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排序方式: 共有119条查询结果,搜索用时 296 毫秒
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Takashi Sayama Tae-Young Hwang Kunihiko Komatsu Yoshitake Takada Masakazu Takahashi Shin Kato Hiroko Sasama Ayako Higashi Yumi Nakamoto Hideyuki Funatsuki Masao Ishimoto 《DNA research》2011,18(2):107-115
Among commonly applied molecular markers, simple sequence repeats (SSRs, or microsatellites) possess advantages such as a high level of polymorphism and codominant pattern of inheritance at individual loci. To facilitate systematic and rapid genetic mapping in soybean, we designed a genotyping panel comprised 304 SSR markers selected for allelic diversity and chromosomal location so as to provide wide coverage. Most primer pairs for the markers in the panel were redesigned to yield amplicons of 80–600 bp in multiplex polymerase chain reaction (PCR) and fluorescence-based sequencer analysis, and they were labelled with one of four different fluorescent dyes. Multiplex PCR with sets of six to eight primer pairs per reaction generated allelic data for 283 of the 304 SSR loci in three different mapping populations, with the loci mapping to the same positions as previously determined. Four SSRs on each chromosome were analysed for allelic diversity in 87 diverse soybean germplasms with four-plex PCR. These 80 loci showed an average allele number and polymorphic information content value of 14.8 and 0.78, respectively. The high level of polymorphism, ease of analysis, and high accuracy of the SSR genotyping panel should render it widely applicable to soybean genetics and breeding. 相似文献
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1. Although in recent years there have been a number of studies demonstrating trophic cascades in terrestrial systems, it is still unclear what environmental conditions enable or enhance such cascades, especially among four trophic levels. 2. In this study, the influence of environmental stress (increased soil pore water salinity) on a four trophic level study system in a Florida salt marsh was examined by experimentally increasing soil pore water salinity. Effects of increased salinity on the quality of the host plant, Batis maritima, were assessed, as were resulting effects on the lepidopteran herbivore Ascia monuste, and the primary parasitoids and hyperparasitoids of its caterpillars. 3. Increased salinity altered host‐plant quality, which subsequently affected the consumer species. These effects of altered plant quality cascaded up through the herbivore and primary parasitoid to the hyperparasitoid Hypopteromalus inimicus, influencing its density, sex ratio, body size, and initial egg load. 4. These results demonstrate how heterogeneity in environmental stress can result in effects that cascade up through four trophic levels. We suggest that such strong effects at higher trophic levels may be more likely in systems in which relationships are more specific and intimate such as those among hosts, parasitoids, and hyperparasitoids. 相似文献
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MOON THOMAS W.; MUSTAFA TARIQ; HOCHACHKA PETER W. 《Integrative and comparative biology》1971,11(3):491-502
SYNOPSIS. Pyruvate kinase (PK) maximum catalytic rate is dramaticallydecelerated by increasing hydrostatic pressure. In four differentspecies inhabiting different portions of the water column, musclepyruvate kinase displays (1) a reduction in the volume changeof activation, V*. a t higher temperatures, (2) a pH independenceof V*, and (3) a general increase in the activation energy atincreased pressures. Although shared by the four different pyruvatekinases examined, none of these characteristics is criticallyinvolved in the regulation of PK catalysis. In contrast, pressureeffects on another set of characteristics, all vitally importantto control of PK catalytic function, depend upon the speciesorigin of the enzyme. In the case of the rainbow trout, Salmogairdneri, high pressure dramatically reduces pyruvate kinaseaffinities for the two substrates (PEP and ADP), the cationiccofactor (Mg2+), and the negative modulator (ATP). The homologousmuscle enzyme from Oligoplites mundus, another surface dwellingspecies, displays similar responses to pressure. On the otherhand, muscle PK affinities for the same key regulatory ligandsare much less pressure sensitive in the abyssal rattail fishes(Coryphaenoides sp.) and are essentially pressure independentin a vertically migrating midwater sea bass, Ectreposebastesimus. In these latter two species, PK catalytic rates underprobable physiological conditions are determined largely bythese kinetic properties rather than by energy-volume parameters. 相似文献
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HOCHACHKA PETER W.; SCHNEIDER DAVID E.; MOON THOMAS W. 《Integrative and comparative biology》1971,11(3):479-490
SYNOPSIS. At low temperature (3°C), in the absence of substrateand cofactor, trout liver fructose diphosphatase (FDPase) isinactivated by exposures to relatively low pressures. FDP andMg2+ protect against this inactivation; hence, maximum catalysisat pH 7.5 is pressure insensitive, while at more alkaline pH,it is markedly accelerated by pressure. The volume change ofactivation, V*, at saturating FDP and Mg2+ concentrations isabout 40 cm3/mole. The apparent Km for FDP and the Kafor Mg2+ are markedly increased by pressure. At low FDP or Mg2+levels these kinetic properties outweigh V* in determining thereaction rate; hence, under these conditions, piessure retardscatalysis. Similarly, the K4 for AMP is notably pressure sensitive.Comparable effects of pressure on the kinetic constants forliver FDPase from benthic Corypliaenoides are much less pronounced,suggesting that in these off-shore species enzyme-substrate,enzyme-cofactor, and enzyme-modulator interactions have beentailored through evolution for pressure independent catalyticfunction. 相似文献
6.
