Related Articles
Juniperus excelsa constitutes a precious woody species of high ecological value able to grow up to Mountain treeline around the Mediterranean. Nuclear microsatellites were used to shed light on genetic diversity and differentiation of different Mediterranean populations. This information is essential in planning conservation strategies and reforestation programs.
Background and aims
Juniperus excelsa is an important woody species in the high mountain ecosystems of the eastern Mediterranean Basin where it constitutes the only coniferous species found at the tree line. The genetic diversity within and among J. excelsa populations of the eastern Mediterranean Basin is studied in the light of their historical fragmentation.
Methodology
Nuclear microsatellites originally developed for Juniperus communis and J. przewalskii were tested on 320 individuals from 12 different populations originating from Lebanon, Turkey, Cyprus, Greece and the Ukraine.
Principal results
Among the 31 nuclear microsatellite primers tested, only three produced specific amplification products, with orthology confirmed by sequence analysis. They were then used for genetic diversity studies. The mean number of alleles and the expected heterozygosity means were Na=8.78 and He=0.76, respectively. The fixation index showed a significant deviation from Hardy–Weinberg equilibrium and an excess of homozygotes (FIS=0.27–0.56). A moderate level of genetic differentiation was observed among the populations (FST=0.075, P<0.001). The most differentiated populations corresponded to old vestigial stands found at the tree line (>2000 m) in Lebanon. These populations were differentiated from the other populations that are grouped into three sub-clusters.
Conclusions
High levels of genetic diversity were observed at species and population levels. The high level of differentiation in the high-mountain Lebanese populations reflects a long period of isolation or possibly a different origin. The admixture observed in other populations from Lebanon suggests a more recent separation from the Turkish–southeastern European populations.
doi:10.1093/aobpla/plr003
PMCID: PMC3064508
PMID: 22476474
Cupressus semipervirens var. horizontalis, Cupressus semipervirens var. semipervirens, Cupressus semipervirens cv. Cereifeormis, Juniperus communis subsp. hemisphaerica, Juniperus excelsa subsp. excelsa, Juniperus excelsa subsp. polycarpos, Juniperus foetidissima, Juniperus oblonga, Juniperus sabina, Platycladus orientalis and Taxus baccata are Iranian conifers. The antioxidant activity of leaves and fruits of these 11 different taxons were evaluated. The leaves of both male and female, and fruits of these plants were collected from different areas of the country. Methanol extract of leaves and fruits of these taxons were prepared. Antioxidant activity of each extracts was measured using two different tests of the ferric thiocyanate method and thiobarbituric acid. Results indicated that the methanol extracts of leaves, of male and female, and fruits of all these species (27 samples) possessed antioxidant activity when tested with both methods. The antioxidant activity was then compared with those of α-tocopherol (a natural antioxidant) and butylated hydroxytoluene (a synthetic antioxidant). Methanol extract of fruits of C. semipervirens cv. Cereifeormis showed the highest antioxidant activity while the methanol extract of leaves of C. semipervirens var. semipervirens possessed the lowest antioxidant activity. However, our finding showed that most of the tested extracts were showing strong antioxidant activity even higher than α-tocopherol.
doi:10.1093/ecam/nem011
PMCID: PMC1978238
PMID: 17965761
antioxidative activity – conifers, Cupressus – ferric thiocyanate test – Juniperus – medicinal plant – Platycladus orientalis – radical scavenging – thiobarbituric acid test
Juniperus excelsa M.B subsp. Polycarpos (K.Koch), collected from south of Iran, was subjected to hydrodistillation using clevenger apparatus to obtain essential oil. The essential was analyzed by gas chromatography/mass spectrometry (GC/MS) and studied for antimicrobial, antifungal and antioxidant activities. The results indicated α-pinene (67.71%) as the major compound and α-cedral (11.5%), δ3-carene (5.19%) and limonene (4.41%) in moderate amounts. Antimicrobial tests were carried out using disk diffusion method, followed by the measurement of minimum inhibitory concentration (MIC). All the Gram positive and Gram negative bacteria were susceptible to essential oil. The oil showed radical scavenging and antioxidant effects.
doi:10.4103/0974-8490.65505
PMCID: PMC3141302
PMID: 21808554
Antimicrobial activity; antioxidant activity; essential oil; Juniperus excelsa; thin layer chromatography autographic assay
The crystallization of the brazil nut allergen Ber e 2 is reported.
