Dissection of the nuclear genome of barley by chromosome flow sorting

Isolation of mitotic chromosomes using flow cytometry is an attractive way to dissect nuclear genomes into their individual chromosomal components or portions of them. This approach is especially useful in plants with complex genomes, where it offers a targeted and hence economical approach to genome analysis and gene cloning. In several plant species, DNA of flow-sorted chromosomes has been used for isolation of molecular markers from specific genome regions, for physical mapping using polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH), for integration of genetic and physical maps and for construction of chromosome-specific DNA libraries, including those cloned in bacterial artificial chromosome vectors. Until now, chromosome analysis and sorting using flow cytometry (flow cytogenetics) has found little application in barley (2n = 14, 1C ∼ 5,100 Mbp) because of the impossibility of discriminating and sorting individual chromosomes, except for the smallest chromosome 1H and some translocation chromosomes with DNA content significantly different from the remaining chromosomes. In this work, we demonstrate that wheat–barley ditelosomic addition lines can be used to sort any arm of barley chromosomes 2H–7H. Thus, the barley genome can be dissected into fractions representing only about 6–12% of the total genome. This advance makes the flow cytogenetics an attractive tool, which may greatly facilitate genome analysis and gene cloning in barley.     

Cytotoxic activities of Hypericum perforatum L. extracts against 2D and 3D cancer cell models

Cytotechnology - Six extracts were obtained from plant species Hypericum perforatum L., collected at Samsun in Turkey. The aim of this study was to examine the mechanisms of the anticancer activity...     

The Iranian vole Microtus irani occurs in Lebanon (Mammalia: Rodentia)

We studied 1140 bp cytochrome b sequences of social voles from three localities in Lebanon. The results were compared with published sequences representing seven species of social voles. New sequences from Lebanon clustered with reference samples of two species: M. guentheri and M. irani. While M. guentheri was already reported for Lebanon, M. irani is a new addition to the fauna of Lebanon, and the third known record for the species. Animals were collected in two localities above Tripolis at 855 m and 1430 m a.s.l., respectively.     

Differences in transpiration of Norway spruce drought stressed trees and trees well supplied with water

The paper focuses on the evaluation of transpiration as a physiological process, which is very sensitive to drought stress. Reactions of 25-year-old Norway spruce (Picea abies (L.) Karst.) trees to drought were examined during 2009 summer. Sap flow rate (SF), meteorological and soil characteristics were measured continually. Vapour pressure deficit of the air (VPD) and cumulative transpiration deficit (KTD) was calculated. During the second half of the vegetation period, the decrease in soil water content was observed and irrigation was applied to a group of spruce trees, while the second group was treated under natural soil drought. On the days, when the differences in transpiration between irrigated (IR) and non-irrigated (NIR) trees were significant (21 days), transpiration of NIR trees was only 23% of the transpiration of IR trees. We found significant differences in transpiration when the soil water content (SWC) of NIR variant at a depth of 5–15 cm ranged from 10.4 to 13.7%. Under both regimes of water availability, daily transpiration significantly responded to atmospheric conditions. However, the influence of all assessed meteorological parameters on SF of NIR trees was significantly lower than on IR tree. The dependency of transpiration on evaporative demands of atmosphere decreased with the decreasing soil moisture. Cumulative transpiration deficit of the stand during the entire evaluated period was 50.9 mm. The difference between the transpiration of the mean NIR tree and of the mean IR tree was 278.8 L over the assessed period of 47 days (5.9 L per day). The transpiration of NIR trees was 40.3% from the transpiration of IR trees during this period.     

Environmental,geographical and time-related impacts on avian malaria infections in native and introduced populations of house sparrows (Passer domesticus), a globally invasive species

Aim

The increasing spread of vector-borne diseases has resulted in severe health concerns for humans, domestic animals and wildlife, with changes in land use and the introduction of invasive species being among the main possible causes for this increase. We explored several ecological drivers potentially affecting the local prevalence and richness of avian malaria parasite lineages in native and introduced house sparrows (Passer domesticus) populations.

Location

Global.

Time period

2002–2019.

Major taxa studied

Avian Plasmodium parasites in house sparrows.

