Analysis of variation of amplitudes in cell cycle gene expression

BACKGROUND: Variation in gene expression among cells in a population is often considered as noise produced from gene transcription and post-transcription processes and experimental artifacts. Most studies on noise in gene expression have emphasized a few well-characterized genes and proteins. We investigated whether different cell-arresting methods have impacts on the maximum expression levels (amplitudes) of a cell cycle related gene. RESULTS: By introducing random noise, modeled by a von Mises distribution, to the phase angle in a sinusoidal model in a cell population, we derived a relationship between amplitude and the distribution of noise in maximum transcription time (phase). We applied our analysis to Whitfield's HeLa cell cycle data. Our analysis suggests that among 47 cell cycle related genes common to the 2(nd )experiment (thymidine-thymidine method) and the 4(th )experiment (thymidine-nocodazole method): (i) the amplitudes of CDC6 and PCNA, which are expressed during G1/S phase, are smaller in the 2(nd )experiment than in the 4(th), while the amplitude of CDC20, which is expressed during G2/M phase, is smaller in the 4(th )experiment; and (ii) the two cell-arresting methods had little impact on the amplitudes of the other 43 genes in the 2(nd )and 4(th )experiments. CONCLUSION: Our analysis suggests that procedures that arrest cells in different stages of the cell cycle differentially affect expression of some cell cycle related genes once the cells are released from arrest. The impact of the cell-arresting method on expression of a cell cycle related gene can be quantitatively estimated from the ratio of two estimated amplitudes in two experiments. The ratio can be used to gauge the variation in the phase/peak expression time distribution involved in stochastic transcription and post-transcriptional processes for the gene. Further investigations are needed using normal, unperturbed and synchronized HeLa cells as a reference to compare how many cell cycle related genes are directly and indirectly affected by various cell-arresting methods

De la dictadura democrática a la dictadura del proletariado: el debate en el Partido Bolchevique sobre las Tesis de Abril de Lenin

A principios de abril de 1917, Lenin asombró tanto a sus amigos como a sus enemigos cuando, después de llegar a la estación Finlandia, leyó su tesis defendiendo la transición de la Revolución rusa de su primera etapa burguesa a una segunda etapa durante la cual el poder se transferiría a manos del proletariado. Esta nueva política iba en contra de la perspectiva política de lo que Lenin llamaba ahora el ‘viejo bolchevismo’ (la cual, a pesar de rechazar un frente común con la burguesía y abogar por una alianza del proletariado y el campesinado, limitaba la revolución a la consecución de metas democrático-burguesas) y señaló su acercamiento a la perspectiva de la revolución permanente bosquejada por primera vez por Trotsky y otros pensadores marxistas durante la revolución de 1905. Este rearme del Partido Bolchevique dio lugar a furiosas polémicas en sus filas en abril de 1917 y a un giro brusco en sus políticas, que documentamos en el presente artículo.In early April 1917 Lenin astonished both friends and foes when, after arriving at the Finland station, he read his thesis advocating the transition of the Russian Revolution from its first, bourgeois stage, to a second stage during which power would be transferred into the hands of the proletariat. This new policy went counter to the political perspective of what Lenin called ‘old Bolshevism’—which, while rejecting a common front with the bourgeoisie and advocating an alliance of the proletariat and the peasantry, nevertheless limited the revolution to the attainment of bourgeois-democratic goals—and signaled his approach to the perspective of permanent revolution first outlined by Trotsky and a number of Marxist thinkers during the revolution of 1905. This rearming of the Bolshevik Party gave rise to furious polemics in its ranks in April 1917 and to a sharp turn in its policies, which we document in the present article.Fil: Murphy, Kevin. Boston University; Estados UnidosFil: Gaido, Daniel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; Argentin

GUDMAP - An Online GenitoUrinary Resource

The GenitoUrinary Development Molecular Anatomy Project (GUDMAP) is a consortium of laboratories working to provide the scientific and medical community with gene expression data and tools to facilitate research (see "www.gudmap.org":http://www.gudmap.org). The data provided by GUDMAP includes large _in situ_ hybridization screens (wholemount and section) and expression microarray analysis of components of the developing mouse urogenital system (including laser-captured material and FACS-isolated cells from transgenic reporter mice). In addition, a high-resolution anatomy ontology has been developed by members of the GUDMAP consortium to describe the subcompartments of the developing murine genitourinary tract. 

The GUDMAP Database Development Team and Editorial Office - both based in Edinburgh - function to ensure submission, curation, storage and presentation of the data submitted by the GUDMAP consortium. Our collective aim is twofold: 1) to simplify the process of submission so that data is publically available as soon as it is produced; and 2) to organize this information in a database and ensure that the online interface is continuously available and easy to use. Thus far, we have developed a range of tools that help both the submitter and the end user. These include: an online annotation tool that simplifies _in situ_ data submission through an ontology-based graphical user interface; a database interface that allows users to browse and query expression data, and to filter data by organ system; a heat-map display of microarray data and analyses. Furthermore, the Edinburgh team has developed a GUDMAP Disease Database that queries associations between genes, genitourinary diseases, and renal/urinary and reproductive phenotypes. In collaboration with GUDMAP consortium members at the CCHMC (Cincinnati Children's Hospital Medical Center), the Disease Database is being extended to include mammalian phenotypes mapped to OMIM entries. 

By virtue of its impressive dataset and its ease of use we hope that the GUDMAP Website will continue to serve as a powerful resource for biologists, clinicians and bioinformaticians with an interest in the urogenital system

De la dictadura democrática a la dictadura del proletariado: El debate en el Partido Bolchevique sobre las Tesis de Abril de Lenin

A principios de abril de 1917, Lenin asombró tanto a sus amigos como a sus enemigos cuando, después de llegar a la estación Finlandia, leyó su tesis defendiendo la transición de la Revolución Rusa de su primera etapa burguesa a una segunda etapa durante la cual el poder se transferiría a manos del proletariado. Esta nueva política iba en contra de la perspectiva política de lo que Lenin llamaba ahora el "viejo bolchevismo" (la cual, a pesar de rechazar un frente común con la burguesía y abogar por una alianza del proletariado y el campesinado, limitaba la revolución a la consecución de metas democrático‐burguesas) y señaló su acercamiento a la perspectiva de la revolución permanente bosquejada por primera vez por Trotsky y otros pensadores marxistas durante la revolución de 1905. Este rearme del Partido Bolchevique dio lugar a furiosas polémicas en sus filas en abril de 1917 y a un giro brusco en sus políticas, que documentamos en el presente artículo.Fil: Murphy, Kevin. Boston University; Estados UnidosFil: Gaido, Daniel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; Argentin