Peanut and tree-nut allergies have attracted considerable attention because of their frequency and their lifelong persistence. Brazil-nut (Bertholletia excelsa) allergies have been well documented and the 11S legumin-like seed storage protein Ber e 2 (excelsin) is one of the two known brazil-nut allergens. In this study, Ber e 2 was extracted from brazil-nut kernels and purified to high purity by crystalline precipitation and gel-filtration chromatography. Well diffracting single crystals were obtained using the hanging-drop vapour-diffusion method. A molecular-replacement structural solution has been obtained. Refinement of the structure is currently under way.
doi:10.1107/S1744309107051445
PMCID: PMC2339761
PMID: 18007055
brazil nut allergy; Ber e 2; cupin superfamily; allergenicity
During a study on the mycobiota of brazil nuts (Bertholletia excelsa) in Brazil, a new Aspergillus species, A. bertholletius, was found, and is described here. A polyphasic approach was applied using morphological characters, extrolite data as well as partial β-tubulin, calmodulin and ITS sequences to characterize this taxon. A. bertholletius is represented by nineteen isolates from samples of brazil nuts at various stages of production and soil close to Bertholletia excelsa trees. The following extrolites were produced by this species: aflavinin, cyclopiazonic acid, kojic acid, tenuazonic acid and ustilaginoidin C. Phylogenetic analysis using partial β-tubulin and camodulin gene sequences showed that A. bertholletius represents a new phylogenetic clade in Aspergillus section Flavi. The type strain of A. bertholletius is CCT 7615 ( = ITAL 270/06 = IBT 29228).
doi:10.1371/journal.pone.0042480
PMCID: PMC3428331
PMID: 22952594
Cyperus rotundus, Caesalpinia bonducella, Tinospora cordifolia, Gardenia gummifera, Ailanthus excelsa, Acacia arabica, Embelia ribes and Ventilago maderspatana from Melghat forest were screened for their antibacterial potential against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Proteus vulgaris, Salmonella typhi, Shigella flexneri, Salmonella paratyphi, Salmonella typhimurium, Pseudomonas aeruginosa, Enterobacter aerogenes by disc diffusion method. Out of these medicinal plants Caesalpinia bonducella, Gardenia gummifera and Acacia arabica showed remarkable antibacterial potential. The phytochemical analysis had showed the presence of Cardiac glycosides in all extracts (aqueous, acetone, ethanol and methanol) of Acacia arabica, Gardenia gummifera and ethanol, methanol extracts of Caesalpinia bonducella. Flavonoids were present in Gardenia gummifera, Ailanthus excelsa and acetone, methanol extracts of Acacia Arabica. Tannins and phenolic were present in Cyperus rotundus, Embelia ribes, and organic extracts of Ventilago maderspatana.
PMCID: PMC2816464
PMID: 20448847
Antibacterial activity; Melghat; Medicinal Plants; Phytochemical
Background
We report here the isolation and characterization of a new compound Ailanthus
excelsa chloroform extract-1 (AECHL-1)
(C29H36O10; molecular weight 543.8) from
the root bark of Ailanthus excelsa Roxb. The compound
possesses anti-cancer activity against a variety of cancer cell lines of
different origin.
Principal Findings
AECHL-1 treatment for 12 to 48 hr inhibited cell proliferation and induced
death in B16F10, MDA-MB-231, MCF-7, and PC3 cells with minimum growth
inhibition in normal HEK 293. The antitumor effect of AECHL-1 was comparable
with that of the conventional antitumor drugs paclitaxel and cisplatin.
AECHL-1-induced growth inhibition was associated with S/G2-M
arrests in MDA-MB-231, MCF-7, and PC3 cells and a G1 arrest in
B16F10 cells. We observed microtubule disruption in MCF-7 cells treated with
AECHL-1 in vitro. Compared with control, subcutaneous injection of AECHL-1
to the sites of tumor of mouse melanoma B16F10 implanted in C57BL/6 mice and
human breast cancer MCF-7 cells in athymic nude mice resulted in significant
decrease in tumor volume. In B16F10 tumors, AECHL-1 at 50
µg/mouse/day dose for 15 days resulted in increased expression of
tumor suppressor proteins P53/p21, reduction in the expression of the
oncogene c-Myc, and downregulation of cyclin D1 and cdk4. Additionally,
AECHL-1 treatment resulted in the phosphorylation of p53 at serine 15 in
B16F10 tumors, which seems to exhibit p53-dependent growth inhibitory
responses.
