Dynamic filtration of the variability of expression patterns of zygotic segmentation genes in Drosophila

An analysis of the quantitative data obtained by processing the confocal images showed that the early variability of expression patterns of zygotic segmentation genes in Drosophila drastically decreases by the time of the onset of gastrulation. The following components of variability were examined: the scatter of the levels of gene expression in different embryos, the time and sequence of the formation of expression domains, the type of their formation, and the domain positioning. It was found that the positioning error at the level of zygotic genes is dynamically filtered with time.     

Registration of the expression patterns of Drosophila segmentation genes by two independent methods

MOTIVATION: To construct an integrated map of Drosophila segmentation gene expression from partial data taken from individual embryos. RESULTS: Spline and wavelet based registration techniques were developed to register Drosophila segmentation gene expression data. As ground control points for registration we used the locations of extrema on gene expression patterns, represented in 1D. The registration method was characterized by unprecedented high accuracy. A method for constructing the integrated pattern of gene expression at cellular resolution was designed. These patterns were constructed for 9 segmentation genes belonging to gap and pair-rule classes.     

Aspartate and Alanine Aminotransferases in Early Development of the Keta

We studied the activities of the marker enzymes of physiological state and adaptive reactions, aspartate and alanine aminotransferases, in early development of the keta Oncorhynchus keta. Aspartate aminotransferase with pH optima 6.8, 7.0, 7.6, and 8.0 and alanine aminotransferase with pH optima 7.0, 7.4, 7.6, 7.8, 8.0, and 8.2 were found in the eggs, larvae, and fry. The succession of enzymes with different pH takes place during ontogenesis, as well as stage specific changes in their activity. The maximum enzymatic activity was recorded in the larvae during their rise for afloat. A correlation was established between the dynamics of enzymatic activity and soluble nitrogen and amine nitrogen contents.     

Prediction of gene expression in embryonic structures of Drosophila melanogaster

Understanding how sets of genes are coordinately regulated in space and time to generate the diversity of cell types that characterise complex metazoans is a major challenge in modern biology. The use of high-throughput approaches, such as large-scale in situ hybridisation and genome-wide expression profiling via DNA microarrays, is beginning to provide insights into the complexities of development. However, in many organisms the collection and annotation of comprehensive in situ localisation data is a difficult and time-consuming task. Here, we present a widely applicable computational approach, integrating developmental time-course microarray data with annotated in situ hybridisation studies, that facilitates the de novo prediction of tissue-specific expression for genes that have no in vivo gene expression localisation data available. Using a classification approach, trained with data from microarray and in situ hybridisation studies of gene expression during Drosophila embryonic development, we made a set of predictions on the tissue-specific expression of Drosophila genes that have not been systematically characterised by in situ hybridisation experiments. The reliability of our predictions is confirmed by literature-derived annotations in FlyBase, by overrepresentation of Gene Ontology biological process annotations, and, in a selected set, by detailed gene-specific studies from the literature. Our novel organism-independent method will be of considerable utility in enriching the annotation of gene function and expression in complex multicellular organisms.     

A novel strategy for enzymatic synthesis of 4-hydroxyisoleucine: identification of an enzyme possessing HMKP (4-hydroxy-3-methyl-2-keto-pentanoate) aldolase activity

A two-step enzymatic synthesis process of 4-hydroxyisoleucine is suggested. In the first step, the aldol condensation of acetaldehyde and alpha-ketobutyrate catalyzed by specific aldolase results in the formation of 4-hydroxy-3-methyl-2-keto-pentanoate (HMKP). In the second step, amination of HMKP by the branched-chain amino acid aminotransferase leads to synthesis of 4-hydroxyisoleucine. An enzyme possessing HMKP aldolase activity (asHPAL) was purified 2500-fold from a crude extract of Arthrobacter simplex strain AKU 626. Sequencing of the asHPAL structural gene showed that the purified enzyme belongs to the HpcH/HpaI aldolase family. The 4-hydroxyisoleucine was synthesized in vitro from acetaldehyde, alpha-ketobutyrate and l-glutamate using a coupled aldolase/branched-chain amino acid aminotransferase bienzymatic reaction.     

Regression Model for Time to Flowering of Chickpea Landraces

Russian Journal of Genetics - Regression models for time to flowering had been developed for VIR chickpea landraces collected in Turkey and Ethiopia. Predicted flowering time coincides closely with...     

Microanalytical methods: latex agglutination and immunoenzyme analysis in the diagnosis of meningococcal infection

Modified polystyrene latexes with high adsorption capacity, comparable to that of latexes produced by Difco Laboratories (USA), have been developed in the USSR. Diagnostic latex preparations for the detection of meningococci of serogroups A, C, Y and Haemophilus influenza, type b, prepared on the basis of these new latexes, have shown high specificity and sensitivity in experimental and clinical tests.The latex preparations for the detection of serogroup B meningococci requires further improvement. The use of latex preparations, together with other laboratory methods, in the diagnosis of meningococcal infection has promoted the etiological confirmation of the disease in 84% of cases; this method has proved to be 1.5 times more effective than the bacteriological one and not less sensitive than the enzyme immunoassay, while being more specific.