Six barley chlorophyll (Chl) mutants, viridis, flavoviridis, chlorina, xanhta, lutea, and albina, differed in the contents of Chl (a+b) and carotenoids (Cars). In accordance with their Chl-deficient phenotype, the Chl a and b and Car contents of mutants decreased from viridis to albina, only xantha had the same or even higher concentration of Cars as the wild type plant. The albina mutant completely lacked and xantha had a significantly reduced photosynthetic activity. We found quantitative differences in protein contents between wild type and mutant plants, with the lowest concentration per fresh mass in the albina mutant. Chl fluorescence analysis revealed that heat-treated barley leaves of both the wild type and Chl mutants had a lower photosystem 2 efficiency than the untreated ones. With 35S-methionine labelling and SDS-PAGE we found that six to nine de novo synthetized proteins appeared after heat shock (2 h, 42 °C) in the wild type and Chl mutants. In albina the expression of heat shock proteins (HSPs) was reduced to 50 % of that in the wild type. Hence mainly albina mutants, with a completely destroyed proteosynthetic apparatus of the chloroplasts, are able to synthesize a small set of HSPs. The albina mutant is a very useful tool for the study of different gene expression of chloroplast and nuclear DNA. and E. Gálová, B. Böhmová, A. Ševčovičová.
The present study devises two techniques for visualizing biological sequence data clusterings. The Sequence Data Density Display (SDDD) and Sequence Likelihood Projection (SLP) visualizations represent the input symbolical sequences in a lower-dimensional space in such a way that the clusters and relations of data elements are preserved as faithfully as possible. The resulting unified framework incorporates directly raw symbolical sequence data (without necessitating any preprocessing stage), and moreover, operates on a pure unsupervised basis under complete absence of prior information and domain knowledge.
RNA optical density (concentration) measurements at the single cell level indicated that differentiation of lymphocytes is accompanied by a slightly decreased nucleolar RNA concentration in contrast to the cytoplasmic rim around the nucleus. On the other hand, the nucleolar size was markedly reduced and the cytoplasmic rim surrounding the nucleus was reduced only weakly. Concerning the calculated rough estimate of the RNA content, the differentiation induced its larger decrease in the nucleoli than in the cytoplasmic rim. These observations indicated that the nucleolar RNA concentration and RNA content together with the nucleolar morphology are more sensitive markers of the differentiation process than the RNA concentration and content in the cytoplasm. Thus, the nucleolar RNA transfer to the cytoplasm in advanced differentiation steps might still be going on regardless of the decreasing or inhibited nucleolar biosynthetic activity. In addition, the presence of ring-shaped nucleoli and micronucleoli characteristic of mature and terminal lymphocytes in some lymphocytic less differentiated steps, i.e., lymphoblasts and prolymphocytes, might indicate the premature differentiation state of such cells.
This review compares the geometry of conduit coronary arteries in man and animals, namely the wall/diameter ratio (1:7.4 and 1:15 respectively). The left and right ventricle volume determines the geometry (segment length and diameter) of both branches of the left coronary artery: ramus interventricularis anterior and ramus circumflexus; the range of deformation of the latter was substantially smaller. The heterogeneity of deformation was also found along the ramus interventricularis anterior, the deformation decreasing towards the apex. The above relations have consequences (i) on the haemodynamics (passive changes in conduit segment resistance), (ii) the deformation of coronary arteries triggers metabolic processes in the coronary wall. Four hours' lasting cardiac volume or pressure overload brought about an increase in the RNA content not only in the myocardium, but also in the coronary artery. The process is reversible. Moreover, the range of the RNA increase is in full concert with the heterogeneous deformability of the respective segment of the coronary tree.