Conclusions
The present data demonstrate the activity of a triterpenoid AECHL-1 which
possess a broad spectrum of activity against cancer cells. We propose here
that AECHL-1 is a futuristic anti-cancer drug whose therapeutic potential
needs to be widely explored for chemotherapy against cancer.
doi:10.1371/journal.pone.0005365
PMCID: PMC2671403
PMID: 19399188
Gibberella xylarioides Heim & Saccas (presumed anamorph, Fusarium xylarioides Steyaert) is the causal agent of coffee wilt disease, an economically important tracheomycosis in Africa. In vitro crosses carried out with Congolese, Ugandan, and Tanzanian single-ascospore/conidial isolates originating from diseased Coffea canephora/excelsa demonstrated a heterothallic mating system, controlled by a single locus with two alleles, MAT-1 and MAT-2. Compatible isolates produced fertile perithecia within 2 to 8 weeks after mating. Mating type (MAT) was characterized by PCR with primer pairs previously developed for the Gibberella fujikuroi species complex (GFC) and for Fusarium oxysporum. All strains analyzed were morphologically identical and corresponded to Booth's description of the “female” F. xylarioides strain. Based on crossing results and MAT-2/translation elongation 1-α (tef) sequence data, G. xylarioides, as currently understood, is demonstrated to encompass at least three “groups”: G. xylarioides sensu strictu Ia, defined hitherto by two “historical” West African strains originating from the severe 1930s to 1950s epidemic (CBS 25852 and CBS 74979); G. xylarioides sensu strictu Ib, defined by two “historical” Central African lowland strains (DSMZ 62457 and ATCC 15664); and G. xylarioides sensu lato II, containing Congolese, Ugandan, and Tanzanian C. canephora/excelsa isolates. Infertility of crosses between the coffee wilt pathogen and known GFC mating populations demonstrates that G. xylarioides sensu lato constitutes a new biological species within the G. fujikuroi complex. MUCL 44532/MUCL 43887 and MUCL 35223/MUCL 44549 are proposed as G. xylarioides sensu lato II MAT-1/MAT-2 reference mating type tester strains.
doi:10.1128/AEM.71.12.8466-8471.2005
PMCID: PMC1317314
PMID: 16332836
Habitat fragmentation is thought to lower the viability of tropical trees by disrupting their mutualisms with native pollinators. However, in this study, Dinizia excelsa (Fabaceae), a canopy-emergent tree, was found to thrive in Amazonian pastures and forest fragments even in the absence of native pollinators. Canopy observations indicated that African honeybees (Apis mellifera scutellata) were the predominant floral visitors in fragmented habitats and replaced native insects in isolated pasture trees. Trees in habitat fragments produced, on average, over three times as many seeds as trees in continuous forest, and microsatellite assays of seed arrays showed that genetic diversity was maintained across habitats. A paternity analysis further revealed gene flow over as much as 3.2 km of pasture, the most distant pollination precisely recorded for any plant species. Usually considered only as dangerous exotics, African honeybees have become important pollinators in degraded tropical forests, and may alter the genetic structure of remnant populations through frequent long-distance gene flow.
doi:10.1098/rspb.2001.1781
PMCID: PMC1088891
PMID: 11703880
This work reports the application of oxygen-(O2-) reducing atmosphere methods on stored shelled Brazil nut (Bertholletia excelsa H.B.K.) packs aiming to evaluate the degree of aflatoxin degradation, nuts lipid oxidative stability, fungi control, and hygienic conditions improvement. The methods applied were (a) ozone: O3, (b) carbon dioxide: CO2, and (c) O2 absorber pads with and without vacuum. From all modified atmospheres evaluated, the best performance was obtained with O3, either with or without vacuum. It was the only nut treatment that was able to degrade aflatoxins. None of the spiked (AFLs: 15 μg·kg−1) nut samples O3- treated had aflatoxins detected up to the LC-MS/MS method LOQ (0.36 μg·kg−1 for total AFLs), thus producing safer nuts. Also it kept the fatty acid oxidation indicator—malondialdehyde stable and improved the sensory attributes for consumer acceptance. In addition, the destruction of fungi and yeast was observed since the O3 application (from 1.8 × 104 cfu/g to NG = no growth). All other treatments stabilized and/or inhibited microorganisms' growth only. By adding CO2 gas also played an important role in the nut quality. Regarding cost, gaseous O3 showed to be of low cost for application in the nut packs.
doi:10.1155/2011/813591
PMCID: PMC3132530
PMID: 21760791
Background
Obesity is a chronic disease associated to an inflammatory process resulting in oxidative stress that leads to morpho-functional microvascular damage that could be improved by some dietary interventions. In this study, the intake of Brazil nuts (Bertholletia excelsa), composed of bioactive substances like selenium, α- e γ- tocopherol, folate and polyunsaturated fatty acids, have been investigated on antioxidant capacity, lipid and metabolic profiles and nutritive skin microcirculation in obese adolescents.
