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991.
Cumaceans are a diverse order of small, benthic marine crustaceans. Phylogenetic hypotheses for the eight currently recognized cumacean families have not been formally proposed. However, based on external morphological traits and Linnean classification, a few conflicting hypotheses of relatedness have been proposed. Family definitions rely on morphological characters that often overlap and diagnoses are based on a combination of non-unique characters. Morphological analysis does not provide a well-resolved phylogeny. In the present study, we use amino acid sequences from the mitochondrial cytochrome oxidase I gene to produce a molecular phylogenetic hypothesis for the families of Cumacea. Phylogenetic analyses at the amino acid level were performed under Bayesian, likelihood, and parsimony methods. Results strongly suggest that families lacking an articulated telson form a monophyletic group. This pleotelson clade, composed of the families Bodotriidae, Leuconidae, and Nannastacidae, is the most derived within the Cumacea. Within this group, the Bodotriidae resolve paraphyletically, with Leuconidae and Nannastacidae embedded within it. Comparison of the molecular phylogeny with that based on morphology suggests that many "diagnostic" characters are homoplasious. 相似文献
992.
Baroja-Mazo A del Valle P Rúa J de Cima S Busto F de Arriaga D Smirnoff N 《Fungal genetics and biology : FG & B》2005,42(5):390-402
D-Erythroascorbate and D-erythroascorbate glucoside have been identified in the Zygomycete fungus Phycomyces blakesleeanus. Ascomycete and Basidiomycete fungi also synthesise D-erythroascorbate instead of l-ascorbate, suggesting that D-erythroascorbate synthesis evolved in the common ancestor of the fungi. Both compounds accumulate in P. blakesleeanus at higher levels than observed in other fungal species. D-Erythroascorbate glucoside reduced dichlorophenolindophenol as effectively as L-ascorbate, but was more stable to autoxidation. D-Erythroascorbate glucoside predominated in spores and stationary phase mycelium. Free D-erythroascorbate accumulated during the exponential phase of mycelial growth and decreased to very low levels in the stationary phase. This suggests an association between growth and free D-erythroascorbate. P. blakesleeanus converted exogenous D-arabinose to D-erythroascorbate and its glucoside. A monomeric NAD-dependent D-arabinose dehydrogenase of 41 kDa was purified to near homogeneity. The enzyme oxidised D-arabinose, L-galactose, and L-fucose. Correspondingly, mycelium converted exogenous L-galactose and L-fucose to L-ascorbate and 6-deoxyascorbate, respectively. The antioxidant role of D-erythroascorbate and its glucoside is discussed. 相似文献
993.
The lipolytic system of Bacillus megaterium 370 was investigated, showing the existence of at least two secreted lipases and a cell-bound esterase. A gene coding for an extracellular lipase was isolated and cloned in Escherichia coli. The cloned enzyme displayed high activity on short to medium chain length (C(4)-C(8)) substrates, and poor activity on C(18) substrates. On the basis of amino acid sequence homology, the cloned lipase was classified into subfamily I.4 of bacterial lipases. 相似文献
994.
Testosterone (T) plays an important role in developing brain, dictating sex-specific behavior and physiology. 3α,5α-Reduced neurosteroids also regulate reproductive behavior. The key enzyme in the biosynthesis of these neurosteroids is 5α-reductase (5α-R), expressed as two isozymes, 5α-R1 and 5α-R2. In this study, T and sesame oil (vehicle) were administered during postnatal sexual differentiation of the central nervous system (CNS) and mRNA levels of 5α-R isozymes, were measured using quantitative RT-PCR in prefrontal cortex of male and female rats with different androgenic status at adulthood. Our results indicate that T concentrations during postnatal sexual differentiation of the rat CNS, among other sex-dependent factors, influence brain levels of 5α-R isozymes in adulthood and the pattern of their regulation by androgen hormones. 相似文献
995.
Erik JM Toonen Pilar Barrera Jaap Fransen Arjan PM de Brouwer Agnes M Eijsbouts Pierre Miossec Hubert Marotte Hans Scheffer Piet LCM van Riel Barbara Franke Marieke JH Coenen 《Arthritis research & therapy》2012,14(6):R264
Introduction
The goal of this study is to investigate whether the -308G > A promoter polymorphism in the tumor necrosis factor alpha (TNFA) gene is associated with disease severity and radiologic joint damage in a large cohort of patients with rheumatoid arthritis (RA).Methods
A long-term observational early RA inception cohort (n = 208) with detailed information about disease activity and radiologic damage after 3, 6 and 9 years of disease was genotyped for the TNFA -308G > A promoter polymorphism (rs1800629). A longitudinal regression analysis was performed to assess the effect of genotype on RA disease severity and joint damage. Subsequently, a meta-analysis, including all publically available data, was performed to further test the association between joint erosions and the TNFA polymorphism. To learn more about the mechanism behind the effect of the polymorphism, RNA isolated from peripheral blood from RA patients (n = 66) was used for TNFA gene expression analysis by quantitative PCR.Results
Longitudinal regression analysis with correction for gender and disease activity showed a significant difference in total joint damage between GG and GA+AA genotype groups (P = 0.002), which was stable over time. The meta-analysis, which included 2,053 patients, confirmed an association of the genetic variant with the development of erosions (odds ratio 0.78, 95% CI 0.62, 0.98). No significant differences in TNFA gene expression were observed for the different genotypes, confirming earlier findings in healthy individuals.Conclusions
Our data confirm that the TNFA -308G > A promoter polymorphism is associated with joint damage in patients with RA. This is not mediated by differences in TNFA gene expression between genotypes. 相似文献996.
