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111.
A. Kotake T. Arai M. Ohji S. Yamane N. Miyazaki K. Tsukamoto 《Zeitschrift fur angewandte Ichthyologie》2004,20(2):150-153
The age and migratory history of the Japanese eel, Anguilla japonica Temminck & Schlegel, collected in Miyako Bay along the Sanriku coast of Japan, was examined using the otolith microstructure and analysis of strontium (Sr) and calcium (Ca) concentrations conducted with wavelength dispersive X‐ray spectrometry by an electron microprobe. The line analysis of Sr : Ca ratios along the life history transect of each otolith showed a peak (ca. 15–17 × 10?3) which corresponded with the period of their leptocephalus and early glass eel stages in the ocean. The mean Sr : Ca ratios from the elver mark to the otolith edge indicated that there were eels with several general categories of migratory history, including sea eels that never entered freshwater (average Sr : Ca ratios, ≥6.0 × 10?3), and others that entered freshwater for brief periods but returned to the estuary or bay. This evidence of the occurrence of sea eels in this northern area indicates that Japanese eels of the Sanriku coast do not necessarily migrate into freshwater rivers during recruitment as do glass eels at the beginning of their growth phase; even those that do enter freshwater may later return to the marine environment. Thus, anguillid eel migrations into freshwater are clearly not an obligatory migratory pathway, but rather a facultative catadromy with seawater or estuarine residents as an ecophenotype. 相似文献
112.
Masao Suzuki Chizuru Tsuruoka Tatsuaki Kanai Takeshi Kato Fumio Yatagai Masami Watanabe 《Biological Sciences in Space》2003,17(4):302-306
We investigated the difference in cell-killing effect and mutation induction between carbon- and neon-ion beams in normal human cells. Carbon- and neon-ion beams were accelerated by the Riken Ring Cyclotron (RRC) at the Institute of Physical and Chemical Research in Japan. Cell-killing effect was measured as the reproductive cell death using the colony formation assay. Mutation induction at the HPRT locus was detected to measure 6-thioguanine-resistant clones. The mutation spectrum of the deletion pattern of exons of induced mutants was analyzed using the multiplex polymerase chain reaction (PCR). Cell-killing effect was almost the same between carbon- and neon-ion beams with similar linear energy transfer (LET) values, while there observed a large difference in mutation frequency. Furthermore, in the case of neon-ion beams 60% of mutants showed total deletions and 35-40% showed partial deletions, while 95-100% of carbon-ion induced mutants showed total deletions. The results suggest that different ion species may cause qualitative and quantitative difference in mutation induction even if the LET values are similar. 相似文献
113.
Hiroyasu Kitashiba Takayoshi Iwai Kinya Toriyama Masao Watanabe Kokichi Hinata 《Sexual plant reproduction》1996,9(3):186-188
The vegetative-to-floral transition ofBrassica campestris cv. Osome was induced by vernalization. Poly(A)+RNA was isolated from the transition shoot apex after 6 weeks of vernalization, the floral apex after 12 weeks of vernalization and the expanded leaves just before vernalization, and cDNAs were synthesized. These cDNAs were used for subtraction and differential screening to select cDNA preferentially present in the transition and floral apices. Nucleotide sequences of the resulting 14 cDNA clones were determined, and northern blot analysis was carried out on six cDNAs. Two cDNA clones which did not show significant similarity to known genes were shown to be preferentially expressed in the floral apex. 相似文献
114.
The holotype of a bothid flounder,Arnoglossus tapeinosomus (Bleeker, 1866), was re-examined and found to bear none of the diagnostic characters ascribed by many authors to the species.
In addition, the shape of the prevomer was clearly different between the holotype and 18 specimens supposedly“A. tapeinosomus.” A. macrolophus Alcock, 1889, which was synonymized underA. tapeinosomus by Weber and de Beaufort (1929), is considered as a valid replacement name for“A. tapeinosomus,” because of the elongated anterior rays in the dorsal fin and a large, dark spot on the posterior dorsal and anal fin bases.A. tapeinosomus is redescribed from the holotype. 相似文献
115.
