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1.
This paper describes a novel approach to study the expression of temperature-related reproductive phenomena such as thermolabile sex determination (TSD) and heat-induced germ cell loss in wild fish populations. The proposed approach is based on the reconstruction of the past thermal history of individual fish through the microchemical analysis of the otoliths (mineralized structures responsible for the sense of balance). As an example, we outline the preliminary results of an investigation on the natural occurrence of TSD in pejerrey Odontesthes bonariensis, an atherinid fish in which all-female to all-male populations can be produced by experimental manipulation of the rearing temperature during the critical time of sex differentiation, from Lake Kasumigaura, Japan. 相似文献
2.
Sugita S Ootsubo T Kadono T Honda M Sako S Miyata T Sakon I Yamashita T Kawakita H Fujiwara H Fujiyoshi T Takato N Fuse T Watanabe J Furusho R Hasegawa S Kasuga T Sekiguchi T Kinoshita D Meech KJ Wooden DH Ip WH A'Hearn MF 《Science (New York, N.Y.)》2005,310(5746):274-278
The impact cratering process on a comet is controversial but holds the key for interpreting observations of the Deep Impact collision with comet 9P/Tempel 1. Mid-infrared data from the Cooled Mid-Infrared Camera and Spectrometer (COMICS) of the Subaru Telescope indicate that the large-scale dust plume ejected by the impact contained a large mass (approximately 10(6) kilograms) of dust and formed two wings approximately +/-45 degrees from the symmetric center, both consistent with gravity as the primary control on the impact and its immediate aftermath. The dust distribution in the inner part of the plume, however, is inconsistent with a pure gravity control and implies that evaporation and expansion of volatiles accelerated dust. 相似文献
3.
大豆皂甙具有多种药理作用,而对大豆制品中各类皂甙的定量分析是研究大豆皂甙药理作用的基础.采用高效液相色谱-差示折光(HPLC-dRI)检测法测定单糖链大豆皂甙的含量.色谱条件为:ODS-AM-303色谱柱(YMC,4.6 mm×250 mm,5μm),柱温40℃,合0.1%三氟乙酸的乙腈-水(40:60)为流动相,流速1mL min-1.Ba、Bb、Bd、Be、αg和βg分别在2.24～11.2、2.35～11.8、1.58～7.92、2.01～10.1、1.38～6.88和1.62～8.12μg范围内线性关系良好,平均回收率分别为92.5%、93.8%、94.1%、95.8%、93.4%和94.2%,RSD为3.22%、3.18%、4.01%、3.53%、4.07%和4.28%.该方法准确度高,重现性好,适用于大豆皂甙样品中各类皂甙的测定. 相似文献
4.
Summary The intergenic spacer region 1 (IGS1) of the nuclear ribosomal RNA gene repeat was examined in three European intersterility groups of the wood‐rot fungus Heterobasidion annosum. The IGS1 elements were informative for restriction fragment length polymorphism (RFLP) fingerprinting the fungal intersterility groups following digestion with two different four‐cutter restriction endonucleases. The fingerprints of isolates from the same intersterility group from different localities shared some fragments in common, but also showed specific fragments suggesting that RFLP of the IGS1 region might be used in population studies. RFLP patterns between isolates from different intersterility groups differed more markedly. RFLP were also detected in the IGS1 region of North American strains of H. annosum and in the related species Heterobasidion araucariae. The results indicate that ribosomal IGS1 region fingerprinting could be a useful tool to identify the fungal intersterility group in Heterobasidion annosum. 相似文献
5.
Feiyun ZHANG Shigemitsu TORIYAMA Mami TAKAHASHI 《Journal of General Plant Pathology》2001,67(1):63-68
The genome of Ryegrass mottle virus (RGMoV) comprises 4210 nucleotides. The genomic RNA contains four open reading frames (ORFs). The largest ORF 2 encodes a
polyprotein of 947 amino acids (103.6 kDa), which codes for a serine protease and an RNA-dependent RNA polymerase. The viral
coat protein is encoded on ORF 4 present at the 3′-proximal region. Other ORFs 1 and 3 encode the predicted 14.6 kDa and 19.8
kDa proteins of unknown function. The consensus signal for frameshifting, heptanucleotide UUUAAAC and a stem-loop structure
just downstream is in front of the AUG codon of ORF 3. Analysis of the in vitro translation products of RGMoV RNA suggests that the 68 kDa protein may represent a fusion protein of ORF 2-ORF 3 produced
by frameshifting. The protease region of the polyprotein and coat protein have a low similarity with that of the sobemoviruses
(approximately 25% amino acid identity), while the RNA-dependent RNA polymerase region has particularly strong similarity
(54 to 60% of more than 350 amino acid residues). The sequence similarities of RGMoV to the sobemoviruses, together with the
characteristic genome organization indicate that RGMoV is a new species of the genus Sobemovirus.
Received 28 June 2000/ Accepted in revised form 14 November 2000 相似文献
6.
