Autofluorescence Reveals Different Histological Localizations of Furanocoumarins in Fruit of Some Umbelliferae and Leguminosae

Differences were shown in histological localization of psoralensof Angelica archangelica, Daucus carota, Sium suave and Psoraleabituminosa. All the fruits examined contained furanocoumarinson the surface. Fruit tissues contained very low (Sium), medium(Angelica) or high (Psoralea) concentrations of these compounds.Seed covers showed low autofluorescence in Angelica but highin Sium . Not all the glands in fruit or seed tissue exhibitedautofluorescence. Embryos always contained furanocoumarins ontheir surface and in their tissues in varying proportions. Autofluorescencecan be homogeneously distributed among all cells of the embryo(Sium) or can be concentrated in certain cells (Psoralea).Copyright1993, 1999 Academic Press Autofluorescence, furanocoumarins     

The architecture of the spleen of the yellow-bellied toad, Bombina variegata

The spleen of the yellow-bellied toad, Bombina variegata , consists of distinct white and red pulps. The well-developed white pulp is formed by a large central lymphocytic region around the numerous blood vessels and by its smaller peripheral ramifications, both surrounded by the more or less developed connective tissue boundary layer. Large peripheral sinuses of the white pulp, filled mostly with lymphocytes, are usually present at the inner side of this boundary. At the outer side of the boundary layer, the lymphocytic marginal zone is often observed. This zone merges into the erythrocyte-rich red pulp formed by cellular cords and small venous sinusoids.
The structure of the spleen of Bombina variegata differs considerably from the spleens of other anuran species studied so far. The highly developed white pulp and its distinct separation from the red pulp may be connected with the important role of the spleen as the main secondary lymphoid organ of B. variegata. The splenic compartmentalization makes the yellow-bellied toads a useful model for experimental immunobiological studies.     

Gold nanoparticles and electromagnetic irradiation in tissue culture systems of bleeding heart: biochemical,physiological, and (cyto)genetic effects

Plant Cell, Tissue and Organ Culture (PCTOC) - This study aimed to analyze the effect of various mutagens on the in vitro development, physiological activity, acclimatization efficiency, and...     

Dominance‐related changes in spatial memory are associated with changes in hippocampal cell proliferation rates in mountain chickadees

It is well established that spatial memory is dependent on the hippocampus in both mammals and birds. As memory capacity can fluctuate on a temporal basis, it is important to understand the mechanisms mediating such changes. It is known that early memory‐dependent experiences in young animals result in hippocampal enlargement and in increased neurogenesis, including cell proliferation and neuron survival. It is less clear, however, whether temporal changes in spatial memory are also associated with changes in hippocampal anatomy and cell proliferation in fully grown and experienced adult animals. In a previous study, we experimentally demonstrated that socially subordinate mountain chickadees (Poecile gambeli) showed inferior spatial memory performance compared to their dominant group mates, in the absence of significant differences in baseline corticosterone levels. Here we investigated whether these differences in memory between dominant and subordinate birds were associated with changes in the hippocampus. Following memory tests, chickadees were injected with 5‐bromo‐2′‐deoxyuridine to label dividing cells and sacrificed 2 days after the injections. We found no significant differences in volume or the total number of neurons in the hippocampal formation between dominant and subordinate chickadees, but subordinate birds had significantly lower cell proliferation rates in the ventricular zone adjacent to both the hippocampus and mesopallium compared to the dominants. Individuals, which performed better on spatial memory tests tended to have higher levels of cell proliferation. These results suggest that social status can affect cell proliferation rates in the ventricular zone and support the hypothesis that neurogenesis might be involved in memory function in adult animals. © 2004 Wiley Periodicals, Inc. J Neurobiol, 2005     

Ploidy-dependent survival of progeny arising from crosses between natural allotriploid Cobitis females and diploid C. taenia males (Pisces,Cobitidae)

