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91.
Preliminary investigation of feeding performance of larvae of early red-spotted grouper, Epinephelus coioides, reared with mixed zooplankton 总被引:5,自引:0,他引:5
Masanori Doi Joebert D. Toledo Ma Salvacion N. Golez Miguel de los Santos Atsushi Ohno 《Hydrobiologia》1997,358(1-3):259-263
Larvae of red-spotted grouper, Epinephelus coioides, were reared inoutdoor tanks with nauplii of copepods (mainly Pseudodiaptomus annandaleiand Acartia tsuensis) and/or rotifers, Brachionus rotundiformis. Grouperlarvae successfully started feeding on early stage nauplii even though theirabundance was as low as approximately 100 individuals l–1 andshowed better survival and growth thereafter compared to those fed withrotifers only. Incidence of feeding reached 100% on day 4 whennauplii were available and only on day 9 when rotifers were given alone.Larvae seemed to be poor feeders at the onset of feeding, attempting tocapture any food organisms in the tank water. Selective feeding ability oflarvae started from day 4 and the larvae then preferred to feed on medium-and large-size nauplii rather than on rotifers as they grew. Larvae appearedto have a better chance at surviving in the presence of early stage nauplii,which were probably caught more easily than rotifers. 相似文献
92.
Distribution of Brain-Derived Neurotrophic Factor in Rats and Its Changes with Development in the Brain 总被引:21,自引:3,他引:18
Ritsuko Katoh-Semba Ikuo K. Takeuchi †Reiji Semba ‡Kanefusa Kato 《Journal of neurochemistry》1997,69(1):34-42
Abstract: A newly established, sensitive, two-site enzyme-immunoassay system for brain-derived neurotrophic factor (BDNF) is described. Using this system, we investigated the tissue distribution of BDNF and developmental changes in tissue levels of BDNF in rats. The minimal limit of detection of the assay was 3 pg/0.2 ml of assay mixture. BDNF was successfully solubilized from tissues in the presence of guanidine hydrochloride but not in any of the other buffers examined. In the rat brain at 1 month of age, the highest level of BDNF was detected in the hippocampus (5.41 ng/g of wet weight), followed by the hypothalamus (4.23 ng/g) and the septum (1.68 ng/g). In other regions, levels of BDNF ranged between 0.9 and 1.7 ng/g. The level of BDNF in the posterior lobes of the cerebellum from rats at 30 days of age was slightly higher than that in the anterior lobes. The concentration of BDNF increased in all regions of the brain with postnatal development. In peripheral tissues, BDNF was found at very low concentrations (0.65 ng/g in the spleen, 0.21 ng/g in the thymus, and 0.06 ng/g in the liver). The subfractionation of the hippocampal homogenate indicated that ∼50% of BDNF was contained in the crude nuclear fraction. Immunoblots of BDNF-immunoreactive proteins extracted from the hippocampus, hypothalamus, and cerebellum contained doublet bands of protein of ∼14 kDa, a value close to the molecular mass of recombinant human BDNF. Immunocytochemical investigations showed that, in the hippocampus, BDNF was localized in the nucleus of the granule cells in the dentate gyrus and of the cells in the pyramidal cell layer. The frequency of cells that were stained in the dentate gyrus was greater than that of cells in the pyramidal cell layer. 相似文献
93.
Sensitization of rhabdo-, lenti-, and spumaviruses to human serum by galactosyl(alpha1-3)galactosylation. 总被引:4,自引:0,他引:4 下载免费PDF全文
Y Takeuchi S H Liong P D Bieniasz U Jger C D Porter T Friedman M O McClure R A Weiss 《Journal of virology》1997,71(8):6174-6178
Vesicular stomatitis virus, human immunodeficiency virus type 2, and human foamy virus, which were produced by cell lines expressing galactosyl(alpha1-3)galactosyl (alphaGal) sugars, were found to be less stable in human serum than those from alphaGal-negative cells, indicating that galactosyl(alpha1-3)galactosylation sensitizes these viruses as well as mammalian type C oncoviruses (Rother et al., J. Exp. Med. 182:1345-1355, 1995; Takeuchi et al., Nature (London) 379:85-88, 1996) to complement killing via natural anti-alphaGal antibodies. Thus, virus killing mediated by anti-alphaGal antibodies may play a role as a barrier to animal-to-human infection of various enveloped viruses. Virus vectors for human in vivo gene therapy based on the viruses mentioned above should be produced from alphaGal-negative cells. 相似文献
94.
Protoplasts derived from tissue-cultured shoot primordia of garlic (Allium sativum L.) initiated successive cell divisions within 4 days and formed small individual calli (0.2mm in diameter) after 5 weeks of culture on Gamborg's B5 medium supplemented with 0.1% casein hydrolysate, 1mg/1 1-naphthaleneacetic acid and 1mg/1 6-benzylaminopurine. Plating efficiency was roughly 5% at the density of 1x104 protoplasts/ml of medium. Adventitious buds developed from the calli during subsequent subculture on Gamborg's B5 medium supplemented with 40mg/l adenine and 10% coconut milk. When transferred to the same medium without supplements, these buds grew into shoots and rooted. The regenerated garlic plantlets were successfully transferred to the greenhouse and grew into whole plants. 相似文献
95.
