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1.
AYAKO TANAKA YOSHIYUKI KUGA YOSHIAKI TANAKA SHIN G. GOTO HIDEHARU NUMATA SAKIKO SHIGA 《Physiological Entomology》2013,38(3):192-201
Quantities of ecdysteroid are compared in the haemolymph and ovaries of the blowfly Protophormia terraenovae Robineau‐Desvoidy (Diptera: Calliphoridae) under reproductive (LD 18 : 6 h at 25 °C) and diapause (LD 12 : 12 h at 20 °C) conditions. The effects of ablation of the pars intercerebralis or ovaries on ecdysteroid quantities and of ablation of the pars intercerebralis on yolk protein expression are examined. Under reproductive conditions, the levels of ecdysteroid in vitellogenic females are high, although the levels in previtellogenic females and females with mature ovaries are low. Under diapause conditions, there are low quantities of ecdysteroid in both the haemolymph and ovaries. Ecdysteroid titres in the haemolymph are not significantly affected by the removal of the ovaries, suggesting that tissues other than the ovaries are also involved in the production of ecdysteroids. Reproductive females in which the pars intercerebralis of the brain is experimentally ablated have ecdysteroid levels that are not significantly different from sham‐operated or intact females. However, yolk protein expression in the fat body is suppressed after removal of the pars intercerebralis. These results suggest that the suppression of ecdysteroid levels in the haemolymph and ovaries is associated with reproductive diapause, and that the pars intercerebralis could play a role in yolk protein synthesis without mediating ecdysteroid production. 相似文献
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Goro?HANYAEmail author Miki?MATSUBARA Hideki?SUGIURA Sachiko?HAYAKAWA Shunji?GOTO Toshiaki?TANAKA Joseph?SOLTIS Naohiko?NOMA 《Ecological Research》2004,19(2):179-188
The mass mortality of wild Japanese macaques (Macaca fuscata Blyth) was observed in a warm temperate forest of Yakushima, southern Japan. Demographic changes of eight troops between August 1998 and August 1999 were studied and 56% of macaques disappeared from the five intensively studied troops. Mortality varied among troops: two troops became extinct, while another troop did not decrease in size. The rate of mortality of the other troops was between 33 and 80%. The variation in mortality among the troops was either the outcome of local concentrations of mortality or of intertroop competition. The rate of mortality decreased with increasing distance from the two extinct troops and with increasing troop size; these two factors could not be separated statistically. The direct cause of death was diagnosed as pneumonia for four out of five fresh carcasses. The fleshy fruit production in autumn 1998 was the lowest in 14years, and macaques had relied on leaves earlier than in usual years. It was exceptionally hot and dry in the summer of 1998. The exceptionally poor fruit production and hot summer of this year, with the resulting shortage of high-quality foods, was consistent with the scenario that mass mortality was due to the poor nutritional conditions. However, the possibility that epidemics caused the mass mortality cannot be ruled out. Our findings proved that primates in a seemingly stable habitat experience fluctuations in demographic parameters under natural conditions. 相似文献
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YUKI TOKUDA TOMOKO IKENO SHIN G. GOTO HIDEHARU NUMATA YOICHI EZAKI 《Biological journal of the Linnean Society. Linnean Society of London》2010,101(1):184-192
Sessile organisms are influenced considerably by their substrate conditions, and their adaptive strategies are key to understanding their morphologic evolution and traits of life history. The family Flabellidae (Cnidaria: Scleractinia) is composed of the representative azooxanthellate solitary corals that live on both soft and hard substrates using various adaptive strategies. We reconstructed the phylogenetic tree and ancestral character states of this family from the mitochondrial 16S and nuclear 28S ribosomal DNA sequences of ten flabellids aiming to infer the evolution of their adaptive strategies. The Javania lineage branched off first and adapted to hard substrates by using a tectura‐reinforced base. The extant free‐living flabellids, including Flabellum and Truncatoflabellum, invaded soft substrates and acquired the flabellate corallum morphology of their common ancestor, followed by a remarkable radiation with the exploitation of adaptive strategies, such as external soft tissue [e.g. Flabellum (Ulocyathus)], thecal edge spine, and transverse division (e.g. Placotrochus and Truncatoflabellum). Subsequently, the free‐living ancestors of two genera (Rhizotrochus and Monomyces) invaded hard substrates independently by exploiting distinct attachment apparatuses such as tube‐like and massive rootlets, respectively. In conclusion, flabellids developed various morphology and life‐history traits according to the differences in substrate conditions during the course of their evolution. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 184–192. 相似文献
4.
