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921.
Local adaptation and ecological genetics of host-plant specialization in a leaf beetle 总被引:4,自引:0,他引:4
The tendency of insect species to evolve specialization to one or a few plant species is probably a major reason for the remarkable diversity of herbivorous insects. The suggested explanations for this general trend toward specialization include a range of evolutionary mechanisms, whose relative importance is debated. Here we address two potentially important mechanisms: (i) how variation in the geographic distribution of host use may lead to the evolution of local adaptation and specialization; (ii) how selection for specialization may lead to the evolution of trade‐offs in performance between different hosts. We performed a quantitative genetic experiment of larval performance in three different populations of the alpine leaf beetle Oreina elongata reared on two of its main host plants. Due to differences in host availability, each population represents a distinctly different selective regime in terms of host use including selection for specialization on one or the other host as well as selection for utilizing both hosts during the larval stage. The results suggest that selection for specialization has lead to some degree of local adaptations in host use: both single‐host population had higher larval growth rate on their respective native host plant genus, while there was no difference between plant treatments in the two‐host population. However, differences between host plant treatments within populations were generally small and the degree of local adaptation in performance traits seems to be relatively limited. Genetic correlations in performance traits between the hosts ranged from zero in the two‐host population to significantly positive in the single‐host populations. This suggests that selection for specialization in single host populations typically also increased performance on the alternative host that is not naturally encountered. Moreover, the lack of a positive genetic correlation in the two host‐population give support for the hypothesis that performance trade‐offs between two host plants may typically evolve when a population have adapted to both these plants. We conclude that although there is selection for specialization in larval performance traits it seems as if the genetic architecture of these traits have limited the divergence between populations in relative performance on the two hosts. 相似文献
922.
Detection of the Free-Living Forms of Sulfide-Oxidizing Gill Endosymbionts in the Lucinid Habitat (Thalassia testudinum Environment)
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Olivier Gros Martine Liberge Abdelaziz Heddi Chaqu Khatchadourian Horst Felbeck 《Applied microbiology》2003,69(10):6264-6267
Target DNA from the uncultivable Codakia orbicularis endosymbiont was PCR amplified from sea-grass sediment. To confirm that such amplifications originated from intact bacterial cells rather than free DNA, whole-cell hybridization (fluorescence in situ hybridization technique) with the specific probe Symco2 was performed along with experimental infection of aposymbiotic juveniles placed in contact with the same sediment. Taken together, the data demonstrate that the sulfide-oxidizing gill endosymbiont of Codakia orbicularis is present in the environment as a free-living uncultivable form. 相似文献
923.
924.
Lin Wei Marc Freichel Martine Jaspers Harry Cuppens Jean-Jacques Cassiman Guy Droogmans Veit Flockerzi Bernd Nilius 《BMC physiology》2001,1(1):3-8
Background
This study describes the functional interaction between the putative Ca2+ channel TRP4 and the cystic fibrosis transmembrane conductance regulator, CFTR, in mouse aorta endothelium (MAEC). 相似文献925.
Carolyn Roitsch Tilman Achstetter Miloud Benchaibi Edwige Bonfils Gilles Cauet Remi Gloeckler Herve Lhte Elisabeth Keppi Martine Nguyen Daniele Spehner Alain Van Dorsselaer Daniel Malarme 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2001,752(2):263-280
Highly purified recombinant adenovirus undergoes routine quality controls for identity, potency and purity prior to its use as a gene therapy vector. Quantitative characterization of infectivity is measurable by the expression of the DNA binding protein, an early adenoviral protein, in an immunofluorescence bioassay on permissive cells as a potency determinant. The specific particle count, a key quality indicator, is the total number of intact particles present compared to the number of infectious units. Electron microscopic analysis using negative staining gives a qualitative biophysical analysis of the particles eluted from anion-exchange HPLC. One purity assessment is accomplished via the documented presence and relative ratios of component adenoviral proteins as well as potential contaminants by reversed-phase HPLC of the intact virus followed by protein peak identification using MALDI-TOF mass spectrometry and subsequent data mining. Verification of the viral genome is performed and expression of the transgene is evaluated in in vitro systems for identity. Production lots are also evaluated for replication-competent adenovirus prior to human use. For adenovirus carrying the human IL-2 transgene, quantitative IL-2 expression is demonstrated by ELISA and cytokine potency by cytotoxic T lymphocyte assay following infection of permissive cells. Both quantitative and qualitative analyses show good batch to batch reproducibility under routine test conditions using validated methods. 相似文献
926.
