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111.
Climatic forcing and larval dispersal capabilities shape the replenishment of fishes and their habitat‐forming biota on a tropical coral reef 下载免费PDF全文
Shaun K. Wilson Martial Depcyznski Rebecca Fisher Thomas H. Holmes Mae M. Noble Ben T. Radford Michael Rule George Shedrawi Paul Tinkler Christopher J. Fulton 《Ecology and evolution》2018,8(3):1918-1928
Fluctuations in marine populations often relate to the supply of recruits by oceanic currents. Variation in these currents is typically driven by large‐scale changes in climate, in particular ENSO (El Nino Southern Oscillation). The dependence on large‐scale climatic changes may, however, be modified by early life history traits of marine taxa. Based on eight years of annual surveys, along 150 km of coastline, we examined how ENSO influenced abundance of juvenile fish, coral spat, and canopy‐forming macroalgae. We then investigated what traits make populations of some fish families more reliant on the ENSO relationship than others. Abundance of juvenile fish and coral recruits was generally positively correlated with the Southern Oscillation Index (SOI), higher densities recorded during La Niña years, when the ENSO‐influenced Leeuwin Current is stronger and sea surface temperature higher. The relationship is typically positive and stronger among fish families with shorter pelagic larval durations and stronger swimming abilities. The relationship is also stronger at sites on the coral back reef, although the strongest of all relationships were among the lethrinids (r = .9), siganids (r = .9), and mullids (r = .8), which recruit to macroalgal meadows in the lagoon. ENSO effects on habitat seem to moderate SOI–juvenile abundance relationship. Macroalgal canopies are higher during La Niña years, providing more favorable habitat for juvenile fish and strengthening the SOI effect on juvenile abundance. Conversely, loss of coral following a La Niña‐related heat wave may have compromised postsettlement survival of coral dependent species, weakening the influence of SOI on their abundance. This assessment of ENSO effects on tropical fish and habitat‐forming biota and how it is mediated by functional ecology improves our ability to predict and manage changes in the replenishment of marine populations. 相似文献
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Expression of alternatively spliced mRNA variants at specific stages of development or in specific cells and tissues contributes to the functional diversity of the human genome. Aberrations in alternative splicing were found as a cause or a contributing factor to the development, progression, or maintenance of numerous diseases. The use of antisense oligonucleotides (ON) to modify aberrant expression patterns of alternatively spliced mRNAs is a novel means of potentially controlling such diseases. Oligonucleotides can be designed to repair genetic mutations, to modify genomic sequences in order to compensate for gene deletions, or to modify RNA processing in order to improve the effects of the underlying gene mutation. Steric block ON approach have proven to be effective in experimental model for various diseases. Here, we describe our experience in investigating two strategies for ON delivery: ON conjugation with basic peptides and lipid-based particulate system (lipoplex). Basic peptides or Cell Penetrating Peptides (CPP) such as the TAT-derived peptide appear to circumvent many problems associated with ON and drug delivery. This strategy may represent the next paradigm in our ability to modulate cell function and offers a unique avenue for the treatment of disease. Lipoplexes result from the intimate interaction of ON with cationic lipids leading to ON carrying particles able to be taken up by cells and to release ON in the cytoplasm. We have used as an experimental model the correction of a splicing alteration of the mutated β-globin intron causing thalassemia. Data on cell penetration and efficacy of correction of specific steric block ON delivered either by basic peptides or lipoplex are described. A comparison of the properties of both delivery systems is made respective to the use of this new class of therapeutic molecules. 相似文献
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O W Petersen P E H?yer J Hilgers P Briand B van Deurs 《Virchows Archiv. B, Cell pathology including molecular pathology》1985,50(1):27-42
Epithelial cell islets in primary monolayer cultures of human breast biopsies were characterized by combined immuno-, enzyme- and DNA cytochemistry as well as by analysis of attachment-, spread- and growth patterns. For cultivation we used explants from reduction mammoplasties, benign lesions, primary carcinomas and metastases. Milk fat globule membrane antigen (MFGM-A) was detected with a monoclonal antibody, and the tetrazolium reaction for glucose 6-phosphate dehydrogenase (G6PDH) as well as DNA content of the cultured cells were quantified. Spreading and growth of individual islets were studied by image analysis. Fibroblast-like cells did not express MFGM-A, and whereas epithelial (MFGM-A positive) cell islets of normal and benign origin showed cells with no or low G6PDH reaction, respectively, the majority of epithelial cell islets from 11 out of 21 carcinomas showed strong reaction. Cell islets with strong G6PDH reaction were sometimes hyperdiploid. Moreover, whereas cell islets with no or low reaction from both benign lesions and carcinomas readily attached and spread in a serum-free medium and showed population doubling times of 30 to 110 h, cell islets with strong reaction from carcinomas and metastatic lesions required serum for attachment and their growth rate was too low to be determined. 相似文献
117.
