Sex chromosome-linked species recognition and evolution of reproductive isolation in flycatchers     

Saether SA  Saetre GP  Borge T  Wiley C  Svedin N  Andersson G  Veen T  Haavie J  Servedio MR  Bures S  Král M  Hjernquist MB  Gustafsson L  Träff J  Qvarnström A 《Science (New York, N.Y.)》2007,318(5847):95-97

Interbreeding between species (hybridization) typically produces unfit offspring. Reduced hybridization should therefore be favored by natural selection. However, this is difficult to accomplish because hybridization also sets the stage for genetic recombination to dissociate species-specific traits from the preferences for them. Here we show that this association is maintained by physical linkage (on the same chromosome) in two hybridizing Ficedula flycatchers. By analyzing the mating patterns of female hybrids and cross-fostered offspring, we demonstrate that species recognition is inherited on the Z chromosome, which is also the known location of species-specific male plumage traits and genes causing low hybrid fitness. Limited recombination on the Z chromosome maintains associations of Z-linked genes despite hybridization, suggesting that the sex chromosomes may be a hotspot for adaptive speciation.  相似文献   

Technological Properties of Yeast Produced Surface Active Compounds in Connection with Their Application in Clean-Up Technologies     

Kristina Lhotska  Marek Sir  Jiri Mikes  Zuzana Honzajkova  Miroslav Minarik 《农业科学与技术》2014,(1):49-59

Biologically produced surfactants （SACs） can mobilize and solubilize non-aqueous phase liquids （NAPL） adsorbed onto soil constituents. The interest in microbial surfactants has increased during recent years due to their lower toxicity, higher biodegradability, selectivity and specific activity under extreme conditions than synthetic SACs. Main output of the project represents preparation of this yeast biosurfactant intended for washing of matrices contaminated by NAPL. The influence of cultivation media composition on biosurfactant production was studied and basic properties （critical micelle concentration （CMC）, minimum surface tension） of isolated biosurfactants were compared with properties of synthetic surfactant with surface tension measurement. The interracial tension of the systems containing aqueous solutions of different concentrations and non-polar substances was measured with petroleum compounds （kerosene Jet A-l）, aromatic and aliphatic hydrocarbons （represented by toluene and hexane）. The solution of biosurfactant Yarrowia lipolytica （YAR） in the concentration range of 0-500 mg/L reduced interracial tension by 80% in all representative systems with model contaminants; biosurfactant Candida bombicola （CAN） was less efficient. Solubilization properties were proved with toluene and hexachlorocyclohexane （HCH） isomers alpha and gamma, and effective concentration of biosurfactants was determined as 100 mg/L for toluene and HCH. SACs produced by lipophilic yeast with non-toxic and non-pathogenic status （Yarrowia lipolytica, Candida sp., etc.） seem to be very promising. The results obtained will be used for the application of biosurfactants in the clean-up technologies as agents for the mobilization of non-polar contaminants as well as for stimulation of bioremediation processes.  相似文献   

Interactions of nanobubbles with bovine serum albumin and papain films on gold surfaces     

Kolivoska V  Gál M  Hromadová M  Lachmanová S  Pospísil L 《Biointerphases》2011,6(4):164-170

Nanobubbles formed on monocrystalline gold/water interface by means of the ethanol-to-water solvent exchange were exposed to the solutions of either bovine serum albumin or papain proteins. Both proteins do not change the position of nanobubbles in water, as observed by in situ tapping mode atomic force microscopy imaging before and after the introduction of the protein. The aqueous environment was subsequently replaced by ethanol. While all nanobubbles were found to dissolve in ethanol in the presence of bovine serum albumin, most of them survived when papain was employed. The protective ability of papain was ascribed to its resistance towards the protein denaturation in aqueous solutions of ethanol. The authors employed in situ atomic force nanolithography to investigate the nanomorphology of the papain/nanobubble assemblies in ethanol.  相似文献   

Organic manure stimulates biological activity and barley growth in soil subject to secondary salinization   总被引：1，自引：0，他引：1  

Yongchao Liang  Jin Si  Miroslav Nikolic  Wei Chen 《Soil biology & biochemistry》2005,37(6):1185-1195