Aurel Pui Ioan Berdan Ir ne Morgenstern-Badarau Aurore Gref Martine Perr e-Fauvet 《Inorganica chimica acta》2001,320(1-2):167-171
The synthesis and characterization of some new complexes with tetradentate Schiff bases derived from bis(salicylaldehyde)etylenediimine, H2Salen are reported in this paper. The Co(II) Schiff bases complexes investigated are: (bis(5-nitro-salicylaldehyde) ethylenediiminato)cobalt(II), (CoNSalen); (bis(-ethyl-salicylaldehyde) ethylenediiminato)cobalt(II) (CoEtSalen); (bis(-ethyl-3,5-diiode-salicylaldehyde) ethylenediiminato) cobalt(II),(CoDIEtSalen); (bis(,5-dimethyl-3-iode-salicylaldehyde)ethylenediiminato)cobalt(II) (CoDMISalen) and (bis(salicylaldehyde)methylene-p,p′-diphenylene)cobalt(II), (CoSalmbfn). The characterization of the complexes was performed by elemental analysis, UV–Vis, FTIR spectroscopy, powder X-ray diffraction and cyclic voltammetry. Pyridine (py), present in the solution of complexes in DMF, coordinates to the metal ion in axial position, inducing a significant decrease of the redox potentials. Significant influences have the substituents grafted on ligands’ molecules. The separated complexes evince catalytic activity in the oxidation reaction of 2,6-di-t-butylphenol with molecular oxygen. These complexes seem capable of forming reversible adducts with molecular oxygen. 相似文献
927.
Long-Range 1H-15N Heteronuclear Shift Correlation at Natural Abundance: a Tool To Study Benzothiazole Biodegradation by Two Rhodococcus Strains
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Pascale Besse Bruno Combourieu Gaëlle Boyse Martine Sancelme Heleen De Wever Anne-Marie Delort 《Applied microbiology》2001,67(4):1412-1417
The biodegradation of benzothiazole and 2-hydroxybenzothiazole by two strains of Rhodococcus was monitored by reversed phase high-pressure liquid chromatography and by 1H nuclear magnetic resonance (NMR). Both xenobiotics were biotransformed into a hydroxylated derivative of 2-hydroxybenzothiazole by these two strains. The chemical structure of this metabolite was determined by a new NMR methodology: long-range 1H-15N heteronuclear shift correlation without any previous 15N enrichment of the compound. This powerful NMR tool allowed us to assign the metabolite structure to 2,6-dihydroxybenzothiazole. 相似文献
928.
Temmerman L Dermaut LR De Mil M Van Maele G Beele H De Pauw GA 《Cell and tissue banking》2008,9(1):11-18
Cryopreservation of teeth before autotransplantation may create new possibilities in dentistry. The purpose of this study
was to examine the effect of a standardised cryopreservation procedure on human periodontal ligament (PDL) cell cultures.
Human PDL fibroblasts obtained from immature third molars of 11 patients were cultured and divided into two groups. The experimental
group was cryopreserved and cultured after thawing. The control group was cultured without cryopreservation. A comparison
was made between cryopreserved and control cells. To evaluate possible differences in the characteristics of the fibroblasts,
the cells in both groups were tested for viability (membrane integrity), growth capacity and alkaline phosphatase (ALP) expression.
The Wilcoxon test for paired comparison between cryopreserved and non-cryopreserved cells was performed for each characteristic.
The results showed that membrane integrity of cells was not influenced by cryopreservation. There was no statistically significant
difference in growth capacity between cryopreserved and control cells. Non-cryopreserved cells were slightly stronger positive
for ALP, but the difference was not statistically significant. From these experiments it can be concluded that the observed
parameters are not influenced by cryopreservation. 相似文献
929.
930.
Baud S Guyon V Kronenberger J Wuillème S Miquel M Caboche M Lepiniec L Rochat C 《The Plant journal : for cell and molecular biology》2003,33(1):75-86
Acetyl-CoA carboxylase (ACCase) catalyses the carboxylation of acetyl-CoA, forming malonyl-CoA, which is used in the plastid for fatty acid synthesis and in the cytosol in various biosynthetic pathways including fatty acid elongation. In Arabidopsis thaliana, ACC1 and ACC2, two genes located in a tandem repeat within a 25-kbp genomic region near the centromere of chromosome 1, encode two multifunctional ACCase isoforms. Both genes, ACC1 and ACC2, appear to be ubiquitously expressed, but little is known about their respective function and importance. Here, we report the isolation and characterisation of two allelic mutants disrupted in the ACC1 gene. Both acc1-1 and acc1-2 mutations are recessive and embryo lethal. Embryo morphogenesis is impaired and both alleles lead to cucumber-like structures lacking in cotyledons, while the shortened hypocotyl and root exhibit a normal radial pattern organisation of the body axis. In this abnormal embryo, the maturation process still occurs. Storage proteins accumulate normally, while triacylglycerides (TAG) are synthesised at a lower concentration than in the wild-type seed. However, these TAG are totally devoid of very long chain fatty acids (VLCFA) and consequently enriched in C18:1, like all lipid fractions analysed in the mutant seed. These data demonstrate, in planta, the role of ACCase 1 in VLCFA elongation. Furthermore, this multifunctional enzyme also plays an unexpected and central function in embryo morphogenesis, especially in apical meristem development. 相似文献