Flavonglykoside in Blüten vonPaeonia arborea undPaeonia suffruticosa

Summary Three glycosides have been isolated fromPaeonia arborea: kaempferol-3--glucoside-7--glucoside (Paeonoside), apigenin-7--glucoside, and apigenin-7-rhamnoglucoside (Rhoifolin).Paeonia suffruticosa also contains these three compounds but its main glycoside is kaempferol-3--glucoside (astragalin), which is present inPaeonia arborea only in traces.     

Use of random amplified polymorphic DNA (RAPD) markers in the discrimination and verification of genotypes in Eucalyptus

We carried out four separate studies using random amplified polymorphic DNA (RAPD) markers to analyse samples of Eucalyptus supplied by several different organisations. The objective was to examine the reproducibility of the RAPD technique and its ability to discriminate between individual genotypes for verification of clonal identities. We found that RAPD profiles that are unique to a genotype can be generated reliably and simply and that even closely related genotypes can be distinguished. In addition, in each of the four studies, we detected cases where the plant material studied had been mis-sampled or mis-labelled (i.e. the RAPD profiles were not consistent with the identification numbers): (1) ramets of a Eucalyptus grandis clone were found to be derived from 2 different clones; (2) ramets labelled as 2 different Eucalyptus hybrid clones were found to be the same clone, owing to a mis-planted clonal hedge; (3) samples supplied as a single progeny of a controlled E. nitens cross were derived from two crosses involving different pairs of parents; (4) mis-labelling was detected for ramets of 4 of a set of 10 clones of E. grandis and E. camaldulensis. For three of the four studies, the detection of genotype mis-identifications was unexpected, suggesting that labelling or sampling errors during the handling of plant material are a frequent occurrence, with potentially serious economic consequences.     

Dynamics of 'immotile' olfactory cilia in the silkmoth Antheraea

Living olfactory sensory dendrites of the silkmoth Antheraea which are modified cilia lacking the central microtubule pair have been observed by means of video microscopy in sensilla from which the apical tips had been pinched off as well as in vitro after isolation. Dendrites project out of the opened hair tips cither spontaneously without manipulation or after application of basal pressure via a syringe connected to the haemolymph side. Spontaneously appearing dendrites can repeatedly project up to ca. 60 mum from, and retract back into, the hairs. They tend to remain straight, but curve if they project too far and bend on meeting an obstacle. The average elongation velocity of the dendrites is 0.4 mum/sec. After application of basal pressure, large numbers of dendrites immediately slide out of the apically opened hairs. These dendrites usually detach at their bases and float free in the solution until settling down at the bottom of the petri dish. They are able to make active movements, for example bending between points of attachment. Dendrites tend to adhere to other dendrites, sometimes making sliding movements against each other. The ciliary olfactory dendrites are backed by a large number of microtubules which appear to be interconnected by fine filaments, most probably microtubule-associated proteins (MAPs). The elongation and shortening of the dendrites is explained here by a sliding-filament mechanism similar to the one acting in 'true motile' cilia. As the cytoskcleton is not as highly organized as in the latter, the resulting movements are limited to elongation and contraction, bending being brought about only passively by apical resistance. Membrane beads have been observed to appear on, and move along, the dendrites. Their number increases with the age of the preparation.     

Decomposing trends in bird populations: Climate,life histories and habitat affect different aspects of population change

Aim

Despite the complexity of population dynamics, most studies concerning current changes in bird populations reduce the trajectory of population change to a linear trend. This may hide more complex patterns reflecting responses of bird populations to changing anthropogenic pressures. Here, we address this complexity by means of multivariate analysis and attribute different components of bird population dynamics to different potential drivers.

Location

Czech Republic.

Methods

We used data on population trajectories (1982–2019) of 111 common breeding bird species, decomposed them into independent components by means of the principal component analysis (PCA), and related these components to multiple potential drivers comprising climate, land use change and species' life histories.