997.
We examined the potential implication of skeletal muscle in the fat-lowering effect observed in mice treated with moderate doses of CLA. In experiment 1, mice fed with a standard-fat diet were orally treated with sunflower oil (control) and 3 or 10 mg CLA mixture/day for 37 days. In experiment 2, mice were fed with a high-fat diet for 65 days. For the first 30 days, they received the same doses as in experiment 1 and, from that time onwards, animals received double doses. Gene expression of key proteins involved in fatty acid transport, oxidation, regulation of lipid and carbohydrate utilization, composition of muscle fiber, and thermogenesis were determined and, in most of them, no major impact of CLA was seen. Therefore, enhancement of fatty acid oxidation in muscle did not seem to contribute to the antiobesity effect of CLA as seen in other studies with higher CLA doses. However, a strong induction of classically associated lipogenic genes such as Fasn (up to twofold) and, particularly, Scd1 (up to ninefold) was found. This activation could contribute to a protective role in muscle cells, since expression of ER stress markers was decreased and inversely correlated with the induction of Scd1.
Electronic supplementary material
The online version of this article (doi:10.1007/s12263-011-0279-x) contains supplementary material, which is available to authorized users. 相似文献998.
Davide Angeletti Letusa Albrecht Karin Blomqvist María del Pilar Quintana Tahmina Akhter Susanna M. B?chle Alan Sawyer Tatyana Sandalova Adnane Achour Mats Wahlgren Kirsten Moll 《PloS one》2012,7(12)
The ability of Plasmodium falciparum parasitized RBC (pRBC) to form rosettes with normal RBC is linked to the virulence of the parasite and RBC polymorphisms that weaken rosetting confer protection against severe malaria. The adhesin PfEMP1 mediates the binding and specific antibodies prevent sequestration in the micro-vasculature, as seen in animal models. Here we demonstrate that epitopes targeted by rosette disrupting antibodies converge in the loop of subdomain 3 (SD3) which connects the h6 and h7 α-helices of PfEMP1-DBL1α. Both monoclonal antibodies and polyclonal IgG, that bound to epitopes in the SD3-loop, stained the surface of pRBC, disrupted rosettes and blocked direct binding of recombinant NTS-DBL1α to RBC. Depletion of polyclonal IgG raised to NTS-DBL1α on a SD3 loop-peptide removed the anti-rosetting activity. Immunizations with recombinant subdomain 1 (SD1), subdomain 2 (SD2) or SD3 all generated antibodies reacting with the pRBC-surface but only the sera of animals immunized with SD3 disrupted rosettes. SD3-sequences were found to segregate phylogenetically into two groups (A/B). Group A included rosetting sequences that were associated with two cysteine-residues present in the SD2-domain while group B included those with three or more cysteines. Our results suggest that the SD3 loop of PfEMP1-DBL1α is an important target of anti-rosetting activity, clarifying the molecular basis of the development of variant-specific rosette disrupting antibodies. 相似文献
999.
Maria del Mar Alguacil Emma Torrecillas Pilar Torres Fuensanta García-Orenes Antonio Roldán 《PloS one》2012,7(10)
The effects of irrigation with treated urban wastewater (WW) on the arbuscular mycorrhizal fungi (AMF) diversity and soil microbial activities were assayed on a long-term basis in a semiarid orange-tree orchard. After 43 years, the soil irrigated with fresh water (FW) had higher AMF diversity than soils irrigated with WW. Microbial activities were significantly higher in the soils irrigated with WW than in those irrigated with FW. Therefore, as no negative effects were observed on crop vitality and productivity, it seems that the ecosystem resilience gave rise to the selection of AMF species better able to thrive in soils with higher microbial activity and, thus, to higher soil fertility. 相似文献
1000.
María Asunción García-González David Nicolás-Pérez Angel Lanas Luis Bujanda Patricia Carrera Rafael Benito Mark Strunk Federico Sope?a Santos Santolaria Elena Piazuelo Pilar Jiménez Rafael Campo Jesús Espinel Marisa Manzano Fernando Geijo María Pellisé Ferrán González-Huix Jorge Espinós Manuel Zaballa Llúcia Titó Luis Barranco Roberto Pazo Enrique Quintero 《PloS one》2012,7(9)