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排序方式: 共有476条查询结果,搜索用时 15 毫秒
91.
The period (per) locus has received much attention in molecular evolution
studies because it is one of the best studied "behavioral genes" and
because it offers insight into the evolution of repetitive sequences. We
studied most of the coding region of per in Drosophila willistoni and
confirmed previously observed patterns of conservation and divergence among
distantly related species. Five regions are so highly diverged that they
cannot be aligned, whereas a region encompassing the PAS domain is very
conserved. Structural and nucleotide polymorphism patterns in the
willistoni group are not the same as those observed in previously studied
species. We sequenced the region homologous to the highly polymorphic
threonine-glycine repeat of D. melanogaster in multiple strains of D.
willistoni, as well as in other members of willistoni group, and found an
unusual amount of conservation in this region. However, the next
nonconserved region downstream in the sequence is quite variable and
polymorphic for the number of repeated glycines. The glycine codon usage is
significantly different in this glycine repeat as compared to other parts
of the gene. We were able to plot the directionality of change in the
glycine repeat region onto a phylogeny and find that the addition of
glycines is the general trend with the diversification of the willistoni
group.
相似文献
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93.
Organic farming is a more environmentally friendly form of land use than conventional agriculture. However, recent studies point out production tradeoffs that often prevent the adoption of such practices by farmers. Our study shows with the example of organic banana production in Ecuador that economic tradeoffs depend much on the approach of the analysis. We test, if organic banana should be included in economic land-use portfolios, which indicate how much of the land is provided for which type of land-use. We use time series data for productivity and prices over 30 years to compute the economic return (as annualized net present value) and its volatility (with standard deviation as risk measure) for eight crops to derive land-use portfolios for different levels of risk, which maximize economic return. We find that organic banana is included in land-use portfolios for almost every level of accepted risk with proportions from 1% to maximally 32%, even if the same high uncertainty as for conventional banana is simulated for organic banana. A more realistic, lower simulated price risk increased the proportion of organic banana substantially to up to 57% and increased annual economic returns by up to US$ 187 per ha. Under an assumed integration of both markets, for organic and conventional banana, simulated by an increased coefficient of correlation of economic return from organic and conventional banana (ρ up to +0.7), organic banana holds significant portions in the land-use portfolios tested only, if a low price risk of organic banana is considered. We conclude that uncertainty is a key issue for the adoption of organic banana. As historic data support a low price risk for organic banana compared to conventional banana, Ecuadorian farmers should consider organic banana as an advantageous land-use option in their land-use portfolios. 相似文献
94.
Nagamura Y Antonio BA Sato Y Miyao A Namiki N Yonemaru J Minami H Kamatsuki K Shimura K Shimizu Y Hirochika H 《Plant & cell physiology》2011,52(2):230-237
The Rice TOGO Browser is an online public resource designed to facilitate integration and visualization of mapping data of bacterial artificial chromosome (BAC)/P1-derived artificial chromosome (PAC) clones, genes, restriction fragment length polymorphism (RFLP)/simple sequence repeat (SSR) markers and phenotype data represented as quantitative trait loci (QTLs) onto the genome sequence, and to provide a platform for more efficient utilization of genome information from the point of view of applied genomics as well as functional genomics. Three search options, namely keyword search, region search and trait search, generate various types of data in a user-friendly interface with three distinct viewers, a chromosome viewer, an integrated map viewer and a sequence viewer, thereby providing the opportunity to view the position of genes and/or QTLs at the chromosomal level and to retrieve any sequence information in a user-defined genome region. Furthermore, the gene list, marker list and genome sequence in a specified region delineated by RFLP/SSR markers and any sequences designed as primers can be viewed and downloaded to support forward genetics approaches. An additional feature of this database is the graphical viewer for BLAST search to reveal information not only for regions with significant sequence similarity but also for regions adjacent to those with similarity but with no hits between sequences. An easy to use and intuitive user interface can help a wide range of users in retrieving integrated mapping information including agronomically important traits on the rice genome sequence. The database can be accessed at http://agri-trait.dna.affrc.go.jp/. 相似文献
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Analysis of growth and division often involves measurements made on cell populations, which tend to average data. The value
of single cell analysis needs to be appreciated, and models based on findings from single cells should be taken into greater
consideration in our understanding of the way in which cell size and division are co-ordinated. Examples are given of some
single cell analyses in mammalian cells, yeast and other microorganisms. There is also a short discussion on how far the results
are in accord with simple models. 相似文献
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Pinheiro C Sousa B Albergaria A Paredes J Dufloth R Vieira D Schmitt F Baltazar F 《Histology and histopathology》2011,26(10):1279-1286
The goal of the present work was to evaluate the correlation of glucose transporter 1 (GLUT1) and carbonic anhydrase IX (CAIX) with the monocarboxylate transporters 1 (MCT1) and 4 (MCT4) and their chaperone, CD147, in breast cancer. The clinico-pathological value of GLUT1 and CAIX was also evaluated. For that, we analysed the immunohistochemical expression of GLUT1 and CAIX, in a large series of invasive breast carcinoma samples (n=124), previously characterized for MCT1, MCT4 and CD147 expression. GLUT1 expression was found in 46% of the cases (57/124), while CAIX was found in 18% of the cases (22/122). Importantly, both MCT1 and CD147, but not MCT4, were associated with GLUT1 and CAIX expression. Also, GLUT1 and CAIX correlated with each other. Concerning the clinico-pathological values, GLUT1 was associated with high grade tumours, basal-like subtype, absence of progesterone receptor, presence of vimentin and high proliferative index as measured by Ki-67. Additionally, CAIX was associated with large tumour size, high histological grade, basal-like subtype, absence of estrogen and progesterone receptors and presence of basal cytokeratins and vimentin expression. Finally, patients with CAIX positive tumours had a significantly shorter disease-free survival. The association between MCT1 and both GLUT1 and CAIX may result from hypoxia-mediated metabolic adaptations, which confer a glycolytic, acid-resistant and more aggressive phenotype to cancer cells. 相似文献
100.
de Oliveira AT Pinheiro C Longatto-Filho A Brito MJ Martinho O Matos D Carvalho AL Vazquez VL Silva TB Scapulatempo C Saad SS Reis RM Baltazar F 《Journal of bioenergetics and biomembranes》2012,44(1):171-178
Monocarboxylate transporters (MCTs) have been described to play an important role in cancer, but to date there are no reports on the significance of MCT expression in gastrointestinal stromal tumors (GISTs). The aim of the present work was to assess the value of MCT expression, as well as co-expression with the MCT chaperone CD147 in GISTs and evaluate their clinical-pathological significance. We analyzed the immunohistochemical expression of MCT1, MCT2, MCT4 and CD147 in a series of 64 GISTs molecularly characterized for KIT, PDGFRA and BRAF mutations. MCT1, MCT2 and MCT4 were highly expressed in GISTs. CD147 expression was associated with mutated KIT (p?=?0.039), as well as a progressive increase in Fletcher's Risk of Malignancy (p?=?0.020). Importantly, co-expression of MCT1 with CD147 was associated with low patient's overall survival (p?=?0.037). These findings suggest that co-expression of MCT1 with its chaperone CD147 is involved in GISTs aggressiveness, pointing to a contribution of cancer cell metabolic adaptations in GIST development and/or progression. 相似文献