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91.
Dimitry Nassonov 《Development genes and evolution》1924,103(3-4):437-482
Ohne Zusammenfassung 相似文献
92.
Mirza M Robinson P Kremneva E Copeland O Nikolaeva O Watkins H Levitsky D Redwood C El-Mezgueldi M Marston S 《The Journal of biological chemistry》2007,282(18):13487-13497
E40K and E54K mutations in alpha-tropomyosin cause inherited dilated cardiomyopathy. Previously we showed, using Ala-Ser alpha-tropomyosin (AS-alpha-Tm) expressed in Escherichia coli, that both mutations decrease Ca(2+) sensitivity. E40K also reduces V(max) of actin-Tm-activated S-1 ATPase by 18%. We investigated cooperative allosteric regulation by native Tm, AS-alpha-Tm, and the two dilated cardiomyopathy-causing mutants. AS-alpha-Tm has a lower cooperative unit size (6.5) than native alpha-tropomyosin (10.0). The E40K mutation reduced the size of the cooperative unit to 3.7, whereas E54K increased it to 8.0. For the equilibrium between On and Off states, the K(T) value was the same for all actin-Tm species; however, the K(T) value of actin-Tm-troponin at pCa 5 was 50% less for AS-alpha-Tm E40K than for AS-alpha-Tm and AS-alpha-Tm E54K. K(b), the "closed" to "blocked" equilibrium constant, was the same for all tropomyosin species. The E40K mutation reduced the affinity of tropomyosin for actin by 1.74-fold, but only when in the On state (in the presence of S-1). In contrast the E54K mutation reduced affinity by 3.5-fold only in the Off state. Differential scanning calorimetry measurements of AS-alpha-Tm showed that domain 3, assigned to the N terminus of tropomyosin, was strongly destabilized by both mutations. Additionally with AS-alpha-Tm E54K, we observed a unique new domain at 55 degrees C accounting for 25% of enthalpy indicating stabilization of part of the tropomyosin. The disease-causing mechanism of the E40K mutation may be accounted for by destabilization of the On state of the thin filaments; however, the E54K mutation has a more complex effect on tropomyosin structure and function. 相似文献
93.
Integrative systematics of northern and Arctic nudibranchs of the genus Dendronotus (Mollusca,Gastropoda), with descriptions of three new species 下载免费PDF全文
Irina Ekimova Tatiana Korshunova Dmitry Schepetov Tatiana Neretina Nadezhda Sanamyan Alexander Martynov 《Zoological Journal of the Linnean Society》2015,173(4):841-886
The taxonomy of common northern nudibranch molluscs of the genus Dendronotus in the vast cold regions of Eurasia remains largely unknown. Abundant material collected in many localities from the Barents Sea, via the Arctic region, to the north‐west Pacific was analysed for the first time. An integrated approach combining morphological and ontogenetic data with molecular four‐gene (COI, 16S, H3, and 28S) analysis reveals seven species, including three previously undescribed. Dendronotus frondosus (Ascanius, 1774) and Dendronotus dalli Bergh, 1879 were commonly considered as amphiboreal species; however, according to this study they are restricted to the North Atlantic and the North Pacific, respectively. In the north‐west Pacific two new species were discovered, D endronotus kamchaticus sp. nov. and D endronotus kalikal sp. nov. , that are externally similar to D. frondosus, but that show significant distance according to molecular analysis and are considerably different in radular morphology. In the North Atlantic a new species D endronotus niveus sp. nov. , sibling to North Pacific D. dalli, is revealed. The separate status of North Atlantic Dendronotus lacteus (Thompson, 1840) is confirmed, including considerable range extension. The essential similarity of early ontogenetic stages of radular development common for species with disparate adult radular morphology (such as D. frondosus and D. dalli) is shown, and its importance for taxonomy is discussed. © 2015 The Linnean Society of London 相似文献
94.
95.
Analysis of ammonia-oxidizing bacteria dominating in lab-scale bioreactors with high ammonium bicarbonate loading 总被引:1,自引:0,他引:1
Vejmelkova D Sorokin DY Abbas B Kovaleva OL Kleerebezem R Kampschreur MJ Muyzer G van Loosdrecht MC 《Applied microbiology and biotechnology》2012,93(1):401-410
The ammonia-oxidizing bacterial community (AOB) was investigated in two types of laboratory-scale bioreactors performing partial
oxidation of ammonia to nitrite or nitrate at high (80 mM) to extremely high (428 mM) concentrations of ammonium bicarbonate.
At all conditions, the dominant AOB was affiliated to the Nitrosomonas europaea lineage as was determined by fluorescence in situ hybridization and polymerase chain reaction in combination with denaturing
gradient gel electrophoresis. Molecular analysis of the mixed populations, based on the 16S rRNA and cbbL genes, demonstrated the presence of two different phylotypes of Nitrosomonas, while microbiological analysis produced a single phylotype, represented by three different morphotypes. One of the most
striking features of the AOB populations encountered in the bioreactors was the domination of highly aggregated obligate microaerophilic
Nitrosomonas, with unusual cellular and colony morphology, commonly observed in nitrifying bioreactors but rarely investigated by cultural
methods. The latter is probably not an adaptation to stressful conditions created by high ammonia or nitrite concentrations,
but oxygen seems to be a stressful factor in these bioreactors. 相似文献
96.
