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961.
Total and radiolabelled proteins from Pinus sylvestris roots, ectomycorrhiza and the ectomycorrhizal fungus Suillus bovinus , were analyzed after separation by 2‐D gel electrophoresis. The purpose was to address the contribution of individual proteins to the development of ectomycorrhiza. In Pinus sylvestris , ectomycorrhiza forms only in the short roots and therefore special attention was paid to the proteins of short roots before formation of ectomycorrhiza. A main result, from comparisons of protein amounts in main and lateral root tips and short roots, was that the specialized growth pattern of short roots is associated with the production of five short root‐specific proteins, and that several proteins of the main and lateral roots are repressed in short roots. At the morphologically different stages of the ectomycorrhiza, only few changes appeared in the amounts of the host and the symbiont proteins. Only one ectomycorrhiza‐specific protein could be distinguished. 相似文献
962.
HOWDY: an integrated database system for human genome research 总被引:1,自引:0,他引:1
Mika Hirakawa 《Nucleic acids research》2002,30(1):152-157
HOWDY is an integrated database system for accessing and analyzing human genomic information (http://www-alis.tokyo.jst.go.jp/HOWDY/). HOWDY stores information about relationships between genetic objects and the data extracted from a number of databases. HOWDY consists of an Internet accessible user interface that allows thorough searching of the human genomic databases using the gene symbols and their aliases. It also permits flexible editing of the sequence data. The database can be searched using simple words and the search can be restricted to a specific cytogenetic location. Linear maps displaying markers and genes on contig sequences are available, from which an object can be chosen. Any search starting point identifies all the information matching the query. HOWDY provides a convenient search environment of human genomic data for scientists unsure which database is most appropriate for their search. 相似文献
963.
Yafei Liu Wai Tuck Soh Jun-ichi Kishikawa Mika Hirose Emi E. Nakayama Songling Li Miwa Sasai Tatsuya Suzuki Asa Tada Akemi Arakawa Sumiko Matsuoka Kanako Akamatsu Makoto Matsuda Chikako Ono Shiho Torii Kazuki Kishida Hui Jin Wataru Nakai Hisashi Arase 《Cell》2021,184(13):3452-3466.e18
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964.
Single ion channel currents can only provide indirect information on channel molecular events (except for timing). In contrast, the electric displacement currents associated with channel gating, termed gating currents, can provide direct information regarding the channel molecule's conformational changes. However, thus far gating currents have been measured only from ensembles of numerous stochastically activated channels and therefore the information they provide is limited. This work presents, for the first time, measurements of gating currents from a single channel molecule. Averaging close to 8000 pre-open currents, aligned to the single channel opening time, enabled the detection of single channel gating currents with a resolution of 2 electron charges. The measured charge displacements show: 1) a slow component, approximately 2 fA above baseline level, assumed to represent stochastic conformational changes, and 2) transients, the most significant of which occur 1.1 and 0.3 ms before channel opening. The transients most likely represent apparent deterministic stages in the gating process. The largest transient current peak was 5.1 +/- 1.6 fA and the total equivalent charge transported across the membrane was 4.7 +/- 2.5 electron charges. This data is unique also in that it presents monitoring of the behavior of a single, well-defined macromolecule. 相似文献
965.
966.
Population structure of a threatened plant, Pulsatilla patens, in boreal forests: modelling relationships to overgrowth and site closure 总被引:2,自引:0,他引:2
Mika Kalliovirta Terhi Ryttäri Risto K. Heikkinen 《Biodiversity and Conservation》2006,15(9):3095-3108
Pulsatilla patens (L.) Mill. (Ranunculaceae) is a threatened plant which in Fennoscandia favours south-facing, warm slopes of pine-dominated
esker forests. The cessation of cattle grazing, modern forestry practices, and especially efficient fire prevention have resulted
in closure of undergrowth vegetation in these forests. Using generalized linear models (GLM), we studied the relationships
between habitat factors (covers of field and ground layer and amount of litter) and the population structure of P. patens in 48 populations in Finland in order to identify favourable conditions for regeneration. The largest populations occurred
at sites with intermediate values of both ground and field layer. The number of juvenile plants was also highest at intermediate
values of ground layer. Dense moss layer and abundant litter had a negative effect on the flowering of P. patens. In conclusion, creation and maintenance of habitat heterogeneity to prevent the closure of undergrowth vegetation is of
paramount importance for the successful reproduction of P. patens. 相似文献
967.