Hosoi Y Ando Y Arakawa M Kasuga K Kojima I Kobayashi M 《The Journal of reproduction and development》2011,57(5):650-654
Fibroblast growth factor 4 (FGF4) promotes isolation of trophoblast stem (TS) cells from mouse blastocysts and maintenance of TS cells in an undifferentiated state in vitro. To date, commercially available, bacterially expressed human FGF4 (RhFGF4) has been used generally for this purpose. In this study, HismFGF4, a 6x histidine-tagged mouse FGF4, was produced in E. coli and purified using heparin column chromatography. We demonstrated that HismFGF4 (25 ng/ml) more efficiently generates mouse TS cells from a single blastocyst than RhFGF4 (25 ng/ml) and that TS cells isolated and maintained with HismFGF4 retained their ability to differentiate into the trophoblast cell lineage in vitro. In addition, TS cells cultured with HismFGF4 (25 ng/ml) were maintained in an undifferentiated state better than with RhFGF4 (25 ng/ml). To the best of our knowledge, this is the first application of a mouse FGF4 derivative for isolation and maintenance of mouse TS cells. 相似文献
7.
Shigemitsu Kimura Susumu Tokumaru Kazuhiko Kuge 《Journal of General Plant Pathology》2008,74(4):275-280
Many fusiform ascospores observed on soybean seeds with yeast spot disease symptoms differed significantly from those of Eremothecium coryli, the known causal agent of yeast spot disease in soybean. On the basis of morphological and physiological characteristics
and sequence data of the internal transcribed spacer regions including the 5.8S rDNA and D1/D2 regions of 26S rDNA, this fungus
was identified as E. ashbyi. Pathogenicity of E. ashbyi was confirmed by reinoculation test. This report is the report on E. ashbyi causing soybean yeast spot disease. In addition, this study showed that E. ashbyi was transmitted by the stink bug, Riptortus clavatus, as was E. coryli, the two Eremothecium yeasts may have been acquired when the stink bug fed on infected soybeans and overwintered in this insect species.
The nucleotide sequence data reported are available in the GeneBank/EMBL/DDBJ database as accessions AB294407 to AB294412
for E. ashbyi EA1, EA7 and EA11. 相似文献
8.
Detection of Fusarium oxysporum f.sp. vasinfectum in cotton tissue by polymerase chain reaction 总被引：2，自引：0，他引：2
A polymerase chain reaction assay was developed for the detection of Fusarium oxysporum f.sp. vasinfectum (FOV), a serious wilt pathogen of cotton in many parts of the world. Based on small nucleotide differences in internal transcribed spacer sequences between 18S, 5.8S and 28S ribosomal DNAs, primers Fov1 (5'-CCCCTGTGAACATACCTTACT-3') and Fov 2 (5'-ACCAGTAACGAGGGTTTTACT-3') were selected. These primers unambiguously amplified a 400-bp DNA fragment of all the FOV isolates tested (from Angola, Brazil, China and the USA) but did not amplify any other isolates of mycoflora associated with cotton, such as F. moniliforme , Verticillium albo-atrum , V. dahliae , Aspergillus sp., F. oxysporum , F. sambucinum or F. solani . A control PCR assay was developed employing the universal primer pair ITS1 and ITS2 which amplified a fragment of approximately 220 bp from all isolates tested. This control assay demonstrated that all fungal DNAs were readily amplifiable, thus confirming that the lack of amplification with Fov1 and Fov2 primers was a result of primer specificity and not of other possible causes, such as DNA degradation or the presence of PCR inhibitors. The assay was effective on samples from the stems, leaves, roots and calli, and from plant tissues both with and without symptoms. This detection system proved to be accurate and sensitive and could aid not only diagnosis but also disease monitoring and forecasting. 相似文献
9.
Beer bran was found to effectively adsorb several organic compounds, such as dichloromethane, chloroform, trichloroethylene, benzene, pretilachlor, and esprocarb. Equilibrium adsorption isotherms conformed to the Freundlich isotherm (log-log linear). Adsorption of these organic compounds by beer bran was observed in the pH range of 1-11. At equilibrium, the adsorption efficiency of beer bran for benzene, chloroform, and dichiloromethane was higher than that of activated carbon. The removal of these organic compounds by beer bran was attributed to the uptake by intracellular particles called spherosomes. The object of this work was to investigate several adsorbents for the effective removal of organic compounds from wastewater. 相似文献
10.
The hybrid vigor typical of F1 cultivars is used to boost biomass production of sorghum (Sorghum bicolor (L.) Moench). The high dry-matter yielding F1 cultivar Kazetachi uniquely shows extremely late flowering and a long culm, and is greatly different from its parents. We investigated the genetic mechanisms underlying these phenotypes by quantitative trait locus (QTL) analysis of recombinant inbred lines derived from a male-fertile line and a restorer line and grown in 3 years. QTL analysis for six traits (days-to-heading, culm length, culm width, culm number, panicle length, panicle number) revealed that the unique phenotypes of the F1 plants were controlled by the genetic combination of 12 or more QTLs detected in at least 2 years. Two putative QTLs for days-to-heading (qDH1 on SBI-01 and qDH6 on SBI-06) would strongly affect the other phenotypes because of their co-localization with QTLs for other traits, as supported by significant phenotypic correlations. These QTLs would be useful for understanding the association of plant type with biomass production in sorghum. 相似文献