Thirty-eight strains of 12Microsporum and 10Arthroderma (Nannizzia) species were investigated by analysis of mitochondrial DNA with 6 restriction enzymes, and classified into 13 genetic groups. The phylogenetic tree of the 13 groups thus established was constructed. On the tree,M. audouinii, M. langeronii, M. rivalieri, M. distortum, M. equinum, M. ferrugineum andA. otae comprise one genetic group and are suggested to be the same species.A. gypseum, A. fulvum, M. duboisii, M. ripariae, A. incurvatum, A. persicolor andA. obtusum are clustered on one of five boughs of the tree indicating their close relation.A. racemosum andA. cajetani are also closely related. 相似文献
96.
Global stability of an SIR epidemic model with time delays 总被引:11,自引:0,他引:11
An SIR disease transmission model is formulated under the assumption that the force of infection at the present time depends on the number of infectives at the past. It is shown that a disease free equilibrium point is globally stable if no endemic equilibrium point exists. Further the endemic point (if it exists) is globally stable with respect to the whole state space except the neighborhood of the disease free state.Research partly supported by the Ministry of Education, Science and Culture, Japan, Grant 05640256 相似文献
97.
Yasushi Isashiki Norio Ohba Toyoko Yanagita Naoko Hokita Norihito Doi Masanori Nakagawa Masayuki Ozawa Noriko Kuroda 《Human genetics》1995,95(1):105-108
We have identified a new mutation of Norrie disease (ND) gene in two Japanese males from unrelated families; they showed typical ocular features of ND but no mental retardation or hearing impairment. A mutation was found in both patients at the initation codon of exon 2 of the ND gene (ATG to GTG), with otherwise normal nucleotide sequences. Their mothers had the normal and mutant types of the gene, which was expected for heterozygotes of the disease. The mutation of the initiation codon would cause the failure of ND gene expression or a defect in translation thereby truncating the amino terminus of ND protein. In view of the rarity and marked heterogeneity of mutations in the ND gene, the present apparently unrelated Japanese families who have lived in the same area for over two centuries presumably share the origin of the mutation. 相似文献
98.
Synopsis Predation on eggs of the angelfish, Centropyge ferrugatus, was observed in the coral reefs of Sesoko Island, Okinawa, Japan. This angelfish released pelagic eggs in pairs at sunset after slow ascents. Of 99 matings of this angelfish, an omnivorous damselfish Amblyglyphidodon curacao approached in 25, and fed on the released eggs in eight cases. The spawning angelfish never attacked the egg-predators. Pairs of this angelfish avoided the egg-predators by delaying mating for several minutes during courtships, and by frequent changes of spawning sites. Of the 25 matings targeted by the egg-predators, the angelfish successfully avoided predation in 17 cases. Eight matings were failures mainly due to lack of any attempt to elude the predator, suggesting that the delayed matings on multiple spawning sites are effective anti-egg predator behaviors. 相似文献
99.
Yuichi Takeuchi Reiko Fukumoto Hirokazu Kasahara Takeshi Sakaki Mitsutoshi Kitao 《Plant cell reports》1995,14(9):566-570
Cotyledons excised from dark-grown seedlings of cucumber (Cucumis sativus L.) were cultured in vitro under UV radiation at different wavelengths, obtained by passage of light through cut-off filters with different transmittance properties. Growth and the synthesis of chlorophyll (Chl) in cotyledons were inhibited and malondialdehyde was accumulated upon irradiation at wavelengths below 320 nm. Exogenous application of scavengers of free radicals reversed the growth inhibition induced by UV-B. Measurement of the fluorescence of Chl a suggested that electron transfer in photosystems was affected by UV-B irradiation. On the basis of these results, the involvement is postulated of active species of oxygen in damages to thylakoid membranes and the growth inhibition that are induced by UV-B irradiation.Abbreviations Chl
chlorophyll
- Fm
maximal fluorescence (dark)
- Fm
maximal fluorescence (light)
- Fv
variable fluorescence (dark)
- Fv
variable fluorescence (light)
- MDA
malondialdehyde
- O2
Superoxide radical
- PS
photosystem
- qN
non-photochemical quenching of fluorescence
- qP
photochemical quenching of fluorescence
- UV-BBE
biologically effective UV-B radiation
- WL(T = 0.5)
wavelength at which 50% transmittance occurs 相似文献
100.
Makoto Matsuoka Masanori Tamaoki Yuichi Tada Tatsuhito Fuyjimura Akemi Tagiri Naoki Yamamoto Yuriko Kano-Murakami 《Plant cell reports》1995,14(9):555-559
Transgenic rice plants (Oryza sativa cv. Nipponbare) carrying 1 or 2 copies of a rice homeobox gene, OSH1, under the control of the CaMV 35S promoter were generated. The transgene caused altered morphology of leaf, such as ligule-replacement and abnormal division of sclerenchyma cells. The phenotype of these leaves resembles that of maize leaf morphological mutant, Knotted 1, which is caused by duplication of the KN1 gene (Veit et al., 1990). The in situ hybridization analysis has revealed that the expression of endogenous OSH1 is mainly localized in developing vascular strands of stem. We have discussed the biological roles of OSH1 in rice based on these results. 相似文献