Effects of the thyroid status on the sarcoplasmic reticulum in slow skeletal muscle of the rat 总被引:1,自引:0,他引:1
The effects of the thyroid status on the Ca++-transporting capabilities of rat slow skeletal muscle (m.soleus) were studied. The oxalate supported Ca++-uptake activity and Ca++-loading capacity of muscle homogenates from hyperthyroid rats showed an approximate 4.2 and 2.5 fold increase, respectively, as compared to values found in the hypothyroid group. Muscle homogenates of euthyroid rats gave intermediate values. The specific activity of oxalate supported Ca++ uptake, but not the Ca++-loading capacity, of membrane preparations enriched with respect to sarcoplasmic reticulum (SR) increased in proportion to the thyroid status. This was paralleled by a 3.5 fold increase in the amount of active Ca++ pumps in the SR preparations in the transition from hypothyroidism to hyperthyroidism as determined by measurement of Ca++-dependent 32P incorporation. These observations are not explained by differences in degree of purification of the examined SR preparations. Protein profiles of the membrane preparations obtained by gel electrophoresis indicated a thyroid-hormone dependent increase in Ca++-pump content relative to other SR proteins. The results suggest that thyroid hormone stimulates the proliferation of the SR and possibly also increases the Ca++-pump density in the SR membrane. 相似文献
118.
M. I. Jsselstijn J. Kaiser F. L. van Delft H. E. Schoemaker F. P. J. T. Rutjes 《Amino acids》2003,24(3):263-266
Summary. Novel synthetic procedures for the modification of non-proteinogenic acetylene-containing amino acids have been developed.
The functionalization either proceeds via zinc/copper-mediated introduction of alkyl substituents, or via tungsten-catalyzed
ring-closing alkyne metathesis reactions.
Received March 28, 2002 Accepted October 3, 2002 Published online December 18, 2002
Acknowledgements These investigations are supported (in part) by the Netherlands Research Council for Chemical Sciences (CW) with financial
aid from the Netherlands Technology Foundation (STW).
Authors' address: Floris P. J. T. Rutjes, Prof. Dr., Department of Organic Chemistry, University of Nijmegen, Toernooiveld 1, NL-6525 ED Nijmegen,
The Netherlands, E-mail: rutjes@sci.kun.nl
2, selected data: 1H NMR (300 MHz, CDCl3) δ 5.32 (d, J = 7.7 Hz, 1H), 4.44–4.40 (m, 1H), 3.76 (s, 3H), 2.75–2.73 (d, J = 5.0 Hz, 2H), 1.44 (s, 9H); 13C NMR (75 MHz, CDCl3) δ 171.0, 155.0, 80.3, 74.6, 52.6, 51.9, 41.7, 28.3, 24.0; mp = 55°C.
