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排序方式: 共有532条查询结果,搜索用时 281 毫秒
31.
32.
Krishnamurthy L Nadeau J Ozsoyoglu G Ozsoyoglu M Schaeffer G Tasan M Xu W 《Bioinformatics (Oxford, England)》2003,19(8):930-937
MOTIVATION: During the next phase of the Human Genome Project, research will focus on functional studies of attributing functions to genes, their regulatory elements, and other DNA sequences. To facilitate the use of genomic information in such studies, a new modeling perspective is needed to examine and study genome sequences in the context of many kinds of biological information. Pathways are the logical format for modeling and presenting such information in a manner that is familiar to biological researchers. RESULTS: In this paper we present an integrated system, called Pathways Database System, with a set of software tools for modeling, storing, analyzing, visualizing, and querying biological pathways data at different levels of genetic, molecular, biochemical and organismal detail. The novel features of the system include: (a) genomic information integrated with other biological data and presented from a pathway, rather than from the DNA sequence, perspective; (b) design for biologists who are possibly unfamiliar with genomics, but whose research is essential for annotating gene and genome sequences with biological functions; (c) database design, implementation and graphical tools which enable users to visualize pathways data in multiple abstraction levels, and to pose predetermined queries; and (d) an implementation that allows for web(XML)-based dissemination of query outputs (i.e. pathways data) to researchers in the community, giving them control on the use of pathways data. AVAILABILITY: Available on request from the authors. 相似文献
33.
Babu PS Krishnamurthy H Chedrese PJ Sairam MR 《The Journal of biological chemistry》2000,275(36):27615-27626
Follicle-stimulating hormone (FSH) regulated growth and function of the ovarian follicle was previously thought to be mediated solely through activation of G(s)-coupled receptors. In this study, we show for the first time that this function is predominantly mediated through the alternatively spliced and novel growth factor type 1 receptor (oFSH-R3) that is also present in the ovary. Immortalized granulosa cells lacking endogenous FSH receptors, when transfected with either oFSH-R3 cDNA (JC-R3) or the G(s)-coupled oFSH-R1 (JC-R1), expressed the corresponding glycosylated receptor. In JC-R3 or JC-R1 cells labeled with bromodeoxyuridine or [(3)H]thymidine, FSH stimulated the cells to progress through S-phase and divide. The growth promoting effect of recombinant FSH in JC-R3 cells was preceded by the rapid activation of ERK1 and ERK2. This effect was hormone-specific and transient. In JC-R3 cells inhibitors like calphostin C, PD98059, Ag 18, or calcium chelators EGTA or 1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/AM inhibited both mitogen-activated protein kinase activation and bromodeoxyuridine incorporation. FSH induced phosphorylation of the FSH-R3 receptor was blocked by pretreating cells with calphostin C. There was no cAMP induction by FSH in JC-R3 cells. The cAMP independent growth promoting effect of FSH is mediated by activation of Ca(2+) and mitogen-activated protein kinase-dependent pathways. Thus, alternative splicing of a G-protein coupled receptor creates the expression of a novel receptor motif that can mediate a widely recognized function of the glycoprotein hormone. 相似文献
34.
A cluster of genes for the biosynthesis of spinosyns, novel macrolide insect control agents produced by Saccharopolyspora spinosa 总被引:2,自引:0,他引:2
Waldron C Madduri K Crawford K Merlo DJ Treadway P Broughton MC Baltz RH 《Antonie van Leeuwenhoek》2000,78(3-4):385-390
Spinosyns A and D are the active ingredients in a family of insect control agents produced by fermentation of Saccharopolyspora spinosa. Spinosyns are 21–carbon tetracyclic lactones to which are attached two deoxysugars. Most of the genes involved in spinosyn biosynthesis are clustered in an 74 kb region of the S. spinosa genome. This region has been characterized by DNA sequence analysis and by targeted gene disruptions. The spinosyn biosynthetic gene cluster contains five large genes encoding a type I polyketide synthase, and 14 genes involved in modification of the macrolactone, or in the synthesis, modification and attachment of the deoxysugars. Four genes required for rhamnose biosynthesis (two of which are also required for forosamine biosynthesis) are not present in the cluster. A pathway for the biosynthesis of spinosyns is proposed. 相似文献
35.
