the numbers of fallen conspecific seeds were significantly higher than or not different from those of heterospecific seeds. Furthermore, the numbers of pulpy seeds that fell directly from the perch plant were significantly higher than those of bird-dispersed conspecific seeds for seven of nine perch plant species. However, the densities of conspecific saplings were significantly lower than those of heterospecific saplings. Most pulpy seeds, therefore, probably do not germinate beneath their mother plants, and conspecific seeds probably accumulate in seed banks or are consumed by herbivores. 相似文献
78.
Ishii Y Maki M Yamamoto H Sasase T Kakutani M Ohta T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(4):501-505
Blood pressure in female SDT-fa/fa rats was periodically investigated at ages 8, 16, and 24 weeks. Furthermore, an insulin therapy was performed for 5 weeks in the female rats at age 11 weeks, and the change of blood pressure was examined. In addition to obesity, hyperglycemia, hyperinsulinemia, and hyperlipidemia, hyperleptinemia and increased urinary angiotensinogen level were observed during the experimental period. Blood pressure was elevated at ages 8 and 16 weeks, but that at 24 weeks was comparable to that in Sprague-Dawley (SD) rats. Heart rate was decreased from age 8 to 24 weeks. Insulin therapy induced good glycemic control and improvement of hyperlipidemia, but the blood pressure was not reduced. Blood pressure in female SDT-fa/fa rats was elevated temporarily. The blood pressure was not decreased by insulin treatment. SDT-fa/fa rat is a useful model to investigate the relation between diabetes mellitus and hypertension. 相似文献
79.
Takahiro Nishimaki Takayuki Ibi Yoshihiro Tanabe Yoshiyuki Miyazaki Naohiko Kobayashi Tamako Matsuhashi Takayuki Akiyama Emi Yoshida Kazumi Imai Mayu Matsui Keiichi Uemura Naoto Watanabe Tatsuo Fujita Yosuke Saito Tomohiko Komatsu Takahisa Yamada Hideyuki Mannen Shinji Sasazaki Tetsuo Kunieda 《Animal Science Journal》2013,84(8):585-591
Japanese Black cattle are at risk for genetic homogeneity due to intensive use of a few sires. Therefore, assessment of the actual genetic diversity of this breed is important for future breeding plans. In the present study, we investigated the genetic diversity within and among eight subpopulations of Japanese Black cattle using 52 microsatellite markers. The parameters for genetic diversity of Japanese Black cattle were comparable to those of other cattle breeds, suggesting that the relatively high genetic diversity of the breed. However, upon comparison among the eight subpopulations, the Hyogo subpopulation showed markedly low genetic diversity. The results of the pairwise FST values, phylogenetic network and structure analysis indicated that the Hyogo population has remarkably high level of genetic differentiation from other populations, while Yamagata, Niigata, Hiroshima and Kagawa populations have low levels of genetic differentiation. Furthermore, multidimensional scaling plots indicated that individuals in some subpopulations were separated from individuals in the other subpopulations. We conclude that while the overall genetic diversity of Japanese Black cattle is still maintained at a relatively high level, that of a particular subpopulation is significantly reduced, and therefore the effective population size of the breed needs to be controlled by correct mating strategies. 相似文献
80.
Allelic frequencies and association with carcass traits of six genes in local subpopulations of Japanese Black cattle 
下载免费PDF全文
下载免费PDF全文 Takahiro Nishimaki Takayuki Ibi Siqintuya Naohiko Kobayashi Tamako Matsuhashi Takayuki Akiyama Emi Yoshida Kazumi Imai Mayu Matsui Keiichi Uemura Hisayoshi Eto Naoto Watanabe Tatsuo Fujita Yosuke Saito Tomohiko Komatsu Hiroshi Hoshiba Hideyuki Mannen Shinji Sasazaki Tetsuo Kunieda 《Animal Science Journal》2016,87(4):469-476
Marker‐assisted selection (MAS) is expected to accelerate the genetic improvement of Japanese Black cattle. However, verification of the effects of the genes for MAS in different subpopulations is required prior to the application of MAS. In this study, we investigated the allelic frequencies and genotypic effects for carcass traits of six genes, which can be used in MAS, in eight local subpopulations. These genes are SCD, FASN and SREBP1, which are associated with the fatty acid composition of meat, and NCAPG, MC1R and F11, which are associated with carcass weight, coat color and blood coagulation abnormality, respectively. The frequencies of desirable alleles of SCD and FASN were relatively high and that of NCAPG was relatively low, and NCAPG was significantly associated with several carcass traits, including carcass weight. The proportions of genotypic variance explained by NCAPG to phenotypic variance were 4.83 for carcass weight. We thus confirmed that NCAPG is a useful marker for selection of carcass traits in these subpopulations. In addition, we found that the desirable alleles of six genes showed no negative effects on carcass traits. Therefore, selection using these genes to improve target traits should not have negative impacts on carcass traits. 相似文献