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991.
Sy Danh Thuong Ritesh Kumar Choudhary Tran The Bach Do Van Hai Bui Hong Quang Gordon C. Tucker Chu Hoang Mau Joongku Lee Changyoung Lee Sangmi Eum 《Nordic Journal of Botany》2017,35(3):272-275
Capparis dongvanensis (Capparaceae) is described as a new species and illustrated from Ha Giang Province of Vietnam. It is morphologically similar to C. lanceolaris and C. fengii, but differs in the number of flowers on peduncles, length of spine and petiole, apex of the leaf, type of inflorescence, petal color, cylindrical ovary without any beak, fruit shape and number of seeds per fruit. Diagnostic morphological characters along with pollen and seed SEM images of C. dongvanensis and allied species are provided. Its ecology, habitat and conservation status are also described. 相似文献
992.
Caroline M. Tucker Marc W. Cadotte Silvia B. Carvalho T. Jonathan Davies Simon Ferrier Susanne A. Fritz Rich Grenyer Matthew R. Helmus Lanna S. Jin Arne O. Mooers Sandrine Pavoine Oliver Purschke David W. Redding Dan F. Rosauer Marten Winter Florent Mazel 《Biological reviews of the Cambridge Philosophical Society》2017,92(2):698-715
The use of phylogenies in ecology is increasingly common and has broadened our understanding of biological diversity. Ecological sub‐disciplines, particularly conservation, community ecology and macroecology, all recognize the value of evolutionary relationships but the resulting development of phylogenetic approaches has led to a proliferation of phylogenetic diversity metrics. The use of many metrics across the sub‐disciplines hampers potential meta‐analyses, syntheses, and generalizations of existing results. Further, there is no guide for selecting the appropriate metric for a given question, and different metrics are frequently used to address similar questions. To improve the choice, application, and interpretation of phylo‐diversity metrics, we organize existing metrics by expanding on a unifying framework for phylogenetic information. Generally, questions about phylogenetic relationships within or between assemblages tend to ask three types of question: how much; how different; or how regular? We show that these questions reflect three dimensions of a phylogenetic tree: richness, divergence, and regularity. We classify 70 existing phylo‐diversity metrics based on their mathematical form within these three dimensions and identify ‘anchor’ representatives: for α‐diversity metrics these are PD (Faith's phylogenetic diversity), MPD (mean pairwise distance), and VPD (variation of pairwise distances). By analysing mathematical formulae and using simulations, we use this framework to identify metrics that mix dimensions, and we provide a guide to choosing and using the most appropriate metrics. We show that metric choice requires connecting the research question with the correct dimension of the framework and that there are logical approaches to selecting and interpreting metrics. The guide outlined herein will help researchers navigate the current jungle of indices. 相似文献
993.
994.
Anne M. Rae Matthieu P. C. Pinel Catherine Bastien Maurizio Sabatti Nathaniel R. Street James Tucker Caroline Dixon Nicolas Marron Sophie Y. Dillen Gail Taylor 《Tree Genetics & Genomes》2008,4(1):97-112
Populus is a genus of fast growing trees that may be suitable as a bioenergy crop grown in short rotation, but understanding the
genetic nature of yield and genotype interactions with the environment is critical in developing new high-yield genotypes
for wide-scale planting. In the present study, 210 genotypes from an F2 population (Family 331; POP1) derived from a cross between Populus trichocarpa 93-968 and P. deltoides ILL-129 were grown in southern UK, central France and northern Italy. The performance of POP1, based upon first- and second-year
main stem traits and biomass production, improved from northern to southern Europe. Trees at the Italian site produced the
highest mean biomass ranging from 0.77 to 18.06 oven-dried tonnes (ODT) ha−1 year−1, and the UK site produced the lowest mean biomass ranging from 0.18 to 10.31 ODT ha−1 year−1. Significant genotype × environment interactions were seen despite heritability values across sites being moderate to high.
Using a pseudo-testcross analysis, 37 quantitative trait loci (QTL) were identified for the maternal parent and 45 for the
paternal parent for eight stem and biomass traits across the three sites. High genetic correlations between traits suggested
that collocating QTL could be inferred as a single pleiotropic QTL, reducing the number of unique QTL to 23 and 24 for the
maternal and paternal parent, respectively. Additive genetic effects were seen to differ significantly for eight QTL on the
maternal map and 20 on the paternal map across sites. An additive main effects and multiplicative interaction analysis was
carried out to obtain stability parameters for each trait. These parameters were mapped as QTL, and collocation to trait QTL
was accessed. Two of the eight stability QTL collocate to trait QTL on the maternal map, and 8 of the 20 stability QTL collocate
to trait QTL on the paternal map, suggesting that a regulatory gene model is prevalent over an allele sensitivity model for
stem trait stability across these environments. 相似文献
995.