It is a matter of controversy whether secondary wall deposition is dependent on lignification during the development of tracheary
elements. To understand this, tracheary element differentiation was studied in the homogeneous calli obtained from the cotyledonary
explants of Cucumis sativus subsequent to treatment with plant growth regulators, such as naphthalene acetic acid (NAA) and
benzylamino purine (BAP), which are necessary for the induction of tracheary elements, along with metabolic blockers such
as 2-aminoindan-2-phosphonic acid (AIP), 2,3,5-triiodobenzoic acid (TIBA) and nifedipine. Calli treated with AIP, a potential
inhibitor of L-phenylalanine ammonia-lyase (PAL), have no PAL activity at any time during the culture period. There was a
complete inhibition of lignification although secondary wall deposition was unaltered. Similar results were obtained using
TIBA, an inhibitor of auxin transport, and nifedipine, a known calcium channel blocker. Thus the present study suggests that
secondary wall deposition in the course of tracheary element differentiation need not to be dependent on lignification.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
36.
Changes in saccharide contents of tea leaves during infection with blister blight fungus Exobasidium vexans Masse was studied.
Saccharose and glucose contents decreased in the blistered portions when compared to the normal regions until sporulation
and remained constant during the entire period of sporulation. Fructose content increased abruptly during the initiation of
sporulation and remained constant up to the end of sporulation in both blistered and non-blistered regions. Starch content
continuously decreased in the blistered region. Peroxidase activity was highly enhanced during the final stages of leaf senescence.
The activity of acid invertase was inversely proportional to the starch content and closely related to the changes in the
saccharose and glucose contents. Protein and chlorophyll contents gradually decreased in the blistered regions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
37.
S. R. Thengane D. K. Kulkarni K. V. Krishnamurthy 《In vitro cellular & developmental biology. Plant》1998,34(4):331-334
Summary Apical and axillary buds ofGlycyrrhiza glabra commonly known as licorice, a plant of repute in the Indian system of medicine, were used for induction of adventitious shoots.
For induction of multiple shoots, Murashige and Skoog’s (MS) medium with N6-benzyladenine (BA, 0.88–8.87 μM) was used. Reduction in major salts of MS medium enhanced the multiplication ratio up to 1∶10. Plants transferred to the
greenhouse showed 90% survival. The present work describes a stepwise protocol for production ofGlycyrrhiza glabra plants on simple minimal media, where very high multiplication rates with healthy root systems were obtained. Roots being
the organ of commercial importance, the protocol has tremendous potential. 相似文献
38.
39.
Subhadeep Bhattacharjee Vinod Kumar Mithileshwari Chandrasekhar Manjari Malviya Andre Ganswindt Krishnamurthy Ramesh Kalyanasundaram Sankar Govindhaswamy Umapathy 《PloS one》2015,10(6)
Tiger (Panthera tigris), an endangered species, is under severe threat from poaching, habitat loss, prey depletion and habitat disturbance. Such factors have been reported causing local extermination of tiger populations including in one of the most important reserves in India, namely Sariska Tiger Reserve (STR) in northwestern India. Consequently, tigers were reintroduced in STR between 2008 and 2010, but inadequate breeding success was observed over the years, thus invoking an investigation to ascertain physiological correlates. In the present study, we report glucocorticoid stress responses of the reintroduced tigers in relation to anthropogenic disturbance in the STR from 2011 to 2013. We found anthropogenic disturbance such as encounter rates of livestock and humans, distance to roads and efforts to kill domestic livestock associated with an elevation in fecal glucocorticoid metabolite (fGCM) concentrations in the monitored tigers. In this regard, female tigers seem more sensitive to such disturbance than males. It was possible to discern that tiger’s fGCM levels were significantly positively related to the time spent in disturbed areas. Resulting management recommendations include relocation of villages from core areas and restriction of all anthropogenic activities in the entire STR. 相似文献
40.