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111.
Rco-3, a Gene Involved in Glucose Transport and Conidiation in Neurospora Crassa 总被引:2,自引:0,他引:2
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Macroconidiation in Neurospora crassa is influenced by a number of environmental cues, including the nutritional status of the growing organism. Conidia formation is normally observed when the fungus is exposed to air. However, carbon limitation can induce conidiation in mycelia submerged in an aerated liquid medium. A mutant was previously isolated that could conidiate in submerged culture without imposing nutrient limitation and the gene responsible for this phenotype (rco-3) has now been cloned. RCO3 exhibits sequence similarity to members of the sugar transporter gene superfamily, with greatest similarity to glucose transporters of yeast. Consistent with this structural similarity, we find that glucose transport activity is altered in the mutant. However, growth of the mutant in media containing alternate carbon sources does not suppress conidiation in submerged culture. The properties of the mutant suggest that RCO3 is required for expression of glucose transport activity, glucose regulation of gene expression, and general carbon repression of development. 相似文献
112.
Carbohydrate and the cytokine response to 2.5h of running 总被引:10,自引:0,他引:10
Nehlsen-Cannarella S. L.; Fagoaga O. R.; Nieman D. C.; Henson D. A.; Butterworth D. E.; Schmitt R. L.; Bailey E. M.; Warren B. J.; Utter A.; Davis J. M. 《Journal of applied physiology》1997,82(5):1662-1667
Nehlsen-Cannarella, S. L., O. R. Fagoaga, D. C. Nieman, D. A. Henson, D. E. Butterworth, R. L. Schmitt, E. M. Bailey, B. J. Warren, A. Utter, and J. M. Davis. Carbohydrate and the cytokineresponse to 2.5 h of running. J. Appl.Physiol. 82(5): 1662-1667, 1997.This randomized,double-blind, placebo-controlled study was designed to determine theinfluence of 6% carbohydrate (C) vs. placebo (P) beverage ingestion oncytokine responses (5 total samples over 9 h) to 2.5 h ofhigh-intensity running (76.7 ± 0.4% maximalO2 uptake) by 30 experiencedmarathon runners. For interleukin-6 (IL-6), a difference in the patternof change between groups was found, highlighted by a greater increasein P vs. C immediately postrun (753 vs. 421%) and 1.5 h postrun (193 vs. 86%) [F(4,112) = 3.77, P = 0.006]. Forinterleukin-1-receptor antagonist (IL-1ra), a difference in the patternof change between groups was found, highlighted by a greater increasein P vs. C 1.5 h postrun (231 vs. 72%)[F(2,50) = 6.38, P = 0.003]. No significant interaction effects were seen for bioactive IL-6 or IL-1. The immediate postrun plasma glucose concentrations correlated negatively with those of plasma cortisol (r = 0.67, P < 0.001); postrun plasma cortisol (r = 0.70, P < 0.001) and IL-6 levels(r = 0.54, P = 0.003) correlated positively withlevels of IL-1ra. Taken together, the data indicate that carbohydrateingestion attenuates cytokine levels in the inflammatory cascade inresponse to heavy exertion. 相似文献
113.
A highly conserved nuclear gene for low-level phylogenetics: elongation factor-1 alpha recovers morphology-based tree for heliothine moths 总被引:8,自引:2,他引:6
Cho S; Mitchell A; Regier JC; Mitter C; Poole RW; Friedlander TP; Zhao S 《Molecular biology and evolution》1995,12(4):650-656
Molecular systematists need increased access to nuclear genes. Highly
conserved, low copy number protein-encoding nuclear genes have attractive
features for phylogenetic inference but have heretofore been applied mostly
to very ancient divergences. By virtue of their synonymous substitutions,
such genes should contain a wealth of information about lower-level
taxonomic relationships as well, with the advantage that amino acid
conservatism makes both alignment and primer definition straightforward. We
tested this postulate for the elongation factor-1 alpha (EF-1 alpha) gene
in the noctuid moth subfamily Heliothinae, which has probably diversified
since the middle Tertiary. We sequenced 1,240 bp in 18 taxa representing
heliothine groupings strongly supported by previous morphological and
allozyme studies. The single most parsimonious gene tree and the
neighbor-joining tree for all nucleotides show almost complete concordance
with the morphological tree. Homoplasy and pairwise divergence levels are
low, transition/transversion ratios are high, and phylogenetic information
is spread evenly across gene regions. The EF-1 alpha gene and presumably
other highly conserved genes hold much promise for phylogenetics of
Tertiary age eukaryote groups.