Hermione C Price Lynne Tucker Simon J Griffin Rury R Holman 《Cardiovascular diabetology》2008,7(1):1-7
Background
Epidemiological studies have revealed a relationship between early growth restriction and the subsequent development of insulin resistance and type 2 diabetes. Ligation of the uterine arteries in rats mimics uteroplacental insufficiency and serves as a model of intrauterine growth restriction (IUGR) and subsequent developmental programming of impaired glucose tolerance, hyperinsulinemia and adiposity in the offspring. The objective of this study was to investigate the effects of uterine artery ligation on the skeletal muscle expression of insulin receptor and key enzymes of LCFA metabolism.Methods
Bilateral uterine artery ligation was performed on day 19 of gestation in Sprague-Dawley pregnant rats. Muscle of the posterior limb was dissected at birth and processed by real-time RT-PCR to analyze the expression of insulin receptor, ACCα, ACCβ (acetyl-CoA carboxylase alpha and beta subunits), ACS (acyl-CoA synthase), AMPK (AMP-activated protein kinase, alpha2 catalytic subunit), CPT1B (carnitine palmitoyltransferase-1 beta subunit), MCD (malonyl-CoA decarboxylase) in 14 sham and 8 IUGR pups. Muscle tissue was treated with lysis buffer and Western immunoblotting was performed to assay the protein content of insulin receptor and ACC.Results
A significant down regulation of insulin receptor protein (p < 0.05) and reduced expression of ACS and ACCα mRNA (p < 0.05) were observed in skeletal muscle of IUGR newborns. Immunoblotting showed no significant change in ACCα content.Conclusion
Our data suggest that uteroplacental insufficiency may affect skeletal muscle metabolism down regulating insulin receptor and reducing the expression of key enzymes involved in LCFA formation and oxidation. 相似文献996.
LSB Mellau RJ Jørgensen PC Bartlett JMD Enemark AK Hansen 《Acta veterinaria Scandinavica》2004,45(3):139
The objective of this experiment was to determine the effect of dietary grain on calcium homeostasis. Six rumen-fistulated dairy cows with 3 or more previous lactations and no history of parturient paresis were randomly assigned to a sequence of diets in a crossover study with 4 periods of 10 days each. Dietary treatments were: A control ration consisting of wrap grass silage alone (1), the control ration supplemented with ammonium chloride and ammonium sulphate salt solution (2), control ration following a period with supplementation (3) and control ration supplemented with increasing amounts of barley from 4 to 10 kg/cow per day, expected to produce subclinical rumen acidosis (4). Daily intake of the diets was adjusted to 14 kg DM/cow per day. On day 11, the calcium-regulating mechanisms in cows were challenged until recumbency by a standardized intravenous EDTA infusion and cows were left to recover spontaneously. Anion supplementation and the feeding of highly fermentable carbohydrate lowered urine pH below 7.0 due to subclinical acidosis. During spontaneous recovery from EDTA induced hypocalcaemia, the cows more quickly regained a whole blood free calcium concentration of 1.00 mmol/L if they had most recently been supplemented with either anionic salts or with increasing amounts of barley, as compared to the basic ration. It is concluded that so-called slug-feeding or 'steaming up' with highly fermentable carbohydrates before parturition in milk fever susceptible cows enhanced calcium homeostasis similar to the effect seen in cows on anionic diets. 相似文献
997.
Comparison of the crystal structures of the KcsA and MthK potassium channels suggests that the process of opening a K+ channel involves pivoted bending of the inner pore-lining helices at a highly conserved glycine residue. This bending motion
is proposed to splay the transmembrane domains outwards to widen the gate at the “helix-bundle crossing”. However, in the
inwardly rectifying (Kir) potassium channel family, the role of this “hinge” residue in the second transmembrane domain (TM2)
and that of another putative glycine gating hinge at the base of TM2 remain controversial. We investigated the role of these
two positions in heteromeric Kir4.1/Kir5.1 channels, which are unique amongst Kir channels in that both subunits lack a conserved
glycine at the upper hinge position. Contrary to the effect seen in other channels, increasing the potential flexibility of
TM2 by glycine substitutions at the upper hinge position decreases channel opening. Furthermore, the contribution of the Kir4.1
subunit to this process is dominant compared to Kir5.1, demonstrating a non-equivalent contribution of these two subunits
to the gating process. A homology model of heteromeric Kir4.1/Kir5.1 shows that these upper “hinge” residues are in close
contact with the base of the pore α-helix that supports the selectivity filter. Our results also indicate that the highly
conserved glycine at the “lower” gating hinge position is required for tight packing of the TM2 helices at the helix-bundle
crossing, rather than acting as a hinge residue. 相似文献
998.