Efficient production of IGG human monoclonal antibodies by lymphocytes stimulated by lipopolysaccharide,pokeweed mitogen,and interleukin 4 总被引:1,自引:0,他引:1
Kaoru Yoshinari Kenji Arai Hideki Kimura Kunio Matsumoto Yutaka Yamaguchi 《In vitro cellular & developmental biology. Animal》1996,32(6):372-377
Summary Extensive screening of the mitogens lipopolysaccharide (LPS), pokeweed mitogen (PWM), andStaphylococcus aureus Cowan I (SAC I), alone and in combination and with and without interleukin (IL) was performed forin vitro activation of regional lymph node lymphocytes from lung cancer patients for the production of human IgG, IgM, and IgA. As
assessed by electrofusion of the lymphocytes following their exposure to these agents with mouse myeloma cells and incubation
of the fused hybridoma, a remarkable stimulatory effect was shown by LPS and particularly by LPS plus IL-4, which was substantially
greater than that of either SAC I or PWM with or without various IL. Optimization studies indicated that the addition of PWM
to LPS and IL-4 in the culture medium further stimulated the human antibody (Ab) production, and that the optimal formulation
for stimulations of human IgG production was a culture medium containing 20 μg/ml of LPS, 1/500 of PWM, and 100 u/ml of IL-4. 相似文献
116.
Parasitic specialization ofGeotrichum candidum citrus race, the causal agent of citrus sour rot, was investigated. Of seven isolates tested for pathogenecity, all could
infect ten species of citrus fruits and edible parts of five species of noncitrus crops. Only one isolate (Ap2), isolated
from soil of an apple orchard, could infect apple fruit. 相似文献
117.
Tomomi Hidaka Masao Goda Tomohisa Kuzuyama Naomi Takei Makoto Hidaka Haruo Seto 《Molecular & general genetics : MGG》1995,249(3):274-280
The biosynthetic pathway for production of the antibiotic fosfomycin by Streptomyces wedmorensis consists of four steps including the formation of a C-P bond and an epoxide. Fosfomycin production genes were cloned from genomic DNA using S. wedmorensis mutants blocked at different steps of the biosynthetic pathway. Four genes corresponding to each of the biosynthetic steps were found to be clustered in a DNA fragment of about 5 kb. Nucleotide sequencing of a large fragment revealed the presence of ten open reading frames, including the four biosynthetic genes and six genes with unknown functions. 相似文献
118.
119.
In vitro 5-day cultures of naive spleen cells with viable Listeria monocytogenes (VLM), but not heat-killed L. monocytogenes, induced CD4+ T cells that produced IFN-γ upon secondary antigen stimulation. The VLM-induced Listeria-specific T cells produced IFN-γ but lacked expression of IL-2 and IL-4. To study the role of IFN-γ in the induction of the IFN-γ-producing T cells, we added anti-IFN-γ mAb to the primary culture and analyzed IFN-γ production upon secondary antigen stimulation. Addition of anti-IFN-γ mAb to the culture suppressed generation of IFN-γ-producing CD4+ T cells, suggesting that IFN-γ is important in the induction of IFN-γ-producing CD4+ T cells. Furthermore, our results showed that depletion of NK cells from spleen cells by anti-asialo GM1 antibody plus complement before culture enhanced induction of IFN-γ-producing CD4+ T cells. Although NK cells are known to produce IFN-γ, the results indicate that NK cell-derived IFN-γ may not be important in induction of the Listeria-specific IFN-γ-producing CD4+ T cells in the culture system. In addition, we demonstrated that IFN-γ expression was high in CD4+ T cells from cultures of spleen cells with VLM at the primary culture level. These results suggest that IFN-γ derived from T cells may enhance production of IFN-γ by CD4+ T cells, while NK cells rather suppress the induction of IFN-γ-producing CD4+ T cells. 相似文献
120.
In Japan, the green seaweed Monostroma is an important source of humanfood. Monostroma nitidum Wittrock (Japanese name: hitoegusa)
is cultivated in brackish waters and estuaries of central to southern Japan. The green seaweed Monostroma grows in the brackish
water area in the upper part of the intertidal zone in the warm waters. Artificial seed culture began with the collection
of many gametes in April. The resultant zygotes were allowed to adhere to plastic settlement boards (20 cm long and 10 cm
wide). The zygoteboards were then cultured in tanks (1 ×2 ×0.5 m) with fertiliser in a controlled growth room (10–87 μmol
photon m-2s-1). The cultivated zygotes on the board in the indoor tanks gradually increased in size from 10 to 40 μm in diameter during
May to early August. Zygote growth became slowed at the end of August. The zygotesmatured in early September, and the plates
were transferred into culture tanks in a dark room for dark treatment. Maturation of the zygote was promoted by providing
dark conditions for two weeks. The production of a concentrated zoospore solution from the mature blades was achieved by adding
fresh water at temperature 2–3 °C above that of the seeding vats. Zoospores were released in large numbers when exposed to
strong irradiance of 100 μmol photon m-2 s-1 for 30 min. The zygotes produced flat unicellular fronds at the germling stage. The technology of artificial seed culture
and zoospore release from the zygotes is based mainly on these experiments.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献