Typical procedure for 5: zinc dust (116 mg, 1.408 mmol) was weighed into a 20 mL flask, which was repeatedly evacuated (with heating using a heat
gun) and flushed with argon. Dry DMF (0.5 mL, distilled from CaH2) and 1,2-dibromoethane (9.2 μL, 0.106 mmol) were added and the flask was heated at 80°C for 40 min. The reaction mixture was allowed to cool to room temperature,
trimethylsilyl chloride (4 μL, 0.035 mmol) was added and the resulting mixture was stirred vigorously for a further 30 min under argon. Iodocyclohexane
(69 μl, 0.528 mmol) was added and stirred at room temperature for 3 h more after which stirring was ceased to settle the zinc.
CuCN (41 mg, 0.458 mmol) and LiCl (40 mg, 0.915 mmol) were heated to 150°C for 2 h and cooled to room temperature. Addition
of DMF (1 mL) formed a soluble CuCN·2LiCl complex within 5 min. After cooling the Cu-complex to −15°C, the organozinc reagent
was added dropwise followed by the bromoacetylene 2 (116 mg, 0.352 mmol). The mixture was allowed to stir overnight at room temperature. Water was added and the suspension was
extracted using heptane, washed with brine, dried (MgSO4) and concentrated. Purification using flash column chromatography (10% EtOAc in heptane) yielded 5 (100 mg, 81%) as a colorless oil. 5: IR ν 3355, 2929, 2852, 2359, 2337, 1749, 1717, 1498, 1447, 1365, 1251, 1181, 1060; 1H NMR (300 MHz, CDCl3) δ 5.28 (d, J = 7.7 Hz, 1H), 4.43–4.38 (m, 1H), 3.73 (s, 3H), 2.69–2.63 (m, 2H), 2.13 (m, 1H), 1.73–1.22 (m, 10H), 1.43 (s, 9H); 13C NMR (75 MHz, CDCl3) δ 171.4, 155.0, 88.1, 79.9, 73.8, 52.3, 32.7, 32.7, 28.8, 28.2, 25.8, 24.6, 23.1; HRMS (EI): calculated for C17H27NO4 309.1940, found 309.1937.
A solution of the tungsten catalyst (7 mg, 10 mol%) in C6H5Cl (2 mL) was treated with a solution of 14 (49.0 mg, 0.120 mmol) in C6H5Cl (5.0 mL) under an argon atmosphere and the resulting mixture was heated at 80°C for 3 h. Evaporation followed by flash
column chromatography (80% EtOAc in heptane) afforded 15 (21.0 mg, 50%; 64% after correction for starting material) and 14 (16 mg, 33%) as colorless oils. 15: [α]D =–14.6 (c = 1, CH2Cl2); IR ν 3313, 2931, 2865, 2249, 1744, 1667, 1520, 1366, 1170; 1H NMR (400 MHz, CDCl3) δ 7.14 (d, J = 8.7 Hz, 1H), 6.08 (d, J = 8.3 Hz, 1H), 4.78 (q, J = 6.8 Hz, 1H), 4.27 (q, J = 7.9 Hz, 1H), 3.73 (s, 3H), 2.17–2.15 (m, 4H), 2.07–1.96 (m, 2H), 1.79–1.52 (m, 4H), 1.45 (s, 9H), 0.89–0.83 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 173.2, 171.8, 155.8, 80.4, 80.2, 79.3, 53.8, 52.5, 51.2, 32.8 (2×), 28.1, 24.6, 24.2, 18.3 (2×); HRMS (EI): calculated for
C18H28N2O5 相似文献
119.
120.
A. Verrips Gerry C. H. Steenbergen-Spanjers J. A. F. M. Luyten R. A. Wevers John H. J. Wokke Fons J. M. Gabreëls Bert G. Wolthers Lambert P. W. J. van den Heuvel 《Human genetics》1997,100(2):284-286
We report a new mutation in the sterol 27-hydroxylase (CYP 27) gene in a Dutch family with cerebrotendinous xanthomatosis:
a G→A transition in the splice donor site in intron 4. This mutation leads to skipping of exon 4, resulting in a loss of 66
amino acids in the CYP 27 enzyme molecule.
Received: 15 March 1997 / Accepted: 26 March 1997 相似文献