Methods
Obese female adolescents (n = 17), 15.4 ± 2.0 years and BMI of 35.6 ± 3.3 kg/m2, were randomized 1:1 in two groups with the diet supplemented either with Brazil nuts [BNG, n = 08, 15-25 g/day (equivalent to 3 to 5 units/day)] or placebo [PG (lactose), n = 09, one capsule/day] and followed for 16 weeks. Anthropometry, metabolic-lipid profiles, oxidative stress and morphological (capillary diameters) and functional [functional capillary density, red blood cell velocity (RBCV) at baseline and peak (RBCVmax) and time (TRBCVmax) to reach it during post-occlusive reactive hyperemia, after 1 min arterial occlusion] microvascular variables were assessed by nailfold videocapillaroscopy at baseline (T0) and after intervention (T1).
Results
T0 characteristics were similar between groups. At T1, BNG (intra-group variation) had increased selenium levels (p = 0.02), RBCV (p = 0.03) and RBCVmax (p = 0.03) and reduced total (TC) (p = 0.02) and LDL-cholesterol (p = 0.02). Compared to PG, Brazil nuts intake reduced TC (p = 0.003), triglycerides (p = 0.05) and LDL-ox (p = 0.02) and increased RBCV (p = 0.03).
Conclusion
Brazil nuts intake improved the lipid profile and microvascular function in obese adolescents, possibly due to its high level of unsaturated fatty acids and bioactive substances.
Trial Registration
Clinical Trials.gov NCT00937599
doi:10.1186/1743-7075-8-32
PMCID: PMC3123174
PMID: 21619692
microcirculation; obesity; Brazil nuts; adolescents; oxidative stress; lipid profile
The central nervous system (CNS) depressant and anticonvulsant activities of iso-6-spectaline (SPEC) were investigated in animal models. The SPEC from Senna spectabilis var. excelsa (Schrad) (0.1, 0.5 and 1.0 mg/ kg) injected by oral route (p.o.) in mice caused a significant decrease in the motor activity up to 30 days after the administration and in the dose of 1.0 mg/kg significantly reduced the remaining time on the Rota-rod apparatus. Additionally, SPEC (0.1, 0.5 and 1.0 mg/kg, p.o.) was also capable of promoting increase of latency for development of convulsions induced by pentylenetetrazole. This SPEC was also capable of promoting an increase of latency for development of convulsions induced by picrotoxin at highest dose. In the same way, the anticonvulsant effect of SPEC was affected by pretreatment with flumazenil, a selective antagonist of the benzodiazepine site of the GABAA receptor. These results suggest possible CNS depressant and anticonvulsant activities in mice that needs further investigation.
doi:10.4103/0975-1483.83772
PMCID: PMC3159278
PMID: 21897664
Fabaceae; open field; pentylenetetrazole; picrotoxin; senna spectabilis
The olive fruit fly, Bactrocera oleae, is the most important pest of olives in olive growing regions worldwide, especially in the Mediterranean basin and North America. Despite the economic importance of the olive fly, the colonization route of this species is unclear. We used nuclear microsatellite markers and mitochondrial DNA to provide information about the population structure and invasion route of olive fly populations in Turkey, as representative of the Eastern Mediterranean region. Adult fly samples were collected from 38 sublocations covering all olive growing regions in Turkey. The simple sequence variability data revealed a significant genetic variability in olive fly populations and a certain degree of differentiation between Mediterranean and Aegean populations. Mediterranean populations harbor higher levels of microsatellite variation than Aegean populations, which points to the eastern part of the Mediterranean as the putative source of invasion. mtDNA results suggest olive flies from the western part of Turkey are closely related to Italo-Aegean flies of the Mediterranean basin and the olive fly populations have invaded the northern part of the Mediterranean basin through western Turkey. In addition, finding specific American haplotypes in high frequencies might indicate that Turkey is the possible source of American olive fly populations. In order to more precisely characterize the population structure and invasion routes of this organism, more DNA-based sequence analysis should be carried out worldwide.
doi:10.1371/journal.pone.0056067
PMCID: PMC3573072
PMID: 23457499
Background:
Biologically active compounds from natural sources are of interest as possible new drugs for different diseases. Over many centuries humans have been mining the bounties of nature for discovering natural products that have been used for the treatment of all human diseases. Ailanthus excelsa Roxb. (Simaroubaceae) is widely used in the Indian system of medicine as an antiasthmatic, antispasmodic, bronchodilator, anticolic pain, anticancer, antidiabetic etc. The plant was also reported for its antiasthmatic, bronchodilatory, antiallegic and many more such activities.