A pot experiment was performed to compare the impact of organic manure on soil enzymatic activity, respiration rate and the growth of two barley cultivars (Hordeum vulgare L.) differing in their salt tolerance under a simulated salinized environment. A plastic pot with a hole (2 cm in diameter) in the center of bottom was filled with an anthropogenic (paddy) soil and placed in a porcelain container containing NaCl solution (3.0 g L⁻¹) such that a secondary salinization process was simulated via upward capillary water movement along the soil profile. A treatment with neither organic manure nor simulated soil salinization was taken as a control (CK1). The organic manure was applied either inside or outside rhizobag made of nylon cloth (40 μm of pore size). The soil was treated with: 20 g kg⁻¹ rice straw (RS), 20 g kg⁻¹ pig manure (PM), or 10 g kg⁻¹ rice straw plus 10 g kg⁻¹ pig manure (RS+PM). No organic manure was added in an additional control treatment (CK2). The results indicated that the placement of organic manure both inside and outside rihzobags significantly increased the activity of urease, alkaline phosphatase and dehydrogenase, as well as respiration rate in both rhizosphere and bulk soils. Also, nutrient uptake by barley plants was enhanced in the treatments with organic manure amended either inside or outside rhizobags. The activity of these enzymes along with the respiration rate was higher in rhizosphere than in non-rhizosphere when organic manure was supplied inside rhizobags, while the opposite was found in the case of manure incorporated outside rhizobags. Among all the treatments, RS+PM treatment had most significant stimulating effects on enzymatic and microbial activity and shoot dry weight of barley, followed by PM and RS. Moreover, more significant stimulating effects on both enzyme activity and plant growth were achieved in the treatments with manure amended inside rhizobags than outside rhizobags. The results of the present study confirmed the view that incorporation of organic manure especially into soil-root zones is an effective low-input agro-technological approach to enhancing soil fertility and minimizing phytotoxicity induced by secondary salinization.  相似文献   

Silicon modulates the metabolism and utilization of phenolic compounds in cucumber (Cucumis sativus L.) grown at excess manganese     

Jelena Dragišić Maksimović  Jelena Bogdanović  Vuk Maksimović  Miroslav Nikolic 《植物养料与土壤学杂志》2007,170(6):739-744

Cucumber plants (Cucumis sativus L. cv. Chinese long) were grown in nutrient solution with increasing manganese (Mn) concentrations (0.5, 50, and 100 µM) with (+Si) or without silicon (–Si) supplied as silicic acid at 1.5 mM. High external Mn supply induced both growth inhibition of the whole plant and the appearance of Mn‐toxicity symptoms in the leaves. The application of Si alleviated Mn toxicity by increasing the biomass production. Although the total Mn concentration in the leaves did not differ significantly between +Si and –Si plants, symptoms of Mn toxicity were not observed in Si‐treated plants. The concentrations of phenolic compounds, particularly in the leaf extracts of cucumber plants grown at high external Mn concentrations, differed from those of plants grown without Si. The increased tissue concentrations of phenols (e.g., coniferyl alcohol, coumaric and ferulic acids) were in agreement with enhanced enzymes activities, i.e., peroxidases (PODs) and polyphenol oxidases (PPO) in the tissues of –Si plants. The activities of both enzymes were kept at a lower level in the tissue extracts of +Si plants grown at high external Mn concentrations. These results suggest that Si nutrition modulates the metabolism and utilization of phenolic compounds mainly at the leaf level, most probably as a consequence of the formation of Si‐polyphenol complexes.  相似文献   

Tradescantia Micronucleus and Vicia Chromosome Anatelophase Assays in Monitoring of Genotoxicity of Urban Soil     

Mišík  Miroslav  Mičieta  Karol 《Water, air, and soil pollution》2002,141(1-4):181-187

Tradescantia micronucleus assay (Trad MCN assay) and Vicia anatelophase chromosome aberration assay (Vicia assay) were used to evaluate genotoxicity of extracts from soil samples. Soil samples from six different sites in area of Bratislava - capital of the Slovak Republic - have been taken. As a negative control soil samples from Botanical garden of medicinal plants, Faculty of Pharmacy, Comenius University were used. Soil samples for Trad MCN assay were extracted with distilled water or 5% dimethylsulphoxide (DMSO). Similarly genotoxicity of sample extracted with distilled water by Vicia assay was evaluated. Two sites were found as most polluted. The results of the study indicate different level of pollution in selected sites.  相似文献   