Simone A. Beckham Sarah E. Boyd Simone Reynolds Charlene Willis Masego Johnstone Angela Mika Pavla Simersk�� Lakshmi C. Wijeyewickrema A. Ian Smith David J. Kemp Robert N. Pike Katja Fischer 《The Journal of biological chemistry》2009,284(49):34413-34422
The scabies mite, Sarcoptes scabiei var. hominis, infests human skin, causing allergic reactions and facilitating bacterial infection by Streptococcus sp., with serious consequences such as rheumatic fever and rheumatic heart disease. To identify a possible drug target or vaccine candidate protein, we searched for homologues of the group 3 allergen of house dust mites, which we subsequently identified in a cDNA library. The native protein, designated Sar s 3, was shown to be present in the mite gut and excreted in fecal pellets into mite burrows within the upper epidermis. The substrate specificity of proteolytically active recombinant rSar s 3 was elucidated by screening a bacteriophage library. A preference for substrates containing a RS(G/A) sequence at the P1-P2′ positions was revealed. A series of peptides synthesized as internally quenched fluorescent substrates validated the phage display data and high performance liquid chromatography/mass spectrometry analysis of the preferred cleaved substrate and confirmed the predicted cleavage site. Searches of the human proteome using sequence data from the phage display allowed the in silico prediction of putative physiological substrates. Among these were numerous epidermal proteins, with filaggrin being a particularly likely candidate substrate. We showed that recombinant rSar s 3 cleaves human filaggrin in vitro and obtained immunohistological evidence that the filaggrin protein is ingested by the mite. This is the first report elucidating the substrate specificity of Sar s 3 and its potential role in scabies mite biology. 相似文献
968.
969.
The mechanisms that underlie the diversification of Neotropical primates remain contested. One mechanism that has found support is the riverine barrier hypothesis (RBH), which postulates that large rivers impede gene flow between populations on opposite riverbanks and promote allopatric speciation. Ayres and Clutton-Brock (1992) demonstrated that larger Amazonian rivers acted as barriers, delineating the distribution limits of primate species. However, profound changes in taxonomy and species concepts have led to the proliferation of Neotropical primate taxa, which may have reduced support for their results. Using the most recent taxonomic assessments and distribution maps, we tested the effect of increasing river size on the similarity of opposite riverbank primate communities in the Amazon. First, we conducted a literature review of primate taxonomy and developed a comprehensive spatial database, then applied geographical information system to query mapped primate ranges against the riverine geography of the Amazon watershed to produce a similarity index for opposite riverbank communities. Finally, we ran models to test how measures of river size predicted levels of similarity. We found that, almost without exception, similarity scores were lower than scores from Ayres and Clutton-Brock (1992) for the same rivers. Our model showed a significant negative relationship between streamflow and similarity in all tests, and found river width significant for the segmented Amazon, but not for multiple Amazon watershed rivers. Our results support the RBH insofar as they provide evidence for the prediction that rivers with higher streamflow act as more substantial barriers to dispersal, and accordingly exhibit greater variation in community composition between riverbanks. 相似文献
970.
Obese visceral adipose tissue remodeling and dysfunction, based on chronic inflammation and local immunological changes, play
major roles in the metabolic syndrome. Therefore, an in vivo visualization technique has been developed to assess the dynamic
interplay between multiple cell types in obese adipose. In vivo imaging revealed close spatial and temporal interrelationships
between angiogenesis and adipogenesis, which were augmented in obese adipose tissue. In addition, increased leukocyte–platelet–endothelial
cell interactions were observed in the microcirculation, a hallmark of inflammation. Upregulated expression of adhesion molecules
contribute to the local activation of inflammatory processes. We also found that large numbers of CD8+ effector T cells infiltrated
into the obese adipose tissue, playing major roles in inflammatory macrophage infiltration into obese adipose tissue, the
induction and maintenance of inflammation, and systemic insulin resistance. Our results demonstrate the power of our imaging
technique to analyze multi-cellular interactions in inflammation in vivo and to evaluate new therapeutic interventions. 相似文献