Objective:
To evaluate the antihistaminic activity of aqueous extract of stem bark of Ailanthus excelsa Roxb.
Materials and Methods:
We have studied the effect of aqueous extract of stem barks of A. excelsa Roxb. at a doses 100 μg/mL in the isolated goat tracheal chain preparation in vitro and 100, 200, 400 mg/kg doses orally in passive paw anaphylaxis in rat, clonidine-induced catalepsy in mice models in vivo for its antihistaminic activity.
Results:
Aqueous extract of stem barks of A. excelsa Roxb. significantly (***P<0.001) inhibits the percentage contraction at concentration of 100 μg/mL in goat tracheal chain preparation. A. excelsa Roxb. extract (100, 200, and 400 mg/kg oral) and dexamethasone (0.5 mg/kg, i.p.) also significantly reduced (**P<0.01) the paw volume at fourth hour and the percentage inhibition was found to be 13.98%, 28.49%, 42.47% and 46.77% respectively. The aqueous extract of stem barks of A. excelsa Roxb. (100, 200, 400 mg/kg, p.o.) and chlorpheniramine maleate (10 mg/kg, i.p.) significantly inhibited (*P<0.05, **P< 0.01) clonidine-induced catalepsy in mice at 150 min after the administration of clonidine.
Conclusion:
The aqueous extract of stem bark of A. excelsa Roxb. possess significant antihistaminic activity (H1-antagonist) and can be attributed to bronchodilating, anti-inflammatory, adaptogenic activity etc. Hence detailed study needs to be conducted to evaluate the phytoconstituent responsible for the above mentioned results and their clinical efficacy in the treatment of related diseases.
doi:10.4103/0974-8490.85014
PMCID: PMC3193625
PMID: 22022173
Ailanthus excelsa Roxb; antihistaminic activity; passive paw anaphylaxis
• Background and Aims The assessment of the genetic variability and the identification of isolated populations within a given species represent important information to plan conservation strategies on a genetic basis. In this work, the genetic variability in five natural populations of Juniperus phoenicea, three from Sardinia, one from Cyprus and the last one in the Maritime Alps was analysed by means of ISSRs, on the hypothesis that the latter could have been a refugial one during the last glaciation.
• Methods ISSRs were chosen because of their ability to detect variation without any prior sequence information. The use of three primers yielded 45 reproducible, polymorphic bands, which were utilized to estimate the basic parameters of genetic variability and diversity.
• Key Results All of the populations analysed harboured an adequate amount of genetic variability, with HS = 0·1299. The proportion of genetic diversity between populations has been estimated by GST = 0·12. The three Sardinian populations are separated, as tested by AMOVA, from the Cyprus and the continental ones.
• Conclusions The results indicate that geographical isolation has represented a major barrier to gene flow in Juniperus phoenicea. This work represents a first step towards a full genetic characterization of a conifer from the Mediterranean, a world biodiversity hotspot confronted with climate change, and thus contributes towards the planning of genetics-informed conservation strategies.
doi:10.1093/aob/mcj024
PMCID: PMC2803359
PMID: 16311272
Juniperus phoenicea L; genetic variation; ISSR; conservation; Cupressaceae
Background
Due to its history, with a high number of migration events, the Mediterranean basin represents a challenging area for population genetic studies. A large number of genetic studies have been carried out in the Mediterranean area using different markers but no consensus has been reached on the genetic landscape of the Mediterranean populations. In order to further investigate the genetics of the human Mediterranean populations, we typed 894 individuals from 11 Mediterranean populations with 25 single-nucleotide polymorphisms (SNPs) located on the X-chromosome.
Results
A high overall homogeneity was found among the Mediterranean populations except for the population from Morocco, which seemed to differ genetically from the rest of the populations in the Mediterranean area. A very low genetic distance was found between populations in the Middle East and most of the western part of the Mediterranean Sea.