Methods

We analysed data from 2,220 samples from 69 localities across all continents, except Antarctica. The influence of environment (urbanization index and human density), geography (altitude, latitude, hemisphere) and time (bird breeding season and years since introduction) were analysed using generalized additive mixed models (GAMMs) and random forests.

Results

Overall, 670 sparrows (30.2%) were infected with 22 Plasmodium lineages. In native populations, parasite prevalence was positively related to urbanization index, with the highest prevalence values in areas with intermediate urbanization levels. Likewise, in introduced populations, prevalence was positively associated with urbanization index; however, higher infection occurred in areas with either extreme high or low levels of urbanization. In introduced populations, the number of parasite lineages increased with altitude and with the years elapsed since the establishment of sparrows in a new locality. Here, after a decline in the number of parasite lineages in the first 30 years, an increase from 40 years onwards was detected.

Main conclusions

Urbanization was related to parasite prevalence in both native and introduced bird populations. In invaded areas, altitude and time since bird introduction were related to the number of Plasmodium lineages found to be infecting sparrows.     

Agrobacterium bohemicum sp. nov. isolated from poppy seed wastes in central Bohemia

Two non-pathogenic strains R89-1 and R90^T isolated from poppy seed (Papaver somniferum L.) wastes were phenotypically and genotypically characterized. Multilocus sequence analysis (MLSA) was conducted with six genes (atpD, glnA, gyrB, recA, rpoB, 16S rRNA). The strains represented a new species which clustered with Agrobacterium rubi NBRC 13261^T and Agrobacterium skierniewicense Ch11^T type strains. MLSA was further accompanied by whole-genome phylogeny, in silico DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses for both strains. ANI and dDDH values were deep below the species delineation threshold. Phenotypic features of the novel strains unequivocally allowed their differentiation from all other Agrobacterium species. Unlike other agrobacteria, the strains were salt sensitive and were able to biotransform morphine alkaloids. The dominant cellular fatty acids are 18:1 w7c, 16:0 and 12:0 aldehyde/16:1 iso I/14:0 3OH summed in feature 2 and the major respiratory quinine is Q-10 (87%). The DNA G + C content is 56 mol%. Microbial community analysis indicated probable association with P. somniferum plant material. Altogether, these characteristics showed that strains R90^T and R89-1 represent a new species of the genus Agrobacterium which we propose to name Agrobacterium bohemicum. The type strain of A. bohemicum is R90^T (=CCM 8736^T = DSM 104667^T).     

Effect of blending lignin biopolymer on the biodegradability of polyolefin plastics

The ability of the lignin-degrading microorganism Phanerochaete chrysosporium to attack polyethylene and polypropylene was investigated using a series of polymer blends containing 10, 20 and 30% lignin obtained from the waste product of pulp and paper industry. In the cultivation medium, lignin peroxidase and Mn(II)peroxidase activities were detected. Degradation was verified by quantitative u.v. spectrophotometric analysis of the cultivation medium and by liberation of CO₂ from the blends. Measurement of the tensile strength after 30-days cultivation showed that the mechanical properties of the polymer blends were decreased during the biodegradation process. The isolation of oligomer fractions by tetrahydrofuran (THF) extraction of biodegraded polymers and their characterization by gel permeation chromatography (GPC), u.v. and Fourier transmission infrared (FTIR) spectroscopy indicates that biotransformation of the lignin component during the cultivation process initiates partial biodegradation of the synthetic polymer matrix.     

Comparison of two ultracentrifugation procedures for separation of nonhuman primate lipoproteins.

A comparison of nonhuman primate plasma lipoproteins isolated by swinging bucket rotor density gradient or fixed angle rotor differential ultracentrifugation is described. Whereas these two methods produced comparable results for the composition of low density (LDL) and high density (HDL) lipoproteins, the very low density lipoprotein (VLDL) fraction isolated with the swinging-bucket rotor contained relatively more cholesterol (free and esterified) and less phospholipid and protein than that fraction obtained with the fixed-angle rotor. Estimations of lipoprotein concentration by agarose gel electrophoresis and particle size by electron microscopy coupled with molar ratios of surface to core constituents indicate that the swinging bucket procedure resulted in a more complete harvest of VLDL particles, especially those in the larger size range.