Results

The first two ordination axes explained substantial proportion of variability of population dynamics (42.0 and 12.5% of variation in PC1 and PC2 respectively). The first axis captured linear population trend. Species with increasing populations were characterized mostly by long lifespan and warmer climatic niches. The effect of habitat was less pronounced but still significant, with negative trends being typical for farmland birds, while positive trends characterized birds of deciduous forests. The second axis captured the contrast between hump-shaped and U-shaped population trajectories and was even more strongly associated with species traits. Species migrating longer distances and species with narrower temperature niches revealed hump-shaped population trends, so that their populations mostly increased before 2000 and then declined. These patterns are supported by the trends of total abundances of respective ecological groups.

Main Conclusion

Although habitat transformation apparently drives population trajectories in some species groups, climate change and associated species traits represent crucial drivers of complex population dynamics of central European birds. Decomposing population dynamics into separate components brings unique insights into non-trivial patterns of population change and their drivers, and may potentially indicate changes in the regime of anthropogenic effects on biodiversity.     

Studies on protein-phosphorylation reactions in isolated chromatin.

The endogenous protein-phosphorylating activity of isolated chromatin was tested. We have found that a group of high-molecular-weight proteins (Mr greater than 50 000) was preferentially phosphorylated when chromatin from mouse ascites cells or from bovine lymphocytes was incubated in the presence of ATP. After disintegration of chromatin by nuclease treatment or by high salt concentration, a larger spectrum of chromatin proteins becomes accessible for phosphorylation by the chromatin-bound protein kinase. Some observations described in this communication may help to partially explain this result. The protein kinase was not found in nucleosomal subunits, indicating a non-random distribution of the enzyme in chromatin. This suggests that enzyme and substrate have to be in close spatial contact for the phosphorylation reaction to occur. Furthermore, we have shown for one protein, histone H1, that phosphorylation sites for the endogenous protein kinase are available on the free but not on the DNA-bound protein, suggesting that phosphate-accepting sites in chromatin proteins may be blocked by protein-DNA or by protein-protein interactions. We also discuss the possibility that chromatin protein kinase occurs in stable complexes with its phosphate-accepting substrates, as has been suggested by the findings of other [Kish, V.M. & Kleinsmith, L.J. (1974) J. Biol. Chem. 249, 750-760].     

CHROMOSOME COUNTS OF COMPOSITAE FROM THE UNITED STATES AND MEXICO

Chromosome counts are reported for 126 taxa representing 122 species and 61 genera of Compositae. First reports include two genera, Stylocline (n = 14) and Chromolepis (n = 19), 17 species, two infraspecific taxa, and one interspecific hybrid. Five additional taxa have chromosome numbers differing from previously published accounts. Carminatia is reinstated to generic status.     

Chemical modifications of Achromobacter collagenase and their influence on the enzymic activity

A study of the influence of chemical modifications on the activity of Achromobacter iophagus collagenase (EC 3.4.24.8) has led to the following conclusions: a modification of 4 out of 80 COOH groups with carbodiimide led to 90% loss of enzymic activity. A 70% inactivation was found after modification of two tyrosines out of 30 with tetranitromethane. The modification of four to six tryptophans out of 16 with 2-hydroxy-5-nitrobenzyl bromide decreased enzyme activity to 36%. This inactivation is accelerated in the presence of collagen. An increase of reagent/enzyme molar ratio led to a modification of 16 tryptophan residues and denaturation of Acahromobacter collagenase. A modification of two arginines out of 18 with 1,2-cyclohexanedione and eight NH2 groups out of 24 with 2,3-dimethyl maleic anhydride does not change the collagenolytic activity. All NH2 groups become available for 2,3-dimethyl maleic anhydride after dissociation of the dimer. A possible analogy of hydrolytic site of collagenase with that of two other known bacterial metalloproteinases (thermolysin and Bacillus subtilis neutral proteinase (EC 3.4.24.4)) is discussed.