A higher migration rate in females versus males was observed by comparing data from X-chromosome, mt-DNA and Y-chromosome SNPs both in the Mediterranean and a wider geographic area.
Multilocus association was observed among the 25 SNPs on the X-chromosome in the populations from Ibiza and Cosenza.
Conclusion
Our results support both the hypothesis of (1) a reduced impact of the Neolithic Wave and more recent migration movements in NW-Africa, and (2) the importance of the Strait of Gibraltar as a geographic barrier. In contrast, the high genetic homogeneity observed in the Mediterranean area could be interpreted as the result of the Neolithic wave caused by a large demic diffusion and/or more recent migration events. A differentiated contribution of males and females to the genetic landscape of the Mediterranean area was observed with a higher migration rate in females than in males. A certain level of background linkage disequilibrium in populations in Ibiza and Cosenza could be attributed to their demographic background.
doi:10.1186/1471-2148-8-75
PMCID: PMC2315647
PMID: 18312628
Biologically active compounds from natural sources are of interest as possible new drugs for infectious diseases. Ailanthus excelsa Roxb. has been used in Indian system of medicine in the treatment of asthma, bronchitis, cold, colic pain, etc. Stem bark of A. excelsa Roxb. has been used as a decoction in traditional claims. So, our traditional claims enforced us to evaluate its bronchodilator activity. We have evaluated its bronchodilator activity in milk-induced leukocytosis and eosinophilia, clonidine-induced mast cell degranulation, bronchoalveolar lavage fluid (BALF), and lung histopathology models. The aqueous extract of stem bark in doses of 100, 200, 400 mg/kg showed significant activity.
doi:10.4103/0974-8490.62955
PMCID: PMC3140105
PMID: 21808549
Bronchodilator; Ailanthus excelsa Roxb.; bronchoalveolar lavage fluid
Juniperus and Cupressus genera are mainly used as diuretic, stimulant, and antiseptic, for common cold and wound healing in Turkish folk medicine. In the present study, essential oils obtained from cones of Cupressus and berries of Juniperus were evaluated for their wound healing and anti-inflammatory effects. In vivo wound healing activity was evaluated by linear incision and circular excision experimental wound models, assessment of hydroxyproline content, and subsequently histopathological analysis. The healing potential was comparatively assessed with a reference ointment Madecassol. Additionally acetic-acid-induced capillary permeability test was used for the oils' anti-inflammatory activity. The essential oils of J. oxycedrus subsp. oxycedrus and J. phoenicea demonstrated the highest activities, while the rest of the species did not show any significant wound healing effect. The experimental study revealed that J. oxycedrus subsp. oxycedrus and J. phoenicea display remarkable wound healing and anti-inflammatory activities, which support the folkloric use of the plants.
doi:10.1155/2012/728281
PMCID: PMC3175711
PMID: 21941588
Background
Population extinction risk in a fragmented landscape is related to the differential ability of the species to spread its genes across the landscape. The impact of landscape fragmentation on plant population dynamics will therefore vary across different spatial scales. We quantified successful seed-mediated dispersal of the dioecious shrub Juniperus communis in a fragmented landscape across northwestern Europe by using amplified fragment length polymorphism (AFLP) markers. Furthermore we investigated the genetic diversity and structure on two spatial scales: across northwestern Europe and across Flanders (northern Belgium). We also studied whether seed viability and populations size were correlated with genetic diversity.
Results
Unexpectedly, estimated seed-mediated dispersal rates were quite high and ranged between 3% and 14%. No population differentiation and no spatial genetic structure were detected on the local, Flemish scale. A significant low to moderate genetic differentiation between populations was detected at the regional, northwest European scale (PhiPT = 0.10). In general, geographically nearby populations were also genetically related. High levels of within-population genetic diversity were detected but no correlation was found between any genetic diversity parameter and population size or seed viability.
