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61.
The pronghorn spiny lobster, Panulirus penicillatus, is a circumtropical species which has the widest global distribution among all the species of spiny lobster, ranging throughout the entire Indo-Pacific region. Partial nucleotide sequences of mitochondrial DNA COI (1,142-1,207 bp) and 16S rDNA (535-546 bp) regions were determined for adult and phyllosoma larval samples collected from the Eastern Pacific (EP)(Galápagos Islands and its adjacent water), Central Pacific (CP)(Hawaii and Tuamotu) and the Western Pacific (WP)(Japan, Indonesia, Fiji, New Caledonia and Australia). Phylogenetic analyses revealed two distinct large clades corresponding to the geographic origin of samples (EP and CP+WP). No haplotype was shared between the two regional samples, and average nucleotide sequence divergence (Kimura's two parameter distance) between EP and CP+WP samples was 3.8±0.5% for COI and 1.0±0.4% for 16S rDNA, both of which were much larger than those within samples. The present results indicate that the Pacific population of the pronghorn spiny lobster is subdivided into two distinct populations (Eastern Pacific and Central to Western Pacific), with no gene flow between them. Although the pronghorn spiny lobster have long-lived teleplanic larvae, the vast expanse of Pacific Ocean with no islands and no shallow substrate which is known as the East Pacific Barrier appears to have isolated these two populations for a long time (c.a. 1MY).  相似文献   
62.
Surveys (in 2002 and 2003) were performed for fungal endophytes in roots of 24 plant species growing at 12 sites (coastal and inland soils, both sandy soils and salt marshes) under either water or salt stress in the Alicante province (Southeast Spain). All plant species examined were colonized by endophytic fungi. A total of 1830 fungal isolates were obtained and identified by morphological and molecular [internal transcribed spacer (ITS) and translation elongation factor-1alpha gene region (TEF-1alpha) sequencing] techniques. One hundred and forty-two fungal species were identified, belonging to 57 genera. Sterile mycelia were assigned to 177 morphospecies. Fusarium and Phoma species were the most frequent genera, followed by Aspergillus, Alternaria and Acremonium. Fungal root endophytic communities were influenced by the soil type where their respective host plants grew, but not by location (coastal or inland sites). Fusarium oxysporum, Aspergillus fumigatus and Alternaria chlamydospora contributed most to the differences found between endophytic communities from sandy and saline soils. Host preference was found for three Fusarium species studied. Fusarium oxysporum and Fusarium solani were especially isolated from plants of the family Leguminosae, while Fusarium equiseti showed a preference for Lygeum spartum (Gramineae). In some cases, specificity could be related to intra-specific variability as shown by sequencing of the TEF-1alpha in the genus Fusarium.  相似文献   
63.
The effect of initial sucrose concentration was investigated in root suspension cultures of Morinda citrifolia to improve root growth and secondary metabolites production, i.e. anthraquinone, phenolics and flavonoids. Besides, oxidative stress level, antioxidant enzymes activity and membranes damage under different sucrose concentration were estimated. A 5% sucrose supply was shown to be optimal for the production of root dry mass, but higher sucrose concentrations of 7–9% inhibited the accumulation of root dry weight (DW). However, the maximum production of anthraquinone (251.89 g L−1 DW), phenolics (165.14 g L−1 DW) and flavonoids (163.56 g L−1 DW) were achieved at 1% sucrose-treated culture, which may be a source carbon skeletons for secondary metabolism. At the same time was observed low oxidative damage, which could be associated with high levels of secondary metabolites and the increased activity of catalase. Although, catalase (CAT) activity were stimulated at 7–9% sucrose-treated cultures, high accumulation of hydrogen peroxide (H2O2) and peroxidation of lipid (MDA) was induced. The observed high activity of CAT and guaiacol peroxidase (G-POD) were not sufficient enough to mitigate the toxic effect of H2O2.  相似文献   
64.