Nolla-Ardèvol V Strous M Sorokin DY Merkel AY Tegetmeyer HE 《Journal of biotechnology》2012,161(2):167-173
Methanogens are of biotechnological interest because of their importance in biogas production. Here we investigate the suitability of sediments from Central Asian soda lakes as inoculum for high pH methane-producing bioreactors. Methane production in these sediments was modest (up to 2.5 μmol mL sediment), with methanol and hydrogen as the preferred substrates. The responsible methanogenic community was characterized based on mcrA gene sequences. McrA gene sequences so far specific to these habitats indicated the presence of two clusters within the orders Methanobacteriales and Methanomicrobiales, one apparently including representatives of the genus Methanocalculus and another distantly related to the genus Methanobacterium. 相似文献
97.
Sorokin DY Zacharova EE Pimenov NV Tourova TP Panteleeva AN Muyzer G 《FEMS microbiology ecology》2012,79(2):445-453
The activity and culturable diversity of sulfidogens were investigated in anoxic sediments of four hypersaline lakes with pH 7.6-8.2 in the Kulunda Steppe (Altai, Russia). Sulfate reduction rates were low, varying from 0.1 to 6.0 nmol HS(-) /(cm(3) h) with a maximum in the top 10 cm layer. Potential sulfidogenic rates with thiosulfate and sulfur as the e-acceptors were higher than with sulfate and were stimulated by formate, lactate, and acetate. Sulfidogenesis was optimal at salt concentrations below 2 M NaCl. Cultivation at 2 M NaCl resulted in the isolation of several strains of moderately halophilic SRB, but no growth of SRB was observed at 4 M NaCl. At lithotrophic conditions (i.e., with formate or H(2) as e-donors), several closely related alkalitolerant strains belonging to the genus Desulfonatronovibrio were isolated. Enrichments at heterotrophic conditions with lactate, propionate, acetate, or butyrate using sulfate or thiosulfate as e-acceptors yielded isolates related to Desulfosalsimonas propionicica, Desulfohalobium utahense, and Desulfocella halophila. Sulfur-reducing enrichments at 2 M NaCl with ethanol produced a member of the genus Halanaerobium, while enrichments at 4 M NaCl with acetate were dominated by archaea, demonstrating for the first time such type of catabolism in haloarchaea. 相似文献
98.
99.
Ofengeim D Shi P Miao B Fan J Xia X Fan Y Lipinski MM Hashimoto T Polydoro M Yuan J Wong ST Degterev A 《The Journal of biological chemistry》2012,287(12):8714-8723
Multiple lines of evidence indicate a strong relationship between Αβ peptide-induced neurite degeneration and the progressive loss of cognitive functions in Alzheimer disease (AD) patients and in AD animal models. This prompted us to develop a high content screening assay (HCS) and Neurite Image Quantitator (NeuriteIQ) software to quantify the loss of neuronal projections induced by Aβ peptide neurons and enable us to identify new classes of neurite-protective small molecules, which may represent new leads for AD drug discovery. We identified thirty-six inhibitors of Aβ-induced neurite loss in the 1,040-compound National Institute of Neurological Disorders and Stroke (NINDS) custom collection of known bioactives and FDA approved drugs. Activity clustering showed that non-steroidal anti-inflammatory drugs (NSAIDs) were significantly enriched among the hits. Notably, NSAIDs have previously attracted significant attention as potential drugs for AD; however their mechanism of action remains controversial. Our data revealed that cyclooxygenase-2 (COX-2) expression was increased following Aβ treatment. Furthermore, multiple distinct classes of COX inhibitors efficiently blocked neurite loss in primary neurons, suggesting that increased COX activity contributes to Aβ peptide-induced neurite loss. Finally, we discovered that the detrimental effect of COX activity on neurite integrity may be mediated through the inhibition of peroxisome proliferator-activated receptor γ (PPARγ) activity. Overall, our work establishes the feasibility of identifying small molecule inhibitors of Aβ-induced neurite loss using the NeuriteIQ pipeline and provides novel insights into the mechanisms of neuroprotection by NSAIDs. 相似文献
100.
Knowledge of genetic variation and population structure of existing strains of both farmed and wild common carp Cyprinus carpio L. is absolutely necessary for any efficient fish management and/or conservation program. To assess genetic diversity in
common carp populations, a variety of molecular markers were analyzed. Of those, microsatellites and mitochondrial DNA were
most frequently used in the analysis of genetic diversity and genome evolution of common carp. Using microsatellites showed
that the genome evolution in common carp exhibited two waves of rearrangements: one whole-genome duplication (12–16 million
years ago) and a more recent wave of segmental duplications occurring between 2.3 and 6.8 million years ago. The genome duplication
event has resulted in tetraploidy since the common carp currently harbors a substantial portion of duplicated loci in its
genome and twice the number of chromosomes (n = 100–104) of most other cyprinid fishes. The variation in domesticated carp
populations is significantly less than that in wild populations, which probably arises from the loss of variation due to founder
effects and genetic drift. Genetic differentiation between the European carp C.c. carpio and Asian carp C.c. haematopterus is clearly evident. In Asia, two carp subspecies, C.c. haematopterus and C.c. varidivlaceus, seem to be also genetically distinct. 相似文献