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114.
Identification of the signalling molecules involved in mesoderm formation in amphibian embryos still presents problems. None of the original candidates, such as activin, have been definitively ruled out, and the new factors, such as the nodal-related genes, have come on to the scene. Of the original candidates, activin has been definitively shown to act as a morphogen, whereas bone morphogenetic protein (BMP)-4 has emerged as a ventral inducer and an inhibitor of neural differentiation. The effects of BMP-4 are antagonized by chordin, a molecule related to the product of the Drosophila gene short gastrulation. 相似文献
115.
M Bailey S Lloyd S C Martin E J Soulsby 《Zeitschrift für Parasitenkunde (Berlin, Germany)》1984,70(2):229-242
Proliferation in vitro of peripheral blood lymphocytes both from horses infected with Strongylus vulgaris and from helminth-free ponies was observed in the presence of extracts of the fourth and fifth stage larvae and adults of S. vulgaris. In addition, S. vulgaris extracts induced transformation in cultures of peripheral blood lymphocytes from sheep and dogs and in mouse spleen cell cultures. Nylon wool non-adherent, T cell enriched fractions of lymphocytes from both mice and horses were stimulated by the S. vulgaris larval mitogen while no proliferation was observed in cultures containing nylon wool adherent, B cell enriched fractions. Macrophage co-operation appeared not to be necessary for S. vulgaris mitogen-induced transformation of spleen cells. The S. vulgaris mitogen stimulated a subpopulation of mouse spleen cells different from those responsive to PHA, Con A and LPS. These cells might be T helper cells since B cells were stimulated to proliferate in the presence of both T cells and S. vulgaris larval mitogen. In addition, the supernatant of in vitro cultured larvae of S. vulgaris induced slight, but significant transformation of equine peripheral blood lymphocytes. Therefore, it is possible that the S. vulgaris mitogen released by both viable parasites and degenerating larvae might induce T cell dependent production of immunoglobulin in vivo and account for the beta-globulinaemia, of which IgG(T) is a major component, in S vulgaris infected horses. 相似文献
116.
Susan J. Dugmore Keith Bailey Charles S. Evans 《International journal of primatology》1984,5(3):235-245
Olfaction plays an important role in the social communication of all prosimians. (The experiment reported in this paper forms
part of an intensive chemobehavioral study of olfaction in Lemur catta (ring-tailed lemur) being carried out in this laboratory.) Five male Lemur cattawere tested on their behavioral responses to paired scent stimuli. Responses measured were (1) total investigation time, (2)
arm-marking, (3) ABO/BO rubbing, and (4) flehmen. Males showed a strong discrimination between the scent stimuli,giving higher levels of response to female scent on measures 1, 3, and 4. This response suggests an olfactory-related preference
by males for female scent under controlled conditions. This preference may be a consequence of the females’ dominance over
males and the brevity of estrus in L. catta,both of which would favor such choice behavior. 相似文献
117.
A mathematical model based on the molecular control mechanisms for lambda dv plasmid replication in a single Escherichia coli cell has been applied to simulate replication of mutant lambda dv plasmids. Model simulations of changes in repressor level and copy number resulting from mutations in the promoter-operator PROR region are consistent with experimental data. Calculated effects on lambda dv plasmid copy number of oligomer formation and of alternations in termination efficiency at tR1 also agree with experiment. The model has been employed to simulate the influence of cro mutants and of cro and tR1 double mutants on copy number and stable maintenance of lambda dv plasmid copy number. The genetic structure included in formulation of the replicon model provides a framework for relating changes in specific genetic loci on the plasmid with resulting alterations in host-plasmid system function. 相似文献
118.
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120.
Identification of lipopolysaccharides and phospholipids of Escherichia coli in polyacrylamide gels.
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Polyacrylamide gel electrophoresis of unfractionated lysates of radioactively labeled cells resolves not only proteins and polynucleotides into discrete bands but also cellular lipopolysaccharides and phospholipids. This allows a determination of the intracellular amounts of all of these macromolecules. In addition, this technique is sensitive enough to detect mutational alterations in lipopolysaccharide structure. Polyacrylamide gel electrophoresis is herein shown to be a useful tool for investigations into the structure of lipopolysaccharides and the synthesis of lipopolysaccharides and phospholipids. 相似文献