Mycorrhizal association of Agrostis capillaris and Glomus intraradices under heavy metal stress: Combination of plant clones and fungal isolates from contaminated and uncontaminated substrates     

Radka Sudov  Pavla Doubkov  Miroslav Vostka 《Applied soil ecology》2008,40(1):19-29

The present study aimed to compare the impact of arbuscular mycorrhizal (AM) fungi on plant growth and heavy-metal (HM)-uptake when both plant and fungal symbionts originated either from contaminated or uncontaminated sites. HM-tolerance of six clones of the grass Agrostis capillaris and three isolates of the AM fungus Glomus intraradices of different origin was first tested separately. Plant clones from the vicinity of a lead smelter showed a consistently high HM-tolerance, whereas the control clones varied in their ability to cope with HMs. The AM isolate from the contaminated substrate also performed better under HM-stress than the isolates from uncontaminated soils. All A. capillaris clones were then grown in a contaminated substrate, uninoculated or inoculated either with a tolerant or non-tolerant G. intraradices isolate. Clones from the uncontaminated site accumulated considerably more HMs in their shoots and roots, regardless of inoculation. The effect of AM inoculation on plant growth and HM-uptake depended on the particular combination of plant clone and fungal isolate, without clear differences between tolerant and non-tolerant clones.  相似文献   

Effect of a non‐woven fabric covering on the residual activity of pendimethalin in lettuce and soil          下载免费PDF全文

Miroslav Jursík  Jana Kováčová  Martin Kočárek  Kateřina Hamouzová  Josef Soukup 《Pest management science》2017,73(5):1024-1030

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Antiproliferative and antiangiogenic effects of flavone eupatorin, an active constituent of chloroform extract of Orthosiphon stamineus leaves     

Dolečková I  Rárová L  Grúz J  Vondrusová M  Strnad M  Kryštof V 《Fitoterapia》2012,83(6):1000-1007

Flavone eupatorin is one of the constituents of Orthosiphon stamineus, a medicinal herb used in folk medicine in South East Asia for treatment of various disorders. In our study, we investigated the antiproliferative properties of a chloroform extract of the leaves of O. stamineus and of pure eupatorin. The compound was able to reduce the number of viable cancer cells to the same extent as the extract, with IC(50) values in micromolar range. Moreover, both the eupatorin standard and the extract caused cells to arrest in the G2/M phase of the cell cycle. This clearly demonstrates that eupatorin contributes significantly to the overall extract activity. Induction of mitotic catastrophe, accompanied by key molecular events defining apoptosis, is the mechanism of eupatorin-induced cell death. Importantly, eupatorin (at the doses cytotoxic to cancer cells) did not kill normal cells; it only limited migration of HUVEC endothelial cells and their ability to create tubes. The ability of eupatorin to nonspecifically inhibit many protein kinases was proven and is the probable cause of its cellular effects. In summary, eupatorin emerges as a promising agent in anticancer research.  相似文献   

Quest for the piroplasms in camels: identification of Theileria equi and Babesia caballi in Jordanian dromedaries by PCR     

Qablan MA  Sloboda M  Jirků M  Oborník M  Dwairi S  Amr ZS  Hořín P  Lukeš J  Modrý D 《Veterinary parasitology》2012,186(3-4):456-460

DNA of two species of piroplasmids was detected in dromedaries during a survey of blood protozoans in Jordan between 2007 and 2009. Ten clinically healthy camels (10%) originating from three Jordanian districts were found, using a PCR assay, to harbor Theileria or Babesia species in their blood and no mix infection was determined. Analysis of the partial 18S rRNA gene sequences of these parasites allowed their unambiguous identification as equine piroplasmids Babesia caballi (n=6) and Theileria equi (n=4). In case of latter species, a novel genotype was found in horses. This first molecular-based species determination of piroplasmids from camels further contributes to the growing evidence of low host specificity of piroplasmids.  相似文献