Conclusions
In northwestern Europe, landscape fragmentation has lead to a weak isolation-by-distance pattern but not to genetic impoverishment of common juniper. Substantial rates of successful migration by seed-mediated gene flow indicate a high dispersal ability which could enable Juniperus communis to naturally colonize suitable habitats. However, it is not clear whether the observed levels of migration will suffice to counterbalance the effects of genetic drift in small populations on the long run.
doi:10.1186/1471-2156-12-73
PMCID: PMC3176195
PMID: 21859457
Pollen from cedar and cypress trees is a major cause of seasonal hypersensitivity in humans in several regions of the Northern Hemisphere. We report the first crystal structure of a cedar allergen, Jun a 1, from the pollen of the mountain cedar Juniperus ashei (Cupressaceae). The core of the structure consists primarily of a parallel β-helix, which is nearly identical to that found in the pectin/pectate lyases from several plant pathogenic microorganisms. Four IgE epitopes mapped to the surface of the protein are accessible to the solvent. The conserved vWiDH sequence is covered by the first 30 residues of the N terminus. The potential reactive arginine, analogous to the pectin/pectate lyase reaction site, is accessible to the solvent, but the substrate binding groove is blocked by a histidine-aspartate salt bridge, a glutamine, and an α-helix, all of which are unique to Jun a 1. These observations suggest that steric hindrance in Jun a 1 precludes enzyme activity. The overall results suggest that it is the structure of Jun a 1 that makes it a potent allergen.
doi:10.1074/jbc.M409655200
PMCID: PMC2653420
PMID: 15539389
Background and Aims
High mountain ranges of the Mediterranean Basin harbour a large number of narrowly endemic plants. In this study an investigation is made of the levels and partitioning of genetic diversity in Narcissus longispathus, a narrow endemic of south-eastern Spanish mountains characterized by a naturally fragmented distribution due to extreme specialization on a rare habitat type. By using dense sampling of populations across the species' whole geographical range, genetic structuring at different geographical scales is also examined.
Methods
Using horizontal starch-gel electrophoresis, allozyme variability was screened at 19 loci for a total of 858 individuals from 27 populations. The data were analysed by means of standard statistical approaches in order to estimate gene diversity and the genetic structure of the populations.
Key Results
Narcissus longispathus displayed high levels of genetic diversity and extensive diversification among populations. At the species level, the percentage of polymorphic loci was 68 %, with average values of 2·1, 0·11 and 0·14 for the number of alleles per locus, observed heterozygosity and expected heterozygosity, respectively. Southern and more isolated populations tended to have less genetic variability than northern and less-isolated populations. A strong spatial patterning of genetic diversity was found at the various spatial scales. Gene flow/drift equilibrium occurred over distances <4 km. Beyond that distance divergence was relatively more influenced by drift. The populations studied seem to derive from three panmictic units or ‘gene pools’, with levels of admixture being greatest in the central and south-eastern portions of the species' range.
Conclusions
In addition to documenting a case of high genetic diversity in a narrow endemic plant with naturally fragmented populations, the results emphasize the need for dense population sampling and examination of different geographical scales for understanding population genetic structure in habitat specialists restricted to ecological islands.
doi:10.1093/aob/mcn086
PMCID: PMC2712358
PMID: 18556752
Allozymes; genetic diversity; geographical scale; habitat isolation; Narcissus longispathus; Mediterranean endemism; mountain range; natural fragmented distribution
Background
Schmidtea mediterranea (Platyhelminthes, Tricladida, Continenticola) is found in scattered localities on a few islands and in coastal areas of the western Mediterranean. Although S. mediterranea is the object of many regeneration studies, little is known about its evolutionary history. Its present distribution has been proposed to stem from the fragmentation and migration of the Corsica-Sardinia microplate during the formation of the western Mediterranean basin, which implies an ancient origin for the species. To test this hypothesis, we obtained a large number of samples from across its distribution area. Using known and new molecular markers and, for the first time in planarians, a molecular clock, we analysed the genetic variability and demographic parameters within the species and between its sexual and asexual populations to estimate when they diverged.
Results
A total of 2 kb from three markers (COI, CYB and a nuclear intron N13) was amplified from ~200 specimens. Molecular data clustered the studied populations into three groups that correspond to the west, central and southeastern geographical locations of the current distribution of S. mediterranea. Mitochondrial genes show low haplotype and nucleotide diversity within populations but demonstrate higher values when all individuals are considered. The nuclear marker shows higher values of genetic diversity than the mitochondrial genes at the population level, but asexual populations present lower variability than the sexual ones. Neutrality tests are significant for some populations. Phylogenetic and dating analyses show the three groups to be monophyletic, with the west group being the basal group. The time when the diversification of the species occurred is between ~20 and ~4 mya, although the asexual nature of the western populations could have affected the dating analyses.