Kazuo GOTO Eri KUWAYAMA Ryoko NOZU Masami UENO Nobuhito HAYASHIMOTO 《Experimental Animals》2015,64(2):191-197
In this study, hypochlorous acid solution, a weak acid, provided as drinking water to
rats, was evaluated for its ability to eradicate and prevent Pseudomonas
aeruginosa infection, while monitoring its simultaneous effect on serum
biochemical variables and microbiota in the rat cecum. The results suggest that the
solution could not eliminate the bacteria in the experimentally infected rats; however,
the administration of a 10-parts-per-million (ppm) hypochlorous acid solution as drinking
water was effective in inhibiting horizontal spread of P. aeruginosa
infection among cage mates. Additionally, exposure to hypochlorous solution did not have
any effect on serum biochemical variables of the rat including levels of total
cholesterol, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline
phosphatase (ALP), albumin, total bilirubin, lipase, amylase, urea nitrogen, total
protein, calcium (Ca), phosphorus (P), sodium (Na), chlorine (Cl), except for potassium
(K) levels. The most frequently isolated bacteria in the rat cecum included species
belonging to Bacteroidales, Lactobacillus,
Clostridiales, Erysipelotrichaceae,
Akkermansia, Coriobacteriales, and
Firmicutes. The ratio of the terminal restriction fragment length
polymorphism (T-RFLP) peaks did not differ across rats administered with 5 and 10 ppm weak
acid solution as compared to the control group for any of the bacteria, except for
Erysipelotrichaceae and Firmicutes, where the ratio of
T-RFLP peaks was higher in the 5 ppm group for Erysipelotrichaceae and in
the 10 ppm group for Firmicutes than that in the control group
(P<0.01). The results suggest that the weak acid hypochlorous
solution could not eradicate P. aeruginosa completely from rats. The
solution was effective in preventing infection without affecting serum biochemical
variables; however, some of bacterial microbiota may have changed due to administration of
the solution. 相似文献
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We developed eight polymorphic microsatellite markers from the Sachalin fir (Abies sachalinensis Masters). The number of alleles per locus ranged from eight to 31, with an average of 21.4. The observed and expected heterozygosities ranged from 0.656 to 0.937 and from 0.710 to 0.945, respectively. These markers will be available for population genetic studies and parentage analysis. 相似文献
8.
Dwarfism in bean plants (Phaseolus vulgaris L.) is investigated in relation to the diffusible and extractable gibberel-lins in cotyledonary tissues. These gibberellins were partitioned into four parts prior to thin layer chromatograplty: non-acidic and acidic ethyl acetate fractions, and non-acidic and acidic butanol fractions. Cotyledonary segments from a tall plant (cv. Kentucky Wonder) seem to diffuse, preferentially acropetally, more gibberellins in each fraction than those from a dwarf plant (cv. Masterpiece). The diffusion increases with the length of the segments and decreases with period after sowing. From experiments on extraetable gibberellins, however, it is concluded that these phenomena actually result from differences in the gibbereliin contents of the tall and the dwarf plants, from differences in the gibberellin contents of the distal and proximal parts of cotyledons, and from the gibberellin contents before and after imbibition. Ten kinds of gibberellin-Iike substances are detectable in the diffusates, exudates and extracts from the cotyledons of both the plants; two in the non-acidic ethyl acetate, three in the acidic ethyl acetate (GA1, GA6 and another), two in the non-acidic butanol, and three in the acidic butanol frac—tion. They are almost identical in quality in the dwarf and tall plants, but in the latter they are more abundant in the cotyledons, particularly in their distal part. With respect to the change in content during the period after sowing, the gibberellin-Iike substances are classified in three groups; unchanging, decreasing (GA1, GA6, others) and increasing (butanol soluble glucosyl esters and glucosides of gibberellins)-. The increase of glucose-bound gibberellins and the decrease of free gibberellins during the sowing period suggest the occurrence of conversion. This is obvious only in the tall plants. The gibberellin content in cotyledons is higher in the tall plant than in the dwarf plant. Thus, the marked hypocotyl growth in the tall plants may be dependent on the higher content of gibberellins in their cotyledons and on the higner rate of conversion from free to bound forms. 相似文献
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- Phyllosinol is a phytotoxic metabolite of Phyllosticta sp. Thissubstance at 100 µg/ml produced dark grey necrotic lesionson the leaf of red clover. Sensitivities of various plant speciesto phyllosinol differed both quantitatively and qualitatively.
- Phyllosinol reduced root growth in rice seedlings by 60% at104 M, whereas stimulation of root elongation occurredat a concentration range from 109 to 105 M.
- Phyllosinolat 2.5x104M promoted adventitious root formationin epicotylsof Azukia cuttings by about 100%. Promotion waspartly reducedby simultaneous application of cysteine.
- IAA-induced elongationof isolated Avena coleoptile sectionswas inhibited by phyllosinolat a concentration range from 105to 103M.
- Sulfhydrylcompounds, i.e. cysteine and glutathione relievedinhibitioncaused by phyllosinol in IAA-induced elongation ofAvena coleoptilesections.
- GA3-induced elongation of wheat leaf sections wasslightly inhibitedby phyllosinol at 104M.
- Phyllosinolalso has antibiotic activity. Among the organismstested, Phycomycetesand Gram-negative bacteria appeared mostsusceptible to phyllosinol.
10.
SHIN G. GOTO 《Physiological Entomology》2009,34(1):46-51
Abstract A variant of the flesh fly Sarcophaga similis, which does not enter pupal diapause even under diapause‐inducing conditions, is established by artificial selection. Interline crosses of the wild‐type and the variant revealed that the diapause capability is inherited in an incomplete dominant manner. Neither sex linkage nor a maternal factor is involved in the mode of inheritance. Genetic and genetic–environmental interactions are involved in the induction of diapause. In the wild‐type, the post‐feeding larval period is prolonged in response to short days. However, in the variant, the duration of the larval period under short‐day conditions is identical to that under long‐day conditions. Long‐day responses under short‐day conditions at both the larval and pupal stages in the variant indicate that the responses are established by common factors in both stages. The factors causing the long‐day responses under short‐day conditions at different developmental stages in the variant remain to be identified. However, it is plausible to hypothesize that common factors regulate ecdysteroid release at both the larval and pupal stages, and that malfunction of the system regulating these factors triggers such ecdysteroid release, irrespective of the photoperiod. Hence, the photoperiodic responses disappear in the variant in both stages. The adult stage of the variant has a functional circadian clock, suggesting that the nondiapause phenotype is not necessarily involved in malfunction of the circadian clock. 相似文献