The Arabian Peninsula is a key region for understanding climate change and human occupation history in a marginal environment. The Mundafan palaeolake is situated in southern Saudi Arabia, in the Rub’ al-Khali (the ‘Empty Quarter’), the world’s largest sand desert. Here we report the first discoveries of Middle Palaeolithic and Neolithic archaeological sites in association with the palaeolake. We associate the human occupations with new geochronological data, and suggest the archaeological sites date to the wet periods of Marine Isotope Stage 5 and the Early Holocene. The archaeological sites indicate that humans repeatedly penetrated the ameliorated environments of the Rub’ al-Khali. The sites probably represent short-term occupations, with the Neolithic sites focused on hunting, as indicated by points and weaponry. Middle Palaeolithic assemblages at Mundafan support a lacustrine adaptive focus in Arabia. Provenancing of obsidian artifacts indicates that Neolithic groups at Mundafan had a wide wandering range, with transport of artifacts from distant sources.  相似文献   
65.
Chemotherapy has been used widely to treat cancer, both as a systemic therapy and as a local treatment. Unfortunately, many types of cancer are still refractory to chemotherapy. The mechanisms of anticancer drug resistance have been extensively explored but have not been fully characterized. This study analyzed the occurrences of polymorphism (SNP) in the MDR1 gene in breast cancer patients and determined a possible association with chemotherapy. The study group included one hundred breast carcinoma patients who subsequently received chemotherapy (the regimen generally consisted of commonly used drugs such as cyclophosphamide, adriamycin, 5-fluorouracil, docetaxel and their combinations). Blood samples from 100 healthy individuals are used, as controls were also genotyped for the MDR1 gene. This investigation revealed a significant correlation with response to various regimens of chemotherapy showing a low response to therapy with the CT/TT genotype at (exon 12) 1236 codon (p < 0.001). These findings demonstrate, for the first time, that the polymorphisms in (exon 12) 1236 codon of the MDR1 gene greatly influence the drug response in patients from the Arab population of Saudi Arabia.  相似文献   
66.
Salinity induced changes in the reproductive physiology of wheat plants   总被引:2,自引:0,他引:2  
The effect of salinity on reproductive physiology of wheat wasinvestigated. One set of wheat plants was subjected to increasingsalt levels up to a certain concentration, whereas another setwas given the same concentration in a single application. Theformer was called "gradual" and latter "shock" treatment. Theireffects on pollen viability, germination and activity of starchsynthetase were studied. Gradual treatment seemed to reducethe toxic effects of salts on the viability of pollen grainsand their germination. Seeds obtained from the two sets weregerminated in the same salinities in which their plants hadbeen growing, and the results were compared with those of seedsobtained from control plants growing in a non-saline medium.The seeds of plants from the gradual treatment were better suitedfor germination on a saline medium than those from the shocktreatment or the control group. Salt treatment also increasedthe activity of starch synthetase at the midmilky stage in developinggrains. This phenomenon was considered essential for synthesisof starch in a saline environment. The increase in Na+ and Cl and decrease in K+ contentsof wheat grains in both treatments suggest that the effect ofsalinity on the physiological phenomenon studied is due to changesin the ionic content of the plants. 1 In partial fulfilment of a Ph.D. degree from the Universityof Karachi, Pakistan. 2 Professor of Botany, Director of Research Projects, Head,Plant Physiology Section, University of Karachi, Pakistan. (Received July 11, 1977; )  相似文献   
67.
Tumor suppressor protein p53 induces cell cycle arrest and apoptotic cell death in response to various cellular stresses thereby preventing cancer development. Activation and stabilization of p53 through small organic molecules is, therefore, an attractive approach for the treatment of cancers retaining wild-type p53. In this context, a series of nineteen chalcones with various substitution patterns of functional groups including chloro, fluoro, methoxy, nitro, benzyloxy, 4-methyl benzyloxy was prepared using Claisen-Schmidt condensation. The compounds were characterized using NMR, HRMS, IR and melting points. Evaluation of synthesized compounds against human colorectal (HCT116) and breast (CAL-51) cancer cell lines revealed potent antiproliferative activities. Nine compounds displayed GI50 values in the low micromolar to submicromolar range; for example (E)-1-phenyl-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (SSE14108) showed GI50 of 0.473 ± 0.043 µM against HCT116 cells. Further analysis of these compounds revealed that (E)-3-(4-chlorophenyl)-1-phenylprop-2-en-1-one (SSE14105) and (E)-3-(4-methoxyphenyl)-1-phenylprop-2-en-1-one (SSE14106) caused rapid (4 and 8-h post-treatment) accumulation of p53 in HCT116 cells similar to its induction by positive control, Nutlin-3. Such activities were absent in 3-(4-methoxyphenyl)propiophenone (SSE14106H2) demonstrating the importance of conjugated ketone for antiproliferative and p53 stabilizing activity of the chalcones. We further evaluated p53 levels in the presence of cycloheximide (CHX) and the results showed that the p53 stabilization was regulated at post-translational level through blockage of its degradation. These chalcones can, therefore, act as fragment leads for further structure optimization to obtain more potent p53 stabilizing agents with enhanced anti-proliferative activities.  相似文献   
68.