Conclusions
S. mediterranea is an old species that is sparsely distributed in a harsh habitat, which is probably the consequence of the migration of the Corsica-Sardinia block. This species probably adapted to temperate climates in the middle of a changing Mediterranean climate that eventually became dry and hot. These data also suggest that in the mainland localities of Europe and Africa, sexual individuals of S. mediterranea are being replaced by asexual individuals that are either conspecific or are from other species that are better adapted to the Mediterranean climate.
doi:10.1186/1471-2148-11-274
PMCID: PMC3203090
PMID: 21943163
Background and Aims
This study examines the pattern of genetic variability and genetic relationships of wild olive (Olea europaea subsp. europaea var. sylvestris) populations in the north-western Mediterranean. Recent bottleneck events are also assessed and an investigation is made of the underlying population structure of the wild olive populations.
Methods
The genetic variation within and between 11 wild olive populations (171 individuals) was analysed with eight microsatellite markers. Conventional and Bayesian-based analyses were applied to infer genetic structure and define the number of gene pools in wild olive populations.
Key Results
Bayesian model-based clustering identified four gene pools, which was in overall concordance with the Factorial Correspondence Analysis and Fitch–Margoliash tree. Two gene pools were predominantly found in southern Spain and Italian islands, respectively, in samples gathered from undisturbed forests of the typical Mediterranean climate. The other two gene pools were mostly detected in the north-eastern regions of Spain and in continental Italy and belong to the transition region between the temperate and Mediterranean climate zones.
Conclusions
On the basis of these results, it can be assumed that the population structure of wild olives from the north-western Mediterranean partially reflects the evolutionary history of these populations, although hybridization between true oleasters and cultivated varieties in areas of close contact between the two forms must be assumed as well. The study indicates a degree of admixture in all the populations, and suggests some caution regarding genetic differentiation at the population level, making it difficult to identify clear-cut genetic boundaries between candidate areas containing either genuinely wild or feral germplasm.
doi:10.1093/aob/mcm132
PMCID: PMC2533604
PMID: 17613587
Olea europaea; genetic variability; gene pools; microsatellites; oleasters; population structure
Background
We sought to investigate the single and combined effect of Mediterranean diet, being physically active, moderate alcohol use, and non-smoking on clinical status of 150 elderly people from Cyprus.
Methods
The study comprises individuals enrolled in surveys from Greece and Cyprus. This work includes 53 apparently men and 97 women, aged 65 to 100 years, from various areas of Cyprus. The cohort study was conducted between 2004 and 2005. A diet score that assesses the inherent characteristics of the Mediterranean diet was developed (range 0–55) and then a healthy index was calculated that evaluated four lifestyle habits (range 0 – 4), i.e. non-smoking, alcohol intake, physical activity and adherence to the Mediterranean diet (i.e. above the median of the score).
Results
65% participants had hypercholesterolemia (total serum cholesterol > 200 mg/dl or use of lipid lowering agents). Moreover, 32% of the participants reported physically active, 5% reported smoking habits and 4% that they have stopped smoking during the past decade, while 8% reported alcohol drinking. A positive association was observed between prevalence of hypercholesterolemia and smoking habits (odds ratio = 4.3, p = 0.03), while an inverse association was observed between hypercholesterolemia, alcohol drinking (odds ratio = 0.3, p = 0.04) and adherence to a Mediterranean diet (odds ratio = 0.77, p = 0.02), controlled for age, sex, and other factors.
Conclusion
Adherence to a Mediterranean diet and healthful lifestyle is associated with reduced odds of having hypercholesterolemia among elderly people.
doi:10.1186/1476-511X-4-17
PMCID: PMC1208941
PMID: 16144549
Cedar pollens cause severe allergic disease throughout the world. We have previously characterized allergenic pollen glycoproteins from mountain cedar (Juniperus ashei) that bind to allergen-specific immunoglobulin E (IgE). In the present report, we investigated an alternative pathway of mast cell activation by mountain cedar pollen extract through IgE-independent mechanisms. We show that mountain cedar pollen directly induces mast cell serotonin and IL-4 release and enhances release induced by IgE cross-linking. Concomitant with mediator release, high levels of intracellular reactive oxygen species (ROS) were generated, and both ROS and serotonin release were inhibited by anti-oxidants. These findings suggest that alternative mechanisms exist whereby pollen exposure enhances allergic inflammatory mediator release through mechanisms that involve ROS. These mechanisms have the potential for enhancing the allergenic potency of pollens.
doi:10.1016/j.cellimm.2011.08.019
PMCID: PMC3195927
PMID: 21944563
pollen; cytokines; mast cells; interleukin-4; reactive oxygen species; allergy; serotonin