Microtubules are the primary cytoskeletal constituent of extending neurites. We used antisense morpholinos to knock down expression of neuron-specific Class III beta tubulin in the right half of the neural tube of chicken embryos in ovo. There was a significant (p < 0.01) reduction in the number of Class III beta tubulin immunostained interneurons 24 h following electroporation of the morpholinos when compared with the contralateral side of the neural tube. However, neural crest-derived sensory neurons labeled with the fluorescently tagged morpholinos developed distinct processes. Moreover, there was no significant difference in the number of interneurons labeled on either side of the neural tube with a second marker of developing neurons, anti-microtubule associated protein (MAP) 1b. Neural tubes were also excised and dissociated following antisense or control morpholino electroporation. The resulting neurons were cultured for 48 h and immunostained with anti-Class III beta tubulin and anti-MAP 1b. Neurons that had taken up the antisense morpholino had significantly shorter neurites (p < 0.01) than neurons from the same neural tubes that did not; they also had significantly shorter neurites (p < 0.05) than labeled neurons from neural tubes electroporated with a control morpholino. Thus, normal expression of Class III beta tubulin may not be necessary for neurogenesis in the early avian spinal cord in situ, but is required for neurite outgrowth in vitro. 相似文献
999.
Effects of tenascin-W on osteoblasts in vitro 总被引:1,自引:0,他引:1
Meloty-Kapella CV Degen M Chiquet-Ehrismann R Tucker RP 《Cell and tissue research》2008,334(3):445-455
Tenascin-W is a glycoprotein secreted into the extracellular matrix of developing bones. Here, we have examined possible roles
for tenascin-W in osteogenesis. Purified recombinant tenascin-W, like tenascin-C, increases the number of mineralized foci
in primary cultures of avian osteoblasts and increases alkaline phosphatase activity in vitro. In addition, tenascin-W in
solution promotes the migration of primary osteoblasts across fibronectin-coated filters. The sixth fibronectin type III domain
of chicken tenascin-W contains a phylogenetically conserved KGD motif that is predicted to be available to integrin binding.
To determine whether this motif is potentially functional, we have cultured osteoblasts on KGD-containing peptides and control
peptides. Osteoblasts cultured on peptides with the KGD motif acquire a multipolar phenotype with pseudopods tipped with actin-rich
ruffles, which is similar to the morphology of osteoblasts cultured on recombinant tenascin-W. Moreover, the KGD peptides,
but not the control peptides, promote proliferation in cultured osteoblasts but not alkaline phosphatase activity or migration.
Finally, explanted embryonic frontal bones are significantly thicker when cultured in the presence of tenascin-W, suggesting
that tenascin-W can accelerate the formation of new bone in a complex multicellular environment. 相似文献
1000.
C. A. Meurer R. D. Dinkins C. T. Redmond K. P. McAllister D. T. Tucker D. R. Walker W. A. Parrott H. N. Trick J. S. Essig H. M. Frantz J. J. Finer G. B. Collins 《In vitro cellular & developmental biology. Plant》2001,37(1):62-67
Summary Nine soybean [Glycine max (L.) Merr.] cultivars representing midwestern, mid-south, and southern US growing regions were evaluated at each of three
locations (Athens, GA; Lexington, KY; and Wooster, OH) using uniform embryogenic induction and proliferation protocols in
order to evaluate the portability of soybean somatic embryogenic protocols to different locations. The experimental design
minimized variation between locations by having all cultivars present at all locations on all days. A quantitative weighted
score for primary embryo induction was developed on average embryo number per explant and was used to describe non-embryogenic,
poorly embryogenic, moderately embryogenic, and highly embryogenic responses. Ranking of cultivars remained similar across
all locations, indicating a uniform transportability of the protocol, at least as far as embryo induction is concerned. Continued
proliferation of embryogenic cultures was also measured using a repetitive growth measure but few meaningful conclusions could
be made due to the high level of variability including inconsistent growth of cultures between each subculture. Overall, several
cultivars were identified as being uniformly embryogenic or non-embryogenic at the primary induction phase at all locations,
and we predict that those embryogenic cultivars could be used by any laboratory for high-efficiency induction of embryogenesis.
The best of these cultivars, ‘Jack’, was uniformly responsive across all locations and should be selected as the genotype
most likely to yield positive results when attempting to culture and genetically engineer soybeans via embryogenic protocols. 相似文献