Developmental dysplasia of the hip (DDH) is a congenital condition characterized by abnormality in acetabulum size and/or shape. The incidence rate of DDH differs between different populations with risk factors including positive family history, breech presentation, sex, firstborn status, side of the hip, mode of delivery and oligohydramnios. It is recognized that DDH has a genetic component that exhibit autosomal dominant patterns. Many candidate genes have been studied and found to be associated with the disease; most of them are normally involved in cartilage development and joint metabolism. In this study, the association of four single-nucleotide polymorphisms (SNPs) (rs731236, rs1544410, rs7975232 and rs2228570) in the vitamin D receptor (VDR) gene was studied by a case–control analysis. The study sample involves 50 cases with confirmed DDH presentation and 50 nonDDH controls. SNPs were genotyped using conventional polymerase chain reaction (PCR) and restriction fragment-length polymorphism (RFLP) techniques. Genotype and allele frequencies were analysed using SPSS software. No significant associations were found between the VDR polymorphisms analysed and DDH. Further work need to be performed using genomewide analysis to elucidate the genetic basis of DDH.  相似文献   
69.
The objective of the present study was to evaluate the effects of propolis, pollen, and caffeic acid phenethyl ester (CAPE) on tyrosine hydroxylase (TH) activity and total RNA levels of Nω-nitro-L-arginine methyl ester (L-NAME) inhibition of nitric oxide synthase in the heart, adrenal medulla, and hypothalamus of hypertensive male Sprague dawley rats. The TH activity in the adrenal medulla, heart, and hypothalamus of the rats was significantly increased in the L-NAME group vs. control (p < 0.05). Treatment with L-NAME led to a significant increase in blood pressure (BP) in the L-NAME group compared to control (p < 0.05). These data suggest that propolis, pollen, and CAPE may mediate diminished TH activity in the heart, adrenal medulla, and hypothalamus in hypertensive rats. The decreased TH activity may be due to the modulation and synthesis of catecholamines and BP effects. In addition, the binding mechanism of CAPE within the catalytic domain of TH was investigated by means of molecular modeling approaches. These data suggest that the amino acid residues, Glu429 and Ser354 of TH may play a pivotal role in the stabilization of CAPE within the active site as evaluated by molecular dynamics (MD) simulations. Gibbs binding free energy (ΔGbinding) of CAPE in complex with TH was also determined by post-processing MD analysis approaches (i.e. Poisson-Boltzmann Surface Area (MM-PBSA) method).  相似文献   
70.
Genus Rusa, belonging to the deer family Cervidae is native to the Indo-Malaya Archipelago (IMA). However, detailed information on the Rusa genus in the IMA is limited. This review provides comprehensive information on the Rusa genus in the IMA including, threats and conservation efforts. There are four species of deer in Rusa genus, which is Sambar deer (Rusa unicolor), Javan deer (Rusa timorensis), Visayan spotted deer (Rusa alfredi) and Philippine deer (Rusa marianna). Despite their wide distribution in the South Asian and Southeast Asian regions, they are under serious threats. Some conservation efforts that are being done to protect and conserve them among others are; (1) facilities protection, (2) habitat enrichment programme, (3) Ex-situ conservation, (4) legislations, and (5) captive breeding. Conservation through genetics is also an important step in conserving these species. Recommendations for conservation of the genus are also discussed; 1. maintenance of ecosystem. 2. more effective monitoring system on the existing protected area. 3. ex-situ conservation, and 4. habitat monitoring.  相似文献   
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