Crosses between 21 triploid hybrid Cobitis females and 19 C. taenia (2n = 48) males led to viable progeny; whereas no embryonic development was observed in crosses with tetraploid males (4n = 98). The ploidy status of 491 progenies randomly selected with flow cytometry (316) or chromosome analysis (175) revealed an average of 55.2 % triploids and 44.8 % tetraploids, but the ratio of 3n versus 4n fish did change during development. In the first 2 days after hatching, approximately 65.1 % of tetraploid larvae were observed. Their number decreased significantly to 30.8 and 6.2 % on average during 2–5 and 10–15 months of life, respectively. The karyotype of tetraploid progeny (4n = 98) included 3n = 74 chromosomes of the parental female and n = 24 of C. taenia male. The number of tetraploid progeny indicated indirectly that about 66 % of eggs from 3n females were fertilized with C. taenia. The rest of the eggs developed clonally via gynogenesis or hemiclonally via hybridogenesis into triploids of the same karyotype structure as parental females. We have documented for the first time that (at least under experimental conditions) tetraploids are commonly formed, but are less viable than triploids, and a ratio similar to what is found under natural conditions is finally attained. The current explanation concerning the ploidy and karyotype structure of the progeny confirms that the eggs of 3n Cobitis females are not only capable of maintaining all chromosomes but are also capable of incorporating the sperm genome, thus creating the potential to produce tetraploids.     

Heavy and light forms of some aminoacyl-tRNA synthetases in fraction X,microsomes and cytosol of rabbit liver

Summary Aminoacyl-tRNA synthetase activity for alanine, glutamic acid, lysine and phenylalanine was studied in the three subcellular fractions of rabbit liver: fraction X, microsomes and cytosol. From 60 to 80% of the enzyme activities were found in fraction X and microsomes. Fraction X was especially rich in the synthetase activities. By means of gel chromatography, heavy (over 10⁶ daltons) and light (below 480 × 10³ daltons) forms of lysyl- and phenylalanyl- but only light ones of alanyl- and glutamyl-tRNA synthetase activities were found in all the subcellular fractions studied. It is concluded that in higher organisms (mammals) all aminoacyl-tRNA synthetases, at least in part, are associated with cell structural constituents.Abbreviations ALA, GLU, LYS, PHE alanyl-, glutamyl-, lysyl-, phenylalanyl-tRNA synthetase - PMSF phenylmethylsulfonyl fluoride - BSA bovine serum albumin     

Microwave‐assisted 18O labeling of Fmoc‐protected amino acids

Recently, there has been an increased interest in isotopical labeling of peptides. Although there are several techniques allowing for a complete labeling of all carboxyl groups in peptides, regioselective labeling would be beneficial in many situations. Such labeling requires the use of ¹⁸O‐labeled Fmoc amino acids. We have designed a method for such labeling that is an improvement on a technique proposed earlier. The new procedure is suitable for microscale synthesis and could be used in peptide and proteomics laboratories. Although for the majority of tested amino acids our method gives good labeling efficiency, it is time consuming. Therefore, we have decided to use microwave‐assisted procedure. This approach resulted in reduction of reaction time to 15 min and increased reaction efficiency. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.     

A Comparative Study of Nitrilases Identified by Genome Mining

Escherichia coli strains expressing different nitrilases transformed nitriles or KCN. Six nitrilases (from Aspergillus niger (2), A. oryzae, Neurospora crassa, Arthroderma benhamiae, and Nectria haematococca) were arylacetonitrilases, two enzymes (from A. niger and Penicillium chrysogenum) were cyanide hydratases and the others (from P. chrysogenum, P. marneffei, Gibberella moniliformis, Meyerozyma guilliermondi, Rhodococcus rhodochrous, and R. ruber) preferred (hetero)aromatic nitriles as substrates. Promising nitrilases for the transformation of industrially important substrates were found: the nitrilase from R. ruber for 3-cyanopyridine, 4-cyanopyridine and bromoxynil, the nitrilases from N. crassa and A. niger for (R,S)-mandelonitrile, and the cyanide hydratase from A. niger for KCN and 2-cyanopyridine.