Hyun-Ju Kim Cheol-Su Park Siwon Lee Tae-Young Ahn 《Journal of microbiology (Seoul, Korea)》2014,52(7):554-558
A novel bacterial strain, designated PFS-5T, was isolated from the soil environment with feces of a live poultry farm located in Cheonan, Republic of Korea. Strain PFS-5T was Gram-staining-positive, motile, strictly aerobic bacterium, rod-shaped, and endospore-forming. The strain contained meso-diaminopimelic acid in their peptidoglycan and MK-7 menaquinone. The major fatty acids were anteiso-C15:0 (44.2%), C16:0 (22.2%), and iso-C15:0 (16.7%). The DNA G+C content was 40.1 mol%. Comparative 16S rRNA gene sequence analysis identified strain PFS-5T in the genus Bacillus, exhibiting the highest level of sequence similarity with type strain of B. herbersteinensis D-1,5aT (96.9%), B. humi LMG 22167T (96.7%), B. alkalitelluris BA288T (96.1%), B. litoralis SW-211T (96.0%), and B. luteolus YIM93174T (95.5%). The major polar lipids of PFS-5T were diphosphatidylglycerol and phosphatidylglycerol. On the basis of result from poly-phasic data, strain PFS-5T represents a novel species, for which the name Bacillus cheonanensis sp. nov. is proposed (Type strai PFS-5T = KACC 17469T = JCM19333T). 相似文献
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DONG‐SEOK KIM SOOK‐YOUNG KIM SEONG‐JOON MOON JIN‐HO CHUNG KYU‐HAN KIM KWANG‐HYUN CHO KYOUNG‐CHAN PARK 《Pigment cell & melanoma research》2001,14(2):110-115
Ceramide is a bioactive sphingolipid that mediates a variety of cell functions. However, the effects of ceramide on cell growth and the melanogenesis of melanocytes are not known. In the present study, we investigated the actions of cell‐permeable ceramide and its possible role in the signaling pathway of a spontaneously immortalized mouse melanocyte cell line, Mel‐Ab. Our results show that C2‐ceramide inhibits DNA synthesis in Mel‐Ab cells and G361 human melanoma cells in a dose‐dependent manner. Cell cycle analysis confirmed the inhibition of DNA synthesis by a reduction in the S phase. To investigate the ceramide signaling pathway, we studied whether C2‐ceramide is able to influence extracellular signal‐regulated kinase (ERK) and/or Akt/protein kinase B (PKB) activation. We demonstrated that phosphorylated Akt/PKB is decreased by C2‐ceramide, whereas phosphorylated ERK was only slightly affected. Therefore, the C2‐ceramide‐induced inactivation of Akt/PKB may be closely related to the reduced cell proliferation of Mel‐Ab cells. Furthermore, we assessed the effects of C2‐ceramide on the pigmentation of Mel‐Ab cells. The results obtained showed that the melanin content of cells was significantly reduced by C2‐ceramide at concentrations in the range of 1–10 μM, and that the pigmentation‐inhibiting effect of C2‐ceramide is much greater than that of kojic acid at 1–100 μM. In addition, we found that the activity of tyrosinase is reduced by C2‐ceramide treatment. Our results demonstrate that C2‐ceramide reduces the pigmentation of Mel‐Ab cells by inhibiting tyrosinase activity. 相似文献
9.
ANTHONY M. ROSSI MELISSA MURRAY KELLY HUGHES MARTIN KOTOWSKI DANIEL C. MOON PETER STILING 《Ecological Entomology》2006,31(6):557-563
Abstract 1. Immature stages of the gall midge, Asphondylia borrichiae, are attacked by four species of parasitoids, which vary in size and relative abundance within patches of the gall midge’s primary host plant, sea oxeye daisy (Borrichia frutescens). 2. In the current study, a bagging experiment found that the smallest wasp, Galeopsomyia haemon, was most abundant in galls exposed to natural enemies early in the experiment, when gall diameter is smallest, while the wasp with the longest ovipositor, Torymus umbilicatus, dominated the parasitoid community in galls that were not exposed until the 5th and 6th weeks when gall diameter is maximal. 3. Moreover, the mean number of parasitoids captured using large artificial galls were 70% and 150% higher compared with medium and small galls respectively, while stem height of artificial galls significantly affected parasitoid distribution. Galls that were level with the top of the sea oxeye canopy captured 60% more parasitoids compared with those below the canopy and 50% more than galls higher than the plant canopy. 4. These non‐random patterns were driven primarily by the differential distribution of the largest parasitoid, T. umbilicatus, which was found significantly more often than expected on large galls and the smallest parasitoid of the guild, G. haemon, which tended to be more common on stems level with the top of the plant canopy. 5. Large Asphondylia galls, especially those located near the top of the Borrichia canopy, were more likely to be discovered by searching parasitoids. Results using artificial galls were consistent with rates of parasitism of Asphondylia galls in native patches of sea oxeye daisy. Gall diameter was 19% greater and the rate of parasitism was reduced by almost 50% on short stems; as a result, gall abundance was 24% higher on short stems compared with ones located near the top of the plant canopy. 6. These results suggest that parasitoid community composition within galls is regulated by both interspecific differences in ovipositor length and preferences for specific gall size and/or stem length classes. 相似文献
10.
ABSTRACT Central nervous system (CNS) of arachnids is still mysterious and has a rich unexplored field compare to what is known in insects or crustaceans. The CNS of the spider, Achaearanea tepidariorum, consists of a dorsal brain or supraesophageal ganglion and circumesophageal connectives joining it to the subesophageal mass. As the segmentation of the arachnid brain is still under discussion, we classify the brain as a protocerebral and tritocerebral ganglion depending on the evidences which generally accepted. The subesophageal nerve mass underneath the brain is the foremost part of the ventral nerve cord. All of this nerve mass is totally fused together, and forming subesophageal ganglia in this spider. In the brain, the nerve cells are packed in the frontal, dorsal and lateral areas, but are not absent from the posterior and ventral regions. In addition, the nerve cells of the subesophageal and abdominal ganglia are only restricted to the ventral and ventolateral regions. The CNS of the spider, Achaearanea tepidariorum is similar in feature to the Family Araneidae. 相似文献